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First ride on a Blur, impressed but some feedback required: Blur vs 5-spot (66 posts)
|  First ride on a Blur, impressed but some feedback required: Blur vs 5-spot | Martino
Jun 9, 2003 9:53 PM | | Dears,
today I had my first longish ride on a Blur: a Large (which almost fits me although I would get a medium) with fox AVA/Flot. My impressions are pretty much similar to what has been posted in this forum. I report them below but I am mostly curios about some feedback re: blur vs 5-spot.
PLUSES:
(1) feels very rigid and one can hammer on the pedals without much, if any, bob: this is quite nice especially for something that uses a GT STS like myself (you do not stand up on a STS, unless you want to stop).
(2) it is very plush, and in particular eats up square edged obstacles very well without much if any kick back.
(3) it gives a good sense of confidence. I did a series of 6-steps stairs after few minutes of riding, both rolling over and dropping in, with no apparent problem; the bike is tight and stable.
(4) I could not detect any brake-jack
MINUSES:
(1) on a flat the bike starts to "roll" a bit especially if you pedal smoothly. (It also bobs if you stand without pedaling, but it is not very important.)
(2) the bike cries out, in my opinion, for a 5" fork or at least for something better then a Fox float. The differnce between the plush and smooth rear VVP and the harsh front fork was quite noticeable, bad enough to unbalance the bike. I can only imagine how well the bike would ride with a good fork upfront
IMPROVEMENTS: (1) might be fixed by the new 5th dimension shock and (2) will be fixed by a nicer coil fork.
QUESTION: I am tempted to go for the Blur instead of the 5-spot, I am light (145 pounds) and the Blur might be all I need. I can easily see using it to do some aggressive cross country including jumping and some aggressive downhill. It feels more plush then my STS (which has 4.75") and it is at least as stable at speed and under impact.
But ... any opinions? Has anybody tried the 5-spot and the Blur? What about traction, how do they compare in the rough or uphill? |
| 5" fork | Jordan
Jun 9, 2003 10:09 PM | | unfortunately, you can't run anything more than 105mm on a blur. not to say that a blur with a marzocchi marathon s wouldn't rip, but if you want that extra travel, you're outta luck. |
| re: First ride on a Blur, impressed but some feedback required: Blur vs 5-spot | Dougal
Jun 10, 2003 12:32 AM | | You won't notice any brake jack on the blur, it'll squat under braking. For many people this would be the single most noticable difference between that and the 5-spot. The 5-spot will stay more active, giving you more traction and better suspension behaviour with the back brake on.
Next step is riding the 5-spot.
Dougal.co.nz |
| Hey Dougal? | Mario
Jun 10, 2003 12:42 PM | | Wow, interesting study you have on your page... I really like all your explanation on suspension. It would be nice if you added the VPP design to your study or at least add some comments about it!!!
Did you look at the 5-spot vs the Azonic Sabre vs the Ellsworth ID? To me these 3 should behave relatively the same, what do you think? Also, would you see a difference between the 3 above and the Titus Switchblade or Spec Enduro?
Thanks for your comments, very interesting. |
| Hey Dougal? | Dougal
Jun 10, 2003 2:21 PM | | Sorry I haven't yet got to ride a Sabre or ID. The ID's I've seen have had very tall BB's and the sabre is rumoured to be several pounds heavier than the 5-spot.
The enduro doesn't climb or accelerate as well as the 5-spot (in fact almost I've ridden does). It's far from a slouch but still not as good, I haven't ridden the switchblade either but I'd expect it to fit in just above the Enduro.
I'm riding a modified 2000 Bighit. I've got the suspension sorted to pedal and brake in a very similar manner to the 5-spot, but I still have issues with the geometry, namely the 22 inch toptube (size large).
I'll get around to adding VPP stuff one day. It's not actually anything special, just another application of the four bar. IMO the horst link design is a better one.
Dougal.co.nz |
| Enduro doesn't climb/accelerate as well as 5-spot. Why not? | Mike Bay
Jun 10, 2003 2:38 PM | | Is it the geometry? Both have Horst Links so what makes one bike climbs/accelerates better than another? Does the 5-Spot brakes better than the Enduro too? Thanks in advance Dougal. |
| Enduro doesn't climb/accelerate as well as 5-spot. Why not? | Dougal
Jun 10, 2003 8:21 PM | | Yes they're both horst links, but the Instant Centre (intersection of top link and swingarm) is a lot lower and more rearward on the Enduro. This makes it squat more under acceleration/climbing and braking than the 5-spot will.
So the 5-spot stays more level under acceleration and the rear wheel will hook up better under braking. Keep in mind that I am splitting hairs here, comparing very good (the enduro) to what I consider the best trail bike out there (the 5-spot).
Dougal.co.nz |
| I went to your website to try to understand this stuff. | Mike Bay
Jun 11, 2003 1:13 AM | | "This effective pivot is the point which the chain line must pass through to give no torque on the suspension."
- I understood this part.
"If the COM lies above the line then the suspension will compress under acceleration, if it lies under then the suspension will extend under acceleration. A completely neutral bike has the COM on the same line as the effective pivot and the contact patch."
- Could you draw in the forces and pivot points to show this?
"Brake Effect on Rear Suspension"
- I'm still confused so I should study it again.
PS: I know we're splitting hairs here but the engineering is very interesting to me. Thanks again. |
| I went to your website to try to understand this stuff. | Dougal
Jun 11, 2003 1:23 AM | | Sorry the website is a bit behind. I've had some drawings planned for about the last year that haven't been put up yet, other stuff just keeps coming up.
But keep checking, eventually I'll get it sorted.
Dougal.co.nz |
| Are you a Mechanical Engineering student? | Mike Bay
Jun 11, 2003 1:58 AM | | If so, I don't know how you even have time to produce your website. Nice site btw. I've visited your site off and on for a year or more now. I can't wait to see the new info posted. Hopefully it'll help me and many others to better understand suspension designs. Speaking about suspension designs, do you have your own design? I'm fairly new to mountain biking and forgive me if I offend anyone but there sure seems to be much room for better engineered suspension, drive train, etc.
Thanks,
Mike
BSME but got type-casted into the thermal science area many years ago. Mechanics still interest me but I can't remember much if it anymore. |
| Yep. | Dougal
Jun 11, 2003 4:57 AM | | Yep, for only another six months if all goes well. But you're right about the time bit, I haven't been able to go mountainbiking in about a month, I've had 1.5 days outside the computer labs in that time.
Surprisingly there's little in a BE that deals directly with suspension. Control and dynamics come the closest, but they make many generalisations to make the maths fit the behaviour.
It's strange how mechanical engineering and mountain biking fit. Years ago here the uni MTB club was started by engineers. In the 8 or so years it's had only three non engineers as president. This year only one person on the committee isn't an engineering student.
Which branch of Thermal Science are you in?
Dougal.co.nz |
| I went to your website to try to understand this stuff. | Mike Bay
Jun 11, 2003 1:26 AM | | "This effective pivot is the point which the chain line must pass through to give no torque on the suspension."
- I understood this part.
"If the COM lies above the line then the suspension will compress under acceleration, if it lies under then the suspension will extend under acceleration. A completely neutral bike has the COM on the same line as the effective pivot and the contact patch."
- Could you draw in the forces and pivot points to show this?
"Brake Effect on Rear Suspension"
- I'm still confused so I should study it again.
PS: I know we're splitting hairs here but the engineering is very interesting to me. Thanks again. |
| That seems backwards... | Tullebukk
Jun 11, 2003 2:18 AM | | How are you computing anti-squat?
Everyting I have read regarding anti-squat geometry computes it something like this. Draw a vertical line through the front axle. Project the center of gravity forward to where it intersects that vertical line. Draw a line from the contact patch of the rear tire through this intersection. This is your line for 100% anti-squat (see the diagram below). If the IC of the rear suspension is above this line (as it is in the diagram), you will have suspension extension under acceleration, and if it's below this line, you will have compression (squat). Since the IC of the Enduro is closer to the 100% line than is the IC of the 5 Spot, I would expect the Enduro to squat less from acceleration/climbing. Are you computing anti-squat differently?
 |
| Squatting. | Dougal
Jun 11, 2003 5:04 AM | | Well that's my own little theory.
I also use the squat theory you've shown above, but I have a few issues with it. On paper my bike comes out with less squat than the 5-spot, actually above neutral and just into the jacking range. But I can still feel it squatting under power.
I don't know the exact origins of that formula, but I think it's empirical and based on keeping the COM at the same height under acceleration. This uses squat at the back to counter lift at the front.
My own EP theory means the suspension extends at the front and doesn't compress at the back. The result is similar to a wheelie on a hardtail.
Regarding the Enduro and 5-spot. The COM of a bike is much higher than on your diagram. The intersection height (H) is much lower than the COM on the Enduro but close to the COM on the 5-spot.
This fits with riding observations.
Dougal.co.nz |
| Squatting. | Tullebukk
Jun 11, 2003 6:59 AM | | I didn't quite follow that last part. I was thinking the intersection height is lower with the 5 Spot than with the Enduro. Anyway, I will be interested in seeing the description on your website once it's updated.
As far as the origins of the formula, I have seen it in few places. There is an on-line derivation here:
http://www.mae.wmich.edu/Courses/Courses.html
Click on the link on the right entitled "Lecture7 - LongWtTransf.ppt" |
| Squatting. | Dougal
Jun 11, 2003 2:26 PM | | Thanks for those links, I'll check them out when I have the time. I can't find any pics of the Enduro linkage right now, I'll get back to you on that one.
Dougal.co.nz |
| Squatting. | Tullebukk
Jun 12, 2003 1:50 AM | | You probably figured this out already, but I forgot to state that you have to click on the "ME465 Vehicle Dynamics" link before you can click on the weight transfer lecture link ("Lecture7 - LongWtTransf.ppt"). |
| Chainline and a different diagram | Steve from JH
Jun 11, 2003 6:09 PM | | You have to factor in the chainline when computing anti-squat. On a chain driven vehicle your diagram only holds if the chainline is passing through the instant center. If not then you use the point of intersection of the chainline and the swingarm line (line from axle through IC). This point is variously known as the pole of moments or the instant center of forces. You draw your line from contact patch through this point to compute the anti-squat.
On the Enduro the chainline passes through the IC in about the lowest gear ratio. On the 5-Spot, Azonic, and Id (and other Ellsworth bikes), it occurs in a gear right in the middle of the range.
Now 100% anti-squat is way too much for energy efficient pedaling. Instead the diagram below shows how the linkage should be arranged (in my opinion). What we're trying to control is not the squatting during acceleration but the "winding up" of the suspension during the increase in pedal force that leads to acceleration. We don't want the center of mass to move up or down
b instead
of accelerating horizontally.
The above mentioned bikes correspond to this diagram pretty well if we assume 25% sag and a center of mass located at about the height of the saddle and right above the BB. The Enduro does too, but as I said, in a very low gear. |
| Chainline and a different diagram | Tullebukk
Jun 12, 2003 9:10 AM | | Hi Steve,
Yeah, I was assuming a neutral chainline in both cases. Of course, to get the net amount of "anti-squat" you would have to account for chainline (and possibly chain growth as well). However, I would think that using the chainline to control anti-squat may not be the best design. You would end up with a bike that didn't squat as much while accelerating, but you would loose some suspension activity. Since you are not accelerating most of the time, I am not sure that this is a good tradeoff. It seems like you would be better off placing the IC such that you get the desired amount of anti-squat (and anti-dive) if that's possible. It seems like this would also help keep the bike from squatting too deeply into it's travel when climbing. However, I am not sure if it's possible to place the IC such that you get optimal anti-dive and anti-squat.
I would really like to see a description of the pole of moments diagram. Do you know of an on-line source?
aka Zag |
| Pole of moments diagrams | Steve from JH
Jun 13, 2003 6:24 AM | | Here are some diagrams scanned from my copy of MOTORCYCLE DESIGN AND TECHNOLOGY by Gaetano Cocco, a product of the Aprilia Motorcycle engineering dept.
The first one is the basic diagram.
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The second one is a hypothetical situation where the swingarm has compressed so far that the PofM is below the ground line and the torque changes from extending to compressing.
.jpg)
The third one is with a drive shaft instead of a chain. The PofM is now identical with the pivot.
.jpg)
Because the chain pull angle (sigma) in the drive shaft example is so steep, there will be too much extension, so drive shaft equipped motorcyles these days usually have 4-bar linkages. Now the PofM is identical with the IC and is farther forward.
And finally here is a diagram showing the anti-squat related to the squat produced by load shift. In the picture the bike would have more than 100% anti-squat. 100% anti-squat would occur if angles sigma and tau were equal.
 |
| Formulas from RACE CAR VEHICLE DYNAMICS | Steve from JH
Jun 12, 2003 6:21 AM | | Here are some formulas I copied from Milliken's RACE CAR VEHICLE DYNAMICS. They are for anti-lift during rear wheel braking, the opposite of anti-squat.
The derivation assumes that the instantaneous trajectory of the contact patch is tangent to an arc around the instant center. That in turn assumes what could be called the locked wheel scenario. That is, the reaction force at the ground to the torque of the wheel acts on the wheel and the frame member to which it is attached as though they were locked together.
It seems to me that disagreement over this last point is what lies behind a lot of the theoretical arguing over suspension bicycles. There doesn't seem to be any disagreement in the automotive or motorcycle community. |
| Formulas from RACE CAR VEHICLE DYNAMICS | Tullebukk
Jun 12, 2003 9:10 AM | | Hi Steve,
Yes, I have seen the same formula used for anti-squat (due to weight transfer only, not including chain effects). Using the diagram I posted above you get:
Percentage of anti-squat = (tan ß / (h/L)) * 100
100 % anti-squat if tan ß = h/L
If tan ß < h/L then squat will occur.
It's the same formula that you are using for anti-dive.
I have seen the same formula used for anti-dive as well, except you have to account for the percentage of braking supplied by the rear wheel as follows:
The angle for 100% anti-dive tan ß = h / (L * (% rear brake))
You use the same formula for front anti-dive, except you use % of front brake. I am not sure, but I would guess that you would have to sum the two to get the net effect.
Your formula appears to be for rear wheel braking only (i.e 100% rear brake). However, I am not sure if that is a good model, because a large percentage of the braking comes from the front wheel. Plus, there may be some braking forces acting on the rear suspension members of a bike that could be neglected for a car or motorcycle, because the masses and accelerations are much higher (orders of magnitude probably) for vehicles then they are for a bikes.
You can find a fairly interesting derivation of these formula's on line at the following link:
http://www.mae.wmich.edu/Courses/Courses.html
Click on the link entitled "ME465 Vehicle Dynamics", then click on the "Lecture 7 - LongWtTransf.ppt". However, you need powerpoint to view the lecture.
aka Zag |
| The Azonic frame weight, Enduro climb, Balfa 2-step... | Mario
Jun 10, 2003 5:34 PM | | Dougal, your comments are again very interesting.
- The previous guy's question about why the Enduro is a little slower/worst climber than a 5-spot is also right on? Any comments? The Enduro is such a good deal for the money one has to understand exactly why he would pay quite a bit more for a 5-spot...
- The Azonic weight!!! Yea, this frame is also quite a good deal and it's weight is some kind of a mistery. I've seen all sorts of numbers on the internet ranging from 6.5 to 9 pounds!!! I think I'll write to Azonic and try to clear things up...
- Have you ever looked at a Balfa 2-step? I went in a store today that carried those frames and to my "non technical" eye, I would say the suspension design is quite similar to VPP (Blur, Hollowpoint). What's your opinion?
Thanks |
| The Azonic frame weight, Enduro climb, Balfa 2-step... | Dougal
Jun 10, 2003 8:24 PM | | See my answer to Mike just above. The Enduro is damn good, the 5-spot just happens to be better.
In addition I haven't looked at the 2-step for quite a while, but I remember it being a heavier bike built for abuse.
Dougal.co.nz |
| I had to make the same decision | WarrGuru
Jun 10, 2003 6:50 AM | | I originally was going to buy a Blur. I rented one and took it out for a day. I put about 35 miles on it. All dirt....steep[ climbs...steep decents...long fireroad climbs.....singletrack claimbs and decents..etc. I really put it through it's paces. I liked the bike.
When I got home, my wife asked my why I wasn't smiling from ear-to-ear. I told her that even though I like the Blur a LOT.....It just wasn't different enough from my Fuel 98. If I bought the Blur....I'd never ride the Fuel again. Then I rode a Turner 5-Spot.
WOW. What a bike. It climbs better than the Blur (small difference there, but still a difference), decends way better. It can take a 5" fork up from without voiding the warranty (like the Blur). You can fit a 2.5" tire on the 5-Spot...the blur maxes out at 2.1", limiting tire choices. I bought the 5-Spot and am sure that I made the right choice....for me.
I'm not too concerned about weight. I wanted a plush trail bike. Now I have the 5-Spot with a Marz Z1 FR fork (sweet fork), Romic shock, XT setup, Hayes Mag Hydros, Thompson stem, Easton carbon post, Conti Vert Pro tires (2.3). It's a great setup.
A buddy of mine was about to buy the Blur....then he rode my 5-Spot. He's having his 5-Spot built right now.
Good luck with your choice. They're both great bikes. |
| Interesting, thank you, can you elaborate a bit on climbing? | Martino
Jun 10, 2003 7:08 AM | | The weight difference is indeed very minimal, just 1 pound (3/4 with titanium spring) which is fairly irrelevant under any situation.
A question about the Romic: does it give any chance to stand up if needed? Again, I am used to my GT STS and I am not looking for hard-tail firmness but just for something that does not sink under when you stand (the GT is almost comical when you stand BUT it gave the impression to accellerate BETTER than the Blur when seated).
I wonder where I can try a 5-spot in the Bay Area ... |
| Fully's on climbs, and about the Romic... | J.S.
Jun 10, 2003 7:17 AM | | Fully active suspensions get superior traction on technical climbs -- they just grip the ground better since they are better able to hug the terrain and not bounce off rocks/debris. The 5-spot is fully active, but the Blur is not (VPP rear end is affected by chain tension).
If you decide to go with a Romic on a 5-spot, it's quite easy to crank down the compression knob 4 clicks and hammer up hills with no bob while still being able to yield to hits. I'm riding a Romic on a Truth, and its linkage is similar to the 5-spot (4 bar parallelogram linkage pointed at IC). It climbs very well without fiddling with the compression knob, but you can still crank down the compression for a more firm ascent. |
| Interesting, thank you, can you elaborate a bit on climbing? | WarrGuru
Jun 10, 2003 10:01 AM | | The 5-Spot climbs extremely well. Comparing it to the Blur......There is less bob (believe it or not) with the 5-Spot and Romic. Both bikes climb well, but the more active design of the 5-Spot allows it to climb better than the BLur when the terrain is really rough.
THe Romic is amazing. Yes, you can stand and hammer and you'll be amazed at the firmness...yet the big hits are still plush.
As far as the weight difference......it will end up being more than half a pound. You'll want a 5" fork with the 5S....more weight. I went with a Marzocchi Z1 FR.......add another 1-1.5 lbs. Guess what.....it still climbs great due to the ETA. There is a weight penalty, but it totally worth it for the ride.
You can build a 5S to be about 27 pounds if you're a weight weenie. I have a bike like that already.....I wanted a great trail bike and that's exactly what I got. |
| Interesting + Weight differences (if it matters) | Martino
Jun 11, 2003 9:08 PM | | Very interesting about the Romic and climbing firmness. I Completly agree with you about buildng a solid trail bile.
For the record: the STS frame and shock is probably around 7.3-7.5, with cartridge bearings, and I used it happily for many years.
The Turner is 7.0 or 6.75 (titanium)
The Blur is 6.0
A Marathon SL is 3.8, more or less like the float?
So the lightest Frame + fork is 9.8 (Blur/Marathon or Float)
the heaviest is 12.3 (Turner + Z1/Sherman Coil)
So within 2.5 pounds of weight (which is slightly more then 1.% of my riding weight, that is 2.5 pounds over around 180 including shoes, water pants etc) there are a bunch of solid to very solid frame-fork configurations ... |
| What about that head angle? | Tullebukk
Jun 10, 2003 7:55 AM | | What do you think of the somewhat slack 69 degree head angle? I know it's not slack for a 5" travel bike, but there must be some disadvantage when climbing compared to a bike with the steeper head angle like your Fuel, isn't there? |
| What about that head angle? | WarrGuru
Jun 10, 2003 10:06 AM | | There is a slight penalty on the steepest of climbs. The Fuel climbs better, mostly due to my laid-out position on the Fuel vs the more upright position on the 5S.
The slacker head angle has little effect on the climbing. The Fuel is quicker on tight, fast, twisty singletrack. The Blur is between the 2 ...and the 5S is a little slower.
Nothing can touch the 5S on the way down the hill...be it singletrack, fireroad, jumps, etc. |
| I had to make the same decision | SilverFish
Jun 10, 2003 10:00 AM | | WarrGuru, question, do you think the Truth rides like a Fuel 98 or 100? I know the Truth is more durable in quality, but overall ride do they match pretty close? |
| I had to make the same decision | WarrGuru
Jun 10, 2003 10:07 AM | | I've never ridden a Truth, so I can't answer that question. I would expect it to have quicker steering than the 5S....more like the FUel....but that's just a guess. |
| I just rode a 5-spot the yesterday (different opinion) | Dave from Derry
Jun 10, 2003 12:38 PM | | and loved it. What a bike! I love trying a new bike on my very familiar trails. I agree with almost everything you said--with exception to climbing. I took the Turner up 3 different climbs (very steep, very rocky climbs) and then repeated on my Blur. I have taken a bunch of bikes up these climbs to this point as a means of fair comparision. I thought it climbed very well for the amount of travel, maybe a little better than a Heckler, as good as an XCE, and definetly not as good as my Blur. It certainly outperformed my Blur descending (matching or perhaps besting the Heckler and the XCE in this regard)
I was surprised how well the 5-spot handled with the 69 HA. It felt really good in tight singletrack.
The Blur does not max out at a 2.1 tire. I run 2.2 in the rear with room to spare. (And I am riding in the Northeast where it has been raining since march.)
It is funny how different people have such different experinces riding the same bike. All the more reason to try before you buy. Although with the above mentioned 4 bikes, it is hard to go wrong. |
| 5-spot suits free-riding better | J.S.
Jun 10, 2003 7:10 AM | | Between the Blur and 5-spot, it sounds like the 5-spot is better suited for your riding style (from past posts, it sounds like you do some free-riding). Other considerations:
1) since you want a 5" fork up front, the Blur is not a viable option. They only support max 4", or 105mm, up front.
2) Turners frames are built very strong and beefy... better suited for stairs, drops, jumps, and similar obstacles.
3) Turner geometries are tuned for stability, especially on decents. However, they still hook up on climbs very well.
You'll find that the 5-spot's fully active nature quite a difference from the STS -- no stinkbugging, no requirement to stay seated, etc. It will be a nice upgrade.
Don't wait too long to order -- summer won't wait! |
| Get the TALAS!!! | Nat
Jun 10, 2003 12:00 PM | | Yep, you need the TALAS. You know you want it. |
| Thank for the suggestion, but I am looking for a good fork | Martino
Jun 10, 2003 12:11 PM | | The Talas does not work well at all for my body weight (145) + it would still void the warranty.
If anything I would use my Z1 SL on the blur and hope for the best. |
| It sounds like... | J.S.
Jun 10, 2003 12:32 PM | | It sounds like you've alread decided on the Blur. If you're set on an SC-VPP, why not consider a V10?
Also, isn't the Z1-SL a 130mm fork? If its travel is (permanently) shortened below 105mm, then the Blur frame may keep its warranty. If not, SC will not cover the frame for any reason short of paid service. |
| Not really: very undecided. (And thanks to everybody by the way) | Martino
Jun 10, 2003 2:45 PM | | No not really, I am really unsure between the Blur and the 5-spot. What is a V10?
I liked the Blur it is light and more in line with my body weight ... but I also love 4-bars which I think are more "consistent" then the VPP. The thing that I found a bit diconcerting about the BLUR is its "change in personality": it is quite a different bike depending on how you pedal it.
The LTS/STS had 3 main problems
(1) Severe BOB when standing
(2) suspension kick-back
(3) some limited brake jack.
The Turner linkage will get rid of (2)-(3) and the Romic should limit (1) quite a lot ... which will make the resulting bike close to a super-bike ...
and yes, of course the Z1 SL 130mm will completely void the warranty ... at my weight I will probably never run a risk of breaking the Blur (I used a Z1 on the STS for 5 years, the frame, not famous for its strength, was just warranted for 3 years and it is still running strong)
and yes, in further response to Nat: of course I love Foxes (I saw one yesterday 3 times in Golden Gate Park!!!, can you believe that in a while there will be bears in GG park), I am just not sure I want one in my home!! |
| So after you get your Fox fork you'll post pics, right? nm | Nat
Jun 11, 2003 4:28 AM | | |
| Yes, and I will put ash on my head and go on my knees to ask forgiveness from the fox-gods (nm) | Martino
Jun 11, 2003 8:03 AM | | |
| V10 and misc... | J.S.
Jun 11, 2003 8:11 AM | | The V10 is SC's downhill VPP. Since you're looking for a trail bike with 5" travel supported up front, the V10 isn't a viable option.
Having ridden both Horst-link and single-pivot bikes a few years, I definitely favor fully active suspensions. They simply work better for the type of riding I do (moderate XC), maximizing power transfer, comfort, and traction without interference from either braking nor pedalling.
I know I've seen Turners in a downtown San Carlos bike shop... searching for the shop name now, but so far no luck. |
| Well, yep, no, indeed the VPP is for daredevils + skylift | Martino
Jun 11, 2003 2:40 PM | | let me know if you can dig out the San Carlos! thanks |
| A couple thoughts | Jaybo
Jun 10, 2003 1:03 PM | | First, Turners can do no wrong on this board. They are nice bikes, but not for all souls. Second, the Turner is a coil over bikes that is not going to be as snappy as the Blur. Third, the Blur is a full pound lighter then the 5 Spot. Fourth, the Blurr is roughly $600 cheaper then the 5 Spot.
I would probably go with a Blur if I were you. It makes more sense since you are so light. It would be snappier, lighter, and quicker. You don't like the Float? Most people love this fork. I ride a Vanilla, but I'm a coil over guy. Oh, I would buy a 5 Spot because I like the all mountain ride of the 5 Spot and I'm not 145lbs. I'm also not concerned about a few pounds on the bike.
Jaybo |
| A couple thoughts | Dougal
Jun 10, 2003 2:25 PM | | Why exactly will the 5S not be as snappy as the Blur?
The Blur I haven't ridden, but snappier than the 5S I don't think is possible, acceleration depends on the suspension geometry, not what type of spring is holding up the rear.
Dougal.co.nz |
| You are right | Jaybo
Jun 11, 2003 8:18 AM | | I would love to ride a 5 Spot. Would you agree that an air spring bike tends to be a bit more snappy then a coil over bike due to a coil's active ride? I'm not sure I do, but I have been thinking about that for a while. By the way, I like coil over bikes much better.
Jaybo
PS I'm talking out my tail because I have never ridden a 5 Spot. |
| You are right | Dougal
Jun 11, 2003 2:28 PM | | There used to be a marked difference, but now as airshocks have become smoother and stiction free it's not an issue and they pedal pretty much the same.
Dougal.co.nz |
| Blur... | erolthegreat
Jun 10, 2003 1:30 PM | | Get the Blur. You don't need the 5-spot. You're too light. It would just slow you down on the climbs.
Also depends on where you live. The 5-spot is ideal for SoCal trails - more fireroads, long climbs followed by fast descents. For tight, twisty, short steep up-and-down east coast singletrack, the geometry of the Blur would be better. |
| Here is another idea, 5-spot with air..... | Mario
Jun 10, 2003 5:50 PM | | Hey, you are light just like me, and you're looking for a nice trail bike. Personnaly I want a 5-6 inches, no bob, light, quick, bike that will descend like a demon for a 150 pounds rider...!
So, my idea would be to build a machine that seems to be unanimously a great frame. The Turner 5-spot. BUT, why not build a 5-spot with an air shock like the new Manitou SPV or CaneCreek CloudNine and then put a Fox Talas fork in front. This would create a really light 5-spot machine for light riders...
Comments? |
| Here is another idea, 5-spot with air..... | Martino
Jun 10, 2003 7:52 PM | | I am not sure the weight saving is worth the possible loss in performance?
The Talas is 4.0 pounds vs 4.3 of the Z1 SL. My experience is that the Z1 can be tuned perfectly for our weight, it is much stronger, and works better.
the lightest air shock is at 200-280 grams, a Romic titanium is around 460.
So you are talking at most, let's see 150 + 200 = 350 grams. ... A VERY LITTLE DIFFERENCE FOR A TRAIL BIKE! |
| Here is another idea, 5-spot with air..... | Dougal
Jun 10, 2003 8:27 PM | | Please don't put an SPV shock on the 5-spot. It doesn't need the bottomout resistance and the damping will be a step down from the Romic. I learned long ago that the performance more than makes up for the weight.
At the end of a long ride will you be more tired from carrying 1lb more of shock to the top, or from being beaten up by your suspension?
Dougal.co.nz |
| late to this topic, but . . . | Motivated
Jun 11, 2003 1:03 PM | | 1) I don't think anyone touched how the 5spot and Blur perform when pedaling out of the saddle. The blur, obviously, is very firm when pedaling out of the saddle, but still soaks up bumps nicely. On my FSR I rarely stood up to pedal because it was very inefficient. On my Blur I stand up frequently because it is efficient, prevents my a$$ from hurting and promotes blood ciculation to my legs. How does the 5spot pedal out to the saddle?
2) Martino, you need to ride the 5spot and make a decision.
3) The blur does not exhibit brake stiffening. |
| late to this topic, but . . . | Dougal
Jun 11, 2003 2:29 PM | | On what do you base your comment #3? The blur does not exhibit brake stiffening!
Dougal.co.nz |
| The Blur has very active braking | Motated
Jun 12, 2003 7:20 AM | | I've logged about 1500 miles on my Blur in the last six months and raced it 4 times. Additionally I'm a mechanical engineer. When I shopped for my bike I compared it to several bikes: new FSR, EPIC, Superlight, Fuel, Racer-X. (The 5spot was not available last December, but I could not have afforded it anyway.) I found that the Superlight, EPIC and Fuel had traction issues when braking over bumps. Big turnoff. I was very interested in the SL and Fuel so was bummed to cross them off my list, but braking performance is very important to me. I consider it one of my strengths - being able to make a pass braking into a corner. The braking performance of the blur was excellent when I test rode it and has proved excellent in every ride I've ever taken it on. I've tried in many ways to induce brake stiffening, but never have I noticed it. In fact on Sunday I was riding on a road next to a rock quarry and noticed the studder strip imbedded in the ground to shake loose rocks off the trucks as the leave. After several passes over this at different speeds, coasting and pedaling I did not notice any change of traction while braking. Maybe it's because I have disc brakes, maybe I'm just good at modulation, but I don't think my skills are anything special and most people will put disks on their blur anyway.
On what do you base this comment "You won't notice any brake jack on the blur, it'll squat under braking. For many people this would be the single most noticable difference between that and the 5-spot."? |
| all 3 VPP I tested had some brake stiffening | derby
Jun 12, 2003 12:16 PM | | I tested 2 different pre-production Intense Spiders, and a pre-production Intense 5.5 inch travel VPP (not yet named). They all exhibited the same rear braking traits over bumps and flats of both the Iron Horse Hollowpoint, Jamis Dakar bikes I've tested, and similar action with slightly better rear braking compliance over bumps as my old Superlight.
Motated (cool handle name by the way, are you are referring to the "Mota" input as in mota-vation?), Moatated is correct that none of them squat under braking monopivots don't squat either But they all don't allow very free suspension extension while there is traction. They all extend a little when using both brakes at the limits of traction (mostly front brake), but the rear wheel skids more easily than my Tracer. Using rear brake only they all remain very stable with only a little extension, while my Tracer extends more noticeably with rear only braking.
VPP's use a lighter spring rate than other bikes with the same travel to statically sag more into travel (1/3 shock stroke is the design static sag). And the VPP uses very fast damping settings for best performance. The lighter springs and faster damping allow freer bump travel activity than a monopivot of the same travel. So the brake "stiffening" over bumps isn't as severe as a monopivot. And it is easier to modulate the rear brake than a monopivot over bumps due to the better bump compliance traction. But every Horst link available is better at rear braking (except the NRS). The VPP rear braking is probably about on par or a little better than an ICT suspension set up for pedaling efficiency, which is less bump re-actively compliant than Horst links mostly due to the much slower damping required for ICT pedal bob control.
The differences are most noticeable in slightly loose stutter bumps, such as braking over washboard dirt roads. The ICT, VPP, and especially the monopivots skip the rear wheel noticeably more than a classic lowered dropout pivot cantilever-beam or walking-beam Horst link of the same travel.
- ray |
| you are wrong. | Motivated
Jun 12, 2003 1:13 PM | | Your answer is very informed, but not about the real-world braking performance of the Blur. Ride one with disc brakes and then post your impressions. There is no indication that the Spider uses identical pivot location and geometry as the Blur so your impressions of those pre-production bikes clearly should have a huge tolerance associated with them, not the absolutes you state.
I like my screenname too - I misstyped it in the above response. |
| I don't believe in magic | derby
Jun 12, 2003 4:21 PM | | There is a rear braking dynamic that occurs with Horst links with shorter upper links that dynamically and significantly increases suspension compression forces when bumps compress the suspension, and alternately relaxes rear brake compression input when the suspension extends upon bump rebound. This active suspension design plus decent rider modulation keeps the rear wheel planted to the ground better than any other design, except a tunable floating brake add on for longer travel bikes.
The VPP's linkage also has a bump dynamic effect from the force input to the frame through the upper link (and from the lower link much more than a Horst is effected in compression by the lower link), but it is similar to the Jamis Dakar, reducing the rear brake induced compression force input as the suspension compresses, and increasing the rear brake induced compression forces as the suspension extends upon rebound. The effect is subtle but is going in the wrong direction to complement bump travel and doesn't enhance rear wheel traction like a Horst link dynamic does.
Due to the lighter than normal springs when sagged correctly to 1/3 travel and very fast damping allowed with the VPP, it is likely more bump tracking than anything in it's travel range besides a short upper linked Horst linkage. So on a relative scale the VPP is more active and plush braking over bumps than nearly all other designs, with the noticeable exception being a similar quality Horst linkage.
Often riders will use too much spring and slower damping than optimum for Horst link suspensions and loose the optimum pedaling and braking potential. I recently realized while riding my Tracer that a little bob actually enhances the pedaling snappiness and efficiency, both on smooth and bumpy surfaces, of the Horst link, unlike any other design (except possibly DW's Hollowpoint linkage for similar pedaling efficiency), due to the active increased acceleration complementary pedal rhythm strength biopace efficiency of the path while bobbing. (The bobbing path is more rearward during the strongest section of the pedal downstroke, then the path relaxes for better bump compliance during the lower section of the pedal down and cross stroke).
A Specialized Enduro when set up correctly with the same quality spring and shock has noticeably better rear braking traction than any VPP set up correctly with the same travel range.
But good riders can modulate rear brakes so even a monopivot (almost) never skids. But they can't brake as hard as they can on a Horst link.
Thanks for the dialog, and the opportunity to think out these things more thoroughly. The VPP is a great design, but a quality Horst design still has a number of advantages. I think the VPP is better, more efficient accelerating, for racing at equal weight. And Santa Cruz and Intense are excellent at producing great handling bikes. A Blur is one of the very few bikes I could see my quality ride spoiled self leaving my Tracer idle for more than one demo ride, also the Hollowpoint, 5-Spot, and Switchblade.
- ray |
| I think this is good for both of us | Motivated
Jun 13, 2003 6:56 AM | | Ray, your writting is very interesting. Not only for the content, but from a logical point of view. My goal here is not to agrue with you it is to make my point clear to potential buyers (that's what this forum is) that the Blur does not exhibit brake stiffening.
#1 I've never questioned the braking performance of good Horst bikes so I don't know why you expend so much effort trying to convince me of their active braking. My last bike was an FSR and my next bike could be a high-end Horst bike.
#2 The rear braking traction of the Blur is excellent - in my world this is a fact based on personal experience and testing (you can search my name for all the on-trail tests I've done). I refuse to let non-owners get away with making statements which contradict that. The best I can offer you is that in your world the braking performance of the Blur is a theory based on geometry, free-body diagrams and assumptions of how forces are introduced to the system. I appologize that I have not taken the time to independently determine how braking forces at the wheel transmit through to the shock. Heck, I don't even have a model of the bike to begin with. I asked SC for one and you can imaging their response.
PS the Blur sag is 1/4: 1.75" stroke/.375" to .5" sag at shock. |
| yes | derby
Jun 13, 2003 1:15 PM | | I'm tending to believe now that the spring stiffness and damping rate has much more influence on bump compliance than suspension geometry and braking torque effects. Both Horst link and even more so the VPP are optimized with lighter spring rate and faster damping. This would make them both top performing under braking. The subtle torque dynamics are probably a very minor influence until we get into longer travel where damping is very fast and springs are a much lighter rate.
The Superlight forward pivot design requires a relatively firm rear spring while damping can be set at a medium speed. So unweighted with a heavier spring weight, the Superlight just isn't as free acting as a lighter sprung Horst or VPP, or even as free acting as a more rearward monopivot.
Thanks for the dialog. I don't mean to be argumentative either. Just trying to present my perspectives from my experiences.
- ray |
| yes | Motivated
Jun 13, 2003 3:15 PM | | And I agree too that the longer VPP designs would start to exhibit brake stiffening. Also the Spider being more racerly could sacrifice some braking activity for snappier acceleration. Have a good weekend. |
| The SC V10 VPP use a floating rear brake to fight .... | Quattro
Jun 14, 2003 4:04 AM | | the rear suspension stiffening under braking. |
| late to this topic, but . . . | WarrGuru
Jun 11, 2003 2:57 PM | | I pedal out of the saddle much as you do. The 5-Spot does quite well in this regard......mostly due to the Romic, imho. I didn't notice any major bobbing or other problems. It seems quite efficient.
How does it compares to the Blur in this regard?....I'd say it's similar. I didn't test the out of the saddle very much on the Blur. I did hammer out of the saddle and thought it did well. |
| re: First ride on a Blur, impressed but some feedback required: | Jubilee
Jun 11, 2003 4:58 PM | | Thanks to all you for posting!! This is the thread I've been waiting for. I canceled a Blur order about 3 weeks ago and ordered a 5 Spot. I ride all mountain and weigh about 210. Sounds like I made the right choice in the end. If I want a lighter ride I can lose 10 lbs off my fat azz. |
| You may not need to order, check around............ | esquire
Jun 11, 2003 5:52 PM | | Even on the front page of mtbr, wrenchscience and supergo (I believe) have them in stock, probably all sizes. |
| You may not need to order, check around............ | Jubilee
Jun 11, 2003 10:12 PM | | Yeah I know. I like to order the big ticket stuff from my LBS. He's a good guy and answers all my dumb questions. |
| Without a doubt, if you have a good LBS, use em!!......(nm) | esquire
Jun 12, 2003 3:16 AM | | |
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