|   Which cassette size to use? | bonker
Oct 15, 2001 8:34 AM | | I'm building my Fuel 100 from the ground up. I am going to put Next LPs on (42/32/22). Which XT cassette size would give me the best range for low-end to top-end and will be good for racing/competitive riding? 11-32, 11-34, 12-34? |
| I would go 12-34..... | RED5
Oct 15, 2001 8:50 AM | | the 12 is better for keeping your chain from jumping off when mud and debrit gets in the cassette. Also, the 34 is a much easier gear than the 32, not that you would really need that on the Fuel. Just couldn't hurt. |
| Agree....who actually uses the 11? | scrappy-doo
Oct 15, 2001 10:16 AM | | there is not many times when an 11 is needed. On my road bike I have a 12-23. The only time Im spun out is on the local road racer ride which has a downhill sprint to the finish.
On my mountainbike, I race with a 42 big ring and a 12-34. Im never out of gears even with the 42-12.
Hell, 42-12 is good enough for Tinker Juarez, 44-12 should be enough for you.
On the other hand, the 11-32 XT casette is a good bargain and very light (on par withe the XTR 12-34) |
| Disagree strongly... | laffeaux
Oct 16, 2001 10:12 AM | | Who uses the 11 tooth? Well that would be me.
If you are using an 22/32/42 tooth front, which you're saying you will, and an 11 tooth rear, I've found that the top end is pretty low. I'd hate to have a 42/12 high end.
I have a bike with a 22/32/42, 11-30 set-up and find that the 42/11 can easily be reached on dirt, and if you ever find yourself riding down a paved hill back to the car after a ride, you'll easily top out. There's many a time that I've reached speeds where pedal input became useless.
My most recent bike has a 46/11 top end and it's so much better. I run a 24/34/46 with a 11-34 rear (9 speed) and think it's great, although expensive to put together.
Good luck. |
| re-read his post | scrappy-doo
Oct 16, 2001 2:29 PM | | he says gearing for competative racing. I race at the pro level all over the world and can think of only one race where Ive needed more than a 42/12. It was in California at the Sea Otter Classic. We were in the home stretch on pavement.
a 42 allows more time in the big ring without dropping to a smaller ring. the 12/14/16 spread of XTR casette is very practical. the silly (yes, silly) 11/12/14 spread of many casettes is just not good gearing for mountain bike racing. you basically have two gears (11 and 12) which are damn near the same at dirt speeds. with the 12 and 14 you have a good fast gear and a good less-than max speed cruiser.
I can get 25+ mph in a 42/12 that is much more than enough for any XC race course.
Talk to Tinker Juarez. Ask him how he manages to ride a 42/12 in 90% of his races. You gonna tell me you are faster than he?
Save the road-bike gears for road bikes. make your MTB gears dirt-friendly and useable. |
| I would go with the 11-32 for a 42/32/22... | clary.
Oct 15, 2001 8:48 PM | | With the 11-32 you get 11,12,14,16,18,21,24,28,32. So you have 11 and 12 (real close, so easy to find the right gear) to match up with the 42 chainring and 32 is low enough with the 22 chainring.
With the 12-34 you get 12,14,16,18,20,23,26,30,34. The 12 is not high enough with a 42 chainring and 34 is too low for a 22 chainring. Good for spin training though.
I use 11-32 with 44-32-22 and 12-34 with 46-34-24 and 12-34 with 48-36-26 and use all the gears, from high to low. I guess you have to try the different combinations for yourself since one person's setup might not suit another's setup. Anyway, what I propose is wide range. |
| Question for clary.... | bonker
Oct 15, 2001 10:22 PM | | I checked out Trek's page and they list 11-34 as their cassette of choice. How much different is it going to be using the 11-32 versus the 11-34? |
| big difference when looking for the right cadence | clary.
Oct 16, 2001 7:35 AM | | With the 11-34 you get 11,13,15,17,20,23,26,30,34. In percentage, the gap between 11 and 13 is the greatest on that cassette. If you have 11, 12 then 14, you can find a cadence that suits you in a fast pace better than 11, 13 then 15. The 34 is too much a low gear for the 22 chainring. Some people like the 11-34 because they state that the 34 is a good gear with the middle chainring. My idea of a drivetrain is that you should have the highest you will use and the lowest you will use, and a useful spread of all the other gears.
Trek's fuel 100 specifications:
SIZES: (S) 15.5", (M) 17.5", (L) 19.5", (XL) 21.5"
COLOR: Starry Night/Candy Blue
FRAME: ZR 9000 Alloy. Trek/VW Team tested. Double butted seamless drawn tubing. Double diamond frame. Custom butted head tube. Bi-axial downtube. Triangulated Rocker Link made of OCLV MC moldable carbon with Ti hardware. Carbon chain and seat stays. Light Disc-O disc brake mount. Cold forged replaceable derailleur hanger. Trek Pro Race geometry. Handmade in the USA. 4.41 lb.
FORK: RockShox SID Race, All Travel 63/80, Dual Air, compression control, pure damp., Ti Nitride stanch., travel
REAR SHOCK: Fox Float RL air spring, self adj. neg. spring, reb. adj. knob, comp. adj. lever, Ni charged
WHEELS: Bontrager Race Lite Tubeless: Trek/VW Team wheel; One of the lightest sets available; Durable and World Class fast; Uses a regular tire/tube, or tubeless tires for increased control and reduced flats; Swiss-made hubs; Race Lite skewers; 625g, 24h front/835g, 28h rear
TIRES: Bontrager Revolt Super-X, 26x48/49 front and rear
SADDLE: Bontrager Race Lite, titanium rails, leather
SEATPOST: Bontrager Race Lite
HANDLEBARS: Bontrager Race Lite
STEM: Bontrager Race Lite
HEADSET: Cane Creek S6 Aheadset
SHIFTERS: Shimano Deore XT
FRONT DERAILLEUR: Shimano Deore XT
REAR DERAILLEUR: Shimano Deore XTR SGS
CRANKSET: Bontrager Race Lite 44/32/22
CASSETTE: Shimano Deore XT 11-34, 9spd
BRAKESET: AVID SD Ti w/Shimano Deore XT levers
PEDALS: Time ATAC Carbon, clipless |
| Correct! For road-riding | scrappy-doo
Oct 16, 2001 2:37 PM | | for road riding/racing your theory on max/min and good spread is right on. In MTB you should think outside that roadie box. In the dirt shifts are many times unplanned. Things happen fast. Hills pop up. Mud bogs you down. You underestimate the steepness of the hill, etc.
The best bet for MTB racing is to have a wide range cassette. a 12-34 seems to best for most people.
The idea is to be able to stay in a given chainring for as much as possible. Front shifts need to be kept to a minimum in off-road riding.
My ideal setup? a 24-31-43 with a 12-34 now if I could only get race-face or TA to cut me those rings in a compact drive BCD. |
| Correct for MTB riders. | clary.
Oct 16, 2001 7:18 PM | | XT Racing (XTR) use 48-36-26 and 46-34-24 chainrings and 12-34 cogs. For low gearing, a 24 front and 34 rear has a ratio of .706. A 22 front and 32 rear which I propose for bonker has an even lower gear ratio of .6875. The geat ratio that you propose 22/34=.647 is even lower that XTR Racing. You must have really weak legs if you think people need that kind of gearing. For the high gearing XT Racing (XTR) uses 48/12=4 or 46/12=3.83 while what I propose for bonker is 44/11=4 or 42/11=3.82. You propose 44/12=3.66 or 42/12=3.5. which is not a high enough gear. For your weak legs, you require your special gearing. For normal people with normal legs, 44-32-22 and 11-32 is right in the ballpark of MTB usage. |
| Correct for MTB riders. | scrappy-doo
Oct 17, 2001 4:49 AM | | you really didnt read my message. Try to get the whole (max gear ratio/min gear ratio) idea out of your head. That is a roadi concept. I am talking about having a wide range of rear cogs to allow one to stay in a given ring longer.
Re-read his post and my post. Please dont re-iterate the whole max/min ratio thing. If that was the case we would all use 20-32-48 rings with an 11-26 rear cogs. we would be miserable riding the singletrack. |
| The general public (99%) will do well with 11-32 x 44-32-22... | clary.
Oct 17, 2001 7:25 AM | | There is 1% of riders who are well justified, have the need, and will tweak their drivetrains to match their requirements. That 99% will not benefit from the 1% solution. |
| It all comes down to PERSONAL PREFERENCE | Voice of reason
Oct 17, 2001 7:38 PM | | Neither is better for everyone. Great discussion, though! |
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