|   Enough clearance? | tamjam
Apr 17, 2002 12:07 PM | | Well since I decided my bashed face calls for 2 days off work, I've got a little extra time to fiddle with the bikes. This is a picture of the non-drive side seatstay on the Ripley I am building up, taken from underneath. I am using an XT BB with a 113 spindle and this is all the clearance I have. It may be hard to see in the picture, but it's only about 3mm of clearance between the crank and the stay. It rotates fine, but should I be using a 118 spindle instead? I am not really sure what "acceptable" clearance is.
thanks,
Brian |
| 5mm<clearance<10mm | seattletim
Apr 17, 2002 12:19 PM | | Hey,
I believe I read in the Rivendell Reader that one should have between 5 and 10 mm between the inside of the crankarm and the chainstay. Seems a bit close to me, Tamjam.....
Tim |
| wow! | bn
Apr 17, 2002 12:20 PM | | that's pretty tight... had the same problem on a cx bike and fixed it 2 days ago. (at least) 2 options- longer BB, but that might affect chainline in a bad way if not adjustable; or since it's on the non-drive side try to find a crankarm that is not as low-profile.
In my case I went with a longer BB (110 vs. 107), but the original one must have been bad because the chainline moved IN slightly (both by measurement and need to adjust front d), and the non-drive clearance improved dramatically. |
| I don't know if 3mm is enough clearence... | T O M A
Apr 17, 2002 12:52 PM | | But I'm sure you'll know the first time you hammer up a hill!
I'm not familiar with that frame, is it stiff?
I've got a cannondale that i've converted into ss commuter duty. the bb had about 1" of lateral flex, when i first rode it the chainring ended up gouging the chainstay! i had to get a longer bb spindle. fortunatly i've got a cassette rear on it so i was able to adjust the rear cog.
Hope you figure it outand it doesn't cost too much! |
| Ibis Ripley | tamjam
Apr 17, 2002 2:48 PM | | TOMA- The Ripley is the Aluminum softail Ibis came out with last year. It's very similar to the Silk Ti in design. Because it's aluminum, I am expecting it to be pretty stiff laterally. And it's going to have gears, so I don't need the same precision chainline like on a SS. But I sure don't want to be banging cranks or rings on the stays.
A new XT BB is only $25, so it probably won't break the bank.
Brian |
| Ibis Ripley | Chequama Mama
Apr 17, 2002 4:02 PM | | I'm guess you're right about lateral stiffness, but taking a chunk out of those stays could be trouble (as you said)
One other thought to consider. I don't know if the cranks are new or broken in. since it sounds like you've got a tapered system, you might lose some of that three millimeters right there due to the taper on the crank getting bigger, etc. You know what i"M talking about, I just can't figure out how to say it. |
| re: Enough clearance? | Mr Pivotless
Apr 17, 2002 5:55 PM | | The Ibis Ripley has a 73mm BB, so according to Shimano, it should use a 118mm XT BB. This gives a 50mm chainline.
With XT cranks, the clearance on the non-drive side should be about 7mm. The chainstays are shaped to provide maximum useage of the room that Shimano cranks provide on the left side. Other cranks that take a straighter line may give less clearance. 3mm is tight. |
| personally, i wouldn't worry about that... | GMF
Apr 18, 2002 9:02 AM | | First off, that area is only halfway up the crank, so it really isn't going to be moving all that much... the only point that i could concede is the migration of your cranks in as you install and remove them numerous times on a square taper.
Other than that, ride it and see if you can hear a *tick tick* on each revolution.
Also, i think it is funny that someone mentioned the rivendell/grant peterson philosophy in reference to race face cranks on an aluminum softtail. Grant would roll over in his grave (if he were in one, but he isn't, so no harm no foul... :-)
-GMF
p.s. hope you are feeling better |
| rivendell philosophy | tamjam
Apr 18, 2002 9:22 AM | | GMF- I must be missing something. I've gone to Rivendell's website to look for any Reader articles relating to this subject and can't find any. Got any links I should look at? And I don't get the reference to Race Face cranks on an AL softail? Granted, I've never owned an AL frame, so there could be some whole world I've been missing out on. Or maybe the knock on my head is affecting my thinking...
thanks, by the way. |
| rivendell philosophy | GMF
Apr 18, 2002 11:14 AM | | My comment about the irony of the rivendell philosophy in reference to your Ripley just comes from having met grant peterson and having a Rivendell All-Rounder in my living room right now. He vehemently shys away from any frame not steel, and not lugged, and not rigid. No criteria of which your ripley meets, i might add :-) I agree with a lot of what he says, but i doubt you'll be cloth-taping those damned flat bars (he hates flat bars, too), shellacking them, and mounting cotton-duck carradice bags on your bike.
Anyway, i guess my point is that his focal point for his philosophies is probably quite different than what the avid mountain biker point of focus is... which is being able to ride off road on some seriously sketchy stuff, going too fast, and generally not caring whether your head tube lug has one point or two.
Keeping cranks narrow is nice, though.
http://www.rivendellbicycles.com/html/101_cranks.html
Sorry, but in my own quick search, i couldn't find the reference to crank clearance with the chainstays. He is ALWAYS harping on crank width, though.
-GMF |
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