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#11
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11T compatible with 1996 Trek road bike?
PS -- unlike the photos at http://sheldonbrown.com/k7.html#hyperdrivec
my hub body has threads on the outside of the hub body running through the top quarter inch or so of the splines' lengths, although the splines run all the way to the top. (I didn't notice if there were any on the inside.) Maybe that makes a difference to whether modification is needed? At least it helps you understand what I meant when I suggested I might grind off the top one or two threads. Craig in NJ On Sat, 02 Jul 2005 09:36:03 -0400, CraigNJ wrote: That's sort of what the mechanic did -- he had the entire old 8-speed cassette on but with the 12t replaced by an 11t, and then the lock ring. He said it looked like he could get the lock ring to tighten. Could he be right that there's no need for additional spacers or grinding down the top lip of the splines to accomodate the 11t securely? Or maybe there's something we can't see that makes it mechanically unsufficient without grinding down the splines a little? I'm thinking that just to be safe, I'll want to do the grinding down anyway. I'm not quite sure how much, though, or at what angle. I'm guessing the best would be straight/flat, not angled, grinding off of the splines down by a distance that is exactly the thickness of the part of the 11t that is not cut through for the splines, e.g., maybe 0.5mm or so. Is that right? That might be just one or two threads, right? That sounds pretty easy to do, and maybe not too dangerous to sacrifice one or two threads. Craig in NJ On 1 Jul 2005 22:50:43 -0700, "JeffWills" wrote: CraigNJ wrote: The local bike shop helped me get a good look -- it's the non-compact body. It sounds like I'll need to grind off a little of the splines at the top, but ... But the mechanic there dropped an 11t cog on top in place of the 12 and seemed able to screw it all together, so he's thinking it won't be necessary to modify the body. Could that be true, or maybe we're just fooling ourselves because we didn't try it with a whole new cassette? The 11-tooth cog will slip on, but you might not be able to get the entire cassette clamped on properly. Put all the cogs and spacers on, including the 11-tooth, and then the lock ring. Make sure all the cogs are tight once you're cranked down on the lock ring. If they're not tight, put a thin spacer on the cassette body before installing the cassette- there's a Shimano spacer that's 0.3mm thick that should do the trick. If nothing wiggles with the lock ring in place, you're good to go. Jeff |
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#12
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11T compatible with 1996 Trek road bike?
CraigNJ wrote:
PS -- unlike the photos at http://sheldonbrown.com/k7.html#hyperdrivec my hub body has threads on the outside of the hub body running through the top quarter inch or so of the splines' lengths, although the splines run all the way to the top. (I didn't notice if there were any on the inside.) Maybe that makes a difference to whether modification is needed? At least it helps you understand what I meant when I suggested I might grind off the top one or two threads. Craig in NJ Yes, that makes sense. You have an original Hyperglide cassette body. The external threads were put on in order to make the body backwards-compatible with the earlier Uniglide cassettes. When the 11-tooth cogs came out, Shimano extended the solid splines all the way to the end of the body, with a relief to allow the 11-tooth cog a little more strength. As I said, if the cassette fits on the body with the lock ring nice and tight and the larger cogs don't move around, you should be OK. If not, grinding down the first thread or two OR putting a thin shim under the cassette should give you enough room to clamp the cassette properly. Ain't bike-mechanicing fun? Jeff |
#13
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11T compatible with 1996 Trek road bike?
JeffWills Wrote:
The 11-tooth cog will slip on, but you might not be able to get the entire cassette clamped on properly. Put all the cogs and spacers on, including the 11-tooth, and then the lock ring. Make sure all the cogs are tight once you're cranked down on the lock ring. If they're not tight, put a thin spacer on the cassette body before installing the cassette- there's a Shimano spacer that's 0.3mm thick that should do the trick. If nothing wiggles with the lock ring in place, you're good to go. Someone suggested. What about slipping the 11T on with one of the remaining sprockets removed? No, this would make the problem _worse_, not better. Shimano 11 tooth sprockets don't have the spline grooves running all the way through (they'd be too weak if they did.) Thus, the 11 can only fit partway onto a Freehub body. If that body doesn't have the truncated splines, the 11 won't go on far enough to clamp the rest of the sprockets and spacers. This is explained in detail (with photos) at http://sheldonbrown.com/k7 Sheldon "3 Minutes With A Bench Grinder" Brown +------------------------------------+ | Immigrants are not our burden, | | They are our wealth --Jane Adams | +------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts shipped Worldwide http://captainbike.com http://sheldonbrown.com |
#14
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11T compatible with 1996 Trek road bike?
To follow up on this alteration to my 1996 Trek 2300 road bike to take
an XT 11-30 casette: I used my Dremel on the hub body to grind off the splines' top outside threads, and was then able to get a Shimano XT 11-30 cogset on & locked down tight. My local bike shop will finish the work with a new XT derailer and appropriate adjustments, etc., so the bike will soon have the wide range I've long wanted. The biggest jumps may take some getting used to, but I'm sure I'll love my new 11T cruising gear and will appreciate the new 30 at least briefly on most rides around here. A couple of discoveries: It was possible to get by without any grinding by putting a very thin spacer ring on before the casette, and then screwing down the lockring tight enough to bend down the top outer treads on the splines. (My local bike shop did that -- I wouldn't have dared try that much force.) I didn't feel comfortable with that (even though it was already done) and proceeded with grinding off the top threads. In retrospect, I should've ground down only the first thread (1mm or less?) on each spline. It didn't need more, and by grinding down two threads (1.5mm or 2mm?) I no longer had the option of using a spacer (e.g., in case I needed to for some other reason) since that would lift the 11T almost above the trimmed-down splines. (Unfortunately, once the top threads were bent down during the attempt with the spacer, it wasn't easy to tell the difference between the 1st two threads.) Anyway, I think there's still enough spline left for the 11T for the swift cruising I'll do with it. A Dremel with cutting disk worked very well. (I didn't need to resort to my big RotoZip with diamond cutting disk.) I had to get rid of the bike's spoke protector in order to accomodate protrusions on the back of the XT's cassette. Otherwise, they would have clamped down against that plastic disk and stopped the wheel from turning. Without the plastic protector there is just barely enough room for those protrusions to clear the spokes. (Using the thin spacer was not enough to get the cassette to clear the spoke protector, if I even wanted to use the spacer approach.) Thank you all for your help & advice. It seems to be working out fine. Craig in NJ On 2 Jul 2005 10:36:13 -0700, "JeffWills" wrote: CraigNJ wrote: PS -- unlike the photos at http://sheldonbrown.com/k7.html#hyperdrivec my hub body has threads on the outside of the hub body running through the top quarter inch or so of the splines' lengths, although the splines run all the way to the top. (I didn't notice if there were any on the inside.) Maybe that makes a difference to whether modification is needed? At least it helps you understand what I meant when I suggested I might grind off the top one or two threads. Craig in NJ Yes, that makes sense. You have an original Hyperglide cassette body. The external threads were put on in order to make the body backwards-compatible with the earlier Uniglide cassettes. When the 11-tooth cogs came out, Shimano extended the solid splines all the way to the end of the body, with a relief to allow the 11-tooth cog a little more strength. As I said, if the cassette fits on the body with the lock ring nice and tight and the larger cogs don't move around, you should be OK. If not, grinding down the first thread or two OR putting a thin shim under the cassette should give you enough room to clamp the cassette properly. Ain't bike-mechanicing fun? Jeff |
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