7 speed shifting problems: Uniglide v Hyperglide
so I recently switched out my 7 speed hyperglide rx100 wheelset with a 7 speed uniglide 600 ultegra wheelset. When I switched, I also bought an 8 speed SRAM chain for the bike.
Here's my problem:
Shifting was perfectly fine with the rx100 + KMC chain, but the ultegra + sram chain is super noisy and slow at shifting to the larger cogs. Dropping down to smaller cogs is fine. I talked to a mechanic and he told me that the problem is in the newer chain made for hyperglides on the uniglide cluster... that the bumps in the hyperglide cluster really help shifting. He also said that after a certain break-in period, the sram chain will work just fine. It pains me to hear the noisy shifting though...
I do have an older shimano chain that came with the bike that had the 600 wheelset, so I can try installing that one. I also have an older Sachs one that I can throw on. I'd just rather not break any chains and just use this one, so I'd like to know your guys' opinions and if the chain + cassette is really the problem. It's not a problem though, I just want to get this thing perfect before the STP on saturday.
If it helps, I'm running 7 speed RSX shifters on 600 ultegra drive train. STI shifters, cassette, and pulleys are all i perfect condition.
Last edited by tomio; 07-12-10 at 09:49 PM.
Uniglide doesn't shift quite as effortlessly as those new fangled hyperglide cogs. I have a sram pc850 chain on a 6 speed uniglide cassette. Yes, it's a little noisy and yes, it takes a little longer to downshift. You just have to hold the shift lever an extra second to make sure it shifts. Also, keeping the chain clean and well oiled seems to make it shut up.
cycles per second
IMO, it's a Uniglide problem and not a chain + cassette combination. There may be chains out there that shift better on the Uniglide tooth profile but I don't think they would be significantly better. I have both Uniglide-6 and Uniglide-7 bikes and the Uniglide-7 has always been much more sluggish, noisy, and generaly problematic than the 6. I ran Uniglide chains originally but primarily used Sedisports as replacements for a long time. Currenly have some cheap KMC 6/7-speed chains on the bikes, and it is not working well on the UG7 at all. I'm thinking about trying a narrower chain on the UG7 to see if will work a little better.
Sweet, I just tried out a friend's HG 7 speed wheel and it shifted perfectly. I guess I'll just move the cassette over. Now why is it that DT shifters don't have a problem shifting on UG, but STI does?