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I have a weird shifting problem that maybe the Slowtwitch braintrust can help me solve. I rode my tt bike on the trainer this winter with a Mavic wheel and 11 speed shimano 105 11-28 cassette. I have di2 set for full synchro and it shifts perfectly with the training wheel on the trainer.
Today I took it off of the trainer to ride outside and put my Zipp 404â€™s on with a SRAM red 11-28 cassette. The RD will shift to the 28 no problem but it will not drop all the way to the 11 on this wheel. No biggie could be spacing diff between the Mavic hub and Zipp hub.
But before I made any RD adjustments I tried the same SRAM red cassette on my Zipp Super nine disc. On that wheel it will drop to the 11 with no problem but will not shift up to the 28.
It would seem to me that the 11 speed hubs on the Zipps should be same spacing and the same cassette should act the same? I can understand the Mavic hub spacing being different from Zipp, and also possible spacing issues between the shimano cassette vs SRAM.
But for the life of me I donâ€™t get why the Zipp wheels with same cassette are on the opposite end of shifting range from each other? Before I start adjusting the RD for one wheel and have it throw off the other even further, what am I missing here?
Last edited by:
: Apr 6, 19 12:23
Don't forget that you are having an issue with two different hubs from a company that has had to re-design their rear hubs six or seven times (I've lost count) over the last decade to address failures resulting from poor designs. I think it's well within the realm of possibility that different Zipp hubs might have different flange and cassette spacing, causing your issue.
Thanks for the reply. Thatâ€™s what I am afraid of as well. Both wheels are 2016 limited editions (Firestrike for the 404 and canyon edition disc) with ceramic speed bearings and 188 hubs but most likely they are different spacing or offset.
I was hoping I could run the 404â€™s as everyday wheels then throw the disc on for races. But if I have to make a bunch of adjustments that doesnâ€™t seem like a good option. I might see if a 1mm spacer will fit on the disc to push the cassette out enough to shift to the 28 cog.
Last edited by:
: Apr 6, 19 3:04
A 1mm spacer is likely to be way too much.
I am only aware of the 1mm or 1.85mm spacers. Perhaps a dumb question but are there .5mm?
You probably need to only make a 3 or 4 click micro adjustment on the middle cog.
Not all rear wheels are "dished" the same. Some rear wheels have more room on one side. This could be the issue and you just need to adjust a screw to allow the rear derailleur to move down to the 11.
However, usually the first place you notice a wheel that is "dished" differently is with the rim brakes as one side is now closer than the other.
I have Mavic wheels and they are dished differently than my Flo or Oval which are interchangeable without adjustment.
Indoor Triathlete - I thought I was right, until I realized I was wrong.
The inner plate of the pulleys (Premier oversized kit) was extremely close to hitting the disc - so much that I couldnâ€™t slip a 1mm spacer between there. There was quite a bit more of hub end exposed for the lock ring, so I added a super thin spaced to the disc and tried it again.
After indexing on the 6th cog, I could get it to climb to the 28 tooth - partial success. But now it wouldnâ€™t drop to the 11 (due to spacing) until I backed out to outer limit screw enough for it to drop.
Swapped the cassette back to the 404 and tried it. Now the indexing was off again and it wouldnâ€™t climb to 28 without either backing the inner limit all the way. So added. Thin spacer and voila it shifted same as the disc.
I probably didnâ€™t need spacers at all except the inner pulley plate being so close to the disc.
The end stops can be set to accommodate both wheel sets, as long as catastrophic derailleur into spokes is prevented.
Di2 will only shift as far as required to shift so if you change wheelsets and trim to that wheelset, there is no reason for Di2 to send derailleurs past the sprokets, in fact, many Di2 bikes have never had their endpoints set and rely totally on the trim to stop overshifting.
If your cage is that close, then the hanger is probably bent and if you run different size teeth on each cluster, that will shift your trim as the cage is no longer swinging in plane with the wheel and may be you total problem or at least a significant contributor.
Align hanger, set end stops to allow full movement on both wheels, trim to each wheel when you fit it.
This is only a couple of button presses so could not really be considered too onerous to change a wheel.
The introduction of 11 speed caused a bit of a tizz with hub makers and many of them increased the overall locknut dimension to try and claw back a little lost wheel strength caused by the extra dishing required to fit 11 speed.
Zipp increased theirs by .8mm in the first versions of 11 speed for this reason.
Discs generally did not suffer, being thinner, so stayed true to standard locknut dimensions.
So depending on exactly which models you have there may be a difference in overall locknut to locknut width.
Variance in wheels here is not uncommon as with some designs (not Zipp), simply adjusting the bearing preload will alter the locknut dimension, so get used to it, it is common and expected to have to trim gears to a different rear wheel, even if the hubs are identical model.
That's just how it is.
But there is nothing preventing you from running both wheels with only a small trim in required.
If you trim in the middle of the cassette there is no chance of derailleurs going too far and rubbing or dropping chains until it is aligned.
There should be no need to run any spacers on any 11 speed road setup on any road wheel apart from those using the thinner MTB cassettes.
Last edited by:
: Apr 6, 19 17:25
Thank you for that. I didnâ€™t think the hangar was bent but will replace to be sure. Both Zipp wheels are the same model year and both are models that do not have bearing preload that can be adjusted (limited edition ceramic). I hear you in the spacers - didnâ€™t seem like that would be needed. I do get minor trim adjustment for different cassette or cog sizes. This was the same cassette swapped between wheels. This wa s the cause of my initial confusion why one wheel would not shift to the 28 and not the 11, then the other would be the opposite.
Don't assume a new hanger is aligned.
There are tolerances in manufacture of the frame and the hanger as well as dropout wear that can alter alignment.
Keep your current hanger, align it.
In many years, I have only ever found 5 new bikes out of the box that the hanger is in alignment, and 2 that came in for service that were straight.
Those two were both titanium with integrated non replaceable hanger.