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I recently got myself a cheap pair of 650B Wilkinson wheels to train on. After doing 50+ miles over 8 weeks, I'm having shifting problems when I change over to my WTB knobbly.

The shift is inconsistent at best. I noticed it appears the chain is slipping. The chain indicator does say it's 0.75% worn. but my bike is fairly new. I probably done at absolute most 100 miles on that chain between the two wheelsets. I have tried playing with the cable tension to no avail.

Why has it worn so quickly?

Do I just need one chain for each wheelset since ones a road cassette and the other is mtb?

2 Answers 2

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There are many variables that you should look at when switching rear wheels, and wear is not really the first place to look, nor is the tire type. The first area is the hub - are the hubs the same? I am going to assume that both wheels have the same number of cogs on the cassette (which eliminates the 8/9/10/11 speed differences), or you would be having other problems. Hubs can have slight positional changes, millimeters, for the freewheel, depending on the manufacturer, so the cassette will seat in a slightly different location on each wheel, relative to the centerline. The second is the cassette. SRAM and Shimano cassettes have slightly different spacing, Shimano and Campagnolo have much larger differences in spacing - you want to stick with the same brand cassette for maximum compatibility. Also, road cassettes and mountain cassettes have narrower and wider ranges of gears, respectively...if you have a 12-32 on the mountain cassette and a 11-23 on the road cassette, you will have a load of extra chain when running the road wheels, and that can cause shifting problems. When switching between wheelsets, at a minimum, you will need to make slight adjustments to the rear derailleur...or you will need to swap chains (or remove a section of the chain, which you can do easily with quick connects), it more than likely will not be a seamless transition.

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Are the cassettes both the same number of gears? Are the hubs identical? Then the cogs should line up perfectly. Since you probably have different brands of hubs and cassettes - the differences add up and put the shifting out. You could fit very thin spacers under the cassette that is slightly left, to try and get the cogs in identical spots. You do not need two chains but you do need to change the chain on time. Try measuring 12 whole links with a ruler - should be 12 inches exactly when new, or 12 1/8 inch is time to change chain.

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  • This may sound stupid, but did you try removing the wheel and reinstalling it so that the frame is pressing down on the wheel and tighten it slowly. This could all be do to a misalignment from a hasty wheel swap. Happens to us all.
    – user26705
    Aug 25, 2016 at 17:34
  • @BTeam this should probably be a comment on the question, not a comment this answer. Or make it a fresh answer.
    – Criggie
    Aug 25, 2016 at 23:32

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