swapping rear wheels and keeping derailleur adjustment?

[jmitro]

How do you racers/ mechanics swap out rear wheels and keep the derailleur adjusted for optimal shifting?

Even with the same brand of wheels (Easton EC90 carbon clinchers vs tubulars) and same cassette, the spacing is slightly different and swapping my tubulars for clinchers leaves the shift adjustment off. I had to put my clinchers back on for the last race in order to use all the cogs.

[yoshirama]

I think the cassette offset is based on two things: your rear hub, and whether the wheel is dished properly. If both wheels are centered properly and have the same hub, the cassette should be in the same location. If the hubs are different or the the wheel is not dished properly, your cassette won't be in the same location.

[JCavilia]

You might be able to play around a bit with thin spacers behind the cassette and get the two wheels closer, but unless it's exactly the same hub model, two wheels will usually place the cassette slightly differently. Hub/freehub design and axle spacing are the determinant factors (not dish -- that moves the rim with respect to the axle).

It's not that hard to adjust the derailleur movement. Should be only a 5-minute job to move the high and low limit screws and adjust the cable.

[Kerry Irons]

I think the cassette offset is based on two things: your rear hub, and whether the wheel is dished properly. If both wheels are centered properly and have the same hub, the cassette should be in the same location. If the hubs are different or the the wheel is not dished properly, your cassette won't be in the same location.

I don't see how wheel dish has anything to do with it. Just because your rim is not properly centered between the stays does not change the location of the cassette cogs relative to the derailleur. If the OP has to adjust the shifting when swapping wheels there is something different about the distance of the cassette cogs from the right axle lock nut.

[MR_GRUMPY]

I can throw in any Shimano wheel, and everything lines up perfectly. I have to make a slight adjistment when I use a Mavic wheel.
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[cxwrench]

I think the cassette offset is based on two things: your rear hub, and whether the wheel is dished properly. If both wheels are centered properly and have the same hub, the cassette should be in the same location. If the hubs are different or the the wheel is not dished properly, your cassette won't be in the same location.

think about that for a minute and get back to us.

[ziscwg]

think about that for a minute and get back to us.

I have and all I can think about is a big deep dish apple pie.............Yum.


Oh, wheel dish....................Nevermind.

[TrojanHorse]

I had to put my clinchers back on for the last race in order to use all the cogs.

Wait, it was off so much you couldn't use a whole GEAR? Wow.

I don't change wheels often but I did last week and needed no adjustments. Even if I do, the difference is usually trivial, as in I can ignore if unless I'm feeling fussy.

[redlude97]

if you leave your limit screws a hair wide you should be able to make any necessary adjustments with cable tension

[Chainstay]

. If the OP has to adjust the shifting when swapping wheels there is something different about the distance of the cassette cogs from the right axle lock nut.

I had an Ultegra hub where I adjusted the position of the axle in the hub by .3mm so I could easily switch wheels without readjusting the shifting.

Here's a thread on it

Shimano casette spacers

[yoshirama]

I don't see how wheel dish has anything to do with it. Just because your rim is not properly centered between the stays does not change the location of the cassette cogs relative to the derailleur. If the OP has to adjust the shifting when swapping wheels there is something different about the distance of the cassette cogs from the right axle lock nut.

I think you're right. I think I had a golden moment of realization that wheel dishing doesn't affect cassette offset while installing a new wheel some weeks back... then promptly forgot about that because of some distraction (probably some deep dish pie). Thanks for reminding me again. I hope I will go longer before I forget this wisdom again.

[NoahD]

I have switched wheels frequently w/o need of much adjustment to rear derailleur; usually I have more issues with brakes. Still, RD adj should only take a minute or two. Having same cassette seems to be important too.

[stevoo]

You can get all of YOUR wheels to run the same (same shifting and limits) by making sure all of your wheels are set up the same. Make sure each of your wheels measure the same from the drive side axle nut face to the center line of the first cog. Basically you are setting a given datum point on the cassette the same on all of your wheels. That way they will all have the cassettes line up exactly the same when installed into the frame in relation to the RD.

The method you choose to perform this standardization I will leave up to you and the tools at your disposal. Can be done by moving the cassette and/or shimming axle nuts.

Bottom line is that if they are all the same dimension from cassette reference point the frame you will be in alignment from one wheel to another.

Actually fairly easy to do this.

I am assuming that all of the cassettes that one chooses to min n match have the same total build up width. Funny to even say this but I have friends that try to mix n match all kinds of weird stack up widths and then wonder why they have challenges and opportunities.