Disc Frame / Multiple Wheelsets - Equalizing Rotor Spacing On All Wheels

[UpFromOne]

Whether road or off-road, if you have a disc frame and use several wheelsets for that frame (presumably different brands of hubs), how do you equalize the rotor spacing for all your hubs?

OR, do you un-bolt/re-bolt the caliper on each wheel change to center the caliper on the rotor?

I have a disc frame with 4 different wheelsets, of differing hub brands. I found that hubs can have anywhere from 12-14mm of spacing from the end cap to the rotor surface. But definitely each and every hub comes in a different spacing.

Me, I've become adept at dis-assembling the axles and shimming them so that the rotors on the different hubs all fit equally in my brake calipers. Just so I don't have to re-bolt the caliper every wheel change.

But maybe you don't go to that extent. So how do you deal with this very nagging issue?

[Francois_Viviers]

Syntace disc shims.

[TonyM]

AFAIK this works only for the 6 bolt disc wheels as there are no disc shims for Centerlock.

[ooo]

Usually Shimano, Formula, Novatec centerlock hubs have the same spacing
Different Shimano centerlock rotors have different spacing, this can help to fit offspec hub:
For example, small spider rotors (SLX) have different spacing than big spider rotors (XT)

centerlock spacer is just a shim, it can be found cheap in bulk, or expensive in small quantities in some autoparts catalogs

[mattr]

Wheels manufacturing do an assortment of shims. Can't get on their website right now to check thicknesses.

And i *think* that you can use cassette shims for centrelock, but they don't come in many/enough sizes (you'll probably need 0.1-0.2 accuracy to stop rubbing on most disc brakes, cassettes you can probably get away with twice that, and you can easily adjust at the shifter too)

[stormur]

Pointless. You'll never get satisfactory result. Only way is to use same hubs, cassettes and rotors, only rims as variable. Even then it may be not 100% "fine" ( manufacturing tolerances ) . But usually is.

[ms6073]

Even then it may be not 100% "fine" ( manufacturing tolerances ).

One would think but my wife and I have identical wheelsets built on DT Swiss 240S Straightpull center;ock 24/24
hubs and I cannot simply swap our wheels without re-centering the calipers.

[joejack951]

Pointless. You'll never get satisfactory result. Only way is to use same hubs, cassettes and rotors, only rims as variable. Even then it may be not 100% "fine" ( manufacturing tolerances ) . But usually is.

I don't understand this post. Why is it a pointless endeavor, or did you mean 'pointless' in some other way?

There is simply no reason why a group of hubs and rotors could not all be shimmed to achieve the same rotor position. Find the hub with the greatest offset and make all others match. If trying to make up ~2mm, you may want to look into longer bolts for 6-bolt mount, or modifying the disc's spider for centerlock to preserve thread engagement.

[NovemberDave]

AFAIK this works only for the 6 bolt disc wheels as there are no disc shims for Centerlock.

We have these. https://novemberbicycles.com/collection ... -pack-of-4

They work fantastically well.

[ms6073]

There is simply no reason why a group of hubs and rotors could not all be shimmed to achieve the same rotor position.

35mm X 45mm X 0.1mm Washer Shims

Probably what pro mechanics supporting World Cup CX racing in Europe do as the top teams are fielding 2-3 bikes per rider with multiple disc brake tubular wheelsets, almost all with centerlock hubs, so surely they have a similar a solution for shimming rotors as there is definitely no time to constantly realign rotors on a race weekend!

[TonyM]

AFAIK this works only for the 6 bolt disc wheels as there are no disc shims for Centerlock.

We have these. https://novemberbicycles.com/collection ... -pack-of-4

They work fantastically well.

Thanks!!

[F45]

Makes me wonder if the variability is in the rotor, hub, or both?

[ooo]

If rotors are old, then transfer them in case of wheel change to pair them with their native caliper,
rotors may have some differences in fades/burning space alignments with caliper pads
(pads may be not in parallel to braking surface diameters, contact surface on rotor may be higher or lower)

[UpFromOne]

Makes me wonder if the variability is in the rotor, hub, or both?

Definitely both.

And I sometimes use rotor shims too, but they are not available in 0.1mm differences (i.e. 0.3, 0.4, 0.5, etc.). Which to me is the tolerance level I'm looking for.

[atakaoka]

And People ask why pros don't what disc on race.