Bicycle Mechanics - Ultegra for 135mm dropouts?

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View Full Version : Ultegra for 135mm dropouts?


Monoborracho
08-01-07, 07:28 AM
I have a set of Ultegra hubs with Mavic Open Pro rims that I would like to install on my Trek 520, which has 135mm dropouts. Can these Ultegra hubs (130 mm) be adapated/respaced to fit the 135 mm dropouts on the Trek?


capwater
08-01-07, 08:00 AM
Couple of washers on either side ought to work.

rmfnla
08-01-07, 10:33 AM
To do this right you should replace the axle with a 135 mm.

Fortunately, Shimano threading is pretty consistant so you can use almost any MTB rear and then add those washers.

Or, just squeeze the dropouts in a bit since the 520 is a steel frame; 5mm won't hurt a thing.


Gonzo Bob
08-01-07, 10:41 AM
Yes. You don't need a longer axle. The Ultegra axle is 141mm and respacing OLD to 135mm still leaves 3mm per side which is plenty. If the wheel is not built yet, I'd put all 5mm of spacers on the non-drive side to get a stronger wheel (less dishing required). If the wheel is already built and you don't want to redish, put half on each side and adjust the rear derailer accordingly.

HillRider
08-01-07, 04:03 PM
Yes. You don't need a longer axle. The Ultegra axle is 141mm and respacing OLD to 135mm still leaves 3mm per side which is plenty.
Yes, that's good advice. The remaining axle stub is plenty.


If the wheel is not built yet, I'd put all 5mm of spacers on the non-drive side to get a stronger wheel (less dishing required). If the wheel is already built and you don't want to redish, put half on each side and adjust the rear derailer accordingly.
Putting all 5 mm on the non-drive side will maintain the chainline and prevent shifting problems so it's the prefered method.

Reynolds
08-01-07, 09:49 PM
Yes, that's good advice. The remaining axle stub is plenty.


Putting all 5 mm on the non-drive side will maintain the chainline and prevent shifting problems so it's the prefered method.

+1. It's better to put the 5mm spacer on the left and redish. It's a 10 min job.

rmfnla
08-02-07, 12:10 PM
+1. It's better to put the 5mm spacer on the left and redish. It's a 10 min job.

Good call. Don't forget that the axle will need to be re-centered.