I’ve just made a foolish error! I assumed that road bike Axel standards were unlike MTB Axel standards and were, well standard, and bought a rear wheel off eBay for my turbo trainer. However when offering it upto my bike it seems the rear Axel and hub are a different width. The Axel on my bike says 12×157 (Scott Addict) and the wheel I’ve bought (Fulcrum racing) is alot narrower so I guess 12x142mm. Is this correct? and if so can I just get a top hat adapter ? Googling doesn’t seem to throw up a definitive answer and though there seems to be alot of conversion kits out there I’m not are which one I need.

Thanks.

Isn’t 157×12 a DH axle size? 142×12 is about as standard as a bolt through road axle gets unless your wheel is 135×12..?

Everything I can find that references the Syncros wheels that Scott bikes come with state that the road disc wheels are 142×12.

Have you actually tried the wheel in the frame as I would have thought that it’s likely that the 12 x157 on the axle is refering to the overall length of the axle which would be about right for a road bike..  157-142/2 = 7.5mm thick dropouts.

Just checked the axle on my 142×12 hubbed Canyon Endurace and it’s 157mm long so…

I have tried the wheel in the frame and it definitely comes up significantly more narrow than the dropout width by a good distance, so not just a few mm’s for flare of the dropout/seatstay’s. I’ll try to measure the width of the hub and see what it comes up with. The 157mm measurement is on the actual axel itself so could be the length of the Axel instead of the actual hub/drop out width. I assumed it was the latter as if it was an Axel to suit a 157mm drop out width so that explains that. So if the Axel is 157mm long then that indicates a 142mmx12 hubbed bike, so I guess the wheel must be 135. I’ll measure it and see.

Yep, it’s 135mm so my bike must be 142mm, so I need an adapter. I hope I don’t need to faff around with dishing the wheel.

Many hubs have a 20mm or so internal bore with caps just pushed in to fit different frames.  See if you can pull off the 135mm end caps.  If you can, just look for some 12mm through-axle replacements