Hi guys and gals,
I've got a Bombtrack Hook EXT that uses 12x147mm thru axles, and of course came with a fitting wheelset.
A while back I bought a smart trainer so could stay indoors on bad weather days, but getting the blue tire on the wheel is an actual pain in the butt (and thumbs).
Someone gifted me a back wheel that uses a Shimano XT FH-M8010-B freehub with a fixed 30t pinion cassette, but unfortunately that has a 148mm width.
Is there a way to change the silver part out to something shorter?
Thanks for any help and tips
by throwawaybetterpunch
9 Comments
My dude, that’s where the rotor goes.
147mm thru axle? Do you mean the total length og the axle?
Your frame is probably made for a non boost hub, which would be 142mm.
>12x147mm thru axles
This must be a typo because 12×147 isn’t a size of bicycle thru axle. Your frame is meant to accept 12x142mm thru axle hubs. So yes, a “Boost” width 12×148 will not fit and the Shimano hub is not one that you can adapt to the narrower width.
The FH-M8010-B freehub has its spoke flanges ~5mm further apart than the FH-M8010 so the extra width of the hub is due to the physical shell size and not an axle adapter.
[https://si.shimano.com/fr/ev/FH-M8010-B-4003](https://si.shimano.com/fr/ev/FH-M8010-B-4003)
You can remove the left-hand locknut (5), but I don’t know where to find a shorter one. It’s possible to machine off 1 mm if you have the tools.
1. Your bike has a 12×142 not 147.
2. Looks like you have a Shimano FH-M8010-B hub for boost axles (148mm as you say). Checking the exploded view online shows that the “end caps” are actually the inner axle of the hub which engage with the bearings. So no, it wouldn’t be possible to convert this to non-boost.
I suggest you sell this wheel and buy a cheap rear wheel intended for a road/gravel bike instead of an MTB
Edit: my actual suggestion is that you buy a proper trainer instead of rollers, that way you don’t need the second wheel at all, and you can use it with Zwift
Im guessing the previous wheel was 142mm hub width in which case this wheel wont work, you might be able to find a converter kit with different end caps but i have not seem them for shimano wheels.
There’s no such thing as a 12x147mm hubs. Your Hook EXT almost certainly uses 12x142mm hubs.
There is no way to downsize a 12x148mm hub to work on a 12x142mm frame – the brake spacing is too wide. Shortening the axle does nothing to adjust the brake spacing, which is determined by the hub shell itself and can’t be changed.
(Some 12x142mm hubs can have spacers added to fit a 12x148mm frame, but that’s going the opposite direction to what you need.)
Some nomenclature:
Freehub is what your cassette (sprocket for a single speed) attaches to. As pointed out, on the other side of the wheel.
Axle end caps are what you’re really asking about. I’d first question if you have them installed properly. Thru axles aren’t off by 1-2 mm, you’re looking at 6 or 9 mm jumps (142, 148, 157mm standards). Looking at the Bombtrack site, it has a 142 axle length. You might be able to find end caps for the wheel set for the 142 length vs the 148, but you really just need a compatible wheel/hub.
Thank you all for the valuable input! Yes, indeed I meant a 12x142mm axle, and I will probably donate the whole wheel to a local shop.
Learned something again today. I got a little confused with the names of the parts as English isn’t my first language. I appreciate everyone’s answers!