What's with different width rear hubs?

Until recently, I thought there was just a standard width between rear droputs, but of late I’ve seen 142mm (I think) mentioned and a thread on this page asking about 130/135???

How many standards are there, what is the ‘standard’ and is this the new 650b?

I’m guessing it’s a strength thing, but it’s a new one to me.

(non-disc) road bikes are 130mm. QR mtbs are (almost all) 135mm. Disc’d CX/road bikes seem to have standardised on 135mm too.

Originally, mtbs went 135 to allow wider flange spacing and therefore stronger wheels.

I’m guessing it’s a strength thing, but it’s a new one to me.

Isn’t more to do with the increasing width of the cassette?

135mm/142mm are effectively the same hub with slightly different ends.
150mm is a DH semi standard
Specialized invented 142+ which is normal for them but out of step as it’s not actually a measurement….

Originally, mtbs went 135 to allow wider flange spacing and therefore stronger wheels

Not quite true – it was when 7 – and 8 – speed cassettes started to become the norm, Shimano and Suntour went up to 135 to allow for more sprockets. The flange spacing has changed but not by a lot.

Road bikes used to be 120, then 125 and have only recently gone to 130. I believe that 120 is still the norm for track bikes.

There’s also 150 x 12 for DH duties which helps reduce the amount of dish required in the rear wheel.

was 120 where track bikes still are, then went to 126 as more sprockets got added, road stopped at 130 and mtb went to 135, but then someone thought that 142 was a good idea. and with discs comign through on road bikes, you can get 135 and 142 road bikes.

Should also mention some road bikes came at 128…

On the front i think it is 70mm for a few bromptons et al and 100mm for most.

142 is the same as 135×12 bolt thru, just with 3.5mm shoulders either end so you can drop the wheel in, then put the axle through. Rather that trying to line up all the holes and slip it in. Fnarr.

often 170 for a fatbike, possibly more for some ?

Up to 190 for some fatbikes now. Allows a centered 5″ tyre.

I was peering at a Hope wide rear hub a while ago; I forget which. It just had a projection out of the side after the flange – total waste of space as the spoke attachment points were the same as the “normal version”. I hope that’s changed now.

I was peering at a Hope wide rear hub a while ago; I forget which. It just had a projection out of the side after the flange – total waste of space as the spoke attachment points were the same as the “normal version”. I hope that’s changed now.

You’re thinking of a hope 150mm. And why is it a waste of space?

The whole point of 150mm is so you don’t need to dish the wheel and it can be stronger. If the flange was out by the dropout that would be no better than a normal wheel…

Think of it like this – you want the tyre central between the dropouts. But there’s a cassette on the right. So you need equal spacing on the left so your spokes can all be the same length and tension.

I’m sure hope haven’t changed it, as that would be pointless!

The whole point of 150mm is so you don’t need to dish the wheel and it can be stronger. If the flange was out by the dropout that would be no better than a normal wheel…

No, it would still be stronger than a 135m wheel, it would just be stronger one way than the other like a 135mm wheel.

150mm is still dished anyway IIRC, 165mm is/was the dishless standard, but gives chainline issues.

Hmmm, must have been something else. Basically there was space available to reduce the dish, but it was not used. I’m down with dishless don’t you worry.

Spesh 142+ actually moves the cassette out 2mm allowing for wider flange spacing, however these can be replaced with ‘standard’ 142mm rear hubs but the rear mech will need adjusted…