I am going to put together a cheap rear wheel from a hub and rim I have lying about but struggling to get the hub info I need. I found one picture online but hoping someone with better skills than me might be able to confirm as this will be only my second wheel build (last one, a front, is still going strong) and my first attempt at a rear.

The rim is a DT Swiss 533d 27.5 with an ERD of 564

the rear hub is a old QR Shimano rm66 and from what I found I think pitch circle left and right are 45mm with flange distance left 34mm and flange distance right 20.4mm, but I am not sure if these are correct.

if the above is correct then it’s looking like I will get away with 274mm spokes on each side with 14mm nipples?

thanks in advance.

If you have a couple of old spokes lying around it is very easy to measure the ERD yourself. Dt Swiss official numbers might (or might not) include a couple of mm for the PHR washers.

Erd sounds about right for that rim height with eyelets, if those hub dimensions are correct I think 274 on the driveside and just under 275 for disc side with normal 12mm nipples so you could probably get away with 274 both sides, checking hub dimensions is easy, a piece of wood with a 10mm hole drilled in to pop the hub axle into then measure from the wood to the flange, if its an old 135mm qr hub, half that is 67.5 so subtract the centre to flange 34 and the 20.5 from 67.5 and see if your measurements from the wood to flange match.

Vernier caliper with a height gauge is a useful tool for loads of bike related measuring, including hub dimensions.

A manual one and learn to read it because invariably the battery ones are flat when you need them.

Thanks. Don’t know why I didn’t think to just measure as above 😳. I will try the bleedin obvious before I post next time 🤣 I was too focused on the online calculator.