docr

Hi all,

I have measured 2 hubs that have nominal over lock nut dimension of 120 mm, and for both of them the actual dimension is significantly less. Specifically:
- rear hub of Miche Primato wheelset has OLD of 118 mm
- Sturmey Archer HBT30 rear hub has OLD of 119.3 mm
Is it normal for hubs to have actual over locknut dimension that is 1 to 2 mm smaller than nominal one?

FBinNY 

Maybe not normal, but certainly not rare.

It's fine as long as the right side freewheel clearance is adequate.

FWIW odds are they're missing a spacer, but that's easy enough to fix if you want.

Aardwolf

I've just built some Campy Nuovo Tipo large flange wheels.

Rear hub has OLD of 119.75 but that includes

13ollocks

I have a digital caliper gauge, but I doubt if the jaws are long enough to directly engage both locknuts of a hub. I would have to "eyeball" to an extent, at which point the actual measurement would be a good guess rather than an exact value. How are you measuring them to the point that you can get to tenths of a millimeter?
In any case, getting the frame to 1-2 mm of nominal is plenty good enough

maddog34

does the miche have a keyed axle slot? are the two keyed washers present between the Cones and locknuts? they are typically about 1mm thick.

as to the Sturmey Archer... wow.. that's pretty close for them!
The Taiwan company that bought all of the Sturmey machinery ended up SCRAPPING IT ALL because it was totally worn out and couldn't reproduce parts accurately... the SA folks admitted to having to Hand-Fit Each hub assembled... they had multiple sizings of each part, and played Mix/Match to sort-of meet specifications.....

I'd add a couple washers to the miche, and leave the SA hub as is.

Iride01 

Are these used hubs? Perhaps a previous owner removed the washers or spacer's that made them the OLD they are spec'd for.

docr

They are both totally new. Miche's wheel is bought form bike-discount.de and SA's hub from cnc-bike.de .

docr

My calipers have jaws of sufficient length to measure the bare hubs - that's what I've done with SA hub. Miche's was measured using the approach described in one of the books about wheel building - put an hub on a surface with a hole in it (to let one end of the axle through) and then measure distance from surface to the second locknut).

docr

I guess you mean spacers that go between locknut and frame (not the ones that go between bearing/cone and locknut). In case of Miche's I would need 2 spacers 1 mm thick and that have serrations on one side (to mimic locknut) - surely it is something that cannot be found in a hardware store..

docr

This is actually kind of funny: I was cold setting my Pompino's frame back to 120mm distance between dropouts (it was 123mm after previous owner trying to use 130mm wheel) and was able to get it to 120.7mm. Before getting rid of the last 0.7mm decided to see how the wheel (Miche Primato) will fit and found out that the hub is 118mm - thus my attempts to do an accurate job with cold setting are kind of futile...

grumpus

You don't want to put a washer between the hub and frame, that will reduce its positive location in the dropout. If washers are needed (and for 2 mm difference they're not needed) put them under the original locknuts.

grumpus

123 mm was a common frame spacing while 126 mm (6 and 7 speed) hubs were taking over from 120 mm (5 speed) as it allowed the use of either type of wheel.

grumpus

Measure the hub with a firm-joint external caliper, then measure that with the digital caliper. 😃

oldbobcat

A coaster brake or internally geared hub might use a spacer between the locknut and the frame. A hub for a derailleur-equipped bike would put the spacers on the inside of the locknuts.

JoeTBM 

Axle washer???

maddog34

and one can make external calipers with a pair of paint stirrer sticks and a nut/bolt... plus a bit of whittling near the jaws end of your new tool.
home despot gives the stirrers away for free.

they also work as horse-sized tongue depressors to see if your pet pony swallowed a burr again....until the little snot bites clean through it.
glad my arm wasn't in there... and so was the pony, unknowingly.