az2008

Background: I have an inexpensive retail bike with a nutted 24-spoke rear wheel. The rim is a deep, "aero" design. I think that helps make it strong (for 24 spokes).

Goal: The front wheel is quick-release. I'd like to have a quick-release rear hub so I could stop carrying a wrench everywhere.

Question: Is it safe to lace the 24-hole rim to the 48-hole hub (every other hole)? It seems like the geometry would be the same. But, will those unused holes will weaken the flange? (More stress on every other hole than the hub was designed for?).

I've seen inexpensive 48-hole freewheel hubs with quick release ($14-$20). [1] I know I could be better off replacing the entire wheel(s) (or, maybe even the entire bike). But, the idea of getting a quick-release for $20 is appealing. And, I would benifit the experience of un-lacing/re-lacing a wheel. (I have a truing stand, wrenches, tensionmeter just begging to be used!).

I've read about lacing 24-hole rims to 36-hole hubs. But, I don't understand what they're talking about. The "every other one" of a 48-hole hub is easy enough for me to comprehend.

[1] Cheap, 48-hole freewheel hub

mrrabbit 

Can't think of any reason as to why not...

However, make sure you use a crossing # that is not more than necessary...yet not too few such that interleaving becomes difficult or results in severly kinked spokes.

Other than that...and the t-chart tab in my spoke calculation spreadsheet page listed below...good luck!

https://www.mrrabbit.net/wheelsbyflemingapplications.php


=8-)

dscheidt

You do realize you need new spokes? (well, there's a roughly zero chance the ones you have are the correct length.)

You don't say what size wheel, but you can get whole wheel for 40 bucks or so. Not a good one, but it'll have the same number of spokes as it's supposed to, which puts it way, way ahead of your plan.

davidad

If the flanges on the new hub are the same diameter there shouldn't be a problem.

AEO

I know it seems like 48/2 = 24, but it's actually not that simple.

spoke holes on the hub are drilled so that they are offset compared to the other side.
when you try and lace it up to a rim that has half the holes, what happens is that the offset will cause the spoke length required to change.
Some spokes will need to be shorter and some will need to be longer than the original calculation.

If it's laced radially, it will work, as the offset is not significant enough to cause problems, but when a tangent cross pattern is used, it will change enough to cause problems.

according to my calculations, if you try and lace it 2x, you'll need 2.25x and 1.75x length spokes

what would be simpler is if you laced a 24h to a 36h hub, as the cross length required for that is 2.17x for all spokes. (24h, 2.17x)

or alternatively, for a dished freehub wheel, it can be laced to a 32h hub, and this will require 16 spokes at 2.38x on the drive side and 8 spokes at 1x on the drive side. (24h, 2.38x and 16h, 1x)

az2008

Thanks. I don't understand all the terminology. I was hoping to cheaply recreate the following pattern:



I know the flange diameter might be different, resulting in new spoke lengths. But, I did think 48 / 2 would work out ok for recreating that pattern.


Oh, my brainey hurts.

I've read a few things (thanks to Google) about 24-h rims to 36-h hubs. But, it was like everyone was talking Martian.

I agree with "dscheidt" that it may be more economical to buy a new wheel. I thought it might be fun to add a QR hub to this rim (cheaply). Get some experience lacing, dishing, truing.

But, I think if I were facing the 24-by-36 thing, I'd probably buy a replacement wheel because that's more advanced than I'm capable.

zzyzx_xyzzy

Simpler plan: replace the axle with a hollow axle. just get a skewer and a hollow axle of the same threading, so the cones and locknuts of your present hub fit on.

Metzinger

^Stop that.

az2008

Thanks. I'll check into that.

I asked my LBS about this a few months ago and they said it's unlikely I could find a hollow axle that would fit. I thought they were talking about getting the cones to match the races in the hub. But, now that you mention it, I'm not sure why I couldn't thread my original cones on. (duh).

I'll have to figure out the threads. At some point I thought it was 26 TPI because it closely matched a 25 TPI thread gauge. But, I notice that 1mm threads are 25.4 TPI.

It sounds like the diameter, thread and the frame spacing (distance between inside of dropouts) is all I need.

I should probably take the axle to my LBS (not the same one that told me it was unlikely to do) and see if they can set me up.

AEO

that sort of pattern will work if you use half the holes of a 48h rim with a 48h hub.

36h hub on 24h rim explanation is here:
https://www.sheldonbrown.com/rinard/36-24.htm

az2008

FYI: After measuring my nutted axle I concluded it is 9.5mm diameter, 26 TPI, and the hollow axle should be 146mm length (135mm dropout space inside the frame, 5.5mm length to fit into each dropout).

Went to my LBS and they had one. Bought it for $13, and they gave me a free skewer from their spare-parts box.

That was a lot simpler than re-lacing my wheel to a new QR hub. (Can't wait to go for a ride without my wrench!).