Cycling UK Forum

I'm rebuilding the wheels of an F frame Moulton using a new pair of alloy rims from SJS cycles (Brompton Alesa 16 x 1 3/8 , 349 silver alloy rim with wear indicators - 28 Hole) the front hub is a generic steel small flange one, the rear a torpedo duomatic, the original rims were steel endricks. Spoke lengths of the old wheels where front - 162mm, rear - 154mm. I haven't ordered the rims yet as I would rather just put in one order to reduce postage. Will I be ok ordering the same length spokes for the new wheels?

Use an online spoke calculator you'll need the ERD of the rim. Check the ERD of the Hendricks and you're looking for a rim with the same ERD all,other things being equal. The length depends on the spoke lacing pattern which is likely 2x or 3x

PhilWhitehurst wrote:Use an online spoke calculator you'll need the ERD of the rim. Check the ERD of the Hendricks and you're looking for a rim with the same ERD all,other things being equal. The length depends on the spoke lacing pattern which is likely 2x or 3x

There are a few, I personally use http://www.prowheelbuilder.com and 'round down'.

Paul Smith SRCC wrote:

PhilWhitehurst wrote:Use an online spoke calculator you'll need the ERD of the rim. Check the ERD of the Hendricks and you're looking for a rim with the same ERD all,other things being equal. The length depends on the spoke lacing pattern which is likely 2x or 3x

There are a few, I personally use http://www.prowheelbuilder.com and 'round down'.

Yes, round down to the closet even size (i.e., for a 161.2mm result fro mthe calculator you want to use 160mm).
The new rims are going to be slightly deeper, so the spokes are very likely to be shorter. And I would use brass spoke washers on steel-flanged hubs

I've just built some of those rims. I think they build up nicely in 28h if you go x2.

If you post the measured hub dimensions we can help out with spoke lengths.

I would normally suggest that you will need different spoke lengths if you build x2. Occasionally (with a smaller flanged front hub) you can use the same lengths front and rear by going x1 at the front and x2 at the rear but this needs to be checked with a spoke calculator.

cheers

Thanks guys, think I've worked out lengths, but I'll take you up on your offer Brucey

dimensions are:
front
spoke hole centre to centre 33.4mm
across flange centre to centre 65.2mm overall 67.2mm

rear
spoke hole centre to centre 58mm
across flange centre to centre 53.6mm overall 55.2mm

Also does anyone know the the correct size seat pin for a mk2 f frame moulton? The one I took out had a brass shim and as I need a longer one it would be nice to have a correct one

I would say that 162mm for the front (built x2) and 154mm for the rear (built x2) would be about right, with those hubs and the single-wall alesa rims.

cheers

Many thanks for that Brucey.