Spoke length help.

I just got my kh moment hub/cranks. The spoke calculator said I need 173mm spokes, this isn’t a common size. I know I can get 175mm spokes, will these still work? It’s 2mm difference.


Yes and no… you could build it with short nipples but not recommended. 171 is a common size and would be better to build with. Although if you go to a KH dealer they should have some KH spokes you can buy, these are also 13g not 14g.


If you are building it onto a box section rim then having spokes that are 2mm too long wont matter as the small sticky out bit will still be a long way from the inner tube. If you have a single wall rim then you can geta away with slighty longer spokes as long as you use decent rim tape.

Look out for running out of thread though, spokes have normally between 8 and 15mm thread. The average is about 10. If you use longer nipples you will just lock/cut the thread to get it to the right tension.

As a general rule the spoke calculator works out the length to the end of the nipple. For wheel building I find it is best to go to bottom of the slot which is about 1.5mm, it is no advantage having them longer.


Some bike shops can order custom cut and threaded spokes at the exat length you need but it will be more expensive.

Spoke head wsahers

If you add spoke head washers, they usually require adding 1 mm to the spoke length. This should leave you only 1 mm long. If the spokes on the built wheel extend through the nipple by only 1 mm they should be managable to cover with rim tape. Some wheel builders start a build with spokes 1 mm long.

Wheel builder Gerd Schraner recommends to always use spoke head washers on every wheel build to make sure that the spoke heads have a better fit for added strenght and to help make sure the wheel will “stand”.

You might see the book “The Art of Wheel Building” by Gerd Schraner.

Spoke washers are definately a good idea and do make better wheels. Although very hard to get hold of in the UK.

Do be aware that the unicycle spoke calculator on the Unicycle.uk.com site does go to the very end of the nipple, not the bottom of the slot as recommended by many wheel buiding books and as some other spoke calculators do. When using a spoke calculator be sure to know where it is measuring from.



you can get 13gage 171mm black spokes from http://www.flatlandfuel.com/ I think tey would work becase the listed size on the kh website is is 172mm
List Price: $24.99

Momentum hub dimensions

Can someone tell me the numbers for spoke calulation programs for the '07 Momentum hub? I want to order a hub and get the spokes without waiting for the hub to arrive.

Pitch circle diameter
Flange distance
Ø of spoke hole
No. of spokes = 36

Pitch circle diameter is the term for the diameter of the circle described by the spoke holes in the hub flange.

Flange distance is the distance the right & left flange is from the center of the hub.

Thanks. Bryon


That should help.

there’s bound to be a good bike shop in your area that can cut or order the exact right spokes. many have a spoke cutting machine, and can just make you some. some will have to order, it should take less than a week if they must order .

It would be cheaper and better to buy them to size. It also may not be as easy as you think to get the thread rolled on 13 gauge spokes, the size is also quite and you do need different rollers.

I am reasonably certain the UDC US have the spokes in stock.