spoke length calculations...

gkerr4

Hello all!

As per a previous post of mine I am looking at having a go at building my own wheels - just for the satisfaction of the build more than anything else.

I am making a set of track wheels to replace the crappy wheels that came on my langster so I am looking at these miche hubs:
http://www.ribblecycles.co.uk/ProductDe ... ID=1319706

and std Mavic Open Sport rims in silver.

I am looking to see what spoke length I should be ordering but i can't find the technial specs for the hubs / rims and I can't find any online calculators with these rims / hubs listed.

Neither the Miche or the mavic websites are particularly helpful

so - does anyone know what the specs are???

all help appreciated

thanks,

Graham

andyp

This may help;

http://www.sheldonbrown.com/rinard/spocalc.htm

gkerr4

hi Andy - got that too - it loks great, but only lists "mavic track" in the hubs - so not sure if that is the same model (large flange / low flange etc..)

also - in the rims - there is Mavic Open 20, open20D, Open4CD, OpenSUP and open pro

but no open sport :-(

robbarker

If you absolutely must know before you order them, phone the manufacturer or Ribble and ask them. I have just built a pair of fixie wheels with Goldtec hubs and CXP33 rims and I simply ordered them and measured them when they arrived.

The two hub parameters you need are pitch circle diameter, the diameter of the hub flange measured centre-of-spoke-hole to centre-of-exactly-opposite-spoke-hole and flange distance, which is the distance from the centre of the hub to the flange, which can be different on each side but shouldn't be on track hubs. These will be the order of 70mm and 40mm respectively, but you need to measure accurately.

If you don't already have a vernier calliper, now is the time to order one - a fiver or so on the 'bay.

Remember you can get away with a lower spoke count on a track wheel as the rear isn't dished like a road wheel. I went for 28 plain gauge spokes laced cross 2 to give a really rigid responsive wheel. I won't be doing much bouncing through city potholes though and if you are, more spokes would be a better bet. If you go for 32 or 36 you should lace cross 3.

I wouldn't skimp on the rims btw - the difference in price between open sports and open pros is about a night in the pub, but you will have to live with your skinflint ways for a lot longer!! A slightly lighter rim makes a significant difference to the wheel's moment of inertia, and the joy of a fixie is the wonderful responsiveness. The CXP33 (stickers removed, natch) is a really good fixie rim due to it's strength and lightness, and you can crank the spoke tension up too as each nipple sits in a cast metal "bucket" to spread the tension.

I know I bang on about it, but if you haven't got Musson's book yet (www.wheelpro.co.uk) then do so!

gkerr4

Hi Rob,

Thanks for the response - I was looking for someone to talk me into upgrading the open sports to pro's - or as you suggest the CXP33's

I want 32 or 36 spokes as the langster is essentially a town bike - it won't be going on a track!

thanks for the pointers - I'll call ribble tomorrow to see if they know - if possible I want to order them all in one-go from ribble and do the 'buy and collect' from their warehouse and do it in a single trip.

thanks again.

Graham

nicklouse

gkerr4 wrote:

I'll call ribble tomorrow to see if they know

So really you do not need to know what length spokes or nipples to use.

Just ask them to supply what you need, they will know the flange ofsets and the diameters and they will also know the ERD of the rim

gkerr4

ok

:oops:


seriously though - I have a technical 'bent' (I guess) and like to know these things..

stoobydale

If you go for the CXP33's you will need 14mm nipples. I have just built my first pair on some Campag Mirage hubs. Haven't had a change to give the wheels a good try yet but the building process was thoroughly enjoyable.