Advice needed please

[hookooekoo]

You can get away with a few mm difference. If the spokes are slightly too short, it may still work, but there could be a small amount of spoke thread visible on the finished wheels. In the opposite case, the risk is that you run out of thread. Those who are perfectionists might not like having a little spoke thread showing.

Also bear in mind that if the wheelbuilder doesn't have the exact length required, they may use a spoke that works, but results in wheels where a little spoke thread is showing. This is one reason why I now like to build my own wheels. If it goes pear-shaped, I've only got myself to blame for how it looks.

Another reason is that last time I got someone to build some wheels for me, they said they didn't like working with lightweight rims (this was a road bike wheel build). When I got the wheels home, I had to spend several hours finishing the trueing process, as it seems that lightweight rims are time consuming to get perfectly true, and they stopped trueing the wheels when the money ran out. For me, that was the end of paying other people, because I had basically paid someone the whole wheelbuilding fee to supply spokes at the correct length, lace the wheels, and then I had to finish the hardest part of the job myself. Next time I did the whole job myself, took my time calculating spoke lengths, and it came out perfect.

 

[hookooekoo]

Let us know how you get on. If you get a wheelbuilder to do it, remember to ask for a couple of spare spokes if you're not reusing the old spokes. If you DIY, there are people who can help you on here.

 

[Magpiegifts]

Really appreciate that

 

[mattr]

Ok thanks, it's such a pain buying new spokes , finding the correct size. Nightmare!

Is it?
I just plug the dimensions into a couple of spoke calculators for a logic check, then order the correct length in a suitable type of spoke.
Only time it comes unstuck is with Ambrosio rims, they don't seem to know how to measure in mm...

 

[ishaw]

Before I built my first wheel, I thought long and hard about it. Some might say over-thought.

You could either do as above and use an online spoke length calculator.

Or as I did, asked the spoke supplier to use the tools of their trade to work out the spoke lengths needed based on information provided to them (or requested by them).

 

[Gtpulse]

I’ve done this a few times now. This is what works for me when I do a swap around as I haven’t been able to find a calculator with the right combinations of rim/hub.
- I back off the axle of the hub of the existing wheel (the one with the rims I want to use) so the end is flush with the flange. I then measure with either an old spoke or similar from centre of the axle to centre of the spoke hole.
- I then do the same on the “new” hub I want to use.
- I work out the difference in mm +/- between the two
- I use a Park rule with the spoke length gauge to measure one of the spokes removed from the wheel with the rim I want to use and the “old” hub
- With this measurement and the +/- between the hubs I can calculate the new spoke length required
- you can cut and roll your own spike threads but the cycle/hozan rollers are £££
- last few times I’ve been able to find the spokes I need either CRC/Planet X etc for less than £20 for 2 wheels worth.


sounds complicated but it isn’t, just need to be methodical, take photos. Worked out perfectly for me with some great wheels, knowing very little other than what I’ve found on here and the web
I had a couple of failures using online calculators - it’s very frustrating lacing a wheel and finding you are a couple of mm too long - I found this out the hard way!

 

[mattr]

Or as I did, asked the spoke supplier to use the tools of their trade to work out the spoke lengths needed based on information provided to them (or requested by them).

Most wheel builders use spocalc or the the manufacturers spoke length calculator to work out spoke lengths. Or the old look up tables. Which were mostly from DT Swiss.

They're all derived from the same basic bits of trig anyway. And very easy to use.

(Or they have a battered old note book with all the builds they've done over the last 40 years with all the parts, spoke lengths and lacing patterns written down...)

 

[Magpiegifts]

I wasn't expecting such a good response, thanks to everyone for the advice.

 

[ishaw]

I think I used these guys when I built some wheels last and couldn't find the right details for the spokes I needed (it may have even been nuke proof hubs).

https://thecycleclinic.co.uk/
I think the later hubs are more similar in flange size to shimano ones, earlier hubs had tiny flanges iirc.

 

[hookooekoo]

If you don't mind potentially wasting a few hours, you could just lace up a wheel with the existing spokes, and see whether the spokes are too short, too long, or just right. When you disassemble the existing wheels, remember to sort the spokes into three piles.
1. Rear drive side
2. Rear non-drive side
3. Front