How do you determine the length of spoke to use when you build a new wheel set?

I am building a set of wheels so that I can ride my mountain bike in the city with slicks.

I brought a set of shimano hubs (32 holes) and a set of ritchey rims.

How do you determine the size of spokes to use for lacing up the wheels?

Thanks in advance.

Have you ever built a set of wheels before? I am guessing you haven't based on this question. To determine spoke length you need to take some measurements of the rim and hub that are going to be rather hard without something similair to a Wheelsmith spoke calculator system. I believe on the DT spokes website there is a spoke calculator if you know what kind of hubs you have and rims and what lacing pattern you want to use. If you have never built a wheel do not expect your first build to come out very well. Your best bet is to either find someone who knows what they are doing and have them teach you or get a good book. Building good wheels takes practice and patience it is just something you get good at by doing it and screwing up a few times.

I'd agree with GMR regarding finding someone to help you out. I too will be building up my first set of wheels around Christmas time, probably. I have a good friend who's been building them for 20 years (?) or so.

He's going to supervise me so I don't make some HUGE mistake. This way, I can learn the "right" way and not screw up my first set. You might want to get some cheapie rims and hubs to try it out on, instead of the Shimano hubs/Ritchey rims you just got.

My $0.02

That's a solid two cents

I had no idea what I was doing when I built my rear wheel on my touring bike. I just went to the LBS bought a rim and laced it up by the way it looked on the old one. I even used the same spokes and no truing stand or dish tool. So far after 5k miles the wheel is still going strong. Either I got lucky or it really is not that hard to do? I say go for it. In fact I am need to build one up now for a mtb. The thing is its really cheaper to just by a whole new wheel. But now at least I have the tools. You may want to look here: https://www.sheldonbrown.com/wheelbuild.html and there are several recommended spoke calculators including one that provided you are using a known rim and hub you need no measurements.

By far the easiest and the most accurate way is to use one of the computerized spoke calculators that have a data base of hubs and rims. It's too hard to figure out how to measure hubs and rims with the accuracy necessary to determine the proper spoke length so I've not had good results doing it that way. My current favorite is the one on the QBP website but you have to have a dealer number to access it.

Incidentally, one of the other posters said that he just bought a rim and laced it up using his existing spokes. I think there are three possibilities:
1. He bought an exact replacement for the rim he had previously.
2. He is incredibly lucky.
3. He is lying.

#2

Because it was not the same rim and I am not a liar.

I believe you. I actually figured the odds were about equal for the three so I'm glad that you wrote back to say it's #2.

https://www.dtswiss.com/index.asp Go to spoke calculator, log as an anon. user, and be prepared. Hub model, # of spokes, rim model, which spoke, (butted, bladed, ti, etc.) spoke nipple length, spoke cross and it will figure it out. (You can put in the info manually, like flange diameter and rim erd, but I try to avoid that route.)

This is a pretty good place to start if you're still planning on building those wheels:

https://www.sheldonbrown.com/wheelbuild.html

https://www.damonrinard.com/spocalc.xls

This one's great.

Lately I've been getting an annoying pop-up box that I just click "ok" on, then proceed.

If you're not familiar with this type of Excel sheet, just click on "rims" down the bottom to get your rim dimensions, then the same for "hubs", then click on "calculator" and punch in the numbers