Bicycle Mechanics - one spoke length for front and rear wheels?

I've never built wheels before - I like to try it. So I've been playing with the online spoke length calculators, looking at some of the hubs I have and some rims I'd like to possibly relace them with. I've noticed that most of the time the front spoke length and the rear spoke lengths are with 1mm of each other - for example, 299 on the front and 297 and 299 on the rear. Can I simply use 298mm spokes in this case? Same with a 650B rim I've been looking at with Campy hubs: 281 front, and 280 and 279 rear -> use 280mm all around? Otherwise I'm buying 18 of the shorter ones and 54 of the longer ones.

(Sorry if this is a basic question. Maybe I should take some wheels apart and measure the spokes?)

You could probably get away with it, but no one is going to be able to tell you until you lace it all up. Then you might discover that you couldn't really get away with it. What you don't want is too few threads engaging, or spoke extending beyond the nipple into the rim. Which is obvious, I suppose.

I wouldn't chance it.

What you don't want is to run out of threads on the rear driveside because the spokes are too long.
If I had to use only one length I'd use the short length, rear driveside and I'd round down any fraction calculated.

Al

I'd get 298's for the front, 298's and 296's for the rear.

I've done it with no problems. I was building a set of wheels with disc hubs, so the rear wasn't dished a whole lot and the front was dished a little bit. All were +/- 1mm of a central figure, so I just bought all one length. Worked like a champ.

I don't know how far of a deviation I would accept...but when I built 1mm was no problem. The wheels are still going strong on my commuter bike 1 year later over some really awful roads.

Thanks for all the advice! I asked the local shop about buying spokes and they said I can order as many as I want in whatever length and the cost is the same (50c to $1 per spoke, depending on the type)- so I'll just get what's needed!

Now I'm thinking on doing a radial lacing on the left rear side, as per Sheldon Brown's recommendation, for a more fatigue resistant wheel.

Now I'm thinking on doing a radial lacing on the left rear side, as per Sheldon Brown's recommendation, for a more fatigue resistant wheel.

I understand the theory but I've never found it necessary. Before you do, pull up the photos of Sheldon's personal bikes. Check out how many of them have half radial rear wheels.

Now I'm thinking on doing a radial lacing on the left rear side, as per Sheldon Brown's recommendation, for a more fatigue resistant wheel.

You may want to re-think that. Radial lacing will void the warranty on most hubs.
If you are really interested in bicycle wheels you should pick up a copy of "The Bicycle Wheel" by Jobst Brandt.

One spoke length to rule them all
One spoke ruler to find them
One hub to bring them all and in the wheelset bind them

You may want to re-think that. Radial lacing will void the warranty on most hubs.
If you are really interested in bicycle wheels you should pick up a copy of "The Bicycle Wheel" by Jobst Brandt.

Have it, read it! The hubs I have are about 20 years old, and I'd never do the front radial. I'm only thinking of the rear non-drive side - the side with less tension on a rear wheel. The idea with radial lacing that side is to decrease the difference in the high and low force levels seen by these spokes, which increases fatigue life. Not sure if JB covers this in his book or not - I can't remember.

One spoke length to rule them all
One spoke ruler to find them
One hub to bring them all and in the wheelset bind them

:) love it!

Did you make that up just now, or has this been around a while?

One screwdriver to rule them all
One rim to find them
One hub to bring them all and in the spoke nipple bind them

:) love it!

Did you make that up just now, or has this been around a while?

Ummm...just made it up.