Ive got the parts coming to make a 700x28c wheel with an oracle hub. This will be my third wheel build but it is my first experience of building a dished wheel so i have a few questions.
Ive ordered all my spokes the same length even though there needs to be an ~3mm difference between the short and long sides. Will this be a problem.
Are there any tips and tricks for centring the rim properly.
Is there anything else i should know that will help the process.
I’ve not built a dished wheel (yet), but I think all spokes being the same length is going to be a problem. It’s common to have two different spoke lengths on dished wheels, and a 3mm difference is a lot when it comes to spoke length.
A dish stick is your friend for centering the rim.
3mm’s is too much of a variance to make it easy, and depending on how accurate your measurements are it might not work at all.
You may be able to get away with doing 4x on the disc side, but I think your spokes will be too short for that.
Just for clarification a wheel is dished correctly when the rim is centered between the bearings. So, if you have built a wheel that had the tire running in the middle of the fork blades, you built a dished wheel. A wheel out of dish is one that the rim is off centered when mounted on the cycle.
What you are talking about is an asymmetrical dishing vs. symmetrical dishing. Most unicycles have symmetrical dishing (same on both sides). This is important so that when you read other pages about disihing you will be speaking the same language, and not getting confused by how they use the word “dishing.”
The best advice I would give you is to get the right spokes. With the right spokes the asymmetric dishing takes care of itself for the most part.
Just gone through the calculator again, not 3mm but 1.5ish
for the disc side, it wants 286.86mm, on the non disc side, 288.33 on a rim with an ERD of 602.
At the moment i have 287mm spokes coming, do i need to find some 290mm ones as well even though the length difference is greater.
Unfortunately though, i suspect i won’t know if it is going to work until i build the thing…
If you get longer spokes a bike shop can cut them down for you.
Depending on your nipples you should be able to build it. Pay close attention to where the spokes on the non-disc side end in relation to the nipple slot. Most nipples allow for a half mm below the slot without sacrificing strength. You don’t want the spoke end at or below the shoulder.
If you are building a rim without eyelets you can lightly chamfer the holes on that side effectively lowering the ERD. That could easily make up the difference, plus it helps the nipples seat in the rim. If you do this it really doesn’t take much, like 2 light turns of a counter sink. All you are trying to do is knock the sharp edge off of the hole.
A dishing tool is nice, but if you’re using a frame as a stand you can just see that it is centered in the frame. As long as the frame is straight you will have good dishing. If you want to get more accurate use calipers to match the space between the frame and rim on both sides.