Wheel Truing

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Introduction

This purports to be a guide to truing spoked wheels. A well-trued wheel is a pleasure to ride, as it acts like a shock absorber for smaller bumps.

WARNING: Plan to spend from 4 to 6 hours on the following process.

Tools

Get something to measure your deflection. You really want to get yourself a dial indicator set ($25 at Harbor Freight tools)

If you’re a cheap-ass, a magic marker clamped so that the tip just barely touches the highest spot (and you lower it as you true, and wipe off the marker as you go) will do in a pinch.

And speaking of magic markers, make your life easier by putting a piece of masking tape all around your rim so that you can number your spokes. It’ll save a lot of time if you need to undo a step, or if you have a troublesome area.

Process

Setup

(I’m assuming you are truing it while the wheel is horizontal)

Take the wheel off your moped, take the tire off, and put the wheel on a truing stand (could just be a piece of pipe through your wheel, with the pipe in a bench vise). The hub should spin freely, with no wobble.

Loosen all the spokes until they go thump instead of ting.

Gross up/down

In this phase, you will be tightening all of your spokes so that the wheel is basically flat, and your rim is centered on the hub. DO NOT OVER TIGHTEN HERE! You will need the spare tension later. You just need to bring the rim in line with the hub’s center.

Gross in/out

Using just a 1/4 turn at a time, adjust the spokes so that when you spin the wheel, it’s mostly round. A 1/8” deflection is fine.

Fine up/down

Now, we get rid of the ‘bumps’ in the wheel. In this phase, your dial indicator (or marker) should be hitting high points either between or right on a spoke. If right on, tighten for spokes that go down, and loosen for spokes that go up. If between, adjust both spokes.

Remember – GO SLOW! Only tighten by a 1/4 turn, then move on to another part of the wheel. If you work only on one side at a time, that side will be over tightened, and, like a spring, will rapidly deflect when you adjust the other side.

You’re looking for a final deflection of about 1/16”, and your spokes should go tang. Not ting yet, but we’re getting there!

Fine in/out

Same as fine up/down, but when you adjust for in/out deflection, you must tighten or loosen two or more spokes at a time – one going ‘up’, and one going ‘down’. They must be adjusted at the same time, and, please check your up/down deflection after every in/out adjustment!

I cannot stress this more – if you over tighten during the in/out phase, you can rapidly warp your wheel out of true. If you check up/down every time, it’s easy to undo what you last did.

Torquing

Now come the what you’ve been waiting for – ting ting ting

This is the trickiest part – you need to gradually adjust all the spokes to be in tension without messing up all of your hard work.

What I usually do is rig up the dial indicator to right where I’ll be doing the adjustments (set for measuring up/down deflection), and tighten only the loosest spokes until the tiniest deflection is measured, then back off a little. I go round and round, slowly torquing it all in, a little at a time, until all the spokes make a nice ting sound. For my wheels, a higher pitched tink sound is too much, and I back off.

You’re Done!

Re-tire and mount your wheel, and have fun!