How to rebuild a motorcycle wheel

Motorcycle Wheel Building Guide

Building up a spoked wheel is probably one of the workshop tasks that is most daunting to a lot of bike builders.  I admit, I don’t have years of experience in motorcycle wheel building, it was something that I used to think was a black art.

After a lot of research, reading and Youtubing it to death, I decided to have a go on my Bonneville T120, and now feel that I can give some common sense advice to anybody deciding to take on the task.  I would even encourage you to have a go, it is very satisfying, and not that hard to do.

The specific techniques are covered very well in lots of places online. I have given the basic steps and the rest of the write up here is to fill in some of the gaps on other things that come up as you build a spoked wheel.

Basic steps to build a motorcycle wheel

  1. Make sure you have the rim the right way round in relation to the hub the nipple pattern may not be symmetrical
  2. Lace up the spokes – they may be different lengths, and have a different bend, take this into account
    1. Do all spokes of one type in one direction and side first 
    2. Flip it over and do the other side 
    3. Do the spokes up relatively loosely. 
    4. As you give them an initial tighten to take up the slack try to get near to the correct offset (see later)
    5. Work your way around the wheel in sequence, tightening each about half a turn at a time
    6. Tighten the spokes up to an even tension, I use the tap the spokes and listen to the “ting” method
  3. Put the wheel in a truing stand so that you can true the wheel
    1. I use the forks or swing arm as a truing stand
  4. Stop it being oval or egg shaped first
    1. Use a pointer against the rim as you spin the wheel, tighten where it is too high, loosen where it is too low, do this to opposite sides equally
  5. Set the side to side run out 
    1. Use a pointer against the rim as you spin the wheel this time
    2. Loosen one side where it pushes against the pointer and tighten the other, a little, to move the rim side to side
  6. Check offset and make adjustments if necessary
  7. Repeat 4, 5 and  6 until within acceptable limits, don’t expect perfection.
  8. Check the “ting” again when this is right it is the final step otherwise you are back to 4 when you tighten them.

How to build up a Triumph Bonneville T120 R conical hub rear wheel

If you are looking at rebuilding a Triumph Bonneville conical hub rear wheel, you have just found a great source of information.  There are numerous forum threads, other motorcycle wheel building articles, even Triumph workshop manuals and technical notes covering the topic of motorcycle wheel building.

But they all seem to miss one thing that is important, the offset!

This is the measurement that positions the hub left to right in relation to the wheel rim.  It isn’t something that you would think of at first.

Triumph Bonneville Wheel hub and rim ready for assembly.

Triumph Bonneville T120 R conical rear hub offset

Wheel building diagram showing offset measurement.

Frequently you are told to measure it, and make the new wheel the same.  Great advice unless your wheel is already in component form, and who is to say it was right in the first place?

I did find a blog that gave a lot of measurements of their wheel, but it was hardly authoritative.

In the end I found a BSA technical note about the same wheel, to be fitted in the same frame.  The measurement is 2.8 inches from the centre line to chain wheel register. Not the easiest thing to measure but I think I got it close enough. The wheel positions well in the swing arm, and the bike steers well.  

To fit it approximately at first I used the measurement from the other blog because it is easier to measure, adjusting towards the BSA figure once it was together.

The problem with just relying on the edge of the hub to rim measurement is that the hubs and rims may have been manufactured differently from the pairing measured.  Using the centre line, and the chainwheel register does give exact fixed points.  

Another wheel offset example.
Spoked wheel offset measured with calipers.

There are some recommendations to position the rim nearer to the primary side for better handling. I think that within a couple of millimetres either way won’t make a massive amount of difference, but like I said I did try to get it as close to the BSA figure as possible.

Triumph Bonneville rear wheel tyre clamps

There is a lot of discussion about whether to use the tyre clamps that were originally fitted to the rear wheel.  These are to stop the tyre moving in relation to the rim when you are riding.

They are often used on Trials and Motocross bikes, but these often run very low tyre pressures so the tyre isn’t held as firmly.  Bonneville’s don’t exactly have tyre shredding power, 🙂 so fast acceleration is unlikely to make the tyre shift.

I think that the tyre pressures are high enough to hold them in place, so my vote is that they are unnecessary.  However if you are rebuilding to standard, or to a standard look then you will need to use them. It’s one of the things you need to consider before buying your new rim, as there are holes required for them to fit through.

Motorcycle wheel components, Rims and Spokes

You will be able to find the correct rim size from the technical information for your bike. They are measured across the width and for older bikes a code number is used to indicate this and the way the rim is formed.

For old Bonneville’s they are WM2 and WM3, but that isn’t the whole story, as the same sizes are used on other bikes, but they may not be interchangeable because of the way the nipple holes are punched.

There are a variety of patterns for this and they need to be appropriate to match the hub you are using. 

Made in England wheel run in stainless steel.

You also need to consider whether you want a chromed or stainless rim, and whether you want to use stainless spokes or not.  My opinion is that if you aren’t going for a completely back to standard rebuild then it is stainless all the way.

Although I don’t think that the way rebuilt bikes are likely to be used future corrosion is going to be a real issue!   

Triumph Bonneville conical rear wheel hub ready for building.

Using stainless steel wheel components

You must use lubricant and anti-seize with stainless to prevent galling and cold welding when building things up (not just wheels) as well as being able to get them apart in the future.

Doesn’t seem to matter what you use for our application, most of the hysteria on forums seems to be about the nuclear industry and marine applications. I suspect with our application on primitive technology bikes that beef dripping would do  However I personally use copper grease! Mainly because I always have it to hand.

Wheel building videos

The videos on Youtube make wheel building look much easier than it is for a beginner. That isn’t saying that it is hard, but you do need to be methodical and considered in your approach.

Some good ones are:- HD Wheel Truing guide and How To Lace And True A Motorcycle Wheel At D-Ray’s Shop (I think the advice in this one is particularly helpful). Check these out below:

Golden Advice on Wheel Building

You will never get it perfect!! I have spent a lot of time moving the rim back and forth a few thou’ chasing my tail. It is also likely that the rim may also have a little built in variation where it was welded, and probably other tolerances in the manufacture of it as well.

I don’t have a truing stand for motorcycle wheel building so I put the wheel back into the rear forks, and used a pointer bungeed to the rear shock, turning the shock spring gave up and down adjustment.  You need to stop it being egg shaped first, then go onto truing it from side to side.

Motorcycle wheel building by feel

Feel is more important than exact torque settings! When you are tightening the nipples, some suddenly feel looser, some tighter (not a lot, but noticeable).

Keeping to what feels like a similar tension seems to work best, rather than going with exactly the same number of degrees of turn. Towards the end 1/8th and 1/16th or even less turns is enough.

Remember you are always need to balance things so once you get to the later stages if you want to tighten one side to move the rim, you also need to loosen the other side by the same amount.  And remember we may be using ¼ or less of a turn on the relevant spokes.

Wheel building spoke spanner.

Spoke adjustment

When motorcycle wheel building, don’t be afraid to bend the angle of the spokes where they go through the hub a bit to get them to sit better. But if you are like me, you will still feel they aren’t quite right for a lot of the time. Go and look at a few different other bike wheels, you will realise yours are pretty good.

Wheel spoke angle bending.
Bending the spoke for better angle when building the wheel.

Nipple torque settings

How tight do you do the nipples? There are specific torque wrenches for this, but unless you are doing a lot of wheels it is probably too expensive, and if you are doing a lot of wheels you will probably develop the feel for it anyway.

Seems that you don’t need to go too tight, very low torque values seem to get mentioned most. However I have seen 40lbs and even 80lbs mentioned. I settled for making the ping of tapping the spokes, sound like a professionally built wheel, looking for a nice consistent ting! 

How scientific is that? I am open to better advice though, do feel free to comment.

Triumph Bonneville T120 R wheel complete with tyre

Having it fully built up, with a nice tyre on and back on the bike is a great feeling.  Just need to put the engine back in my Bonneville T120 project now. 🙂

Rebuilt wheel mounted back onto the Triumph Bonneville.

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