Rebuilding a Spoked Wheel for the Royal Enfield Bullet Part 1: The Pattern Intro

This particular pattern belongs to the Royal Enfield Bullet. Before starting it’s a good idea to take photos of the wheel, recording need to know info for later, such as pattern and layout of the spokes. This is a first for me both tackling a wheel rebuild as well as working on a motorbike so I stand to correction in respect of my terminology/procedures. The layout

The main photo shows the parts laid out with the hub as it would be on the bike, the shorter spokes going in the left (speedo) side of the hub. Here I’m going to tackle the front wheel, bearing in mind that there are 2 different types of spokes in the front wheel. There is the slightly longer 144mm one, and a shorter one 142mm. In addition to the length of the spoke, the 2 types also have different amounts of bend in the hook, which can be seen more clearly in the pic below. The reason for this is that the wheel must be centered between the front forks,

swingarm in the case of the rear wheel, to maintain correct balance and symmetry. In order to achieve this, the rim must be slightly offset with regard to the hub to achieve the correct wheel symmetry. In this case it’s offset to the LHS (left) when looking at the bike from the front, which I call the speedo gear drive side. This means that the shorter spokes will be on that side and the longer ones on the RHS (right) or brake linkage side Loading the hub

Loading the hub with spokes should take approx 5-10 min. I do the whole hub at once, if you do half the hub and then attach the rim, the other half of the hub is blocked by the 1st set of spokes that were installed. This is the way it is on my hub, others may be different, but it’s something you need to keep in mind. Half loaded

Here is the hub half loaded, 10 of the short spokes and 10 of the longer spokes. At this point I turn the hub over and do the other side. I also put a small dab of copper grease on each spoke thread before I start the whole procedure, it prevents corrosion, cold welding or seizing of the spoke and nipple, and accounts for the dark look of the threads in some pics. Completely loaded hub

The completely loaded hub awaiting the rim. Hopefully you’ve kept your wits about

you and not mixed up the spoke sets. Attaching the rim

In this pic the leading edge of the wheel would be to the right. The outer spoke sets I angle up at a trailing angle. (the spoke nipple trails the hook on the hub in the direction of rotation of the wheel) I’ve seen this in a few pics of the bike and presume it’s to take the forces exerted under braking conditions. Thus the inner spoke sets naturally go in the opposite direction, downward at a leading angle to the hub. Starting point

Where to begin? I start at the valve hole area and work my way around the rim clockwise. The 1st spoke seat/dimple points to the bottom layer/brake linkage side, so I cant use that one, which leaves the 2nd dimple, which happily points to the layer that Im working on. Upon popping in the spoke you’ll see that it fits neatly and obviously in the hole. Then I count 4 dimples and pop a spoke in the 4th one till I’ve done all 10 of the upward pointing spokes. Spacing count

Another view of the angle of the spokes to the rim and hub, this way they fall naturally into their respective holes, also the 4 hole spoke spacing can be seen.

Top set complete

The top outer set completed, next the inner (2nd set). The inner set

Now the 2nd set in the top layer, i.e. the downward leading set. I start at the valve hole area again, but this time I count 6 dimples from the 1st upward spoke seat and pop in a

spoke in the 6th hole. It should be obvious to the eye that it points to the correct layer and correct spoke position. Once I have the 1st downward spoke in position, then it’s a simple 4 count again working my way around the rim clockwise till the top(speedo) layer is complete. Complete top layer

The complete top(speedo) layer. Now its time to turn the entire assembly over and start on the other side, namely the brake linkage side. The brake linkage side

The brake linkage side is done in the same way as the speedo side. Firstly I pattern the

spokes so that the outer set points upward but on the left side of the wheel which is now the front, previously they were upward on the right. With the inner set going in the opposite direction, I rest each spoke in the pentagon opening made by the bottom speedo side layer. This setting out of the spokes makes life a little easier as well as preventing blocked spokes. Blocked spoke

A blocked spoke is one which can’t be swung around to its respective seat because other spokes previously installed are blocking its path. Sometimes its just 1 but usually its 2 or 3. The blocking spokes then have to be undone, the blocked spoke swung round to its seat and the undone blocking spokes redone again. Half of the brake link side complete

Here the 1st set has been completed and part of the 2nd set. Finally

Tada!!! The completed pattern. Note the exposed spoke threads, I’ll see to that next. Protruding nipples

Now I screw in all the protruding nipples evenly, till they’re finger tight. I use a rechargeable drill/screwdriver on the lowest torque setting for the job, makes the job go a little faster. Spoke closeup

A close-up of the spoke nipples showing how far I screw each one in, pretty much till the end of the thread. The end

Keeping in mind that this is the first time I’ve done this sort of thing, I took roughly 45min to get to this stage. Your mileage may vary. ☺ The next step is truing the wheel. This involves centering the rim on the hub, in the axial plane (up and down) as well as radially (side to side), but keeping in mind that the wheel must be centered in the front forks.

Here I take a break, being content to sit back and admire my handiwork and the light twinkling on the new spokes for the time being. Of course at this point you could always take the assembly as is to the professionals to complete the rest of the longer and trickier part of the job. Part 2: Truing the Wheel

This part deals with the process of centering the wheel in both planes, vertical and horizontal and ensuring that the wheel is also centered between the forks (front) or swingarm (rear). While the 1st part went fairly quickly, approx 1 hr, this part took me fairly long, approx 2.5 hrs budget your time accordingly. Safety is always a big issue, so to that end I tied the center stand to the front of the bike so that it couldn’t fold. Failure to do will cause the bike to collapse onto the sump or exhaust damaging either or both.

Centering the wheel on the bike

First I center the wheel on the bike in either the front forks or rear swingarm depending on which one I'm tackling. In this case its the rear wheel so back on the bike it goes, setting it up as though ready to ride. In the case of the Enfield its got adjustable cams (notched) to ensure proper chain tension and that the wheel tracks straight. I find it easier to remove the top of the RHS shock and fold it down, as well as remove the mudguard assembly for easy access to the wheel and swingarm assembly. I've installed a threaded rod to act as a pointer in the lower mudguard mounting hole.

In closer

A top view of pointer and rim, I set the valve hole (good ref point) of the rim next to the pointer and center it in relation to the swingarm. This will most likely take some tweaking of the spokes to achieve.

Vertical Adjusting

I like to use the M pattern when doing vertical adjustment, well it looks like an M but I spose it could be a W too. Lets say that the rim when rotated has the highest point at A you would then need to tighten both spoke sets at A, the red set and the blue set to pull down the rim equally at A. Of course by the same token you would need to loosen sets, pink and green at B to give the rim space to move down. I usually tighten a quarter turn at a time, yes it does take longer but the chance of me warping the heck outta my rim is less. I proceed with this rotating to find the high spot and then adjusting till the entire rim is almost within the 0.5mm spec for out of round, then I move on to the side-to-side deviation, that spec is also 0.5mm. Of course if speed is your thing then smaller tolerances would be even more desirable.

Side Adjustments

For this adjustment I rotate the rim looking for deflection to the left, my reference pointer being on the right, and then tighten the spoke at that point that goes to the right side of the hub, as well as a spoke on either side of the identified spoke, making sure they also go to the right side of the hub. This serves to pull the rim over to the right, making sure not to pull the rim further to the right than the valve hole which was my ref point, otherwise the rim/wheel assembly wont be centered in the swingarm/front forks. In the diagram, if the rim is too far to the left A then I tighten the black spoke going to the right side of the hub. Likewise tightening red A spokes would serve to pull the rim over to the left. and Finally

This gap is too large, I use a piece of paper to barely slip through as a reference. Here I will need to tighten spokes going to the right side of the hub to pull the rim closer to the right. Once the rim is centered to my satisfaction then I work my way around the rim giving every spoke a quarter turn, and then once more for good measure. This serves to tension the spokes properly and now they should have a nice ring to them. One last check to make sure everything is still centered and then its on to the tyre installation. I rub my thumb around the rim before installing the tube/tyre to check for any high spokes ( must be filed down) or sharp edges that could cut the tube, saves work later on repairing punctures, and also put back the rim tape that was covering the spoke nipples To finish off I tap around the rim to sort of seat the spokes. Same sort of thing achieved by installing tube and tyre and inflating, then bouncing the wheel on the ground, gently, not like a lunatic. A wheel has a strange knack of bouncing in an unpredictable way like a rugby ball, so its probably better to use a rubber mallet. If all this is doesn’t make sense, then there’s another well-worded spoked wheel repair site to visit http://www.dansmc.com/spokewheels.htm