Hi All,

I've been reading all the threads about spoke length and misalignment when converting to an 18 inch wheel. There seems to be some confusion as to why the spokes do not line up with the holes in the rims, especially those with dimples. The answer is obvious but it took me a while to figure it out.

The front and rear spoke patterns are the same. The difference in the angle of the spokes is due to the disc braked front having a smaller hub than the rear, which uses a drum brake. For a given cross pattern the length of the spokes and the angle which they make with the rim are fixed by the respective inner and outer mounting locations.

If you try to put a front wheel on the rear the spokes will have too much of an angle for the predrilled holes, as seen on the early Ryca bike examples



Now, if you want to put a rear wheel on the front you have the opposite problem, the spoke angle is too much perpendicular to the rim compared to the holes.
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What to do? Best and most expensive is to have the wheel shop drill the holes to match the specifications you give them. They should be able to figure it out.

Another way is to make sure the rim you buy is made for the same sized inner circle as the one on your bike. I did an "Internet Eyeball" calibration and figured out that the Suzuki Savage and XS650 Yamaha have the same approximate rear drum size and spoke hole mounting circle diameter. Therefore the rim I ordered from Mike's XS had the correct angles for the spokes.

However, the same model number rim had the spoke holes drilled at too an acute angle (away from 90 degrees)  for the front.

What to do?

(1)  Pay to ship the non compliant wheel back to Mike's XS. Go to the wheel store and give them the information they need to make a wheel for your particular combination of wheel size and hub spoke hole circle. Expensive.

(2) Lace it up as is with the spoke nipples not seating correctly. This was what people were complaining about on the Ryca builds. Some of the spokes were actually bent. That doesn't seem like good practice.

(3) Weld up the holes in the rim and drill different ones. This sounds rather extreme and possibly unsafe. Labor costs for a good job would be more than option (1).

(4) Modify the wheel rim so that the spoke nipples will seat better.

I think I have a solution that would work and save having to buy another wheel.

What do you guys think should be done?

John in Kalifornia

If you are on a budget and pinchin' pennies and want to adapt a wheel where the holes are not properly aligned.....the only thing you can do is take a drill and drill the existing holes at the correct angle.  This will make the holes slightly oval.....and perhaps the nipple will not seat completely since the hole is not drilled at the correct location in the dimple to match the spoke angle completely.  I looked at this affordable way out for a month or two, and even bougth a NOS Yamaha rear rim....then found out I would have to drill it and I decided I did not want to do that, as Iwould have trouble finding a front and rear rim that matched as explained below.

There are reasonable priced dirt bike rear rims are the correct 2.15 x 18 that we need for our front rim, and you can probably find some that have the holes for a hub with a disc brake and a similar sized hub.  The problem then becomes finding the correct 2.50x18 rear rim that matches the one you got for the front, as dirt bikes use a narrow 21" front wheel.  Also a lot of dual sport bikes use a 17" rear and/or 19" front wheel.  The number of spokes on dirt bikes can also be different from our 36 spokes.

If you are willing to spend a bit more than $ 210 a rim.....you can buy new rims that have the holes "punched" at the proper angle and in the proper location in the dimple.  I bit the bullet and bought mine from Buchanan's.  The holes are punched at the correct angle and they fit like they are supposed to.

belville washers are springs.  unless you complete fit the washer to the rim, it will act as a spring.  Don't know if that will be good or bad, but your wheel will flex a lot more than intended.

if the intent is to distribute load, I think a stainless or alloy washer will be a better option as those will deform to match the hole you've made.

I think, I would slot the hole until the proper spoke angle could be achieved.  Then find a center drill to redrill the back side.  Being this is experimental, I'd go get a crap wheel that only cost scrap value and try it out first.

HEY JOHN,
Thanks for posting this up. As you already know, I've been fighting the exact same issue, and I like some of the suggestions you have posted here.
I definitely think that using a softer, more deformable washer makes the most sense, so that the spoke nipple really seats into the hole. You don't want a spring in there. Brass sounds perfect to me; some sort of fairly thin brass washer.

When you go to drill out and re-shape those holes though, you should really take your time and be careful. I imagine that using hand tools, it would be really easy to take just a little too much meat off of the shoulder, and you need to do all 36 of them exactly right; screw up just one, and your whole rim is toast.

By all means, please let us know how this works out for you!!

To me that seems overly complicated, especially given that you are going to end up with an inexact hole no matter what you do. Remember that the angles are not just flat the way that they appear on paper in your drawings, but some angle to the left while others angle to the right of center.

In my mind I was imagining doing this with a hand drill and/or dremel tool and hogging the holes out until the spokes will fit in at close to the right angle; knowing that the result will be a little sloppy.
From there, I think that your compression washer inside the spoke nipple should make up the difference in the slop, as long as it's not overly sloppy.

I do think that trying to mock up the wheel first and get a clear sense of what the correct angles should be is a good idea. An educated guess is much better than a wild guess.

I also think that part of the problem is that the holes are drilled straight through the aluminum which is somewhat thick. I don't have no fancy computer drawing skills, but I would illustrate it like this:   l l.

If you were to round off the edges of the holes, the nipples would have more freedom to move around, but the center meat of the aluminum would still be roughly tight around the nipple. Sorry, that's terrible english, but I would illustrate that like this:  )  (.

I believe that would allow you some room to move the angle of the spokes around without reducing their hold in the rim.

Does that make sense?

Makes more sense than my overy complicated way of doing things. I'm inside drawing pictures instead of working on the bike because IT'S TOO HOT outside.

John in kooking Kalifornia

John in Kalifornia wrote on 08/11/12 at 13:57:02:


"You knew the job was dangerous when you took it Fred"

Like this?

John in Kalifornia