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.
/
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