I really like the style of sprockets that Bonneville Performance uses on their custom street and super tracker bikes. They features round holes which I think would look good on my Bonneville, what with all the hole drilling I have done! So, I asked my friend Bill Gately where he gets those sprockets. He told me that he has them made by Rebel Gears, out of Tennessee.
I contacted Rebel Gears and explained what I was looking for… a rear sprocket design for a stock 525 chain in 41 and 42 tooth sizes. Sandy sent me a template of a design that would work on my Bonneville with a stock rear bolt pattern. They also told me they could only supply the sprocket in 7075 series aluminum for a price of $62.48 each, plus shipping.
I decided to move forward with this order, and received the new sprockets about a week later.
Last night I mounted the new sprocket on my rear wheel.
I decided to start with the 41 tooth gear since I am already using a 42 tooth steel gear. I want to find out how much it affects high end cruising speeds and lower RPM for better fuel economy. Because of the one tooth difference, I also needed to adjust my chain tension by moving the entire wheel and axle back about 1/4.” This is easy to do with the Triumph Bonneville chain tension adjusters that come stock on the bike.
The stock chain tension adjusters seen in the photo above use an 8mm hex head that is easy to adjust with a ratchet wrench.
I am very pleased with the initial quality and look of these gears. I noticed that the thickness of the gear matched the inside thickness of the chain much better than the former steel sprocket. It’s a much better fit.
Update May 19, 2014
This weekend I was able to put some miles on the Bonnie with the new rear sprocket set up. I really like the improvements in several ways:
- The new look is awesome!
- The slightly lower gear ratio lowers my RPM’s at cruising speeds making long rides more comfortable.
- The ratio is also still high enough that I do not notice any serious loss of “off the line” power… something I am not that concerned about anyway.
- The snug left to right fit of the chain on the sprocket seems to be quieter… maybe it’s also related to being aluminum.
I’m very pleased with the results, I may even order a 40-tooth and try that as well.