Hi everyone, I am finishing my 2012 351cc Bill Blue kitted project this weekend and I will be building a set of spare wheels/tires for road duty. They will be 17 inch rear and 19 inch front. My question is should I go with the standard size of 130 mm rear wide tire or step up or down in width for any reason?

Any help based on experience will be appreciated. Thanks, Mike

 

Depends on what you want. If you want fat, do the 130, if you want a lighter look do a 120. Remember the bigger/heavier the more power it takes to make it spin. Because the tire curvature isn't that much different I doubt you would actually get much better wear with a 130 versus even a 110. It's an inch or two in the middle. And the narrower tires are also less expensive. I'd run a 100/90-19 or maybe a 100/100-19 on the front. My old MotoGuzzi ran a 100, when I put a 110 on it the difference in steering was huge - I think I needed a CDL to operate it. Handled like a dump truck.

I certainly wouldn't go bigger. I was looking at 140 as the biggest for my 650. Fact is my Zephyr 550 runs a 140. Spending a lot of money to wear out the middle near equal.

But that's just my opinion. If I could do so on my new XSR I'd run an 18/19 with a 130 on the back and a 100 on the front with a dirt track style tread. Unfortunately they are 17s and HUGE. A 180 on the back and a 120 on the front about the norm these days. I think the tire companies have a kick back deal with the manufacturers. Build bikes that require $250 and $175 tires due to the rim widths.

 

Thanks, I went with the 130 because the BB 351 engine should pull the 130 tire without any problemsI I am building the 19 inch front and should have that done soon so it will be nice to have a set to swap out for light adventure rides with the Kenda K761 tires. BTW-your cam chain tensioner works like a charm! I finished the 351 build last week and that one part gives me peace of mind.

 

Thanks, appreciate it. Glad to see you didn't go overboard on the tire. Why load the engine down with more rotating mass that will just eat power.