Hi All, Picked up a 150R and had a few build questions. 1) The bike I purchased has 17x2.5 front and rear. Is there a benefit in swapping out the 2.5 rear for a 3.5? 2) Anyone run 120/70s big bike tires front and rear? 3) Is 90 front/115 rear the way to go for tire sizes?
I have 2.5 17s front and rear and run 100/70 on both (XR100). Works for my bike. Ground clearance is limited by footpegs. My swingarm is too narrow for 120/70. I'm sure a 90 front would work on my bike also. If I did that, I'd probably just get two of them and run 90s on both ends. No idea on whether there is an advantage on running a 3.5 on rear.
The 2.5/2.5 is the typical flat track set up. The most common is 2.5/3.5 running Moto3 slicks (90-100 front, 115-120 rear depending on the brand). I think you'll want to swap to a 3.5 rear so you can run the proper 115/120 rear as it would be pinched on the 2.5. I have seen a few bikes over the years with a 3.5/3.5 set up running 120s front and rear (typically big bike fronts) but don't have any first hand experience with them. The 3.5/3.5 with 120s might be an advantage on dirt sections.
Thanks for this info! Got a few more questions. - Do you need to do anything else to an excel rim to be able to use a tubeless tire? - I have not been able to get any shop quotes yet but would it be cheaper to transfer my oem hub to a new 3.5 rim or should I just buy a completely new 3.5 rim/spokes/hub from some place like Procycle?
As far as the tire goes, nope, you don't have to do anything but mount it up with the appropriate tube. I have had great luck with IRC tubes. Part numbers are IRC-59 and IRC-61. You're probably best off to break down your wheel and lace up the new hoop to your existing hub. The spokes could possibly be reused. What is your 2.5 rear rim, is it a black Excel? I know someone that might be interested in buying it, he's putitng a set of rain wheels together for a KTM 85. That 32 hole 2.5 would be perfect for the front.
Ok that makes sense to still use a tube when using spoked rims and tubeless tires. I appreciate the clarification. I was planning to get the 90/115 PMT slicks. PM me your buddies info. I will be selling a black excel 17"x2.5 32 hole rim once I get my new 3.5 rim laced up to my oem hub.
If you're going to run PMTs and you're okay with not running an Excel rim, I'd just send your hub to Bernan at 73motoparts.com. Have him lace up one of his rims and mount the rear tire. He does free shipping over $75 so it would only cost you to ship your bare hub out to him. If you want to stick with Excel, www.ksrwheels.net in PA does the wheels for lots of the MiniGP crowd. Same thing, just send him your hub and spokes (he'll know if your current spokes will work).
Sometimes people hear something totally different than what you tell 'em! For instance..."just throw some BT45s on it and ride it!" is interpreted as "build some 17s and throw on some PMTs!"
