I was thinking about putting Carlisle 25x12x9 knobby tires on my Jetmoto. I'm not sure what would be appropriate for the front, but I definately want larger tires up there too for ground clearance. This won't be happening until Raceway get thier stock of larger rear sprockets in.

Anyone have any thoughts? Knobby is a 2 play, 18lb tire, so it shouldn't hurt too much at lower speeds. What front tires do you think would look decent with these on the rear?

I am also thinking about spacers for the rear so my tires will fall into the ruts that the big quads are making. It still won't have the clearance of the big quads, but 2.5 more inches would help a little. I've bottomed out the front once also, and I was thinking about 25" tires on the front as well, but I'm worried about stress on the hubs.

-JNY

 

I just did the math, and if the stock tires weight 18lbs each (they don't, but that is the weight of the Carlisle Knobby 25x12x9's):

To maintain a gear ratio that is the same as a 15/40 (stock sprocket is indeed 40 teeth) with the bigger tires I need a 14/47 sprocket setup.

I think the one John has coming are 44 tooth, so I'm going to have to turn to a custom sprocket. I can get a blank one and drill out the right bolt pattern, but I was hoping the rear sprocket would match something. It looks like there is 50mm from the center one hole to the center of the hole next to it, so maybe that will help. I don't know exactly how bolt patterns work though. I thought 4x110 wheel pattern meant 110mm from the center of one hole to the center of the next hole. Maybe it is center across to the other side (110mm diameter circle is the center point for the bolts.)

*shrug*
Just thought this info might help someone. Now to hunt bigger tires that will fit the stock front wheels.

-JNY

 

I don't know how much stress bigger tires will put on the hub or wheel bearing, but we broke a spindle and now that i have gotten it all pulled apart these spindles don't look very heavy duty to me. Also with the spindle off my lower ball joint just grinds when you move it. It must be full of sand, the dust covers don't keep much of anything out.

 

Wow I feel like a newbie... What is a spindle? =)

I think I've decided not to go bigger on the front tires. My friend says he has built extended A arms and can make one that will work with a bigger ATV's C-Hubs/ball joints so I could do a big wheel conversion, but it seems like too much work/hassle. I think it would be easier to simply get a set of front springs as well as a rear spring. I'm going to order some square t6061 alluminum tube next week so I can get cracking on a bumper/front rack. I'm also going to hunt some tubing for a snorkle tomorrow.

-JNY