KX125/KDX200 Hybrid Build

Good to hear Steve, glad it's pretty darn close to what you wanted. Good others are seeing the benefits to the rear trials tire! Which one did you end up with? I prefer the Pirelli MT43 myself. It's not as sticky as other trials tires, but will outlast a knobbie by a long shot.

Now KEEP this one! :p
 
My KDX came with a Pirelli MT43 on it. I'm a big fan of the Michelin X11 for competition trials. When this pirelli wears out, I'll throw the michelin on. I'd love to go tubeless like the real trials guys, but that adds another $90 to the price of the tire. Ouch!
 
If it came with it, then you can't complain at all! The other thing I like about the MT43 is that it's DOT legal! It will be interesting to hear the difference between the Pirelli and Michelin trails tires.
 
Steve, since I'm new to the trials tires but was planning on trying one on my 300, what would going tubeless buy you?
 
I'm not 100% sure, but I think the tubless ones would really only help in a competition trials environment. They can be run at 4-6 psi and you don't have to worry about pinch flats or tubes spinning in the tire. Most enduro riders wouldn't want to go as low as 4-6 psi, but on a trail like 5moh, it would rock. I had a plug in my tire, and it never leaked air. i'd love to be able to just carry a tire plug kit and a pump and forget about swapping a tube in on the trail.

Additionally, the tubeless tires have a much softer sidewall, so they squish a lot more (probably not what you want on a trail bike).

In my opinion, it's not worth the extra expense, but it sure was cool not having to worry about a tube in my trials bike.
 
sixstringsteve said:
I'm not 100% sure, but I think the tubless ones would really only help in a competition trials environment. They can be run at 4-6 psi and you don't have to worry about pinch flats or tubes spinning in the tire. Most enduro riders wouldn't want to go as low as 4-6 psi, but on a trail like 5moh, it would rock. I had a plug in my tire, and it never leaked air. i'd love to be able to just carry a tire plug kit and a pump and forget about swapping a tube in on the trail.

Additionally, the tubeless tires have a much softer sidewall, so they squish a lot more (probably not what you want on a trail bike).

In my opinion, it's not worth the extra expense, but it sure was cool not having to worry about a tube in my trials bike.
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The tire plug deal would be super nice for trail side repairs. The pinch flats, I'm not so sure that wouldn't still be a problem. When you get a pinch flat in tubes, you had to pinch it hard enough to pinch through the rubber of the tire. I would think it could still be a problem, granted I'm sure tubeless tires are way tougher, so probably way less likely. I usually run 8-10psi in my rear tires and I've never had a pinch flat on my rear tire.
 
Interesting. So when you have a pinch flat on a motorcycle, it cuts the sidewall of the tire too? On mountain bikes, it usually pinches the tube between the rim and the ground, but leaves the tire in tact.

I've never had a flat on a dirt bike, so I don't know much about that. I just know I suck at changing tires.

The sidewalls of the tubeless trials tires were softer, so the footprint really spread out. It was like the difference between running 25 psi and 8 psi on a rock crawler. That would probably lead to squishy cornering, but it sure rocked in the technical stuff. If I could find a way to lace a trials rim to my hub, I'd do it in a heartbeat just so I could go with a tubeless trials tire in the rear.

My current Pirelli tube-style trials tire is good, but nowhere near as awesome as my old tubeless michelin. I couldn't get that tire to spin if I wanted to. It had so much traction, and would hold a sidehill like nobody's business.
 
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sixstringsteve said:
Interesting. So when you have a pinch flat on a motorcycle, it cuts the sidewall of the tire too? On mountain bikes, it usually pinches the tube between the rim and the ground (inside the tire), cutting the tube but not the tire.

I've never had a flat at all on a dirt bike, so I don't know a thing about pinch flats on a dirt bike.

The sidewalls of the tubeless trials tires were softer, so the footprint really spread out, like the difference between running 25 psi and 8 psi on a rock crawler. That would probably lead to squishy cornering, but it sure rocked in the technical stuff. If I could find a way to lace a trials rim to my hub, I'd do it in a heartbeat.
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It doesn't normally cut the sidewall too (it could easily though), but it's still gotta pinch the tire enough that it cuts your tube, no matter where on the tire it's pinching.
 
I think that's why trials tires are so tall. They're constantly putting their entire weight on a sharp angle and they still don't hit the rim.

trials tire2.JPG
 
I'll be working on the bike tonight if anyone wants to come hang out and work on theirs.

Here's what I've got to do:

1) install new front tire
2) extend the head tube on the exhaust
3) fab new exhaust hangers
4) general maintenance/tune up
 
Sorry Arturo. It ended up being a frustrating night anyway. I pinched my brand new tube when I was installing my front tire. I've literally changed thousands of bicycle tires. I'm very careful where I put my tire irons, and I made sure to stay away from the valve stem. Well, sure enough, that's right where it pinched it. I'll be putting a new tube in tomorrow night. From now on, I'm paying RMATV the $10-15 to install the tire, it's worth it to not have to throw away a new HD tube.
 
Yep, everyone pinches a tube atleast once. I too would pay someone to change them if there was some one close that could do them quick. Most of the time they want you to leave them. I'd rather take a few minutes and just do it in my garage. I'm going to get a rack for changing tires on, I've even thought about an actual changing machine. If I were racing I'd definitely have an actual changing machine.
 
Tonkaman said:
I worked in a bike shop for years, and somehow I still can't successfully change a motorcycle tube
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That makes me feel better. I've spent 5 years in high school and college as a full-time bicycle mechanic. Dirt bike tires suck to install, but I'm getting better. By the way, those stubby tool plastic tire levers are absolute garbage. I hate mine. I'm going to see if RMATV will refund me for them. They're way too thick to do any good.
 
those look cool, I'll have to get some. I do have a bead buddy, that was a huge help.

I see they're out of stock. Rocky Mountain has been out of a lot of good stuff lately.
 
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