XR650R Tire Size

I bought a 2003 XR650R a couple of months ago and unplugged it after about 20 miles. I ride primarily on trails but I also ride about 10% on paned roads. I try not to do a lot of heavy eccelerating while on the pavement but the back tire is wearing extremely fast. I have been shopping for a new tire and I'm leaning towards the pirelli MT21. Could anyone tell me how big I can go or if there are any better choices? Oh yeah most of the trails I ride are pretty sandy.

Any info would be greatly appreciated.

You can go with a 140-80x18 or 120-100x18. I like Michelins and the Michelin Baja is a dot tire and come only in 140-80x18.

I too have a wearing back tire, do either of these tires have any rubbing issues? I ride alot of sand and mud but little hard terrain, any suggestions?

I alternate between two sets of tires/rims. One is MT21's and the other is S12's both 140 rear. No rub problems with either. The rear S12 wears like iron even with some pavement thrown in. Not street legal though.

I've got 3,300 miles of all Ocotillo Wells desert terain on my scooter. I went through the stock Dunlop at about 1200 miles, went through a Bridgestone Gritty ED78 in about 1500 miles, I have Dunlop 756's on it now and I think I'll be lucky to get 800 miles. I have the MAXXIS IT's in the garage qued up for the next change. I run 120X100X18 on the ED78 with no problem, the 756's are 110X100X18, and the MAXXIS' are 120X100X18. This tractor tears up rubber - that's the price of torque. Don't forget the heavy duty Bridgestone innertubes, new rim liners, and lots of Talcum powder! :)


I agree with Moredesert, the Michelin Baja is a great rear tyre. It seems to handle really well in loose surfaces and is not far from the quicker wearing Dunlops & Bridgestones on hardpack. I run mine on all types of surfaces and it seems to wear nearly aswell as an MT21 but with stacks more grip in the dirt. Depending on the length of your chain, and consequently the position of your wheel, you may find it rubs a little on the plastic shock protector. This can be solved by simply trimming the flap with a knife of some description, it is also a good idea to throw a bit of silicone on the heads of the screws that attach it so that they don't come loose and leave the shock shaft exposed to rocks and the like.

On the front I run either a Dunlop K490 or a Michelin Desert and both of these tyres are impressive in a range of situations.

T-Diddy Six Five Oh, I'll be ordering up a new Maxxis IT 110 hear pretty soon.. I still can't believe I have knobs! I have no idea how many miles I've got on this donut but I can easily say that I would be just about done with my SECOND Dunlop 739 about this time compared to my Maxxis IT.

Maxxis - Good.

Thump Father...we will have to have a tire changing party pretty soon. You bring the beer. I'll bring the tire irons! :)

I run mostly S-12 too. They work great in all terrain and are cheaper than the Michelin Baja but are not DOT approved. :)

I dont seem to get as many miles out of my tires. I guess thats becouse of my old man sit-on-my-butt riding style...come to think of it I havent had much lasting success with women either. Anyway...

I love the Michelin Desert in the front. Incredible bite and straight as an arrow. Following Johnny's lead, the Dunlop 606 is another front tire that we have had mixed success with-it sucks in the corners-ya litterally have to learn to slide both wheels at speed in the gravel, good on hard pack and rocks... Cant stand any other front tires. Either wont track straight at speed, bump up and down, or wash out in the corners.

The rear is another story: In BITD and SCORE race conditions Dunlop AT 739 rears last us about 300-350 miles. ED 78's about 250-300. The Pirelli 21's chunked after 250 miles. The S12's chunked within 100 miles. Dunlop 606's have been mixed with two shredding, but two others lasting 350-400+ miles. The Michelin Desert rear seems to be reliable to at least 450 miles-but the 140x80 will rub a bit unless the sub-frame is perfectly straight....!

Havent tried the Michelin Baja-but i imagine its similar.

For open desert racing my take is that the Michelins are an expensive fix, but habit forming...and are as noted DOT. Havent tried the Taiwan made ChienShing/Maxxis yet...amazing what a name change can do for a brand!

Tires. Ride em hard and they wont last long. Its only been a year, what was her name?

Anybody out there that rides deep mud? I am looking for a tire that will work good in mud and deep sand. I have a habit of getting in a little deeper than i should. I need that absolute biggest tire I can fit with the nastiest tread. I do not want or need a paddle as i do ride some gravel and hard terrain as well but not much. I usually go play in some old abandoned gravel pits, lots of hillclimbing, mud pits and DEEP sand. I bought my BRP to ride mud and am not disappointed but i need a better tire.

thanks in advance


The Dunlop 756's have a nice bite for the soft stuff. When I first put them on, I was amazed at the bite in the sand in corners and the roostability in the back - I was on top of the sand in no time. Unfortunately, hardpack tears them up and that is why I am trying the MAXXIS next time. :)

I have been shopping for a new tire and I'm leaning towards the pirelli MT21. Could anyone tell me how big I can go or if there are any better choices? Oh yeah most of the trails I ride are pretty sandy.

Well my riding partner is wearing a back 130 wide MT21 on his 650r. He has been telled by experienced guys that he could do up to 4000km on this tire without problems. We rode it in sand, mud, snow, logging roads, pavement...etc.

The tire is vey solid in all kind of intermediate to hard terrain. Throwing roost on my 426 all the time if I am too close. You will see, you will forget in few seconds that your bike is wearing that DOT tire (not a real knobby)because it offers a lot of traction and stability

We tried it in deep sand and we think the work of the MT21 is comparable to a hard-terrain non-dot knobby tire: more than acceptable performance and stable....

yes we have to say it and say it again: the tire makes the bike stable and is very very predictable on the 650r

The tire allows us to do sliding turns on hard terrain( you know like the guys on dirt tracks) very easily and at amazing speeds

In the snow: the 140 S12 is a lot better but who cares except those crazy guys from Quebec :)

We also have to say that the MT21 feels very safe on the road but a little bit noisy though. (Of course)

We haven't test extreme muddy conditions but until now, it has got the job done in this field also

Briefly, it is a very good tire for somebody who wants to get an aggressive tire for a street legal 650R... the only serious choice IMHO if you only have one rear rim...

Hope that helps!


Thanks to all for the information. This will definately help in the decision making. Oh and one other thing, where I live the police don't realy care if you run a DOT tire or not. When I took it in for inspection with the stock tire they did'nt even bother with the tires but I'm sure thats because most of them ride too. Thanks again...

And what about front tire size ins tock rim?

Edited by babuja

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