MT21 tire question on a XRR

My question is what pressure are you guys running them on and off road at. I had them at 25psi on some fire roads but it seemed way to squirrelly. So I dropped them to around 20 and that helped on the street but still not that confidence inspiring off road. I will be ridding 50/50 and am running NO RIM LOCKS. TIA Clipity

I allways ran them 18 on the street and 12 dirt only,allways with rim lock tho

Run that rimlock and balance it if you're worried. When you pressure down you're going need that rimlock to keep from pulling valve stems.

The MT-21 is about as bad a front dirt tire as you can find, but does ok on the pavement. You need about 20-22 PSI on road and 14-16 offroad, as long as there are not any big boulders at high speed or you will get a pinch flat and dent the rim, then run 18-20... The rear is actually pretty good all around tire, good on the street with about 20-22 PSI for twisty black top and concrete. For long straight Highway, go up to 26-30 if you want. Offroad they will be pretty loose unless you drop to 14-15 PSI. I use 3/8 self tapper screws through the rim, into the tire, 3 per side and have great luck with no rim lock. I have run probably over 18 rear MT-21 tires over the years.

I like the Mt-44 or 32A for the front... Great offroad grip but fast wear on the street. I just change the front and rear at the same time. The MT-21 slides offroad on anything at all, I have never found anywhere but the street where they grip. They are loose on fire roads, sand, rock, desert, single track, etc.

I also use the Dyna beads for velvet smooth balancing. Really seems to make everything smoother, less vibes at the bars, seat, feet, etc.

Good LUCK!!!!

Run rim locks. You will be sorry someday if not. The MT21 rear I love for a dot legal dirt tire. My problem with the front, on all bikes tried, is the knobs tend to wear every other one as if hopping. This makes for bad vibes once worn down a little. I now have to change the front whenever I change the back. Unless ridden on fire roads or dirt, this tire will wear funny on the front.

The rear is the best I have found for my conditions when DSing around here.

I talked to a guy that ran the Baja on a 650R and that is what they were running. Even his mechanic told me to stuff the 140/80-18 in there. Supposed to be one of the toughest tires. I like it. Running 20 psi in back.

I christened my MT21 yesterday, first bush outing.

Not bad on gravel but when I got to an steep uphill road covered with golf ball - tennis ball size rocks, it was pathetic. Just seemed to bounce all over the place with no traction at all, I was ridin with a bud on a WRF 450 and he had a Mich AC10, my old tyre incidentally and he creamed it. I had to turn around and get a run up to build momentum before I could climb it with lots of wheel spin.

I suppose we are stuck in that compromise where you can't have the best of both worlds.

Didn't think of dropping the pressure, don't even know what it's set at.

ran the mt21 and could not get it to hook up no matter what i did. had to take corners at least 20 mph slower when off road. only got 1200 miles out of it. went back to dunlop 606 and have been very happy 1600 to 1750miles before replacment. jmo.

Thanks everyone! I think I will drop the psi down when off road, on road they work great at the 20 psi so Ill run that. When I bought the XRR PO had Kings tires on it and I wanted something more agressive that and the rear was shot. I was in Socal at Chaparral and wanted to try the Dunlop 908 Rally Raid but couldn't see spending $85 and change for the front and $130 for the rear when the Mt21's were around $88 each.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now