Will a 120/90R-18 Fit a 2000 WR400??

120 will fit, HOWEVER, extra traction, although quite cool, is not always what you want.

In the olden days, the giant Terra-Flex meats and the 150/80-18 Metzlers were fitted onto the open bikes. Now, those bikes use the 120's AND they put out 15HP more. My 1980 YZ465 put out 42HP.

My 91 CR250 put out 42HP. That too used a 110 tire.

Food for thought.


'99 WZ/YR (you choose!) with ALL YZ mods, de-octopused, DSP Doug Henry airbox w/ velocity stack, FMF PowerBomb header, Stroker SX-1 silencer, SS front brake line, forked over by Pro-Action (and then fixed by me), OEM YZ tank, IMS YZ seat, gray wire severed, carb mods by Jim Dean, Andy in OZ, & Sir "Taffy" from Jolly Old England, AMA, NESC, and I use MOBIL 1 Oil, with ZERO problems.

Looking for a new tire soon and I was thinking about going a little wider.

Thinking about a Dunlop 606, any advice??

I would recomend a 110-90-18 or a 100-100-18

While the previous replies to this post are generally speaking quite correct, the Dunlop 606 in 120/90-18 is an exception. I currently run a 606 on my WR400FM and it is actually smaller in both width and height than the Dunlop 739 in 110/100-18 that came on the bike stock. Why? Beats me. You would think Dunlop would be consistent with sizing. Perhaps sizings are a little different for DOT tires. FWIW, the 606 has about the same straight line traction as the 739, is much more rock resistant (not counting the 739 AT), lasts 4 or 5 times longer than the 739 (including the AT). The 606 does not have the same abount of grip when leaned over, although it slides very predictably. Hope this helps.

hi all ,

i'll be watching the replies on this one.

my y2k wr400 has a mich comp3 130/90/x18

yes 130 from new , yet the manual states

a 120/90/x18 is the standard size .

i'm also thinking on a dunlop 606 120/90/x18

or a pirelli mt21 same size .

i personally dont rate the mich as its too

soft for dual sporting , i hear the dunlop is

about the best dual sport tyre you can get ?.



portsmouth england

WARNING: The MT21 sizes run small. Go one size up than you want - some go two.

- Sean

Thanks for the response. I'm putting on the Baja Designs kit and am going with the 606s. Thanks again

By the way the dealer looked in the catalog and said the 606 doesn't come in a 110/100. Wonder why?

I put on D606's front and rear about 300 mi ago, have since ridden in all kinds of terrain and have experimented with various tire pressures. The bike is completely different with these tires. Street feels amazing - smooth, predictable. In loose stuff though I find the back end slides more. Once I got used to it I was able to compensate but it definetly slides where the 739 didnt. A guy that has followed me for 70 mi of trails with the 739 noticed something was different right away, that the rear was sliding. Was running 16 psi. Soft stuff and mud on trails seems to work fine.

It's a mystery to me as to why various brands and models of the same size are obviously different! Isn't 120mm the same everywhere :) I guess not.

I have to agree with Kevin, sometimes a wider tire can be appealing, but there are good reasons why you don't want the extra traction. In mud/sand/snow a wide tire won't sink in as much therefore you'll ride on the muck not "in" it. It will also cause more strain on the tranny/clutch--not much but over time it may prove to cause more wear. In loose turns, it will be harder to swing the rear end around by sliding.

I've been running a Vee rubber 100/100 rear with decent success.


'my y2k wr400 has a mich comp3 130/90/x18

yes 130 from new , yet the manual states

a 120/90/x18 is the standard size.'

:) Don't know why, but Euro bikes have bigger tyres, softer springs and different fork ride height than US (taller fork ride height might be to offset taller profile rear tyre) :D


'00 WR400F, YZ Timing, FMF Power Core IV2, Renthal Bars.

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