Larger Section Front Tyre...

[bigiain]

i dunno about roy nexus6' idea of the 190, jacking up the rear to make it steer quicker then putting a 190 on will not only slow the tip in and change of direction down markedly, it will probably make it feel like it wants to tuck on tighter corners. i'd definitely stick with std sizes, but that's just my .02c

You're probably right, but I reckon if he likes the idea of a 190 rear, he should certainly try it out... I like the idea of skinnier tires, and have run a 110/70 front 150/70 rear combination in the past (I'd have that on now except I left my last tire change too late to special order in those weird sizes - stock is a 120/70 160/60 combo on my M750...)

A 190 will definitely steer differently to a narrower rear tire as you point out, but its unlikely to be _dangerously_ differently - so worst case is probably that he'll be out the price of a new tire - I'm sure many people have wasted more than the few hundred dollars a replacement rear tire costs on cosmetic stuff that hasn't worked out long term...

A more likely dealbreaker is that I'll be a little surprised if a 190 rear doesn't foul the chain. I know there's not a great deal of clearance between the stock 170 rear and the chain on a M900 of the same vintage as my bike (1999) - I've heard of people fouling the chain with some brands of 180... Unless the newer bikes run a noticeable wider chainline I don't think a 190 is gonna fit.

big

[Super T.I.B]

A more likely dealbreaker is that I'll be a little surprised if a 190 rear doesn't foul the chain. I know there's not a great deal of clearance between the stock 170 rear and the chain on a M900 of the same vintage as my bike (1999) - I've heard of people fouling the chain with some brands of 180... Unless the newer bikes run a noticeable wider chainline I don't think a 190 is gonna fit.

big

Just ask mmick.

I'm sure he knows something about too wide a tyre, fouling your chain deal. 

[CairnsDuc]

I asked my dealer about fitting a 70 profile tyre, and he advised they do it automatically now because of the extra protection it offers to the rim.

[Spider]

ah...since it seems decided that 70 is the way to go in this case (I have a 70 on the friont and am replacing with the same next week)

If my m1000s has a 190 on the rear - when I replace (probably a month or 6 weeks depending on touring trips etc) should I try a 180 on the rear?

I feel a bit stupid getting into the finer details when the pilot needs sop much work...but I suppose every bit helps.

[goldFiSh]

If I recall correctly, the stock size is a 180. I would take it back to stock and see how it rides...

[Spider]

should have thought of that - it was a 180/55 rear!

thanks!

I'll do that 

[dragonworld.]

The "60" series tyre has a rounder profile with approx the same amount of rubber on the deck whether upright or at lean. The "70" actually gives a better footprint at lean angles.

I dunno 'bout the reasoning for fitting a 70 series tyre as to protect the rim as being that valid, I rode on a 60 series front on my FZR (243kg dry from memory) and never damaged a rim. If the tyre pressures are correct there shouldnt be a problem. The 60's tyre is actually a lot stiffer and has LESS movement in the sidewall.

[goldFiSh]

should have thought of that - it was a 180/55 rear!

thanks!

I'll do that 

Let us know how it goes. I'm sure you're going to notice a pretty big difference

[bigiain]

I dunno 'bout the reasoning for fitting a 70 series tyre as to protect the rim as being that valid, I rode on a 60 series front on my FZR (243kg dry from memory) and never damaged a rim. If the tyre pressures are correct there shouldnt be a problem. The 60's tyre is actually a lot stiffer and has LESS movement in the sidewall.

I completely agree with your logic, but you've gotta go with the real world reports - lots of people (me included) have dinged rims while running 60 profile front tires, almost _nobody_ reports rim damage with 70 profile tires (at least not without _serious_ unusual circumstances).

I've heard suggestions that the rims Ducati fit are made from noticably soft metal - perhaps thats why your FZR coped better? The other possibility is that the higher weight of the FZR required higher air pressures - a ~180kg Monster only asks for 30.5psi (2.1bar in the '00 owners manual), I'll bet the FZR ran closer to 40psi...

big

[dragonworld.]

I completely agree with your logic, but you've gotta go with the real world reports - lots of people (me included) have dinged rims while running 60 profile front tires, almost _nobody_ reports rim damage with 70 profile tires (at least not without _serious_ unusual circumstances).

I've heard suggestions that the rims Ducati fit are made from noticably soft metal - perhaps thats why your FZR coped better? The other possibility is that the higher weight of the FZR required higher air pressures - a ~180kg Monster only asks for 30.5psi (2.1bar in the '00 owners manual), I'll bet the FZR ran closer to 40psi...

big

Yep Ian, I used to run 36 in the front. Yamaha reckoned 40psi but I found that was waaaay too much. 

There are a lot of variables in this discussion I know but in my experience with bike training where we used to check riders bikes over pre course, it was almost without exception that rider DIDNT have enough air in their tyres. 

Also taking into account that some tyre gauges are pretty rooted and inaccurate!! Particularly the ones at servos.

That in itself is not really a problem so long as the rider uses bike feel and tyre appearence to judge whether the pressure is close to correct and then use the pressure reading as a yardstick.

[loony888]

big, i wouldn't say fitting a 190 is dangerous, probably the opposite, as it will make the handling slower and docile, but, the 190 with jacking up the rear will definitely make it handle strange compared to a stock set up. good point about the chain clearance, my 888 with a power 180 barely fits, and i mean barely!.

dragonworld, i think the fact there's less flex in the sidewall is most of the problem, the force is transferred through to the rim, which are notoriously soft, rather than being absorbed by the larger more compliant sidewall of a 70. my old 748sp had a 60 std and i dinged it, dunno how though, i didn't remember hitting a pothole.


paul.

[monstermick58]

Some thing make the beast with two backsed up there, see my reply in the identical post




                                         Mmick