New radials on the '85.

[mzbk2l]

Back in 2007 or so, I bought a rear wheel on ebay and had Kosman do the 17" conversion, but I've never gotten around to putting a tire on it... the ME880s that were on the bike seemed to wear so well, it just never bacame a priority. A nail in the tire on the Hayabusa finally forced me to buy some tires last week, so I went ahead and got four - two for that and two for the Max.

I went with the Michelin Pilot Road 3's for both bikes; the Vmax got 180/55ZR17 for the rear and 110/80ZR18 for the front.

Because of several comments on the forum, I was curious as to the effect of mixing a radial and a bias ply tire. I swapped the front only and went for a 20+ mile ride with a RP3 up front and my old Metzeler ME880 on the rear. All I noticed was a VAST improvement in handling. I did not notice any issues with quirky or squirrely cornering or riding. I was too anxious to get the rear mounted to go any further, so that's the end of my contribution to the debate on mixing radial and bias ply tires.

I came home and installed the Kosman wheel (which I had already mounted the RP3 onto) and took it out again. WOW! It's like riding on a different motorcycle. It sounds the same, but almost no part of the handling feels like my Vmax. Taking a curve on the ME880s, the bike always felt like it was "tipping over" as I leaned into the curve. With the RP3s, it's as stable as if it was on rails. If I lean a little bit, it holds that until I lean more or straighten out. If I lean more, it holds that angle. Completely different from the old tires. One oddity (to me) is that the handlebars almost feel "locked" into the straight position while I'm cornering. The slightest lean absolutely instantly sends the bike where I want it, but those bars do not want to let me give any input the way they used to with the old tires. The bike turns much more quickly and precisely and confidently, but it's a different method of riding than it was on bias ply tires.

Another great difference is the way it handles bumps in the road. Many exits here have the raised dots as you move over into the exit lane, and on the ME880s, it was "hold on for dear life" time as you crossed bumps like that, or a shift in the level of the pavement. The RP3s hardly notice such things - the bike now crosses smoothly with no side-to-side shifting as it goes over. Much more confidence-inspiring to ride.

The only negatives (or probably neutrals) are 1) that I'm not sure I like the look of the wheel yet, and 2) that the bike no longer feels "planted" in the upright, straight ahead position. I used to be able to shift my hips or butt all over the place and the bike just motored along the path it was on. It's so much more responsive now that rearranging myself on the seat has the effect of moving me as if I was starting to corner. That's going to take some getting used to.

Overall, I'm extremely pleased with the results and kind of bummed that I waited so long to do it!


Some before pics:

And as it sits now:

P.S. - no swingarm clearance issues at all. In fact, I was able to move the washer back to its stock location, after 10+ years of sitting in the differential making room for the 170mm cross-sections of the numerous ME880 tires the bike has been wearing.

 

[srk468]

I think it looks really sharp personally, did you notice an increase in cruising rpm with the radial? I have a Kosman 18x6 on mine with a 200/50-18 and the height is practically identical to the old 170 Shinko I used to run plus it fills up the rear fender nice. I think it looks awesome and with the better handling you'll get used to riding it and adjusting your position.

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[DMAN999]

Great Info on the Kosman Rear with a 180 fitting with a Stock Swing Arm and about running that Radial front w/a Bias Rear.

What is the width of that Kosman Rear rim (stock width is 3.5") ?

 

[m-cman]

Just for info, if you have the 18" Kosman the 170/60 is the widest that will fit a stock swingarm and does require the washer swap.

 

[Diablotin]

I had the same feeling with the PR3 after installing them. I exactly got the same size. The 180/55 is way better than the 190/50 on a 5.5". And the 110/80 looks like it was meant to be for the front.

How many psi did you put? 38/42?
I use this pressure but I find it a bit stiffer on front.

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[mzbk2l]

I think it looks really sharp personally, did you notice an increase in cruising rpm with the radial?

You know, I hadn't even paid attention to that. I've been so busy feeling out the tires and watching how I ride (I'm still under 100 miles) that I missed watching for something so basic. I'll have to monitor that in the future.

What is the width of that Kosman Rear rim (stock width is 3.5") ?

I went with the "standard" 5.5-inch conversion they do, as mentioned on the old vmaxoutlaw site.

I had the same feeling with the PR3 after installing them. I exactly got the same size. The 180/55 is way better than the 190/50 on a 5.5". And the 110/80 looks like it was meant to be for the front.

How many psi did you put? 38/42?
I use this pressure but I find it a bit stiffer on front.

Thanks for the feedback on your impressions of the handling - it's nice to know I'm not out in left field on that.

I haven't played with the pressures yet to find out what works best... I set them both at 40 for the break-in, but I'll adjust a bit from there.

 

[DMAN999]

I went with the "standard" 5.5-inch conversion they do, as mentioned on the old vmaxoutlaw site.

Thanks, that's what I figured but I wanted to make sure.
If I ever go radial it will probably be that same setup.
I just can't see spending almost as much on a set of Rims and a new swing arm as I paid for my whole bike.

 

[Fire-medic]

Thanks, that's what I figured but I wanted to make sure.
If I ever go radial it will probably be that same setup.
I just can't see spending almost as much on a set of Rims and a new swing arm as I paid for my whole bike.

You can just buy a used Kosman and re-use the stock front, for two tires, which you may have to replace anyway, and 'Bob's yer uncle.' New swingarm not required, unless you want a fat tire, or want to drag-race w/ a longer one.

I still think the #1 change for a VMax is radials (that would be, "two of them.") because of the improvements in handling.

 

[Diablotin]

I had the same thoughts. I will stick with that pressure for few more weeks too as the tire still have the pins.

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[mzbk2l]

I think it looks really sharp personally, did you notice an increase in cruising rpm with the radial?

This morning on the way to work I kept trying to upshift, only to find myself already in 5th gear. I'm guessing my ear is detecting higher rpms than I'm used to.

 

[DMAN999]

You can just buy a used Kosman and re-use the stock front, for two tires, which you may have to replace anyway, and 'Bob's yer uncle.' New swingarm not required, unless you want a fat tire, or want to drag-race w/ a longer one.

I still think the #1 change for a VMax is radials (that would be, "two of them.") because of the improvements in handling.

That's exactly what I was saying and why I asked the questions I asked.
Kosman 5.5" rear with Stock front rim and I'd be all set for a fairly reasonable price.
That's ALOT cheaper than 2 new rims plus Swing arm Plus whatever else it would take for those wider rear tires to fit.
I don't know if or when I'll do it but it has me thinking.

So who has a 5.5" Kosman they want to sell cheap ??? :rofl_200:

 

[one2dmax]

The kosman is the cheapest way to go though by far not the best for optimum performance (handling). A 180/55 will normally fit in the stock swingarm (even with our Carr wheels).

 

[srk468]

The kosman is the cheapest way to go though by far not the best for optimum performance (handling). A 180/55 will normally fit in the stock swingarm (even with our Carr wheels).

Sean is right, Kosman's are heavy but so are most aftermarket wheels with the exception of the Carr's and the dynamags..

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[Fire-medic]

'srk468' said, "Kosman's are heavy..."

Think of it as a flywheel, storing energy to release for that dazzling-burst of acceleration! I bought a 5.5" x 17" Kosman on here and I am very satisfied w/it. I went w/Bridgestone BT-023's and am pleased w/the characteristics of the rubber: braking, acceleration, transitions, all far-better than any bias-ply rubber I've used in 20 years of VMax ownership, and I always bought premium rubber. When I first got it, I was ordering a new K491 Dunlop about every 4-6 months, and I wasn't drag-racing. I just rode them that-hard, and that-far. I did the transition to radials for <$800, buying a used Kosman rear, two new Bridgestone sportbike tires (BT-023's) and using the stock front. If I ever get-around to it, I may have my front altered to a wider wheel, 3.5" and I expect to be even happier w/the bike's steering & braking, since the footprint will allow a 120 then instead of a 110. Or, if you want to maintain a 'lighter' steering feel, stay w/the 110 and gain precision, as the 3.5" width is optimal for the 110 width tire.

 

[m-cman]

The kosman is the cheapest way to go though by far not the best for optimum performance (handling). A 180/55 will normally fit in the stock swingarm (even with our Carr wheels).

The offset must be different between the Kosman and the Carr's. My 18" Kosman had to have the washer swap even with the 170/60 tire.

 

[mckzx9]

I put the carr's on my bike last year. By far the best thing I ever did to my bike. Just wish I would have got the 3" extended swing arm. But like you said its like driving a different bike. It's hard to explain. You have to feel it for yourself.
Warning if you can't afford radials do not drive a friends vmax with radials. That's what happened to me. Thanks Garrett LMFAO. :rofl_200:

 

[one2dmax]

The wider front will be a benefit. Even the heavy RC's (heaviest wheels) will make the vmax see a benefit from the Radial tire.