Rear wheel modification for radial tire

[Newklear]

Hey All,

Another newbie question.......

Many of you are saying that on of the best things that can be done for the VMAX is to get some radials on it.

Surfing around a bit, I found SKRACING (skracingproducts.com) and Sandy Kosman who modifies the rear wheel to accept a radial. ($595)

1) Please educate me as to why the wheel has to be modified to accept a radial and why the stock one won't accept a radial. The parts guy at the dealership doesn't understand either.

2) Has anyone had this done by Kosman or anyone else?

3) What tires would you all recommend? 17" or 18"?

Thanks!!!

Newklear newbie

 

[DMAN999]

The problem is they don't make 15" Radial Tires that will work on our Bikes.
They Only make 15" radials for Very light , low speed Scooters.
So a 17" or 18" rim must be mated to our Hub so it can work with our Shaft drive AND fit a Radial Tire.

 

[ninjaneer]

you have to modify the rear, or replace it, because there is no radial that will fit the stock rim

search a little more and you'll find that many have as used kosman's services
http://lmgtfy.com/?q=site:www.vmaxforum.net+radial+tire

as far as 17 or 18, it's really up to you

Regards from my Taptalking Hercules Android

 

[srk468]

I had Kosman do mine, it's 18"x6" now and I'm running a 200/50-18 Shinko verge on it but you have to notch the swingarm deep to run that wide of a tire and its also preferable to extend it 3" for clearance on the brake side. I think you can run a 180/55-18 stock length and just minimal notching though. I prefer the look of the 18's because it fills out the fender nicer and it also gets you closer to stock height so your not turning a bunch more rpm's out on the road. I had to do a bit of work to get my wheel looking this nice but a Kosman weldup is more affordable than aftermarket wheels but it does add some weight, only way to get radials and be lighter is hookup with Sean for some Carr wheels.

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[m-cman]

I have a Kosman 18" rear wheel and it works well. The best bet would be the Carr. wheels from Sean but I couldn't afford those. I have the old version with the bolt-up construction. The newer Kosman's are welded. I prefer the 18" for looks and maintaining similar circumference so the rpm's remain close to the same. The 17" effectively lowers the ratio resulting in higher rpm at every speed. You can put a wider tire on the 17" as the swingarm narrows the farther the tire goes into it. The widest I could use is a 170/60-18 and it required a washer swap. The wheel offset also figures into the max size you can use. The Kosman offset is not as bad as some and the tire looks centered from behind.

 

[Newklear]

Thanks, guys......two more follow up questions......

1) To keep it simple (the KISS principle!) to go with an 18" without having to do anything, what size can I put on?

2) Do you have to do anything with the gearing with an 18"?

3) How about speedo accuracy?

 

[wildweasel_pt]

1- Don't know if you can even go with a 180 as swingarm narrows towards front
2- The rim gets bigger but tire profile gets smaller, do your math
3- Speedo comes from front wheel by cable

 

[mproy]

Before I had an extended swingarm I run a 180/55/18 on carr wheel with stock swingarm no problem.

 

[sdt354]

I've got about 4mm clearance on the left with a 180/55R/17. Stock swingarm. No washer swapping. http://www.tacomaworld.com/forum/tirecalc.php You might be surprised at the 17"
tires that will give you stock height. I like the lower profile and with the Venture drive it's
about stock ratio. With the OEM Pumpkin it brings the rpm's up in a bit. But you'll screem through the gears. It's true though that some added space above the rear tire might not look
appealing to some.

 

[davesax36]

My 190/50/17 requires the swap, loosening the final drive, and letting the air out of the tire to get the wheel on there. I don't even think going to the 180/55 will eliminate that stuff, but it would be pretty much stock height. I'm gonna do that next with some michelin pilot road 3s.

 

[Rusty McNeil]

180-18 fit fine with no washer swap when I had stock swingarm and RC wheel.

Didn't have to loosen/remove the diff to install. Just let all the air out, ,Vaselined the sidewall and forced it in.

200/55/18 and notched requires me to do the same plus loosening but not completely disengaging the diff. but the force required is way up there.

I think next time I'm either going to remove that plastic trim ring on the diff. or else trim it down with a dremel, it looks mostly cosmetic to me anyway at least for a garage kept bike.

 

[m-cman]

It appears based on all the responses that it is not only tire/wheel size but offset that determines fit. My Kosman has little or no offset so is closer to the left side of the swingarm and requires the washer swap with a 170/60-18 tire. Some can fit a 180 so their wheel must have some offset to the right. Or every bike is different with terrible production tolerances... :biglaugh:

 

[gamorg02]

i had kosman do a 17", they do amazing work.

you want the best wheels? tlak to sean though about cazz.

 

[davesax36]

So does the trim ring do nothing?

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[m-cman]

So does the trim ring do nothing?

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I thought it was there to help keep the area clean.

It is a pain to install a wide tire though. My 170/60-18 required me to let the air out of the tire and move a lot of stuff and still had problems.

 

[BGPKR]

I also plan on doing this toward the end of winter. I plan on using Kosman.

 

[sdt354]

I haven't herd of a Kosman weld failure yet. That old school stack of dime weld looks great. I've got the bolt together wheels and am doing cosmetic work on both this off-season. Stronger bolts are getting installed too. Possibly bigger bolts depending on how much meat is between them. I've got a matching set now thanks to Sean. If I had the $$ there would be Carro's front and back. They are very nice looking and light
Steve-o.

 

[m-cman]

I had my bolt-up Kosman powdercoated and polished the bolts and added an orange stripe to match the custom paint.