Considering Kosman 18" Rear, 19" Front

[Glen007]

I'm considering going through Kosman to have my rear converted to 18x5.5 and the front to 19x3 and likely running 180/55r18 and 120/70r19 tires. I'm mainly looking for the best handling option for radials while not breaking the bank. Also, I've heard that some people have run the 180 Metzeler's just fine without notching the swingarm, while others have cautioned not to. I'm currently running a 170/80b15 (Shinko) and it seems like I still have enough room to go 180, though this is mere speculation. My question would be, does this seem like the best bang for buck when converting to radials or are there better recommendations?

Thanks,

Glen

 

[m-cman]

The probable reason you hear different reports on the 180 is having either 17" or 18" rear wheels. I have a 18" Kosman and the largest tire I can fit is a 170/60 and it requires a washer swap. The 18" wheel goes farther into the swingarm and it narrows the farther you go into it. A 17" wheel doesn't go in as far and therefore the swingarm is wider at that point, allowing a wider tire.

A 19" front wheel may present problems we are not aware of since I haven't heard of anyone doing that. Fender clearance being one. I'm curious if anyone has any input on that. :confused2:

 

[Glen007]

Good to know about the rim diameter and the swingarm narrowing, I hadn't thought of that. The 120/70r19 would actually be a hair smaller so I think I should be okay there (25.61 vs stock 25.8 diameter). Does 170/60r18 & 120/70r19 sound okay handling wise?

 

[donnelly317]

Do you know how much it will cost to punch the rims threw kosman???? I ask because why not do the rear to a 17" and buy this kosman front 17" off Sean for 450... then you will have the best handling option.. the big plus is the avalablity of radial tires and all the different manufactures and compounds they make in 17... plus tires are usually cheaper in 17

http://vmaxforum.net/showthread.php?t=15229&page=5

 

[gamorg02]

Check the tire manf as they may want a 3.5" to put a 120 front

 

[Glen007]

Ballpark estimate is $550 per wheel + shipping, but I emailed Kosman earlier today for a specific quote for what I want. I just checked a Metzeler tire range chart and the rims permitted for the 120/70r19 are 3.0-3.75" so I should be good there. I didn't really have a reason for the 18 rear and 19 front other than trying to find a setup close to the stock ply tire diameters and of course filling out the fenders. I've seen pictures of the matching 17 rear and front setups and it looks a bit odd to me, maybe better with lowered fenders...

 

[donnelly317]

Got cha.. just throeing it out there. Exactrep sells this front fender. Im getting it because I just got 17" for mine. Fills it out nice!

http://www.exactrep.com/acatalog/--Angular-17---Front-Mudguard-66.html#SID=15

 

[Redbone]

Got cha.. just throeing it out there. Exactrep sells this front fender. Im getting it because I just got 17" for mine. Fills it out nice!

http://www.exactrep.com/acatalog/--Angular-17---Front-Mudguard-66.html#SID=15

What size 17" tire are you going to run?

 

[donnelly317]

Pm sent

 

[[email protected]]

18 rear and 19 front is a good looking combo. I think that is what custom max has on his bike. I had a picture of a red max with RC wheels in 18 and 19. Sean was working with jedi on converting some harley wheels awhile back. Not sure what happened to that.

Not as many tire choices as 17s with that combo but, the vrod had those sizes so there will be options.

A 190/55/17 is damn close to oem size. The front does look odd if you don't lower the fender. If you mount a usd front end it blends in nicely.

 

[1967vmax]

If i could do it over again i would just save up an buy Morleys wheels an swingarm. I did go with Rc wheel and i do like them but they are heavy also remember when you start doing the washer swap you are affecting the tracking of the bike as well as the engagement of the rear diff , with my Rc 18" front and rear my bike tracked to the left.

 

[one2dmax]

The Kosmans or any other wheel out there for that matter (almost any other anyway) are going to be heavier then our Carrozzeria's. We do sell the RC's and have sold the 18/19 combo before and it works ok. Still, they are heavier. You can fit up to a 180 on the rear depending on the wheel offset.

Please verify if Kosmans' pricing is still the same. I was led to believe his pricing had gone up quite a bit. Of course our Carr's are higher cost but you can resell your wheels to help offset that some.

Sean

 

[aj660]

Or you can do the same as me... I'm going to buy a 17" rear wheel and radial tires. I'm going to keep my stock front rim because I don't want to spend too much right now. The Kosman 17" rear (180 55 17) and stock front rim (110 80 18) makes the most $$ sense for me.

 

[Glen007]

So the more I look into this the more it makes sense to have a notched swingarm to hold a 180/55r18 as I haven't been able to find any other 18" tire packages using a 160 or 170 wide tire.

 

[Rollie]

Continental makes a ContiRoad Attack 2 in size : 160/60 ZR 18

 

[m-cman]

So the more I look into this the more it makes sense to have a notched swingarm to hold a 180/55r18 as I haven't been able to find any other 18" tire packages using a 160 or 170 wide tire.

When I bought my tires, the only manufacturer with a 170/60-18 tire was Dunlop. Not sure if they even have one now. However, several do have the 160/60-18. I will have to get that size when I replace my current rear. I also went with the 110/80-18 instead of the 120/70-18 with the stock front rim.

 

[1967vmax]

I also should have added that Sean made my swingarm and added the offset into the swingarm so it now tracks straight as an arrow.

 

[Glen007]

I would love a set of Carr's, but the price makes it tough to pull the trigger. After doing research on wheel and tire packages, I'm leaning towards having the rear only converted and running a 180/55r18 and 110/80r18. I called Kosman and they quoted $595 + shipping to convert the rear to 18x5. The price is awesome but I'd be without a rear wheel for 3+ weeks during the start of riding season. It would be great to find a stock wheel that's already converted in the same price range so that I can avoid the downtime. I've checked eBay and the forum thread, but no luck. I suppose I could start looking for a 17" rear, but that would probably involve a new rear end exchange to keep cruising RPMs reasonable.

 

[aj660]

I suppose I could start looking for a 17" rear, but that would probably involve a new rear end exchange to keep cruising RPMs reasonable.

A new rear end exchange? I guess I'm confused. There are many on this forum with 17" rear 180/55/17 and 110/80/18 front. I don't remember reading that anything needs to be changed. Your speedometer will be off a bit but that's pretty easy and inexpensive to fix.

 

[gamorg02]

I would love a set of Carr's, but the price makes it tough to pull the trigger. After doing research on wheel and tire packages, I'm leaning towards having the rear only converted and running a 180/55r18 and 110/80r18. I called Kosman and they quoted $595 + shipping to convert the rear to 18x5. The price is awesome but I'd be without a rear wheel for 3+ weeks during the start of riding season. It would be great to find a stock wheel that's already converted in the same price range so that I can avoid the downtime. I've checked eBay and the forum thread, but no luck. I suppose I could start looking for a 17" rear, but that would probably involve a new rear end exchange to keep cruising RPMs reasonable.

A new rear end exchange? I guess I'm confused. There are many on this forum with 17" rear 180/55/17 and 110/80/18 front. I don't remember reading that anything needs to be changed. Your speedometer will be off a bit but that's pretty easy and inexpensive to fix.

I have a 190/50/17 and a venture rear diff would be nice, but the accel is good as well. Sean might be willing to send kosman a rim on exchange for a fee.