I own a 2006 Suzuki Eiger manual and I've been contemplating upgrading from the stock Dunlop tires to something a little more aggressive. I would like to have a new set of rims as well just for a convince standpoint where I can swap out the tire packages with ease depending upon my chosen riding style.

I've been reading where putting a 26" tire on my particular machine may result in a loss of power unless I did some other performance modifications such as jet kit, air filter, and/or exhaust. I might consider a jet kit and filter, but certainly not an exhaust system. What I do not completely understand is why this is the case if you were to utilize an aluminum wheel that is substantially lighter than the original. Is it just the fact that the ATV is turning a larger diameter tire? Would the weight savings of the aluminum wheels compensate for the larger diameter tire? Also, it seems that people like to upgrade to a 26" or 27" on the Eiger for the added ground clearance of +1 or +2, but that math doesn't seem right to me. If 26" is the diameter of the tire, then it seems that you would only be gaining 1/2" by upgrading from 25" tires.

If I am correct in saying that 26" tires would only gain me 1/2" of GC, then I'm not sure if I would choose to perform that upgrade, but I might upgrade to aluminum rims and 25" tires if I could gain a little extra horsepower.

Help me understand the affects of wheel weight and tire diameter please so I can make the right decision.

 

well the diameter vs ground clearence is right. for every inch of tire diameter, you'll gain half an inch of clearence

 

The ground clearance depends on the tire. I stayed at my stock size, 26", and i still gained an inch of clearance. Look at my swamplites, and see if you like them, They are a good aggressive tire, that works excellent in mud, snow, rocks, and hardpack. If you went from a 25" dunlop, to a 26" swamplite, you would gain quite a height increase

 

I agree with v2rider, different tires seem to have different diameters even though they have the same size written on the side. When I put my three quads next to each other on the trailer my 2002 sp 700 with 25" good year rawhids are actually taller than my 06 sp 800's 26" PXTs. And my 04 500 25" badlands are just small. I just got 27" mudlite XTRs on 14" SS wheels and they are close to 2" taller than stock 26".

If you stayed the stock diameter and went a size larger in width that would be enough with an aftermarket tire. May I sugest the new mudlite XTR. Go to ITP and read the magazine reviews. Dirtwheels sold me!

 

trentmh,

You are right about sizes. You only gain 1/2 clearance for every inch. So to get some real world clrearance advantage a 27-28" tire would be great but power suffers greatly. Even if you have the power to turn them it will never be like stock. Power does not make up for gearing. If you go from a 25-26 it would not make much sense for the simple fact of the power loss. Most do it because it looks cool and some because of the thicker tread but if you dont have the power to push the bigger tires then it would be a big waste of money and it would also make you look stupid getting stuck in the mud and you cant turn them let alone the stress that it would cause on the drive train. In a way getting lighter rims will make up for some of the tire weight but most 26" tires with agressive tread will easily outweigh the savings of the lighter wheel. Also its the rotating mass that takes power. Yes you are saveing weight but its not where the weight needs to be lost. The weight saved is closer to the center of the unsprung weight. Not much centrifugal force near the center of the wheel. You need to lose the weight further out because of the centrifugal force. Its easier to move more weight near the center then it is the further you go out from the center.

The Swamp liter are pretty light. The 25" would work fine because they are a tall 25 but they dont have the thick tread in the 25" tire. I had 25" Mud Lite XL"s. These were agressive and heavy. It was hard to wheelie and in thick mud they were harder to turn. Now with the 25" Swamp Lites it wheelies without struggle and turns the tires like they were stock. I did not change size much but the weight was huge and power suffered because of it.