Tire size affecting gear change?

bean86 · #1 (**permalink**) 02-12-2008

Hey fellows. I just bought bought some 18 inch mx maxxis razors. I had 20 inch shredders on it and I was wondering how much it will gear it down compared to a gearing change. I am running stock gearing now and it already has great bottom end so i was wondering if i need to make a gearing change to keep it about the same. Thanks

vspec · #2 (**permalink**) 02-13-2008

Your acceleration will go up,and your top speed will go down some.

bean86 · #3 (**permalink**) 02-13-2008

Yeah but I was wondering if any knew of what the tire size change is equal to changing the gearing. say like is it about going down one tooth on the front sprocket or what?

lt250racer · #4 (**permalink**) 02-13-2008

Here are a couple of things that may help......

((M.P.H. x Gear Ratio) / Tire Diameter) x 336 = RPM_______

Sprocket gear chart......
http://pinnedoutracing.com/gearratiochart.aspx

ky 2stroker · #5 (**permalink**) 02-13-2008

i'd try going up one tooth on the front sprocket

fastR of puppets · #6 (**permalink**) 02-13-2008

id say its about the equivilent of droppind one tooth, but your gunna love those tires, ive used 18 inch holeshots, tamers, kendas, and razr mxs, and the razrs have always been the best, they slide so nice on turns, and hook up amazingly well for an 18

strokeittwice443 · #7 (**permalink**) 02-13-2008

ive got 18s on my 450 and went up one tooth on the front sprocket still felt like there was some top end missing, or maybe thats just the true feeling of a 4-stroke. idk.

1882 · #8 (**permalink**) 02-13-2008

I went from stock 20's to 22's on this 'sumbitch along with going from 16/40 to 16/35. Combine this with 82 rear wheel HP and what did I get? Triple digit top end, daddy likes!

bean86 · #9 (**permalink**) 02-15-2008

Well i glad to hear you all like those tires. I was going to go with holeshots then when i saw that they wanted 240 for rims and tires and only 160 for the razors I decieded to switch. Also i have heard nothing but good things about the razors so i am excited to use them. Just wish it would fricken warm up outside. I think i will try the gearing where its at and then make adjustments if need be. I was just needing to know what to change. thanks