Rear tire size for '83 ATC250R need opinions

[D Rock]

I need your opinions in what size tires to buy for my 250R. I have 18" tires on it now and I'm running stock gearing (13 front/42 rear). I want to have more top end speed and not have to ride in 5th gear everywhere. I was thinking about getting 20" tires and buying a 14 tooth front sprocket. I thought this would get me closer to what the stock setup was with the 22" tires. I thought a set of 22" tires might make it look bad. What do you guys think I should do? I don't want to order 20" tires and wish I bought 22" tires.

[Enginerd]

I need your opinions in what size tires to buy for my 250R. I have 18" tires on it now and I'm running stock gearing (13 front/42 rear). I want to have more top end speed and not have to ride in 5th gear everywhere. I was thinking about getting 20" tires and buying a 14 tooth front sprocket. I thought this would get me closer to what the stock setup was with the 22" tires. I thought a set of 22" tires might make it look bad. What do you guys think I should do? I don't want to order 20" tires and wish I bought 22" tires.

Maybe you should consider keeping the 18" tires and just buying a new 15-tooth front sprocket. The 18" tires lower the trike, and their shorter sidewall resists rolling over in turns. These make the trike handle noticably better than tall 22" tires. Besides, a sprocket is much cheaper than new tires.

By the way...I am kind of biased. My 84 has 18" turf tamers(Check my Sig pic) and it handles so much better than it did with the 22" balloons it had previously. Its amazing!

[D Rock]

Thanks for the reply... I just think the 18's look too small on the trike. I would never put 22’ balloons on. I decided to go with 20" Kenda knarly's from DK & a 14 tooth.

http://www.denniskirk.com/jsp/tpl/tire/atvtireproduct.jsp?skuId=&store=&catId=&productId=p653248&leafCatId=&mmyId=[/URL]

I think these tires will still keep the bike low, but not too low and still have rigid sidewalls. These are sport tires not balloons.

I know by going from a 18" tire to a 20" tire will only get me an extra inch of ground clearance but I think it will be nice.

I used this online calc to get things figured out. That is if it's correct. From what I can tell with the 13/42/22" set up you'd get a top speed in 5th gear of 58 mph (seems a bit high but for example only) With a 13/42/18" in 5th gear top speed is reduced to 48 mph. A 14/42/20 would be right around 57 mph which is close to the stock set up. The 15/42/18 would get around 55 which would be close enough to the stock setup and it'd be cheaper like you said.

Link to calc:

http://home.earthlink.net/~gellett/250r.htm

Too late now! I really don't care for the 18's that I have. The previous owner cut every other row of tread off and had studs in the tires at some point. Again like I said I just feel like the bike is too low with them as well. Having the stock setup with the 18's just suck in the trails and in the open is my feeling.