18" and 20" tires

[hellshot00]

I made a post a while back considering 18 inch back and 20 inch front tires well i went out and did it and finally got a little ride in yesterday. I am happy with the mod it does catch many more rocks but with the armadillo skidplate there is no problems what so ever. There is a slight gain in bottom end too not significant but noticeable. All in all i am quite happy with them.

[trx400Rider]

Good to hear man. I was considering that combo, but decided the 22s on front and 20s on back better suited me. Although I really like the way 18s look on 8 inch rims.

[hellshot00]

yeah the looks is really what got me to even consider the idea but i have 0 complaints

[slightlybent47]

You need a gear change to get back to where it was with the 20’s on there. I went from a 39 rear sprocket to a 36 when I made the tire change. The low end torque you noticed was form the smaller tires that dropped your top end speed. You should be having trouble keeping the front end down with the smaller tires.

This calculator should help.
http://home.earthlink.net/~gellett/400ex.htm

[BenHonda400ex]

Originally posted by slightlybent47
You need a gear change to get back to where it was with the 20’s on there. I went from a 39 rear sprocket to a 36 when I made the tire change. The low end torque you noticed was form the smaller tires that dropped your top end speed. You should be having trouble keeping the front end down with the smaller tires.

This calculator should help.
http://home.earthlink.net/~gellett/400ex.htm Sorry but I don't really understand that, I thought if you had a smaller tire you would go faster? And bigger tire would be heavier slowing you down. That's confusing :confused:

[slightlybent47]

It’s not how fast the tire turns, it’s how much distance you travel for one revolution of the tire. An 18” tire travels less distance then a 20” every time it turns.

Use the calculator and change the values on the calculator like the tire size and sprocket size and then hit calculate and you will see how it changes your speed per gear your in.

Play with it and see what you learn. Then get back to me.

[hellshot00]

im aware of the more acceleration no top end it was actually why i did it haha. Where i ride is all trails and having top end isnt really worth it and with the tires i can still keep up with everyone quite easily and have fun playing with power