what gear ratios?

[diggy]

Although its not a super single, I have a tzr250 chassis with a heavily modded yfz450 motor. What gearing is everyone using? I haven't ridden during a track day or race weekend yet, but am getting close to finishing it up. Right now I have a 15/36 on it. The gearing calculator I have gives a top speed of 109 which seems to be a little low. What recommendations does everyone have?

[Kris VanOrden]

Which track?

[diggy]

Seems a little moot. It's not like these bikes are going to go 140+ so there's no use gearing them like that. I was just trying to get an idea of ranges. Seems like pretty tall gearing will top out at 120 or so. For the most part 120 is slow for any track, so I was just wondering if the bikes can pull the taller gears and still be functional. But to answer your question, I'm planning on using the bike in socal, so it's streets of willow and possibly a california speedway (autoclub) track day. Since the liter bikes can go 170+ there, the ~55hp of a super single won't get you anywhere near appropriate gearing.

[Kris VanOrden]

I was going to run some taller gearing because i Hope to be faster in the corners that will keep speeds up. 109mph just doesnt seem like enough at all.

[diggy]

yeah I know. I've been putting this bike together, and from what I have right now (15/36) I'm at 109mph
.
When you consider that stock gearing on an 06 yz450f is 14/51, 15/36 looks weird! When I ride the bike (just on the street working out bugs) its not really impressive at all. The gearing is just SOOOO different than the wheelie machines that motocrossers are and I feel that at 109mph at 10500rpm I'm still under geared.

I don't think that I can get smaller than a 36, so I might check out a 16, but probably a 17t drive sprocket.

Do you have a gear calculator? I have one that is pretty good if you need one