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14/43 vs 15/43

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I have a 2004 WR450. I'm trying to order my sprockets. My tire is a 160/60/18. I'm trying to see what would be a better gear. Using gear calculators at redline of 11,000rpm 14/43 gives a top speed of 110mph and 15/43 gives a top speed of 118mph. What I am mainly worried about is the difference in low end grunt between the two. I like some low end AND high end. I know I realistically won't be going more than 110 with a street hooligan, but I also don't know how realistic it is to pull a bike to redline in 5th with that gearing... Also, cruising at 70mph would either be fine?

Thanks,

Mike

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I have a 2004 WR450. I'm trying to order my sprockets. My tire is a 160/60/18. I'm trying to see what would be a better gear. Using gear calculators at redline of 11,000rpm 14/43 gives a top speed of 110mph and 15/43 gives a top speed of 118mph. What I am mainly worried about is the difference in low end grunt between the two. I like some low end AND high end. I know I realistically won't be going more than 110 with a street hooligan, but I also don't know how realistic it is to pull a bike to redline in 5th with that gearing... Also, cruising at 70mph would either be fine?

Thanks,

Mike

Wow you sure about 14/43 giving you 110mph, i myself reckon 15/43 would be struggling to give you that considering all the wr450f's i see around with 15/39 or 16/42 gearing etc.

To be honest though i don't think you could kill the wr450f's street hooligan side but more or less just make it a little bit harder for the rider :)

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Well, no I am not sure. This is theoretical based on optimal conditions I assume, this is the numbers I got from the gear calculator. Take in mind that my rear rim is an 18" which adds 4-5mph on the top end over a 17" rim with same profile tire. Also, I used redline RPM as 11000...I think that is what the WR450 is but maybe a bit less or a bit more...I have my grey wire cut some say this raises the limit others say it doesnt...I don't really know. All I know is that set up like it is now with stock gearing and dirt rims I hit the rev limiter anytime I want...This thing rips!!!

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I think what I will do is go with a 14/43...see how it works out, and if I need more I'll change to a 15 front for a bit more. The reason why I'm sticking with a 43 rear is because that is the smallest size they make in the IRONMAN sprocket. If I want more...then a few dollars and I can switch to the 15...or 16 even. Good plan???

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I run 16/41 with my DRZ 470. Dyno'd it puts out a bit over 50 Hp. It will go about 108 (true mph) and runs out of power at around 8,500 (HP peak). I doubt you could get a stock or even midly modded WR450 over 110.

110 on a SM makes for a very squireely ride. The only reason I run the gearing I do is because 1st is so short, I cannot get halfway through an intersetion without havinf to to shift. Also, fifth gives me a easy cruising rpm at 75.

Looking at ratios and seeing theroretical top speeds is pointless unless you have the power to pull it. Ratio selection should be based on how and where you ride. If you rarely hit the highways, are in a city, lower gearing can be more fun. If you race, selection is based on the number of gear changes between corners. Where I live, the lowest speed limit is 50. Back country roads, nary a driveway for miles, I can fly on at 90, so tall gearing for me makes sense.

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Well, the 450 I have has FMF Titanium Exhaust, Powerbomb header, JD Jet kit, fully modded airbox, Twin Filter, R&D Powerbowl, Zip Ty carb mods ,and YZ cam. It is pretty powerful. As far as high speed, I have a stabalizer to help with that. Will I be traversing the roads at 110mph...hell no. city will be 50mph...highway jaunts will be 70-85mph. I just want the bike to be capable of somewhere in that area. I know what you mean though...gearing without the power to utilize the gearing is pointless...which is why I'm thinking with a 14/43 I'd be able to use all of my gear available..and if I needed to widen the ratios I could go to a 15/43. I guess I'll just have to try it out and see.

Thanks for your input and help,

Mike

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