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Old 06-13-2007, 07:50 PM   #1
East Coast OP
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Question Klr Front Sprocket 15 Vs 16 T.

A quick question. My plans are to change to a 16t countershaft / front sprocket vs the stock 15T. Recently I was reading that some individuals consider this to be counterproductive. I ride 80% highway and am planing a trip in the near future. I was hoping to increase my top speed, decrease the RPM / vibration and increase the fuel milage. I realize the first gear will be fastish and the bike may be a bit less reponsive at some RPM and gearings.

My question is this - some say the top speed will be reduced due to less torgue produced with the larger sprocket? Seems unlikly to me.

example...... post number 17
http://www.klr650.net/forums/showthr...t=13293&page=2


opinions from anyone who had tried this....
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Old 06-13-2007, 08:14 PM   #2
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Quote:
Originally Posted by East Coast
My question is this - some say the top speed will be reduced due to less torgue produced with the larger sprocket? Seems unlikly to me.
Uhhh... you didn't actually say what kind of bike, though apparently it is a KLR. I never had a KLR, but on my DRZ in top gear (stock) it was torque limited rather than rev limited. So what limit is reached first on a KLR? If it's not rev limited, then no, dropping the revs even further (if it can't reach redline with the stock sprocket to begin with) won't make it go any faster.

How fast do you want your KLR to go? People usually gear them stiffer to reduce the revs for comfort and engine longevity, not to make them go faster. I'd think the engine would already push it as fast as the chassis and dualsport tires like it, already.

But yeah, it is plausible if the stock bike (of whatever kind) doesn't reach redline at top speed in stock form. Most stock street legal vehicles don't.
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Old 06-13-2007, 08:45 PM   #3
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I've heard . . . and keep in mind it's all hearsay . . . but I've heard that a 16t will actually decrease mpg on a KLR.

fwiw . . . I'm still running stock gearing and have had no issues whatsoever either on the highway or in the woods.
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Old 06-13-2007, 08:57 PM   #4
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I just geared mine *down* to a 14 and I'm getting ready to do 5400 miles (Divide ride plus there and back from Omaha).
I personally wouldn't even gear a KLR up to 16 if I was doing all road riding.
The thing feels a little over-geared with the stock 15 to me. Trying to cruise at more than 70~75 on a KLR is silly IMHO though.
I did 160 miles a couple of weeks ago, about half interstate at 70 and half gravel/dirt roads. This was all loaded down with my gear for the Divide ride too. I was worried about the gas mileage with the higher revs, but still got 50 mpg I was gonna bring a 15t sprocket along in case I couldn't stand the revs, but I'm just gonna leave the 14 on there.
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Old 06-13-2007, 09:17 PM   #5
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With the standard 15T countershaft sprocket, a KLR650 has an overall high gear ratio of 5.16 to one. That 's pretty high -- not quite as high as a stock DR650, but pretty high anyway. The 16T might allow the bike to go faster in certain situations, like downhill or with a tail wind, but I would guess the engine probably struggles to reach redline even with the 15 on level ground.

Gas mileage would depend on how you ride it. I'll bet you could do better with the 16 if you were willing to modify the way you ride to suit the gearing, but even then I doubt it would be much of an improvement.

However, if it was my bike and I wasn't doing any off-road, I'd go ahead and try the 16. I'd rather idle along in 5th and downshift to 4th to pass or go up a hill than deal with the buzz. But everybody's tolerance for that kind of thing is different, and a lot of people prefer maximum acceleration.
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Old 06-13-2007, 09:25 PM   #6
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Quote:
Originally Posted by Krabill
I've heard . . . and keep in mind it's all hearsay . . . but I've heard that a 16t will actually decrease mpg on a KLR.

fwiw . . . I'm still running stock gearing and have had no issues whatsoever either on the highway or in the woods.
Well I am running a 17tooth front, and have never had better mileage period. At the least, 62 city. and 68 highway. Now I am slow to accelerate, but I am still riding at 70 to 80mph.

Best I could get with a stock front was 61, that was never going over 55mph.

Personally, if your jetting is spot on, and your bike runs well, I would run the taller gearing for intown and travel. Now if you like to hotrod, or go off road, then I would suggest stock or lower gearing.
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Old 06-13-2007, 09:27 PM   #7
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My experience with the 16t:

No improvement in top speed. I think the bike actually ran a little faster in 4th.

No improvement in mileage.

Top gear roll-on sucked.

A dog around town.

Slightly more relaxed at cruising speed, but not worth all the negatives, IMO.

But stock KLRs vary in their power output. If you have an unusually good one, cut a slim aero profile, and air your all-street tires up hard, you might realize a higher top speed. But like the guy said, My KLR won't pull red line in top on a 15t, won't even come close with luggage. I mostly use 15/43 now, but sometimes carry a 14t if I'm going to be someplace like Moab for several days.

Kawasaki really got the stock gearing right for most purposes.
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Old 06-13-2007, 09:35 PM   #8
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Quote:
Originally Posted by judjonzz
My experience with the 16t:

No improvement in top speed. I think the bike actually ran a little faster in 4th.

No improvement in mileage.

Top gear roll-on sucked.

A dog around town.

Slightly more relaxed at cruising speed, but not worth all the negatives, IMO.

But stock KLRs vary in their power output. If you have an unusually good one, cut a slim aero profile, and air your all-street tires up hard, you might realize a higher top speed. But like the guy said, My KLR won't pull red line in top on a 15t, won't even come close with luggage. I mostly use 15/43 now, but sometimes carry a 14t if I'm going to be someplace like Moab for several days.

Kawasaki really got the stock gearing right for most purposes.
Yea, I agree that Kawa got the stock gearing right for most purposes.

Jud I could never get my bike to redline for the longest time either. When I leaned it out alot, is when it started pulling redline. Honest engine here, with my current setup, I am amazed at how strongly I can pull a 17th front. My roll on is great, and I can hit in the 110 mph range without too much difficulty!!. Who knows, maybe she is ready to blow
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Old 06-14-2007, 07:12 AM   #9
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just finished my first tank with a 16t front. made a couple other changes at the same time. new tires should have helped mileage. went from dynojet stage 2 140 main jet to stock 148 and 16t front. mileage actually went up 1mpg, without the main jet may have picked up a couple more mpg. that was also increasing highway speed from 65-70.
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Old 06-14-2007, 07:45 AM   #10
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1st gear

While I think the KLR functions with a 16, I don't even like the 1st gear and clutch action on the street with the 15. I think my KLR is very responsive and tuned/jetted pretty spot-on, but 1st gear is waaaay too freakin' high. I run a 14 all the time and love it. I can't imagine what a KLR with a 16 would feel like on even a moderate trail or jeep road. I see first gear as a bigger problem than top gear. At most the 15 is probably as big as a KLR should optimally go, but if the engine will pull it and one wants it, then what's the harm. I would tend to think a heavily loaded KLR with a 16 would be a real dog in stop-and-go situations.
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Old 06-14-2007, 08:25 AM   #11
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The gas mileage part of the equation depends complete on your speed, and has very little to do with the top speed available.

You will get the best gas mileage if you ride at the peak of your torque curve, so, if you find the peak of you torque curve, and gear you bike so that is the rpm you cruise at, your mileage will increase.

With my DR, top gear happy place with a 15t is about 65, with a 16t it's about 70.

So - a 16t may not give you a higher max speed, but, if you cruise at 70+ all day, it will likely give you better gas mileage.
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Old 06-14-2007, 09:26 AM   #12
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The KLR650 produces maximum hp at 6,500 rpm and redlines a 7,500. With the stock 15/43 gearing it is doing about 75 mph (indicated) 70 mph (true) at 5,000 rpm and about 91 mph (true) at 6,500 rpm. Most KLRs a capable of more than 91 mph so higher gearing will produce higher top speed. The 16T will give you about 97 mph at 6,500. I am running 15/38 gearing which is about equavelent to a 17T and can pull a little more than 100 mph at on flat ground with no tailwind.

Mileage doesn't vary much with gearing changes. I get 48-52 mpg at 70 mph (true) depending mostly on how much headwind I have.
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Old 06-14-2007, 10:56 AM   #13
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+1 on the 14tooth

I put over 30k on my 89 and I stayed with a 14t, The bike just plain ran better, pulled 5th gear better and for off-road I even went to a 13t
14 was perfect, would never go back to a 15, bike sucked with it.
But then again I would never go back to a KLR again either.
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Old 06-14-2007, 11:08 AM   #14
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A better alternative is to go with a 14 & 16 t front with a 45 rear to have the best of both worlds. If my memory serves me the street config is 3% higher than stock but put the 14 on for off road riding and really enjoy the difference.
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Old 06-14-2007, 11:26 AM   #15
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Eh?

Quote:
Originally Posted by viverrid
Uhhh... you didn't actually say what kind of bike, though apparently it is a KLR. I never had a KLR, but on my DRZ in top gear (stock) it was torque limited rather than rev limited. So what limit is reached first on a KLR? If it's not rev limited, then no, dropping the revs even further (if it can't reach redline with the stock sprocket to begin with) won't make it go any faster.

How fast do you want your KLR to go? People usually gear them stiffer to reduce the revs for comfort and engine longevity, not to make them go faster. I'd think the engine would already push it as fast as the chassis and dualsport tires like it, already.

But yeah, it is plausible if the stock bike (of whatever kind) doesn't reach redline at top speed in stock form. Most stock street legal vehicles don't.


Did you read the title.... :)
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