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sprocket question

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I am running a 16 tooth front sprocket and the stock 45 rear,at 55-60 it still seems to be screaming,will a 43 or 42 rear really make it any better or should i just run the 45. Im highway and back road riding the bike.

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That's pretty tall to begin with but yes dropping to a 42 rear would be the same as going to a 17t front (no such thing I think). 1t front = 3t rear

So yes it would a noticable difference, but I'm really surpised you think it screaming with the gearing you have now.

I ran 14/37 on my 350 and it was VERY relaxed at 60mph and your's is geared still higher! 14/37= roughly 16/43

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I am running a 16 tooth front sprocket and the stock 45 rear,at 55-60 it still seems to be screaming,will a 43 or 42 rear really make it any better or should i just run the 45. Im highway and back road riding the bike.

My old man has a XR400R and has 15/40 gearing and itll cruises at 60 all day long :thumbsup:

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With the 40 rear sprocket does the chain seem to eat throught the swingarm guard? If i go to a 43 rear then i would have just about the same gear ration as your dad with 15/40, 16/43 is 2.69 ratio and 15/40 is 2.67 ratio.

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Here is a gear RPM vs. MPH calculator that I downloaded a while ago. I uploaded onto Sendspace - scroll down and use the download link with the moving red arrow. Ignore all the advertisement BS (I'm too cheap to pay for a premium account). It is a MS Excel file.

http://www.sendspace.com/file/2xc3zc

I have the same issue with my XR4. By that calculator, on a stock tire, stock gearing, at 60mph, you are running almost 6000rpm. From my experience, I would say that's about right. If I'm going to go on a long run at high speeds, I run a 16 / 40. That brings it down to just under 5000rpm at 60mph. Tire size obviously effects this, that's why the calculator asks you to input yours.

If I remember correctly, the XR350 has a wider gear ratio, but I could be wrong.

The second sheet will show MPH at Different RPMs in each gear. Just input the information requested and leave the formulas alone.

Take it for what it's worth. It seemed to be pretty close to me, but I didn't make it and I don't have time to go back and check all his gear ratios.

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With the 40 rear sprocket does the chain seem to eat throught the swingarm guard? If i go to a 43 rear then i would have just about the same gear ration as your dad with 15/40, 16/43 is 2.69 ratio and 15/40 is 2.67 ratio.

I don't have that issue. I have a spare set of wheels that I have street tires on. I have a 40T sprocket on the rear for street.

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I'm kind of baffled that you think it's screaming with a 16/45 also. I'm running a 15/48 and I get down the highway at 55-60 with no worries. If I'm taking a road trip I flip on a 16 front. Changing the fronts usually doesn’t require a chain change.

Edited by XR-rated
add "way"

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i run the 15/45 for the dirt and use 16/45 on the street and seems fine to me. i usually run about 60-65 mph and have a little left over for passing but then i'm screaming.

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guess im just used to riding my brothers 2009 KLR 650 on the highway,it only runs like 4000 rpm at 60-65 mph, that thing is like a cadillac compared to my xr, but i prefer my xr for the short road sections and the woods the klr is just a road bke(too heavy for much else).

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Here is a gear RPM vs. MPH calculator that I downloaded a while ago. I uploaded onto Sendspace - scroll down and use the download link with the moving red arrow. Ignore all the advertisement BS (I'm too cheap to pay for a premium account). It is a MS Excel file.

http://www.sendspace.com/file/2xc3zc

I have the same issue with my XR4. By that calculator, on a stock tire, stock gearing, at 60mph, you are running almost 6000rpm. From my experience, I would say that's about right. If I'm going to go on a long run at high speeds, I run a 16 / 40. That brings it down to just under 5000rpm at 60mph. Tire size obviously effects this, that's why the calculator asks you to input yours.

If I remember correctly, the XR350 has a wider gear ratio, but I could be wrong.

The second sheet will show MPH at Different RPMs in each gear. Just input the information requested and leave the formulas alone.

Take it for what it's worth. It seemed to be pretty close to me, but I didn't make it and I don't have time to go back and check all his gear ratios.

Doh, of course you're right. 6 speed......... :thumbsup:

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I ran 16 45 for a while when I was in dual sport mode. I just changed over to 15 42, so I can run the case saver I have. I also bought a 13 and 14 tooth to play with if the going gets tough. If Im really going on a long trip I can run 16 42 as well. With 15 42 and a 120 rear tire, I turn about 5500 at 59 mph, give or take a little.

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Isn't 15/40 stock gearing in the UK and Aus. bikes?

I run 15/47 when doing single track and sandy ORV trails, 16/47 (just barely taller than stock) for dual sporting. Can cruise 55 with no trouble but I'm usually only on back roads and doing 45-50 just chuggin along.

IMO, the 400 should have had a 6 speed. Little lower/tighter gap between 4th and 5th, 6th gear a little taller than 5th is now.

Thats why the KTM's are so popular, I run 14/52 on mine and it'll just chug ( < 5000 rpm) along at 60-65. 1st thru 5th feel about the same as the XR's with stock gearing, 6th is just a overdrive for transport sections or road use.

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You are right michigan, the only thing I miss from my xr250r is the 6th speed... My 400 is a little too slow for road riding but if I gear it to go faster, the first gear will be too fast for very tight trail and I will always have to play with the clutch. In fact, I could go way slower without the clutch on the xr250 (with 13-48 gearing on a pre-1995 model)

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Hey guys, I'm new here. Recently bought an '02 XR400. I put a baja designs turn/brake light kit on it and got it plated due to crazy gas prices! The guy I bought it off of had it geared for strictly dirt, with a 14t on the front. I just put a 16t up front and it made a HUGE difference on the streets! My question is, is the case saver and sprocket guard would not fit with the 16t up front. Is it okay to run without either one? Or do they make anything that will fit with a 16t? I am running with no case saver or sprocket guard. I ride mostly roads with a little trail riding. Any input is much appreciated. Thanks!

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Hey guys, I'm new here. Recently bought an '02 XR400. I put a baja designs turn/brake light kit on it and got it plated due to crazy gas prices! The guy I bought it off of had it geared for strictly dirt, with a 14t on the front. I just put a 16t up front and it made a HUGE difference on the streets! My question is, is the case saver and sprocket guard would not fit with the 16t up front. Is it okay to run without either one? Or do they make anything that will fit with a 16t? I am running with no case saver or sprocket guard. I ride mostly roads with a little trail riding. Any input is much appreciated. Thanks!

Here is what I did. I took a drum sander on a die grinder to the stock case saver and enlarged the radius a little bit. I then drilled out the mount holes a couple sizes bigger. This will let you atleast run the case saver with the 16T front. The cover might rub a little but you can drill out the mount holes on that as well if you want. Atleast mod the case saver to work just in case you throw a chain. :thumbsup:

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