Ok who is running a 15/45 combo for street/dirt?

[Foxridere3361]

Ok I'm tired of sifting through old threads trying to find an answer is a 15/45 combo suitable for hwy/off road about 70/30%? I went from a 14/48 to a 15/48 and it seems better but still I only have a top speed of 75mph and that's riding it pretty hard. And at 60 it still seems like it's winding a bit to much for my liking. I want to be able to cruse to work going 60 and still take it off road with out having to burn the clutch up. Is anyone using this set up if so what's top speed and will it run at 60 without rapping the crap out of the bike. Thanks!!

Long live the thumper!.... BRRRAAAAP

[Trailryder42]

I'm guessing this is for is 400. 15/45 is stock gearing. Works well for trailriding. Going from 15/48 to 15/45 you will see about the same difference as you did going from 14/48 to 15/48. You'll probably drop RPMs by about 400 or so and and increase speed by about 5 mph.

I think if I were going to ride it 75% street, I'd go higher still on the gearing. See if you can find some something smaller than a 45 or put a 16 front on it. It will be no billy goat on the trails, but it should still be ridable.

[ozcalxr4]

i ride 50 / 50.. 15 / 45 is what i like... mind you i avoid highways and ride 45 -55 on road when possible... she ll climb a tree tho in the backwoods... 

[Oil Baron]

I consider the XR transmissions to be close ratio.

 

If you want wider gearing, the solution is to carry tools and change countershaft sprockets for varying conditions.  Gear it tall so you're not buzzing the motor on the highway and carry a small gear for tough single-track.

[Foxridere3361]

i ride 50 / 50.. 15 / 45 is what i like... mind you i avoid highways and ride 45 -55 on road when possible... she ll climb a tree tho in the backwoods...

Any idea on top speed? I'm not that worried about it just curious.

Long live the thumper!.... BRRRAAAAP

[Foxridere3361]

I'm guessing this is for is 400. 15/45 is stock gearing. Works well for trailriding. Going from 15/48 to 15/45 you will see about the same difference as you did going from 14/48 to 15/48. You'll probably drop RPMs by about 400 or so and and increase speed by about 5 mph.

I think if I were going to ride it 75% street, I'd go higher still on the gearing. See if you can find some something smaller than a 45 or put a 16 front on it. It will be no billy goat on the trails, but it should still be ridable.

Thanks for the advice!! Where I live the trails/dirt roads are literally on my way home from work so I will be taking many detours on a regular basis just trying to find that happy medium so I can do both at the drop of a hat.

Long live the thumper!.... BRRRAAAAP

[JoeBlow Kokomo]

Ok I'm tired of sifting through old threads trying to find an answer is a 15/45 combo suitable for hwy/off road about 70/30%? I went from a 14/48 to a 15/48 and it seems better but still I only have a top speed of 75mph and that's riding it pretty hard. And at 60 it still seems like it's winding a bit to much for my liking. I want to be able to cruse to work going 60 and still take it off road with out having to burn the clutch up. Is anyone using this set up if so what's top speed and will it run at 60 without rapping the crap out of the bike. Thanks!!

Long live the thumper!.... BRRRAAAAP

You can't gear a single cyl 4 stroke making 35hp to run 60 mph comfortably AND be able to offroad with the same gearing.

Would take a 6 speed for that.

Everything is a compromise. You go any taller than what you have and you won't be happy offroad unless it's really flat where you ride.

[702inda509]

I consider the XR transmissions to be close ratio.

 

If you want wider gearing, the solution is to carry tools and change countershaft sprockets for varying conditions.  Gear it tall so you're not buzzing the motor on the highway and carry a small gear for tough single-track.

I would agree with carrying a 15 with you and changing it out with a 16 will be one of the best compromises. Easy enough job to switch at the trailhead.

Here's another option, stock is 15/45 which is 3/1 ratio. Say you go to 16/42 you could get tall street gearing of 2.6/1 and carry a 14 for trails and your back to a 3/1 and would be like stock gearing. I am not sure of the XR4s ability to pull those gears ,but just some thoughts.

[XR-rated]

As others have said, I run a 47 rear and a 16 front for the week days.  I change the front to a 15 for the weekends.  10 minutes and you're good for the trails.

[Foxridere3361]

As others have said, I run a 47 rear and a 16 front for the week days. I change the front to a 15 for the weekends. 10 minutes and you're good for the trails.

Thank you Sir!!! That's all I needed to hear!

Long live the thumper!.... BRRRAAAAP

[ozcalxr4]

Any idea on top speed? I'm not that worried about it just curious.

Long live the thumper!.... BRRRAAAAP

 

i can do 60 if i wring its neck...

 

too many rpm for me tho to hold it there... i feel happier with the rpm cruising at 50 and just over if the road allows for that speed..

[xr250rrr]

according to this site http://www.rickramsey.net/XR250R.htm

the original gearing on the xr250r is 13/48

 

I am currently running 13/39 and it goes hard on the road. when it comes to offroad it turns sh*t,

 

I wouldn't recommend running a ratio like this unless you are using it for highway use only

 

 

if I go smaller on the from and go too 12/39 do you think this will give me a little more low end power so i can ride offroad more comfortably?

 

 

by the way imriding 80 % road and 20% dirt/hills

[Oil Baron]

Gearing is different and more demanding on a 250.  A 12t with your 39 is not low enough for trails and will wear through the swingarm slider if you leave it on a long time.  39 divided by 13 gives a ratio of 3.00 which is great on the road for a 250.  13/48 is 3.69 which is great for almost all trails.

 

https://www.thumpertalk.com/topic/1076977-xr250-street-vs-trail-gearing-and-custom-case-saver/?p=11483330 

 

.

Edited May 18, 2014 by Baja Rambler

[Kev_XR]

USA Stock 15/45 is good for about 75 mph.

In Australia, where XR400R's come with blinkers and are suitable for street use, the gearing is 15/40.

 

I ride mostly in the woods and street, so I use 14/45.    A short trip on the freeway is teeth clenching.   I keep it around 60/65 mph, is near max.

 

There are dozens of gear ratio calculators online.

https://www.google.com/search?q=gear+ratio+calculator

 

 

Having a 14/45 gearing and bringing along a 15 tooth counter sprocket was dubed "The XR400R sixth gear".  

It takes a few minutes to change, but it worth it if there is a huge terrain change.

Edited May 18, 2014 by Kev_XR

[Foxridere3361]

USA Stock 15/45 is good for about 75 mph.

In Australia, where XR400R's come with blinkers and are suitable for street use, the gearing is 15/40.

I ride mostly in the woods and street, so I use 14/45. A short trip on the freeway is teeth clenching. I keep it around 60/65 mph, is near max.

There are dozens of gear ratio calculators online.

https://www.google.com/search?q=gear+ratio+calculator

Having a 14/45 gearing and bringing along a 15 tooth counter sprocket was dubed "The XR400R sixth gear".

It takes a few minutes to change, but it worth it if there is a huge terrain change.

I found one last night and a 3.0 gear ratio is what I'm gonna run. So a 16/48 will get me there made a new case saver to fit a 16t counter sprocket now to I'm pretty proud of it!!

Long live the thumper!.... BRRRAAAAP

[Kev_XR]

Honda ships 15/45 and 15/40 for the XR400. I would tend to follow their lead and gear around a 15 front sprocket.

[Foxridere3361]

Honda ships 15/45 and 15/40 for the XR400. I would tend to follow their lead and gear around a 15 front sprocket.

So I went on a cruse tonight with the 15/48 gearing and I think I'm gonna leave it. I will just cruse at 55mph instead of 60 the bike seems to be ok at that speed. I also saw that there isn't really going to be enough room to run a 16t counter and still keep my case saver so if I still want a 3/1 ratio I'll just do it with the 45t rear.

Long live the thumper!.... BRRRAAAAP

[michigan400]

I used to run 16/47. Still good off road, ok on road. I felt it had a comfy cruise speed of 53-55 at the most.

I've also ran 16/45. About the same IMO, maybe 3mph faster at same rpm. Still not great on road, not great off either. I always felt it was compromise gearing but its to high for off road and to low for any street riding past a couple miles.

Now I have a 43T rear on. 16/43 is perfect on road, cruises 60mph no problem. I can switch to a 15 front for close to stock (little taller) or a 14T front for a little lower than stock.

Rear tire height and pressure can give or take away a couple mph also.

Drill out the holes on your case saver about 2 sizes larger, dremel the inside radius just a bit, rounding the back and it should fit. Took about 5 minutes to do mine.

Edited May 19, 2014 by michigan400

[Kev_XR]

15/40. 0.375. Stock in AU

16/45. 0.355

15/45. 0.333. Stock in USA

14/45. 0.311

15/48. 0.3125

15/49. 0.306

In general, 1 front tooth = 3 rear teeth. This applies to sprockets in the 40-50 tooth range.

As you can see, 14/45 and 15/48 are close.

[Oil Baron]

Kev.  You are doing your division a bit different than what I'm used to.  I checked Rick Ramsey's site as well.  We are dividing the larger number by the smaller number such as 45/15 equals 3.00.