Top speed question, GEARING for street use.

I know there has been simialar posts but they don't help. I have a 2000 xr650r with stock 14/48 gears, that is plated with baja designs and I would like doing more dual-sport.

From my speedometer the top speed is like 95++mph but rapping the krap out of it. I would like a top speed of around 115mph. What gearing should i use? Does 15/45 gearing make me go that fast? Whats the best overall dual-sport gearing? Also i will use the stock chain. Thanks

2000 xr650r

plated

uncorked

15/45 gearing would give you 108 mph at the same rpm as you are now running at 95 mph. 15/42 gearing would (theoretically) give you 116 mph at the same rpm, however this gearing would be way too high for dual sport gearing I would think.

i just changed my gearing today from 14/48 , to 15/45

havent tried it out yet, but after quite a bit of research i thinks it the best for road riding/dual sporting

i just changed my gearing today from 14/48 , to 15/45

havent tried it out yet, but after quite a bit of research i thinks it the best for road riding/dual sporting

Where did you get the Rear sprocket? did you get a good deal?

I'm thinking of doing the same thing, I have the 15 on already but am tired of

cruising around at 60 / 65.

hey mudshark

unfortunately i live a couple of thousand miles from you

but i just went through a local honda dealer, the rear sprocket was 55 NZ $

and the front was 20 NZ $ , which to me seemed a good price.

i also slapped on a pair of pirelli mt 90's

from what iv heard , fuel mileage improves quite a bit , like an extra 5 -10 miles to the gallon .

Its interesting that the new 05 and 06's come with 15/45 stock now .

XR650R street/sm use: -stock motor 15x45 a 42

- with power mods: 15 x 42 a 40

Mine did 186km/u on the highway ,last friday (in the rain) 15x40 with motorwork.Still short:i will go for a 16 front or a 38 rear :thumbsup:

If you are looking for top end speed, the easiest way to do it is:

1. Unscrew XR gas cap.

2. Roll XR away.

3. Roll R1 under gas cap.

4. Throw XR gas cap away.

4 easy steps to double your top speed.

If you are looking for top end speed, the easiest way to do it is:

1. Unscrew XR gas cap.

2. Roll XR away.

3. Roll R1 under gas cap.

4. Throw XR gas cap away.

4 easy steps to double your top speed.

No I do not want to go over 80-90mph but I was just wondering what everyone uses for dual-sport riding. I don't want any more top end speed, i just want a gear change so i don't have to rev it up to cruise down the interstate. I wish I also had a R1 but the xr650r fits me better. Also a R1 don't go double the top speed, Top speed of a R1 is 180mph + -.

Just for everyone to know, here's the equation to figure out top speed gains: (this is in theory).

Your stock gearing:

14/48= .292 (gear ratio)

Your thinking of:

15/45=.333 (gear ratio)

Now take those two values, and set up a cross multiply equation:

(Current Gear Ratio) (New Gear Ratio)

----------------------- = -------------------

(Current Top Speed) (New Top Speed)

So, in this case. Take the New Gear Ratio times Current Top Speed and then devide by the Current Gear Ratio and you'll know the New Top Speed.

.333*95=31.635

31.635/.292=108.34 mph New Top Speed with 15-45 gearing.

Thanks a lot for that formula, helps a lot. For anyone with stock 14/48 gearing wanting to go up a little to 15/45 look at this. If you don't want to buy two new sprockets 16/48 gearing is exactly the same as 15/45 gearing. Stock chain should work ok. Not 100% sure.

I know there has been simialar posts but they don't help. I have a 2000 xr650r with stock 14/48 gears, that is plated with baja designs and I would like doing more dual-sport.

From my speedometer the top speed is like 95++mph but rapping the krap out of it. I would like a top speed of around 115mph. What gearing should i use? Does 15/45 gearing make me go that fast? Whats the best overall dual-sport gearing? Also i will use the stock chain. Thanks

2000 xr650r

plated

uncorked

Speedometer? What speedometer?

I like it alot so far. But have only used it for 15 miles.

Ditto - but I made the mounting myself, I didnt like the ignition being in the

way of the trip-reset knob

Speedo1.JPG

Do you guys feel comfortable at 90+ on a XR650R? Once I hit 80 to 85mph my bike feels kinda sketchy.

Do you guys feel comfortable at 90+ on a XR650R? Once I hit 80 to 85mph my bike feels kinda sketchy.

Anything over 80 and the wind blows you off the bike :thumbsup:

But it's nice to have gearing that'll let you cruise at 70 / 75 without beating

the motor to death...... and a speedo so you don't get caught :thumbsup:

I wasn't sure what I was running since I've only had the bike a few months. I just checked and I'm running 15/48. It seems to be perfect for me. I can run comfortably at 70 to 75 on the street without the motor screeming. I take it off-road once in awhile and still seems to have descent low end.

Thanks a lot for that formula, helps a lot. For anyone with stock 14/48 gearing wanting to go up a little to 15/45 look at this. If you don't want to buy two new sprockets 16/48 gearing is exactly the same as 15/45 gearing. Stock chain should work ok. Not 100% sure.

Yep. A 110 link chain will work just fine with a 15/45 combo and will give you a rev limited speed of 114 mph with stock tires.

56791732-M.jpg

Thanks a lot for that formula, helps a lot. For anyone with stock 14/48 gearing wanting to go up a little to 15/45 look at this. If you don't want to buy two new sprockets 16/48 gearing is exactly the same as 15/45 gearing. Stock chain should work ok. Not 100% sure.

Ive looked everywhere for a 16 - can't find anything bigger than 15.

If you have found one please let me know where. :thumbsup:..... not even

sure if it would fit ??

Ditto - but I made the mounting myself, I didnt like the ignition being in the

way of the trip-reset knob

Speedo1.JPG

The speedo/key switch off ebay is great. Also the key switch is not in the way of the trip reset. Also the stainless steel metal off the one on ebay is the sweetest looking one i have ever seen. I recomend it to anyone.

The speedo/key switch off ebay is great. Also the key switch is not in the way of the trip reset. Also the stainless steel metal off the one on ebay is the sweetest looking one i have ever seen. I recomend it to anyone.

Yes it is well worth it, but what about the 16T CS sprocket. You mentioned a 16T

Do you know where to get one? I've looked all over for one but can't

find one.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now