Faster top end sprockets needed

[speedfreek]

Right now my bike will do 90 plus mph and I would like to get about 5-10 more mph from it. The front sprocket is a 15t and I don't think I can go bigger because of the case. The rear is a 36t and I believe I had to buy a special hub so I could go this small on the rear. I dont think I can go any smaller on the rear, the sprocket is pretty thin just to be able to get it over the hub.

Do I have to get another hub? Or is this as small as I can go on the rear?

I am not getting taller tires. And I have a Durablue axle. If I have to get another hub, where can I get one from. Thank you.

[speedfreek]

Here is a pic of the hub that I have.
http://i90.photobucket.com/albums/k264/pnewell44/250R/0818001327.jpg

[hondamancbr03]

This is not a for sure answer but here is a company i have delt with, they are great people and can build just about anything on a CNC.

If it can be done they can do it.....Just remember, custom=$$$

http://jjandaracing.com/contents/en-us/d18.html

[wilkin250r]

Wow, more top than 15/36 isn't going to be easy.

What kind of revs are you running at 90mph? If you're looking to break that 100mph mark, it might be in your ENGINE, rather than your gearing. A little more power in the upper revs might get you there.

[shane125]

I have a 33 tooth of the rear and I am running a durablue axle. Seems to clear everything fine no issues so far and that the way it was when i got a year ago.

[speedfreek]

Originally posted by wilkin250r
Wow, more top than 15/36 isn't going to be easy.

What kind of revs are you running at 90mph? If you're looking to break that 100mph mark, it might be in your ENGINE, rather than your gearing. A little more power in the upper revs might get you there. My bike screams. I am very happy with it BUT most shee's that I ride with will get me on top end but only by about 5 more mph. We sometimes race for long distances. My bike will be in front till about 85-90mph then the shee's will slowly come by. I think I can still out run them out of the hole if I gear it for 5 more mph. I would like to drop only 2 teeth on the rear just to see if I like it.

When I race, I shift very fast from 2nd to 5th. The tranny gears seem very close and my bike seems to like to pull harder if the gears were farther apart.

For those who think I mabe lying, I held a GPS and when I let off it said 93.7mph.

I have a ported (by me) rad valve. At the time I bought it, it was the best thing for the 250R. Now I read where the delta may be better. It may give me more rpm's but really, at top speed my bike seems to be revving as high as it does through the gears.

I deff think I have the power for more mph.

[89trx250r]

Mabye you should wear less clothing or eat less food then your 250 wouldnt have to do as much work to haul your big *** and you'd get your 5mph's :)

[matt250r21]

What year tranny do you have. I know 86 year Rs had a taller 5th and 6th gear over 87-89. I think Sidewinder and Sprocket Specialist make 33T rear sprockets that fit the stock axle hub as well.

[morse250r]

ebay there are 34's and 35's
i have both and they fit on oem hubs aswell as aftermarkets call john at sand toyz unlimited he has a 16 front 25.00 so you could do a 16/34 combo or at least a 16/36 easily

heres a link to show you the ratios
http://www.angelfire.com/pa5/cannondale/88_89trx.html

[speedfreek]

Originally posted by 89trx250r
Mabye you should wear less clothing or eat less food then your 250 wouldnt have to do as much work to haul your big *** and you'd get your 5mph's :) lol, i do need to lose some weight!

[speedfreek]

Originally posted by morse250r
ebay there are 34's and 35's
i have both and they fit on oem hubs aswell as aftermarkets call john at sand toyz unlimited he has a 16 front 25.00 so you could do a 16/34 combo or at least a 16/36 easily

heres a link to show you the ratios
http://www.angelfire.com/pa5/cannondale/88_89trx.html Thank you guys. I don't think a 16 will clear my case. I had to take off the case saver with this 15. (or maybe it is a 16?) Either way, I think the links yall gave me will get me what I'm looking for on the rear, thank you.

Oh, my trans is an 87.

[rsss396]

16 fits with no saver

[2-330s]

on the 1/2 mile i've ran 15/34. they clocked me at 93. it was still pulling when i had to back out for the corner.

[speedfreek]

Originally posted by rsss396
16 fits with no saver Thanks bro. It just looks close. I will be ordering one today!

[speedfreek]

Originally posted by shane125
I have a 33 tooth of the rear and I am running a durablue axle. Seems to clear everything fine no issues so far and that the way it was when i got a year ago. Can you post a pic of the hub and sprocket. I cannot find anything on ebay this small that will fit my hub.

If you look at the pic I posted you can see how thin it is in some places.

I have been looking for a 16t front with no luck either. Does anyone know if a cr250r sprocket will fit the countershaft on a trx 250r?

[speedfreek]

Originally posted by matt250r21
What year tranny do you have. I know 86 year Rs had a taller 5th and 6th gear over 87-89. I think Sidewinder and Sprocket Specialist make 33T rear sprockets that fit the stock axle hub as well. Ok, I just found a 16t front from Sprocket Specialist, thanks. I'm getting one now!

[regg187]

sorry to bring up an old post ,
try this:
http://home.earthlink.net/~gellett/250r.htm

[speedfreek]

Originally posted by regg187
sorry to bring up an old post ,
try this:
http://home.earthlink.net/~gellett/250r.htm How many rpm's would you say a 310 would turn? With a trx 11 pipe?

I bet my tire swells up taller than 20'' at top speed.

[speedfreek]

Ok, I just put my 16t sprocket on and the chain is hitting the case saver bottom bolt mount casting. You can see where it's rubbing where I'm pointing to it with a screwdriver.

Will this be ok to ride or is it going to eventually break off the mount?
http://i90.photobucket.com/albums/k264/pnewell44/250R/250r.jpg

[gandgracing]

I think it will be OK. I just put my 16 on last night and it cut a groove into the chain slide. I'm still going to run it. Hope you are using a good chain. I was scared ****less at first to do a holeshot.

[morse250r]

i took a die grinder and took out the material untill it went freely figured to run a case saver again ill make a spacer or throw a few washers behind the saver