JR 50 gearing choices

[cbrbob]

My son raced his first Hare Scramble he is 7 and his JR 50 needs more low end pull. It has a 28 tooth rear sprocket and was wondering if a 38 tooth would be to much.
Thanks
Bob

 

[Jasle]

I have not worked directly with the JR but a 10 tooth change is HUGE.  I usually go 2 teeth at a time.  Not more than 4 teeth change for sure.  If you change 10 teeth you going to run in to chain problems.  you chain will be too short.

     You could unlock the secret gear.  there is a tab inside that you can grind off.  This will give a second lower gear.    instead of just nuetral you'll have 1-n-2

 

[cbrbob]

Jason,
Where do I find the steps to do this?
Thanks
Bob

 

[Vic]

Originally posted by cbrbob
Jason,
Where do I find the steps to do this?

Post a fax number and I'll send you some info. .

 

[cbrbob]

Thanks
Fax number is 727 399 1165
thank
Bob

 

[Jasle]

hey vic could you also fax to 480-963-1494? I'd like to see what you have as well! Thanks Jason

 

[cbrbob]

Jason,
Do you have any info on this? It was your suggestion tp alter the gear box.
Thanks
Bob

 

[Jasle]

I don't really have info on it other that what was posted here before.  I have heard from several people on this list that have done it.  I have never personally seen it done.  I'd love to do one but don't have any Jr's around right now.  From what I understand you just remove the right side cover and there is a tab that sticks out at you as being in the way of the shifting mechanism.  Grind that down so you can shift and thats it.  Directions were posted quite some time ago but I didn't save them.

     I think this was done to fit within the AMA rules for single speed bikes in the class 3 but I am just speculating as to why they would quit allowing the gear to be used?

 

 

 

[Vic]

Jason, there's no answer at that number. Very aggravating. :silly:

 

[cbrbob]

Vic
Thanks for the Fax and have a good ThanksGiving
Bob

 

[Jasle]

Originally posted by Vic
Jason, there's no answer at that number. Very aggravating. :silly:

Sorry about that.  We just got a new machine.  It must not be set up properly.  I won't be back in til next wednesday.  I'll PM you when its fixed.  Sorry for the aggravation!!!  Our old one was like 6 years old and sounded like a freight train when a fax came in.  I only tested the send not recieve function on Wed.. :ugg:

 

[Vic]

Don't PM me. Post it here or e-mail me at [email protected] . You are the third person in as many days who has asked me to fax them something when they were not ready to receive it. You get one more chance. ;)

 

[MikeeeP]

The 2 speed thing works well. I didn't do the mod to the one I just sold, but after riding it, it has more top end than a PW could ever hope for! The low range is okay maybe as fast/same as a PW, but the top end is where you notice the 2 speed JR shine. If you were to add the larger rear sprocket, to go with this, it'd be a little rocket.

MP

 

[Jason81]

I did this mod to my sons first bike. In my opinion it is worthless. The first gear you gain is so low that is is worthless for anything short of climing a hill and a kid of the age and skill level for a JR 50 will not even consider shifting. The JR 50 is a back yard machine. My son broke his in half ($400.00 for a frame but I just welded it) and this is a common problem so dont let your son start jumping it. For racing harescrambles I would get a XR 50 for a rider at that level. The Honda is bullet proof and will do it all. My son did manage to blow the shock out of it doing some 18' doubles.... Kids are nuts....
Jason

 

[Jasle]

vic...fax number is good now! 480-963-1494 thanks jason

 

[Jasle]

got it! thanks vic