where can get an oversize front sprocket for a ksr moto worx 125?

[777]

ive had a look on google, to no avail. it looks like you could go up quite a few teeth on the front. it has a rather strange spline fitting, which ive never come across before. any help would be appreciated.

[fastbob]

If I still worked in a bike shop and I had a JT Sprocket book to hand I look at all the variables and work it out by a process of elimination .

[777]

If I still worked in a bike shop and I had a JT Sprocket book to hand I look at all the variables and work it out by a process of elimination .

theres an online catalouge

[Mississippi Bullfrog]

If you go up a few teeth you'll raise the gearing which may make a 125 less able to hold higher gears at speed. The usual trick on 125s is that they are over geared from the factory so you drop one tooth at the front. That lets the engine rev higher in higher gears so they can hold top gear better on open roads.

[777]

If you go up a few teeth you'll raise the gearing which may make a 125 less able to hold higher gears at speed. The usual trick on 125s is that they are over geared from the factory so you drop one tooth at the front. That lets the engine rev higher in higher gears so they can hold top gear better on open roads.

i know

[fastbob]

If I still worked in a bike shop and I had a JT Sprocket book to hand I look at all the variables and work it out by a process of elimination .

theres an online catalouge

 

There is .

[fastbob]

If I still worked in a bike shop and I had a JT Sprocket book to hand I look at all the variables and work it out by a process of elimination .

theres an online catalouge

 

Well off you go then , measure all the relevant features and dimensions and make a note of the chain pitch then start eliminating sprockets until you are left with the correct one .

[777]

If I still worked in a bike shop and I had a JT Sprocket book to hand I look at all the variables and work it out by a process of elimination .

theres an online catalouge

 

There is .

any chance you could take a look? i cant find it on there

[fastbob]

theres an online catalouge

 

There is .

any chance you could take a look? i cant find it on there

 

How can I find it if I don't know any of the dimensions ? How many teeth do you want ? You have to know the chain size , the internal hole size , the number of splines , any threaded holes , any raised bosses etc etc .

[fredc]

on ebay - 13 tooth front sprocket

https://www.ebay.co.uk/itm/333114514905?var=0&gclsrc=aw.ds&&gclid=EAIaIQobChMI4rX7qP3O5wIVCbLtCh0UvAOxEAQYCiABEgLm5fD_BwE

edit: includes a drawing with dimensions

Edited February 13, 2020 by fredc

[fastbob]

That's right , I have also come to that conclusion . But our friend wants to change the number of teeth . I think there might have been a misunderstanding that the BIKE would be listed on the JT site but that's unlikely because it one of dozens of obscure Chinese bikes. My method of sprocket finding used to be to draw a sketch of all the variables and dimensions and then go through the JT book until I found it and then look at teeth options . Now that we have the data we can go through the JT site to see whether it's available in other sizes . The distinguishing feature of this sprocket is the recessed area where the lock washer sits.

[fastbob]

Ok here it is . Have a good evening . https://www.esjot.com/en/motorcycle-sprockets/motorcycle/572865/

[fastbob]

ive had a look on google, to no avail. it looks like you could go up quite a few teeth on the front. it has a rather strange spline fitting, which ive never come across before. any help would be appreciated.

 

Here . https://www.esjot.com/en/motorcycle-sprockets/motorcycle/572865/

[skyrider]

what would people do on this forum without Bob he is one very handy guy to have around

[gogs01]

Can the OP let us know how he gets on with a front sprocket a few teeth over standard ? I'd be interested to find out whether his bike would be able to pull top gear on anything other than a downhill run.

[fastbob]

Can the OP let us know how he gets on with a front sprocket a few teeth over standard ? I'd be interested to find out whether his bike would be able to pull top gear on anything other than a downhill run.

 

Check the link , there are only two size options , 13 and 14 teeth . More options available for rear sprockets .

[gogs01]

..... there are only two size options , 13 and 14 teeth . More options available for rear sprockets .

 

No surprise there. One tooth is a significant increase on a 13 tooth front sprocket, probably similar to dropping three teeth on the rear sprocket. Either one would probably see the bike struggle to get much use of top gear, although I could be wrong of course .....

[fastbob]

Some response from the OP would be nice . I spent nearly an hour researching this and I'm beginning to wonder why I bother sometimes .

[skyrider]

dont panic Bob you are doing a great job keep it rolling

[dynax]

dont panic Bob you are doing a great job keep it rolling

 

I agree but also a thank you from OP's would at least acknowledge the effort

[Mississippi Bullfrog]

Some response from the OP would be nice . I spent nearly an hour researching this and I'm beginning to wonder why I bother sometimes .

 

I am not surprised. His earlier response was rude and unhelpful.

[James in Brum]

Where was Fastbob rude? I looked back through and cannot see something I read as rude.

[Mississippi Bullfrog]

Where was Fastbob rude? I looked back through and cannot see something I read as rude.

 

Not Fastbob, the OP. It is unusual to want to go up a few teeth at the front on a small capacity engine. When I mentioned this to try to understand the reason behind his request he just said he knew. Some explanation or saying what he was trying to achieve would have helped.

I figured then he was just being lazy and once he'd got what he wanted we'd never hear from him again.

[gogs01]

..... Not Fastbob, the OP. It is unusual to want to go up a few teeth at the front on a small capacity engine. When I mentioned this to try to understand the reason behind his request he just said he knew. Some explanation or saying what he was trying to achieve would have helped.

I figured then he was just being lazy and once he'd got what he wanted we'd never hear from him again.

 

I thought exactly the same.

It's difficult to understand why people would ask for help, get that help, and not take the time to post a simple "thanks". They might get good advice (even the ones who "know") or they may need more help in the future .....

[James in Brum]

Okay we are all on the same page, I thought the expectation of someone doing all the work was a bit rude.