Sprockets

The sprockets on my bike are very rusted and are the originals so I am looking to replace them.

Is this the correct one: http://www.monkeybike.co.uk/acatalog/ST ... 5_38T.html

15 teeth on the front and 38 teeth on the rear?

Seems to be a good price for the set because the rear one costs more than both of them at CMS!

Thanks

Just done some research. The CT70 had a 38 tooth rear sprocket so I presume this set is the right one. It is listed under the 6v ST70 of the MBUK website so it must be correct.

Hopefully you can confirm Wannes because I am going to order the following from MBUK this afternoon:

- 2 x Inner Tube
- Spark Plug (CR7)
- Sprocket Set

Thanks

James, yes these are the standard sprockets for your ST70.
The rear sprocket is indeed the Dax version, so the proposed set is the right one.
Maybe you could order a new chain as well? It's recommended to replace this together with your sprockets.
I assume you already know, but to make sure you do, you could chnage the size of the sporckets if you like:
- bigger front sprocket: higher top, slower acceleration
- smaller front sprocket: lower top, faster acceleration
- bigger rear sprocket: lower top, faster acceleration
- smaller rear sprocket: higher top, slower acceleration

Waynus wrote:James, yes these are the standard sprockets for your ST70.
The rear sprocket is indeed the Dax version, so the proposed set is the right one.
Maybe you could order a new chain as well? It's recommended to replace this together with your sprockets.
I assume you already know, but to make sure you do, you could chnage the size of the sporckets if you like:
- bigger front sprocket: higher top, slower acceleration
- smaller front sprocket: lower top, faster acceleration
- bigger rear sprocket: lower top, faster acceleration
- smaller rear sprocket: higher top, slower acceleration

Hi,

Yeah I will getting a new chain as well but not sure which one: http://www.monkeybike.co.uk/acatalog/Sp ... hains.html

And yes, I know about the ratios etc for sprockets. I was reading about it yesterday and was tempted to go for smaller rear sprocket but the bike doesn't really have enough power. If I had a bigger engine I would definitely go for it though!

With a bit of luck I am going to order the sprockets and tubes today ready for next week.

My bearings (4 of them) were waiting for me when I got home last night. They are made by 'FAG'

Wow, speaking of bad marketing...

Well, yous it's possible to increase the engines power in many ways.
1) faster ignition / flywheel: it's possible that your current flywheel has 2 'arms' on the inside, which will slow the flywheel down at higher rpms.
2) bigger carb/manifold: a 18mm carb + manifold could increase the power
3) valves cam: not sure this is the correct English name, there are plenty of race cams available.
4) cilinder: replace the cilinder + piston with a 85cc version.

But I guess you'll be looking at these things later on...

Just ordered some more bits:

Sprocket Set
Chain
Spark Plug
2 x Inner Tubes

Good idea to have everything ready, so you can put all pieces in place next week.
DID chains are good, no worries!
Remember you've got yet to shorten them yourselves.

Waynus wrote:Good idea to have everything ready, so you can put all pieces in place next week.
DID chains are good, no worries!
Remember you've got yet to shorten them yourselves.

Didn't get a DID chain, I just ordered the standard one on that ST70 page.

I doubt I will get it all finished next week, I need to get some bits shotblasted which might take a while.

Hoping to have it on the road within the next few weeks though (fingers crossed)!

Remember to cover the parts with paint as soon as they're sandblasted.
Naked metal rusts faster than you'd imagine!

Waynus wrote:Remember to cover the parts with paint as soon as they're sandblasted.
Naked metal rusts faster than you'd imagine!

Thanks for the advice!

Looks like I had better get the paint and primer ordered then! Paint is going to cost me £30 and primer £15

This is starting to get expensive