15 tooth front sprocket

[Tordi]

Hi Folks,

two weeks ago I ordered 15 t. frontsprocket for the CRF, but the dealer I bought the Honda from isn´t able to get it on time - I´m going on holiday in three days and want to take the CRF with me. With a bigger sprocket installed.

Any hints which sprocket from which other bike will fit, so I can try with that?

Thanks.

[noob_with_150]

omg 15? it will where a hole in your case in no time flat that is if it will even turn with a 15 tooth.

[AR15 guy]

http://www.off-road.com/dirtbike/projects/crf230f/1/

They did it.

[noob_with_150]

Okay do they have any follow up to there project about how much wear is on it?

[CR250oldtimer]

Okay do they have any follow up to there project about how much wear is on it?

Why would you be concerned with a 15T??

If anything the entire system including the chain will last longer as it has a larger turning radius therefore not pinched so much as the stock 13T.

I have a 14T on with no signs of wear. Not that a 230 with less than 20HP and a 520 chain will ever cause much wear…

Unless you go with disposable aluminum sprockets like Renthal.

[Crf230 Rider]

Hey Oldtimer, with that 14 T up front, did you lose much acceleration with it?? How much faster is it? I'm kinda tired of how slow this pig is.I bet first gear is a lot better now.

[Tordi]

omg 15? it will where a hole in your case in no time flat that is if it will even turn with a 15 tooth.

Funny guy.

Meanwhile I found out where to get one here in Germany. Don´t know if you have that Korean "Kymco"-brand over there, but there´s a Kymco ATV with 50ccm, that has a 15 tooth sprocket fitting in the CRF.

I allready installed it, you have to bend that metal plate at the case a little bit and cut a small rubber nose from the front chain guard.

I needed that bigger sprocket as I go on holiday to Greece and take the CRF with me, will be trail and street riding there and the 13 tooth is far to small for that, reving the engine up to the sky when going 60 mph. I have the "stree-legal"-Version made bei HM Italy:

Here are the pics with the new sprocket, the only bigger thing to do was cutting out a piece from the chain cover. The original chain was to short, I installed a 520/112.

Before:

After:

Cutted cover:

Will give some infos how it works when I´m back.

[AR15 guy]

Let us now how 1st and 2nd feel. Stock they are WAY to low IMO. I rarely even use 1st. I normally just start off in 2nd since 1st is gone in a flash.

[Crf230 Rider]

When I drag Race I always dump it in second, I find it's faster.

[RTLkyuubi]

hehe, changing the front sprocket makes a load of difference!! Eairler today I installed a 17tooth front sprocket on my 110, (stock: 14tooth) And it flys! I actually use 1st now But with the extra speed youve got to remember to brake sooner or harder, After installing my new sprocket I tuck it for a test ride and nearly fell off 3 times becuase I braked too late Have good fun in Greece. Btw people hate it when you go to the pool at like 6am

Ryan.

[Tordi]

I rarely even use 1st. I normally just start off in 2nd since 1st is gone in a flash.

The same with me, I only use first if I go to the woods for very slow crawling over trees and that stuff. And I also "dual-use" the bike, as I always take it with me when I´m on the way with the RV (that´s what I originally bought it for, before I recognized what a lovely little lady the CRF is...)

I will have a GPS with me, so I can check the *real* speed after the conversion.

Does anyone know how this conversion effects the speedo? I never checked where it get´s it signal from, out of gearbox? Asking that because I felt like the speedo is displaying more speed than before the conversion.

[Tordi]

Btw people hate it when you go to the pool at like 6am

Ryan.

Going into a pool in Greece is a very funny idea

I think using the sea will be the better way to get wet.

[noob_with_150]

Ohhh whoops didn't see it was a 230 im pretty sure it won't fit on a 150 .

[Torqd]

the motor cases and parts are all the same... and the frame is the same.... so if it fits the 230 it will probably fit the 150... On a 150 it is hard to pull a 14t let alone a 15t in the upper gears...

[upinsmoke]

Does anyone know how this conversion effects the speedo? I never checked where it get´s it signal from, out of gearbox? Asking that because I felt like the speedo is displaying more speed than before the conversion.

If connected to tranny going with a higher gear ratio it will read slower, going down reads faster. If connected to the wheel, it will not effect anything.

With my street bikes I always run -1 tooth on the front and it has read about 5 mph over at 60-80 mph, but the error goes up the faster you go because it is a ratio. For you it might read 10 mph slower.

[Tordi]

Just to give some info about the effect of 15 tooth: it´s really great!

You can use 1st gear as a full working one even on road, the bike feels totally different after the conversion. Not that revving like hell-thing anymore, on road it´s just a small motorbike that behaves like it should.

Off Road there is not the big change I was afraid of. I thought I´ll probably burning the clutch when going rockcrawling, but it worked. Only in really difficult situations where you are at absolutely low speed - e.g. climbing fallen trees or down some big rocks - it really could be lower. I think for that a 14 tooth would be quite perfect.

Maximum speed didn´t change, but now I can go in 6th wide open without beeing afraid the engine will blow off from its rpm...

This trail was the most tricky one I tried (up and down) and it perfectly worked even with the bigger ratio:

I can recommend the bigger sprocket.

[jefffoxsr]

Very nice info. Thanks.

[ebeck]

Split the difference. A 14 front and a 47 rear is the same as a 14.7 front and stock rear if it were possible. It is what I did. I had to buy a new rear sprocket for weight. Havent tried it yet though but you can use the front sprocket cover unmodified and still and get real clost to 15 tooth.

Here is some reference gearing

stock is 3.85

15 tooth is 3.33

14/47 is 3.38

14/46 is 3.29

[FATHER AND SON CRF]

http://www.off-road.com/dirtbike/projects/crf230f/1/

They did it.

When they did this they had the smaller 428 chain on, not as much trimming involved.

[ebeck]

It was not a 428 it was a 520 chain in that article.