14 tooth front sprocket questions.

[bigchris]

Im thinking off swapping the gearing on my naked curvey from a 15t front sprocket to a 14t. Will i need a new chain and rear sprocket when i do this or will i be ok just changing the front sprocket?

Thanks

[warrenhewitt10]

changing it to 14 tooth will mean the chain is now too big, logically it means you will get lots less miles from the chain due to not being able to adjust it any more.

Im not sure how much difference in chain lengths there is changing to 14 tooth, im sure someone will be here soon to confirm

[coxxy]

You should have enough adjustment on the rear axle to take up the slack on the existing chain. Getting the front sprocket off can sometimes be tricky and require a nut gun to loosen it depending who has torqued it up and how long ago it was touched. Why change to a 14T anyway - we race with a 15 on nearly all circuits and are not disadvantaged generally. Changing the rear sprocket by adding teeth (say from a 44 to 46) has almost the same effect and is easier to accomplish?

[hardhat_harry]

I believe the ratio is 3 teeth on the rear to one tooth off the front. I run a 14 front but I may move to a 15 as coming out of tight bends you do get a big lump of torque which you have to manage with the throttle which can be interesting with a quick action throttle :). If your changing the sprockets I would recommend doing a 520 conversion.

[Berlin]

changing it to 14 tooth will mean the chain is now too big, logically it means you will get lots less miles from the chain due to not being able to adjust it any more.

Im not sure how much difference in chain lengths there is changing to 14 tooth, im sure someone will be here soon to confirm

What a load of tosh!

Why post this tat?

If you don't know, don't post!

Bigchris,
Its fine. We gear bikes plus or minus 2 teeth on the front and up to five on the back and the same chain works, and amazingly, doesn't wear out any quicker either!

The only one to watch for is down on the front and the back as this can wear the Swing arm. But one tooth down on the front is absolutely no problem. Have you bought your sprocket yet, because if not, I've got a load of 14's here and I think some of them are brand new. You can have a used one for the price of the postage (still in good nick).

C

[yorkie_chris]

It will probably be fine. If your chain and rear sprocket are badly worn you should replace those too.
There will probably be room to take up slack unless in case of bad wear.

I don't like 14t front, it increases chain stress and thus wear. Better IMO to increase teeth on rear.

Changing the rear sprocket by adding teeth (say from a 44 to 46) has almost the same effect and is easier to accomplish?

It is only easier if you have the slack available to take up on chain.

[warrenhewitt10]

not sure.... was thinking about it logically, smaller sprocket at the front, shorter chain? am I wrong?

[barwel1992]

14 front will ware the guide and chain, go with a 2 or 3 up on the back

[Berlin]

Well, I've just measured the bikes in the garage with both a 14 and a 15 tooth on them and it from what I've just measured, it ain't. There's going to be fractionally more wear on the guide and you'd be lucky to wear it out in three years. Going down to a 12 maybe would.

C

[bigchris]

What a load of tosh!

Why post this tat?

If you don't know, don't post!

Bigchris,
Its fine. We gear bikes plus or minus 2 teeth on the front and up to five on the back and the same chain works, and amazingly, doesn't wear out any quicker either!

The only one to watch for is down on the front and the back as this can wear the Swing arm. But one tooth down on the front is absolutely no problem. Have you bought your sprocket yet, because if not, I've got a load of 14's here and I think some of them are brand new. You can have a used one for the price of the postage (still in good nick).

C


Sent you pm mate,

[Berlin]

Just for the record, the difference in radius between a 14 and a 15 tooth sprocket is 2.5mm. When sat on the bike there's negligible difference in pressure exerted on the guard as the angle has changed too little to actually measure. So any extra wear will be from extra torque and that is down to how much wrist you use anyway, so no need for concern on extra wear.


C

[yorkie_chris]

Just for giggles let's have a look at what's going in...

15 teeth
525... 5/8" pitch... 238.125mm circumference. effective radius 37.9mm

14 teeth
35.4mm effective radius.


edit:
lol, snap

[yorkie_chris]

so no need for condern on extra wear.


6% difference in chain tension for the same wheel torque and thus tractive effort... so less wrist is going to create the same chain wear as before.

[Berlin]

Actually measured, with a digital vernier, in a freezing garage,

14 tooth 61mm diameter at bottom of troughs. Radius 30.5mm
15 tooth 66 mm diameter " " " " . Radius 33.0mm

difference 2.5mm :)

AKA "A gnats chuff"!

[barwel1992]

i tell you what, you two are sad.... :D

[Berlin]

Just call us "Mythbusters"! ;)

[andrewsmith]

Just call us "Mythbusters"! ;)

perfectionist maybe more apt :smt040

[barwel1992]

Just call us "Mythbusters"! ;)

no, sad will do ;)

[yorkie_chris]

i tell you what, you two are sad.... :D

It's 10PM, Saturday night.

Rather than being in my preferred alehouse swaying slightly due to the inebriating effect of multiple pints of Yorkshire's finest bitter. Instead I'm at home, on the computer.


Trust me mate I don't need you to tell me I'm sad!

[barwel1992]

hahaha :D you have it light

im sat at the GF's house with Piers morgans life story on the tv........... about Cheryl Cole ........ now that is SAD

:D

[andrewsmith]

hahaha :D you have it light

im sat at the GF's house with Piers morgans life story on the tv........... about Cheryl Cole ........ now that is SAD

:D

:winner:

[hongman]

Hey, nothing about Cheryl Cole is sad!

[andrewsmith]

Hey, nothing about Cheryl Cole is sad!

ever met a geordie lass?

[hongman]

Yep ;)

[andrewsmith]

a proper geordie lass :offtopic:

http://chavspeak.info/wp-content/uploads/2009/10/do-not-kill-all-chavs.jpg

[coxxy]

"It is only easier if you have the slack available to take up on chain"

And one does, which is why its easier..........................;)

[hongman]

My eyes are bleeding

[coxxy]

braided brake lines for hair, race chain for jewellery, no doubt a 14T sprocket as a wedding ring............luvvly! :thumbsup::thumbsup:

[barwel1992]

ok back to this again, how much ware will a 14t front add on the chain, as im currently geard to high i think and im not replacing a £45 rear sprocket just yet :p

[MattCollins]

ok back to this again, how much ware will a 14t front add on the chain, as im currently geard to high i think and im not replacing a £45 rear sprocket just yet :p

Buy three sprockets and rotate them at each service to spread the wear.

[barwel1992]

its not the sprockets that im bothered about its the chain but MR zoran from TWF said it would be fine

[MattCollins]

Worn sprockets accelerate the wear on the chain. The counter shaft sprocket is the fastest wearing part in the system.

[yorkie_chris]

I'm with Matt, worth doing if you do lots of miles. With plenty oil the front sprocket is first part to wear and that will then destroy chain.

[barwel1992]

ok so basically i will get one and try it if i like it then i will swap every 4k