Author Topic: Spline drive sprocket....  (Read 298 times)

Offline Feeble

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Spline drive sprocket....
« on: May 15, 2020, 06:20:17 PM »
I guess I have screwed up here then...


I have just gone to install my new parts as follows...


Cranks - https://www.sourcebmx.com/products/united-severance-cranks?variant=20342378233967


Bottom bracket - https://www.sourcebmx.com/products/united-supreme-euro-bb?variant=20033412300911&loc=gb&lang=en&currency=gbp&gclid=Cj0KCQjw-_j1BRDkARIsAJcfmTHKnfUUXI0lwKemzO49uQZwAy8utr6UFSDlrwzYPztviIF50mELiDwaAud9EALw_wcB


Sprocket - https://www.sourcebmx.com/products/profile-galaxy-spline-sprocket-22mm?currency=gbp&lang=en&loc=gb


It was all going fine until I have gone to try the chain on the sprocket and it is too narrow!  >:(  I am guessing it needs to be narrow, as I have a KHE Geisha freecoaster, so a wider chain would not sit nice in the freewheel...


Is there any alternative 25t spline drive socket that would suit a thin chain, as I can't find one. This is depressing... It seems quite hard to buy the right parts these days!

Offline Feeble

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Re: Spline drive sprocket....
« Reply #1 on: May 15, 2020, 06:29:27 PM »
I'm guessing the problem comes from having that St Martin eco flat crank. It is a mountain bike style chain I think. So maybe I can get a suitable alternative freewheel for the Geisha hub... And a new chain.

Offline nosubsteve

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Re: Spline drive sprocket....
« Reply #2 on: May 15, 2020, 10:58:51 PM »
"-9T cog can use narrow 3/32" chains such as the KHE Tanga or normal 1/8" width chains"

So it is narrower, but a normal BMX chain should work fne.

Offline DaddyCool

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Re: Spline drive sprocket....
« Reply #3 on: May 15, 2020, 11:55:53 PM »
Hi Feeble,
there is no problem at all to run a "normal" BMX chain (1/8") on a driver or sprocket which is made for 3/32" (narrow) chains. The teeth are just 3 mm wide for 1/8" chains and 2 mm for 3/32" chains. So the chain would have some side-to-side play, but this should not be a problem. So you could just buy a 1/8" chain...
But: These are heavier and from my experience a high quality 3/32" chain does the job for flatland. What I did several times: Grind down the teeth of the sprocket to 2 mm width! With a belt sander it is just some time you need to spend. Of course the sprocket does not look so nice any more, but if you do it on the "backside" I think you can accept this. This would be the easiest way.

Offline Feeble

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Re: Spline drive sprocket....
« Reply #4 on: May 16, 2020, 08:09:22 AM »
Two great replies. Thanks guys, things might not be so bad after all!  ;D

Offline out~riding

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Re: Spline drive sprocket....
« Reply #5 on: May 18, 2020, 03:17:38 PM »
the standard is 1/8 chains,
KHE and a few others went 3/32" many years ago to loose weight but that trend passed.

Offline DaddyCool

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Re: Spline drive sprocket....
« Reply #6 on: May 30, 2020, 11:55:44 PM »
Not for me  ::)
I even use 10-speed chains (which is 10/128 I think) without any problems and they are super light... You can easily save 100 g here. But I do not have my chain super tight. I assume this would not work so long.