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View Full Version : Smaller cog on a 16"er with SA 3 speed hub

Caaah
04-19-08, 09:59 PM
Has anyone changed the stock rear cog on their 16in folder (with a SA 3 speed hub) for a smaller one? On my Curve D3, I never use 1st gear and I wish I had a little more speed on top, so I'd love to try swapping the cog out. Unless I'm counting wrong, it looks like there is a 14t one on there currently. Do they even make a smaller one?
somnatash
04-20-08, 01:51 AM
Hi,
if I interpret the website
http://www.sturmey-archer.com/index.php
right, then you can change to 13teeth (...sprocket teeth: 13T through 22T)
LittlePixel
04-20-08, 05:04 AM
Harris Cyclery (Boston MA) stock sizes down to 14t here (http://sheldonbrown.com/harris/sturmey-archer-parts.html)
alecw35
04-20-08, 09:18 AM
think Ive got a 13.

bikes like old moultons have them
Caaah
04-20-08, 07:25 PM
Cool! 13t sturmey archer would be awesome if I could find one...googling is getting me nowhere. Anyone have better luck finding one?
stevegor
04-20-08, 07:30 PM
If you can't find one, you have the option of a larger front chainring or using a dremmel on a standard Shimano 13t cog and grinding the unwanted tabs off...a la Sheldon Brown, R.I.P.
arctos
04-20-08, 09:17 PM
I believe that Old Maillard Freewheel cogs have the same three notches for mounting single cogs on a SA hub. You may find a 13 tooth cog that way.

One source maybe at:
http://www.cafedevelo.com/index.php?act=viewProd&productId=389
LWaB
04-20-08, 09:34 PM
Brompton sell suitable 13T cogs in 1/8" and 3/32".
Caaah
04-21-08, 09:33 AM
If you can't find one, you have the option of a larger front chainring or using a dremmel on a standard Shimano 13t cog and grinding the unwanted tabs off...a la Sheldon Brown, R.I.P.

Is there any disadvantage to switching the front chain ring instead of the rear cog?
Caaah
04-21-08, 09:36 AM
I believe that Old Maillard Freewheel cogs have the same three notches for mounting single cogs on a SA hub. You may find a 13 tooth cog that way.

One source maybe at:
http://www.cafedevelo.com/index.php?act=viewProd&productId=389


I saw they have this one...

http://www.cafedevelo.com/index.php?act=viewProd&productId=463

Would that work?
arctos
04-21-08, 12:12 PM
I saw they have this one...

http://www.cafedevelo.com/index.php?act=viewProd&productId=463

Would that work?

No. That is a thread on track cog rather than a slide on cog with three notches held in place by the snap ring on the hub.

Look at your SA hub and cog set up so you have a mental picture of what you need. Or remove the snap ring and cog to see exactly how it works.

I notice that Cafe Velo is in the process of moving to a new larger location in another city so some delay in getting a cog seems inevitable.
stevegor
04-21-08, 08:30 PM
Is there any disadvantage to switching the front chain ring instead of the rear cog?

Yes, it is usually more expensive to buy a front chainring than a rear cog, because it has more teeth and you will probably need to lengthen the chain, but if you can't find a 13t to suit the SA hub that might be your only option, unless you pull out the dremmel........
BTW, I'm not sure how many more teeth you would want on the front, 2 or 4 or more, but I recently upgraded my tandem's largest 'ring from 48t to 52t, which gives me a pleasing increase at top speed.
Caaah
04-22-08, 08:50 AM
Yes, it is usually more expensive to buy a front chainring than a rear cog, because it has more teeth and you will probably need to lengthen the chain, but if you can't find a 13t to suit the SA hub that might be your only option, unless you pull out the dremmel........
BTW, I'm not sure how many more teeth you would want on the front, 2 or 4 or more, but I recently upgraded my tandem's largest 'ring from 48t to 52t, which gives me a pleasing increase at top speed.

Ok, cool. I'll have to weigh the two options for a bit.
alecw35
04-22-08, 12:46 PM
I got a Campag Fifty six tooth chain ring on ebay for 99p.
Might fit it to one of my 20" wheeled bikes.

If you use bigger chainrings, there may be frame clearance issues.
Ive got a 52t on my Puch Minisprint cruiser bike. It hits the chainstay.
Have to dent the tube in a bit, to clear it. Bike companies do that.

Also if you've got a front mech it might need moved. Which might be difficult on some frames.

Also smaller cogs on rear wheel will put the chain nearer the chainstay. So be carefull for clearance
stevegor
04-22-08, 02:29 PM
Excellent advice alecw35 :)
Caaah
04-22-08, 03:17 PM
I got a Campag Fifty six tooth chain ring on ebay for 99p.
Might fit it to one of my 20" wheeled bikes.

If you use bigger chainrings, there may be frame clearance issues.
Ive got a 52t on my Puch Minisprint cruiser bike. It hits the chainstay.
Have to dent the tube in a bit, to clear it. Bike companies do that.

Also if you've got a front mech it might need moved. Which might be difficult on some frames.

Also smaller cogs on rear wheel will put the chain nearer the chainstay. So be carefull for clearance

Ahhh...these are all things I wouldn't have realized until buying a bunch of parts. :eek: Thanks for the info!