What size rear cog for Raleigh Sport in the City?

Replies to This Discussion

Permalink Reply by Mike Bullis 5.5-6.5 miles on November 29, 2010 at 8:16pm

Any of the three will be a big improvement. I run a 22 out here in the Fox Valley, great for the hills. I've run a 20 out here and it was fine but I keep my bike set up for the 3ST.

www.bikesmithdesign.com carries 21t SA cogs.

Permalink Reply by olloyd1 on November 29, 2010 at 8:16pm

Last three speed I set up was for winter. So the top speed is what I like the gearing to be on a very lightweight single speed. Then I have two lower gears.
Sheldon brown's gear calculator is great for figuring this stuff out. There is options to put in hub gears.
Just type in the tooth ration you want for one of the gears and see if the others will compliment it or not.
Otherwise, stick a 22t cog on it. shimano will fit just fine.

Permalink Reply by Far'arned Retrogrumpalunkus #63 on November 29, 2010 at 8:46pm

Thanks for the fast replies!

I think I might go with the 22 as I'm a wuss and this bike is going to be mostly a tweed cruiser. I might run into some hills with it someday if I ever bring it back to Madison.

That cotter press at Bike Smith really speaks to me. So far I use the Sheldon method of a REALLY BIG HAMMER and just bite the cost of replacing them as they don't cost that much. But that press would be really sweet.

Permalink Reply by Far'arned Retrogrumpalunkus #63 on December 1, 2010 at 11:39am

I've done a bit of figuring and I think I've finally settled on the 22T cog which gives me a 42.5_56.7_75.6 gear-inches in each of the 3 speeds according to Sheldon Brown's gear calculator using the values of: 26" nominal wheel size, 170mm crank, 48T chainring, 22T replacement cog, and the S/A AW wide-ratio hub.

The stock 18T cog is giving me 52.0_69.3_92.4.

Did I get any of those numbers wrong?

Sure, top gear will be a little low at 75.6 but not too bad. This is a heavy bike after all and there are no downhills around. 57 gear-inches sounds about right into the wind and 42.5 still sounds a bit tall for low gear but getting it any lower would really hurt the topside.

Permalink Reply by James B on December 1, 2010 at 11:59pm

Not even sure I should admit to this technique for cotter pins but it seemed to work fine.... I have spare bench vise that I used like a giant press. Kinda funny to look at and a bit of a large thing to handle however it means no hammering near a 50 year old bike frame and one less gadget that sits in a toolbox most of the time

James Baum said:

Thanks for the fast replies!

I think I might go with the 22 as I'm a wuss and this bike is going to be mostly a tweed cruiser. I might run into some hills with it someday if I ever bring it back to Madison.

That cotter press at Bike Smith really speaks to me. So far I use the Sheldon method of a REALLY BIG HAMMER and just bite the cost of replacing them as they don't cost that much. But that press would be really sweet.

Permalink Reply by Alan Lloyd on December 29, 2010 at 12:37pm

I find the 18-tooth cogs, or thereabouts, fine for the flatlands around here and it is only in the hill country I find I need the 22-tooth cogs, but I'm not much of a spinner!

Once I have my 3-speeds set up for the likes of the Lake Pepin 3-speed tour I find 1st almost too low to be of much use around Chicagoland and am missing out on the top end?