gear ratios for city riding?

10timesbetter

just curious to see what you guys ride in the city, and how fast you can go?

right now i've got 39/14, and i can get about 25 mph before my legs start flapping around and i feel like some kinda fish, I think i'm gonna work on going up to 44/14, and maybe get another front sprocket, something like ....say 48 for when i know i'm not going anywhere that involves any large hills,

geoffs

I ride a 42/16 which is about 71". I have managed 63kms/hr (39mph) downhill and worked out with the gear calculator(gear calc/) that I was spinning at about 190rpm. riding a fixie is all about spinning smoothly

cheers

geoff

10timesbetter

39mph? haha, were your feet on the pedals? or is this not a fixed gear? my legs are going faster at 30mph than i care for, let alone 40mph, not to mention, with my gears, your legs would be spinning even faster than mine at those speeds,

how are people getting the numbers for their gear ratios? just add the two numbers together?

geoffs

It's fixed. It's a track bike that I have put a front brake on. great to ride but I have to be careful with the panic stops to avoid cars as the back wheel comes off the ground abit to easily as the wheelbase is short.

Gear ratios are worked out usally as "gear inches". This is based on the equivalent wheel diameter of a high wheel bicycle. to find out more, try reading some of Sheldon Brown's
articles on fixed gear bikes.

DrBlasto

I realized this is a very old topic, but seriously... I ride a 41/16 with 700c wheels and 170mm cranks (an old Nishiki 10-speed-turned-Urban Streetfighter) and the fastest I've managed, on a downhill, absolutely spun-the-hell-out-like-I've-never-pedaled-before-or-since, is 26mph.

If you're getting 39mph on a 42-16, then either you're superhuman, or your computer is calibrated incorrectly.

AzzaC

190rpm!! Is that wheel revolutions or crank?? I assume crank, as you are talking about 'spinning'

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geoffs

Crank revolutions.
I am definitely not superman, perhaps drblasto just needs a steeper hill? I should include that I am back to doing only 20kms/hr going up the short hill to King Street. Its always fun keeeping up with the cars!

Cheers

Geoff

akoid1973

Hi, I've built a commuter bike from a salvaged Scott Pro Racing MTB Steel frame. I had the LBS fit horizontal dropouts at great expense and fitted a Sturmey 7 speed after reading Sheldon Brown's glowing reports. Since then Single Speed has really taken off and I decided to try one gear to work and back. Lo and behold it was so much fun I've become a convert. The current ratio is 44 X 16 but I reckon in a few month I'll get a bigger ring 46/48 or go down to 15 at the back. I reckon I can crank it up to 25mph at the moment but the two slight descents i encounter make me freewheel me the bottom at about 30mph. Hope this helps, Graeme

chiryu

I hope this helps. (Front/rear)

uphill I use 42/32, when cruising along 42/28, 42/24, when I'm riding downhill 42/11.

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Chi

Meek One

I believe him. You probably have never ridden a fixie down a mountain before. This spring I hit right around 200rpms in a 48x17 in what should be the 70-80km/h range. I'll never forget the experience either. Around 160rpms I was bouncing violently on the saddle and thought I was going to get 'bucked' off , but instead something happened to my hips and they 'released' and 160-200rpms was smoother as the bike accellerated having the 'brake' (read hips) released. Since that day I can spin out gears with virtually no bounce whatsoever. AWESOME

__________________
-Meek
"Some people train to look pretty. I just train so I can be the strongest man there is. And then again, I'm already pretty." -Magnus Samuelsson

Meek One

I ride my Langsters standard 48x16 usually. I think 48x14 tends to be too tough on the knees if you aren't warmed up. FWIW a lot of trackies do their initial warm-up with a 48x16 too.

__________________
-Meek
"Some people train to look pretty. I just train so I can be the strongest man there is. And then again, I'm already pretty." -Magnus Samuelsson

simon london

I ride a 42/16 around London - ideal but max speed about 22mph before that flapping feeling

Meek One

I see a lot of people riding the 42x16 combo too. I wanted to try it but alas was too lazy to break down my chain...

__________________
-Meek
"Some people train to look pretty. I just train so I can be the strongest man there is. And then again, I'm already pretty." -Magnus Samuelsson

huhenio

Lo and behold .... 42x16 for me. The 42 is the small ring on my formerly geared bike, and 16 is whatever the LBS had in hand. It works fine for me on the rolling hills around here, but I am yet to asess what kind of damage I am doing to my knees.

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2003 Gary Fisher Zebrano (standard gearing)
Comfort commuter with drop and aero bars.
Think of a Buick.

1974 Schwinn Traveler Fixed Gear Conversion (42x13)

Think of some medieval torture element that goes fast

Wheelist, show me the bike!!!!!!!