Nov 29, 2001 10:24 AM
|I have a question.
Been thinking about getting a single speed bike for commuting/winter riding.
How do you choose gearing?
Is it based on Effort (i.e. gearing that will allow you to maintain a certain heartrate)?
Is it based on cadence?
Nov 29, 2001 10:39 AM
|Based mine first on what the "average" seemed to be (42/16 ish I found)then adjusted on what cadence/effort I liked to cycle at, given the route I was riding. Lots of the SS/Fixed sites have some gearing suggestions/charts, e.g.
Nov 29, 2001 10:49 AM
|Gearing is also based on topography, personal strength, quality of road, etc. The advice here and over on the singlespeed board will give you a good start, then it's like a personal religious quest to find the final perfect chainring:cog combo.
I started with a nice steel BMX ring that fit my oldschool 5 bolt crank. I've got 3 freewheels to swap out. My three combos:
44:16 - Fastest, good in nice summer weather
44:17 - My best all around gear
44:18 - For when the wind is high, the hills are steep, or the traffic stops a lot.
Another way to approach it would be to use the cadence calculator here: http://www.analyticcycling.com/GearSpeedCadence_Page.html
and use the max cadence you want to pedal to find which gear ratio will give you your desired max speed.
Confused? good. Now start with 44:17 and play from there
|Depends on hills, wind and style.||MB1|
Nov 29, 2001 10:57 AM
|We started with what Sheldon Brown sold us-39/14 fixed. I spin more than Miss M so I changed to a 15 fixed.
Now I use 42/16 fixed and 42/17 freewheel. Miss M still uses the 39/14 fixed and 39/16 freewheel. The reason we use harder gears fixed is the downhills. It is tough to ride down the short but steep hills around here in a real easy fixed gear. SS you can gear down a little for the climbs and just pedal at the top of the downhills.
BTW after a few thousand miles fixed and SS I have come to realize that the best reason to make the change is fun. SS or fixed is a whole lot of fun and a nice change from our geared bikes.
|BTW I've got a 58cm fixte for sale.....nm||MB1|
Nov 29, 2001 10:58 AM
|You know better!||Ads don't belong here.|
Nov 29, 2001 1:51 PM
|pimp your junk in the marketplace|
|BTW I've got a 58cm fixte for sale.....nm||Len J|
Nov 29, 2001 2:16 PM
|What is standover & top tube length?
Nov 29, 2001 3:55 PM
Nov 30, 2001 7:17 AM
|What is it and what do you want for it? You can e-mail w/ the details if you like. I've been looking for one-I have a SS but it's really old, heavy, and a bit too small for me.|
|Depends on hills, wind and style.||Len J|
Nov 29, 2001 2:15 PM
|My real question is (as I reflect), what do you use the SS for? If I use it for LSD rides wher I'm keeping my heartrate down, I would gear differently then If I wanted to "Push" a little. How do you guys decide?
|Those guys are too tough for me; start with 2:1||cory|
Nov 29, 2001 11:33 AM
|Local wisdom around here, in a dead-flat valley surrounded by 7,000-foot passes, is to begin with 2:1 gearing and adjust. I started at 38:20 because of the hills, and it's been pretty close--I spin completely out at about 18mph, but if I went higher, I couldn't muscle up the big hills. I don't know where those guys are riding 42:16, but it would only work for me in Kansas.|
|2:1 is for dirt isn't it? Len is looking for a commuting setup.||MB1|
Nov 29, 2001 3:54 PM
|Here in DC we have a fairly flat downtown surrounded by hills. We have done road centuries with the gearing I described earlier (no passes around here, we call them "Gaps"). The climbs around here are steep not long-mostly.
I believe Len lives on the Eastern Shore of Maryland-dead flat with occasional killer winds.
Nov 29, 2001 1:37 PM
|It's a tough choice. It totally depends on where you ride, fitness, the alignments of the planets, etc. |
I live in a 'hilly' area. I ride a 34:17 mtn bike and a 44:18 Fixed Gear.
34:17. 2:1 is great for slightly hilly areas or very hilly areas if you are very strong. Most mtn bikers would gear down so they can climb the granny gear climbs.
44:18. But, you said around town, winter riding so you probably mean a roadbike. 44:18 works well for me in the hills. I can climb almost all paved roads. Almost. But, I have a tough time descending. Ouch.
If you look at regular track bikes for flat riding, they have much bigger gears, like 52:17. That would suck unless you were only riding flats.
|First rule of singlespeeding ... its not that critical.||Humma Hah|
Nov 29, 2001 6:50 PM
|Wanna go faster, pedal faster.
Wanna climb a hill, pedal harder.
That said, since the dawn of cycling, the preferred gearing for most all around road work has been around 75-80 "gear inches" or so (gear inches is wheel diameter times gear ratio, or the diameter of a straight-cranked "penny farthing" high-wheeler's wheel), which works out to around 2.5:1 gearing with a typical roadbike wheel.
Off road, 2:1 gearing is a good starting place, maybe a bit lower in serious mountains. I've run 2:1 on pavement for several months straight to improve my high-speed spin, and it works remarkably well.
I'm heading out to the garage in a few minutes to put on a fresh chain, and simultaneously swap my 2.3:1 chainwheel out for a 2.56:1, the stocker that came on the bike 30 years ago. I've had the 2.3:1 on since Solvang last spring, which was a mite hilly for a cruiser. 2.56 is better for around here.
Really flat areas might warrant a little higher. Track bikes routinely run very high ratios, 3:1 to as high as 4:1, and speed record bikes have insanely high ratios.
Nov 30, 2001 3:34 AM
|Speed and cadence. I used Sheldon Brown's gear calculator to figure out my gearing. My comfort zones are 90-110RPM and about 30-36km/h. A 42x16 gives me a cadence of 100RPM at 33kmh. It also allows me to go as low as 20km/h without going below 60RPM - that's how slow I go in a really nasty headwind on the dykes in our polders. |
I can hold a cadence up to about 120 with reasonable comfort and I can stay with a group going close to 45-50km/h if I really have to and I know the road's not to long. Oh, and Sheldon Brown also has everything in miles if you don't want to do the conversion :)
|It Depends On You...||Greg Taylor|
Nov 30, 2001 6:28 AM
|As you can tell from the responses -- recommendations all over the place -- the gearing that you choose really depends on you and where you will be riding. One way to tackle it is to take your geared bike out on your commute and then leave it in a gear that you can comfortably use for the entire ride. Don't shift. Try that a couple of times, using different combinations. Find the one that you like, and then figure out how many gear inches that combo represents. Voila! You have your gearing choice.
I use a 46 x 16 combo for commuting and general farting around on my fixed gear dumpster dragster. It gives a hair over 75 gear inches, so I can keep up decently on rolling terrain. It can get dodgy on downhills. I've got a 52 ring that I want to try at next year's Seagull Century...
Someone here posted a link to a really neat utility that is designed to help you select fixie gearing. The Java version gives you a lot of data for each gearing selection (speed at different rpms, gear inches, etc). I've reposted it below.