do you know why does the sheldon brown calculator asks for crank length? is that his own take on the gear inches calculation?
er, isn't that bicycle repair man? nice :)
The Coaster Brake Challenge recommends around 50 gear inches for racing cruisers. Note that most of their courses are hilly.
Here is a site to help determine crank length http://www.machinehead-software.co.u...alculator.html
Running 40x16 on my Primus Mootry. Looks like it's just a tick under 67 gear inches. Anyone else running a gear this low? I don't mind spinning but I really have nothing on downhills.
I am making a SS and was wondering if a BMX style gear would work for the rear?
Just built my first SS with a KHS frame and parts I had laying around. 42x17 doesn't need a chain tensioner and is OK for city riding, since I'm not concerned about speed. I'm 60, FWIW.
Quick update, I'm now running 46x20 FW (that's freewheel) for a singlespeed of 61-62 gear inches.
Its not slowing me down any and if anything, my average speed as increased as I am accelerating through corners and climbing faster than I used to. Squirrelli paced me using his bike computer and we were cruising at 19-21 mph. My cadence was 110 rpm with sprint accelerations to 27 mph (145 rpm). Since its a 20T freewheel, I have no issues with spinning out down hills as I can coast. But I do spinout on the flats now when pushing it. This ratio however is a blessing where I live because there is always a headwind blowing - also much easier acceleration and less strain on the knees.
46t Eighth Inch front to 17t all-city rear:
46t Eighth Inch to 14t Dura-Ace rear:
Just wanted to share, at least with the Brassknuckle, that the difference between a 14t and a 17t is roughly 1/3rd the dropouts
For me, the stock 48x16 on my Bianchi Pista is OK for a track workout without running out of spin, but its 81 inches is too high a gearing for riding around the neighborhood and city. It's relatively flat in the city here and gearing down to 48x18 (~72") is working well for me. There are some good rollers with short but steep grades in the rural areas. I'd have to gear the fixie down further for that, probably by another 8-10 inches into the mid to low 60's.
I share the observation that spinning faster, including on a road bike with a triple chainring and 10 cogs, goes faster. I see too many guys around here mashing their geared road bike pedals with slow cadences when they could be faster if they geared down a cog. Frequently riding a fixed track bike helps for smoother spinning on a geared road bike. FWIW I'm 58, nearly 59.
Great to see this sticky on gearing with its use of gear inches!
I am running 46/18 - 69 inches on the fixie I just completed - it is my first build at 50 yrs old. 15 miles ridden to date, with this AM being my first commute on the bike. There are some small hills on the route and building up speed leading to the hill resulted in minimal effort on the climb. Feels good in the flats as well. I have a brake and coupled with pedal resistance have not had any issues going down steeper hills either...
Running 45/17 here in Maine. Seems good so far. New to fixed gear with in the last 2 month's at 53 yrs old.
Running a 46 15/17 flipflop, with the 17 being a freewheel. With 700 tires, that puts me at about 81/71.
I'm up northern Indiana. No hills to speak of, and the wind isn't too bad, though given that this is my first ssfg bike, I wish I would have gone a bit lower, but I enjoy it well enough.
Thanks for the thread!
Question about gearing. :)
From experience on my geared bike 38 with 15 is almost perfect. That's arount 67 gear inches. A bit hard to start from traffic light, but I quickly build up revs and soon almost feel I need a higher gear. Nearest higher is about 71 gear inches (48 with 18) and higher than that is some 77 gear inches (38 with 15) which is too much 99% of the time (except when going down hill).
According to this, on a single speed, guess perfect would be 44/17, or 48/19 (if there is such combination). Is this OK for flat in town use?
For those doing vertical dropout conversions, this page is amazing!
is 51.9 a good starting point for gi on a mtb?
Sounds like a pretty good spot. I tried 55.5 on my 26er and found it too high to get up some hills. But it was pretty close to what I want.
I'm currently running 46/16 on 700x35c tires (78.1 GI according to bareknucklebrigade.com's Rabbit). Great on flats once I get going. Not so great acceleration compared to other riders I see. And a little tougher than I want on hills.
Question... I'm going up to 17T (73.5 GI) because of the hills and lack of acceleration. I have a flip flop hub though, so I'm wondering what I should put on the other side. Would going up to just 18T (69.4 GI) on the other side make sense? Should I go up 2 teeth with my "other" gear? 46/19 would put me at 65.8 GI. I'm not old nor do I have bad knees (Puppypilgrim's ranges).
Also, how much would I be moving my axle in the track-end flip flopping to 1-2 more teeth? Switching to bigger tires had me add a half link and move the axle about 2/3 of the way back in the track-end, so I don't have much room to play with.
This will be freewheel/freewheel by the way.
It looks as tho my photos got their links cut... but I was able to get 3 teeth difference on mine (14t vs 17t) but if I were you, I'd go 18. That way, if it does feel too easy, you can always swap over to the 16 side.... Though I am a huge fan of low gears and spinning
hai uncle 60
My current gearing is 52x16, 85.7 GI. I'm buying a new crankset, comes stock with a 46t chainring. If I throw a 14t cog on the back, making it 46x14, 86.7 GI, it should perform pretty much the same, right?
Someone second me...