Highest possible gearing / All sorts
10-19-07, 07:42 PM
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Highest possible gearing / All sorts
Over the last couple of years I've seen several threads about lowest gears. I even started one myself. A quick search for highest gears didn't give me too much. So how about it? What kinds of highest gears do you have on your machines? 52 X 12s? Please distinguish between commercially available gearing including the Schlumpf system, homebrew using standard parts, and frankenbike creations. All are welcome. I have a 44 X 14 on my commuter bike and know of a nearly 400 gear-inch high on John Howards' Bonneville speed bike.
10-19-07, 09:29 PM
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i think some folding bikes come with 64-68 tooth big rings. but, they are using 16 or 20 inch wheels.
I got 52x11 and 53x11 on my 700c road bikes. pretty sufficient for me, i've got to be going downhill to take advantage of gearing that high.
I got 52x11 and 53x11 on my 700c road bikes. pretty sufficient for me, i've got to be going downhill to take advantage of gearing that high.
10-19-07, 10:21 PM
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You can get some bigass chainrings for the old-school TA Cyclotouriste cranks (up to 68t, with larger sizes available). Combine that with a cassette with an 11t cog, and you've got a recipe for some ridiculous gearing.
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10-19-07, 10:54 PM
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This is what I used to have.
I now have a 48 x 11.
I now have a 48 x 11.
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10-19-07, 11:02 PM
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A friend of mine works in a machine shop, and builds recumbents. He's got his own brand name - Peterbuilt. But he also does some work with a HPV team, and machines their Cos2 chain ring. He showed me the one he was sending them for an event ... that thing was HUGE!
I just did a search on the internet and came with a little bit of info about that chain ring:
https://www.recumbents.com/wisil/cos2/cos2progress.htm
I just did a search on the internet and came with a little bit of info about that chain ring:
https://www.recumbents.com/wisil/cos2/cos2progress.htm
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10-19-07, 11:09 PM
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The "Track Racing- pulled by motorcycle" thread on the track racing forum mentions a 63x16 arrangement, i think it is.
10-19-07, 11:47 PM
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I dunno if it would work with a full size bike and mega-huge chainring combo, but the Shimano Capreo Cassette for folding bikes goes as low as NINE (9) Teeth. 68T/9T = insanely high 
I'd think that you would need some monster quads to push that. Or help from gravity going down a hill...
I'd think that you would need some monster quads to push that. Or help from gravity going down a hill...
10-20-07, 06:57 AM
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Don't forget that a big part of the gear inch formula is the outside diameter of the drive wheel. Outside diameter of drive wheel (in inches) times number of teeth on front sprocket divided by the number of teeth on the rear sprocket equals gear inches.
As far as my own bikes, I've got nothing unusual to report in regard to gear inches.
As far as my own bikes, I've got nothing unusual to report in regard to gear inches.
10-20-07, 11:10 AM
#11
hello
10-20-07, 01:44 PM
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This bike was used for a static roller cycling record so no air resistance was ivolved.
52/11 for me, or 48/12 depending on bike. First is stock, second, I'm not sure.
10-20-07, 06:02 PM
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One of the tadpole trikes (a Greenspeed I think) has a 70T big ring standard--but once again, the reason for that is that it's got a little rear wheel, 20" or 16".
Hostel Shoppe (online, and which caters to recumbents) has a couple different brands of chainrings, up to 68T with a couple larger I think. They had one that went to 80T a couple years ago; the only thing I can imagine that would be used on normally would be that there are lowracers that use 16" wheels front and rear.
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10-20-07, 07:36 PM
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Sheldon Brown pushing a 72T ring. (From this page.) Again, small wheels. There are also cassettes that go down to 9T for folders.
10-20-07, 08:12 PM
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Another recumbent here. I've got a 26x1.25 tire and run a 56/11 high gear. That makes for about 125 gear-inches. Mine is more-or-less standard stuff: 105 crank with Vuelta 30/44/56 chainrings and a SRAM 11-30 cassette.
10-20-07, 08:35 PM
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One reason I can't ride as fast as BlazingPedals is that I also run a 56x11 high gear, but with a 20x1.5 tire.
SluggishPedals
SluggishPedals
10-21-07, 09:53 PM
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There are no numbers, but a couple of neat images on this page:
https://www.canosoarus.com/08LSRbicycle/LSR%20Bike02.htm
Note the double-reduction drivetrain in the second image!
https://www.canosoarus.com/08LSRbicycle/LSR%20Bike02.htm
Note the double-reduction drivetrain in the second image!
10-21-07, 11:11 PM
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There are no numbers, but a couple of neat images on this page:
https://www.canosoarus.com/08LSRbicycle/LSR%20Bike02.htm
Note the double-reduction drivetrain in the second image!
https://www.canosoarus.com/08LSRbicycle/LSR%20Bike02.htm
Note the double-reduction drivetrain in the second image!
139mph (first picture) at 180rpm on 20" wheels is a gear ratio of about 13. That's something like 115x9.
152mph (second picture) at 180rpm on 20" wheels is a gear ratio of about 14.5. That's something like 53x12 on the first chain and 40x12 on the second.
While I'm at it, that "Ultimate Bike" above did 207mph on rollers. Assuming 700c wheels and 180rpm again, the gear ratio is 15. Looks like the chainring is about 20" in diameter, so about 120 teeth. Cog would have to be 8T, but it doesn't look that tiny. How fast are these guys spinning? Is there a 2x internal hub in there?
