Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

General Cycling Discussion Have a cycling related question or comment that doesn't fit in one of the other specialty forums? Drop on in and post in here! When possible, please select the forum above that most fits your post!

User Tag List

Reply
 
Thread Tools Search this Thread
Old 10-19-07, 07:42 PM   #1
ken cummings
Senior Member
Thread Starter
 
ken cummings's Avatar
 
Join Date: Dec 2005
Location: northern California
Bikes: Bruce Gordon BLT, Cannondale parts bike, Ecodyne recumbent trike, Counterpoint Opus 2, miyata 1000
Posts: 5,601
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
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.
ken cummings is offline   Reply With Quote
Old 10-19-07, 07:57 PM   #2
NoRacer
Isaias
 
NoRacer's Avatar
 
Join Date: Sep 2005
Location: Essex, MD
Bikes: Ridley X-Fire (carbon, white)
Posts: 5,179
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
53 x 11 - all Shimano Ultegra
NoRacer is offline   Reply With Quote
Old 10-19-07, 09:29 PM   #3
Bekologist
totally louche
 
Bekologist's Avatar
 
Join Date: Oct 2004
Location: A land that time forgot
Bikes: the ever shifting stable loaded with comfortable road bikes and city and winter bikes
Posts: 18,025
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
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.
Bekologist is offline   Reply With Quote
Old 10-19-07, 10:21 PM   #4
x136 
phony collective progress
 
x136's Avatar
 
Join Date: Sep 2006
Location: San Hoosey
Bikes: http://velospace.org/user/36663
Posts: 2,981
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
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.
__________________
x136 is offline   Reply With Quote
Old 10-19-07, 10:54 PM   #5
Machka 
Long Distance Cyclist
 
Machka's Avatar
 
Join Date: Jan 2003
Location: I ride where the thylacine roamed!
Bikes: Lots
Posts: 46,236
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 335 Post(s)
Quote:
Originally Posted by NoRacer View Post
53 x 11 - all Shimano Ultegra
This is what I used to have.

I now have a 48 x 11.
Machka is offline   Reply With Quote
Old 10-19-07, 11:02 PM   #6
Machka 
Long Distance Cyclist
 
Machka's Avatar
 
Join Date: Jan 2003
Location: I ride where the thylacine roamed!
Bikes: Lots
Posts: 46,236
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 335 Post(s)
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:
http://www.recumbents.com/wisil/cos2/cos2progress.htm
Machka is offline   Reply With Quote
Old 10-19-07, 11:09 PM   #7
StephenH
Uber Goober
 
StephenH's Avatar
 
Join Date: Sep 2007
Location: Dallas area, Texas
Bikes:
Posts: 11,282
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 21 Post(s)
The "Track Racing- pulled by motorcycle" thread on the track racing forum mentions a 63x16 arrangement, i think it is.
StephenH is offline   Reply With Quote
Old 10-19-07, 11:47 PM   #8
fat_bike_nut
Senior Member
 
Join Date: Feb 2007
Location: San Francisco!
Bikes: 2010 Surly LHT (main rider and do-everything bike), 2011 Bike Friday NWT (back-up bike and multi-modal)
Posts: 909
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
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...
fat_bike_nut is offline   Reply With Quote
Old 10-20-07, 06:57 AM   #9
well biked 
biked well
 
well biked's Avatar
 
Join Date: Jul 2005
Bikes:
Posts: 7,088
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
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.
well biked is online now   Reply With Quote
Old 10-20-07, 08:18 AM   #10
MichaelW
Senior Member
 
Join Date: Feb 2001
Location: England
Bikes:
Posts: 12,926
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
This bike was used for a static roller cycling record so no air resistance was ivolved.
MichaelW is offline   Reply With Quote
Old 10-20-07, 11:10 AM   #11
roadfix
hello
 
roadfix's Avatar
 
Join Date: May 2003
Location: Los Angeles
Bikes:
Posts: 18,587
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Quote:
Originally Posted by well biked View Post

As far as my own bikes, I've got nothing unusual to report in regard to gear inches.
Me too. I don't need more than 100 GI.
roadfix is offline   Reply With Quote
Old 10-20-07, 01:44 PM   #12
M_S
Senior Member
 
Join Date: Dec 2006
Bikes:
Posts: 3,693
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by MichaelW View Post
This bike was used for a static roller cycling record so no air resistance was ivolved.
So why the aeoro stuff?


52/11 for me, or 48/12 depending on bike. First is stock, second, I'm not sure.
M_S is offline   Reply With Quote
Old 10-20-07, 06:02 PM   #13
Doug5150
Senior Member
 
Join Date: May 2005
Location: IL-USA
Bikes:
Posts: 1,661
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by ken cummings View Post
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? ...
Some recumbents come standard with 60+T rings, but these usually have a 20" rear wheel and no mid-drive.

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.
~
Doug5150 is offline   Reply With Quote
Old 10-20-07, 07:36 PM   #14
CaptainCool
``````````````
 
CaptainCool's Avatar
 
Join Date: Feb 2007
Location: san jose
Bikes:
Posts: 763
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Sheldon Brown pushing a 72T ring. (From this page.) Again, small wheels. There are also cassettes that go down to 9T for folders.
CaptainCool is offline   Reply With Quote
Old 10-20-07, 08:12 PM   #15
BlazingPedals
Senior Member
 
BlazingPedals's Avatar
 
Join Date: Dec 2004
Location: Middle of da Mitten
Bikes: Trek 7500, RANS V-Rex, Optima Baron, Velokraft NoCom, M-5 Carbon Highracer, homebuilt recumbent
Posts: 8,943
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 102 Post(s)
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.
BlazingPedals is offline   Reply With Quote
Old 10-20-07, 08:35 PM   #16
JanMM
rebmeM roineS
 
JanMM's Avatar
 
Join Date: Jan 2006
Location: In Central IN
Bikes: RANS V3, RANS V-Rex, RANS Screamer
Posts: 13,395
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 31 Post(s)
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
JanMM is offline   Reply With Quote
Old 10-21-07, 09:53 PM   #17
GRedner
Senior Member
 
Join Date: Aug 2006
Location: Brookline, MA
Bikes:
Posts: 514
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
There are no numbers, but a couple of neat images on this page:
http://www.canosoarus.com/08LSRbicycle/LSR%20Bike02.htm

Note the double-reduction drivetrain in the second image!
GRedner is offline   Reply With Quote
Old 10-21-07, 11:11 PM   #18
CaptainCool
``````````````
 
CaptainCool's Avatar
 
Join Date: Feb 2007
Location: san jose
Bikes:
Posts: 763
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by GRedner View Post
There are no numbers, but a couple of neat images on this page:
http://www.canosoarus.com/08LSRbicycle/LSR%20Bike02.htm

Note the double-reduction drivetrain in the second image!
Let's see.

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?
CaptainCool is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 10:04 AM.