10 Tooth Cog?
03-14-10, 06:58 PM
#1
Senior Member
Thread Starter
Join Date: Nov 2008
Location: TX
Posts: 2,620
Bikes: Orbea Orca Trek 5500 Trek Equinox
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
10 Tooth Cog?
I'm looking for a 10 tooth cog for a Shimano hub. And before every goes all "Sheldon Brown" on me with gear inch calculators and questions about speed at X rpm etc, let me explain. This is for a friend who loves to push big gears, and there is a local TT that has a long downhill, that normally has a tailwind. It's a short TT and the average speed is around 32-33 mph for winners. He has a 58 tooth front chainring that he can put on, but that makes all of his gears taller, and he really only wants this one gear for a specific section of the TT. So, anyone have a lead on such a thing? I know it exists, but where to find one?
03-14-10, 07:05 PM
#2
Senior Member
Join Date: Jul 2005
Location: Backwoods of Ontario
Posts: 2,152
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Are you sure it exists? I believe that smaller than 11 tooth simply is too small for to fit over a Shimano freehub body. You'd have to get into BMX hubs or have a Capreo freehub (that is incompatible with standard freehub parts) to get 10 tooth.
And just to go "Sheldon Brown" on you, try this.
https://www.sheldonbrown.com/harris/k7.html#capreo
And just to go "Sheldon Brown" on you, try this.
https://www.sheldonbrown.com/harris/k7.html#capreo
03-14-10, 07:06 PM
#3
Senior Member
Join Date: May 2007
Location: Santa Cruz Mountains
Posts: 6,169
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
There's no 10t cog for normal Shimano hubs. It wouldn't fit. You can go to a 9t cog on the Capreo hub- it's made for bikes with small (20") wheels. The freehub body is smaller than normal hubs.
03-14-10, 07:26 PM
#4
Senior Member
Thread Starter
Join Date: Nov 2008
Location: TX
Posts: 2,620
Bikes: Orbea Orca Trek 5500 Trek Equinox
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Saw the Capreo, but the hub body is a smaller diameter. I think SPR, or SRP made a 10 tooth cog awhile back.
03-14-10, 10:40 PM
#5
Senior Member
Join Date: Jun 2004
Location: Northern Nevada
Posts: 3,811
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Not to get all gear-inchy on you, but is the diff between a 58-11 and 58-10 even enough to feel? I wouldn't know--I can't turn either one.
03-14-10, 10:45 PM
#6
Senior Member
Join Date: Sep 2009
Posts: 589
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
03-14-10, 10:53 PM
#7
shut up and ride
Join Date: Nov 2005
Location: noho
Posts: 1,947
Bikes: supersix hi-mod,burley duet tandem,woodrup track,cannondale cross,specialized road
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
maybe run 52 or 53 or something like that as a small ring and the 58 as the big ring. it might take some work as you would have to flip the small ring around and remove any pin for the crankarm. just a thought...
or just use the 58. a 53x12 and a 58x13 are pretty much the same gear inches and a 53x11 and a 58x12 are similar as well
or just use the 58. a 53x12 and a 58x13 are pretty much the same gear inches and a 53x11 and a 58x12 are similar as well
03-14-10, 11:38 PM
#8
Over the hill
Join Date: Mar 2006
Location: Los Angeles, CA
Posts: 24,372
Bikes: Giant Defy, Giant Revolt
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 996 Post(s)
Liked 1,204 Times
in
690 Posts
About 5 mph at 120 RPM. I could turn one... if the back wheel was lifted off the ground.
__________________
It's like riding a bicycle
It's like riding a bicycle
03-15-10, 08:10 AM
#9
pan y agua
Join Date: Aug 2005
Location: Jacksonville
Posts: 31,302
Bikes: Willier Zero 7; Merlin Extralight; Calfee Dragonfly tandem, Calfee Adventure tandem; Cervelo P2; Motebecane Ti Fly 29er; Motebecanne Phantom Cross; Schwinn Paramount Track bike
Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 1447 Post(s)
Liked 724 Times
in
371 Posts
I know you said not to go Sheldon on you, but 53/11 at 120rpm is 46.1 mph I'm thinking that if you're over 46mph on the downhill portion it may be more efficient to really tuck in and recover anyway, given that the power it takes to go from 46 mph to 47 mph is a hell of a lot.
And I'm no TT expert, but my understanding of why some time trialers run bigger chainrings is not mostly to get a gear bigger than 53/11, but to make the other ratios, shifts, and chain angles work better. Going to a 10, as oppossed to putting on a bigger chain ring will not help with those issues.
Finally, the smaller the cog, the less efficient the drivetrain, so you'd have some frictional losses going to the 10.
And I'm no TT expert, but my understanding of why some time trialers run bigger chainrings is not mostly to get a gear bigger than 53/11, but to make the other ratios, shifts, and chain angles work better. Going to a 10, as oppossed to putting on a bigger chain ring will not help with those issues.
Finally, the smaller the cog, the less efficient the drivetrain, so you'd have some frictional losses going to the 10.
__________________
You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.
You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.
Last edited by merlinextraligh; 03-15-10 at 08:18 AM. Reason: typos
03-15-10, 08:26 AM
#10
Primate
Join Date: Jan 2006
Location: gone
Posts: 2,579
Bikes: Concorde Columbus SL, Rocky Mountain Edge, Sparta stadfiets
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 5 Times
in
5 Posts
Where did 120 rpm come from? Is that what you guys spin during TTs?
03-15-10, 08:31 AM
#11
pan y agua
Join Date: Aug 2005
Location: Jacksonville
Posts: 31,302
Bikes: Willier Zero 7; Merlin Extralight; Calfee Dragonfly tandem, Calfee Adventure tandem; Cervelo P2; Motebecane Ti Fly 29er; Motebecanne Phantom Cross; Schwinn Paramount Track bike
Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 1447 Post(s)
Liked 724 Times
in
371 Posts
I doubt many people TT at 120 rpm's. However anybody should be able to spin effectively at 120 rpm, So for a short dowhill effort it would not be unreasonable to spin at 120 rpms.
But even take 100rpms and you're at 39 mph.
I'm betting on most courses for the vast majority of people that's plenty enogh gear, and if its not, you're still better off going to a bigger chanring.
But even take 100rpms and you're at 39 mph.
I'm betting on most courses for the vast majority of people that's plenty enogh gear, and if its not, you're still better off going to a bigger chanring.
__________________
You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.
You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.
03-15-10, 08:45 AM
#12
Over the hill
Join Date: Mar 2006
Location: Los Angeles, CA
Posts: 24,372
Bikes: Giant Defy, Giant Revolt
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 996 Post(s)
Liked 1,204 Times
in
690 Posts
Sorry, I just put 120 RPM in there because it provided a constant, and the higher the RPM, the greater the mph difference. As Waterrockets said, though, it's questionable as to whether there is any gain in pedaling vs. just tucking more aero after about 40 mph.
__________________
It's like riding a bicycle
It's like riding a bicycle
03-15-10, 09:14 AM
#14
on your left.
Join Date: Nov 2007
Location: Blacksburg, VA
Posts: 1,802
Bikes: Scott SUB 30, Backtrax MTB
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
03-15-10, 12:07 PM
#15
Senior Member
If you're really hell bent on a 10 tooth cog, take a larger cog to a gunsmith and have them machine it for you. I know a few guys that used to do this to get an 11 tooth before they became common. But still, not 100% sure there's enough material to actually achieve it and/or have it strong enough to work.
04-10-17, 12:13 PM
#17
Banned
Join Date: Aug 2015
Posts: 163
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 68 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
04-10-17, 12:19 PM
#18
Senior Member
Join Date: Feb 2017
Location: Geneva, IL
Posts: 361
Bikes: 2015 Storck Scenero G3 (Force 22)
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 125 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I understand the naysayers, but I say GO FOR IT! Totally savage.
Edit: Oh shoot; I didn't realize this was a zombie thread!
Edit: Oh shoot; I didn't realize this was a zombie thread!
Last edited by gsindela; 04-10-17 at 12:36 PM.
04-10-17, 12:24 PM
#19
Senior Member
Join Date: Jan 2010
Posts: 39,229
Mentioned: 211 Post(s)
Tagged: 1 Thread(s)
Quoted: 18409 Post(s)
Liked 15,520 Times
in
7,324 Posts
Zombie thread apocalypse is alive and well.
04-10-17, 12:44 PM
#20
Senior Member
Join Date: Jan 2010
Location: TC, MN
Posts: 39,520
Bikes: R3 Disc, Haanjo
Mentioned: 354 Post(s)
Tagged: 1 Thread(s)
Quoted: 20810 Post(s)
Liked 9,456 Times
in
4,672 Posts
04-10-17, 12:46 PM
#21
Senior Member
Join Date: Jan 2010
Posts: 39,229
Mentioned: 211 Post(s)
Tagged: 1 Thread(s)
Quoted: 18409 Post(s)
Liked 15,520 Times
in
7,324 Posts
04-10-17, 02:31 PM
#22
Senior Member
04-11-17, 06:59 PM
#24
Senior Member
Join Date: Aug 2014
Posts: 4,286
Mentioned: 21 Post(s)
Tagged: 0 Thread(s)
Quoted: 1096 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Was it just me, or did anyone else notice that everyone was missing the point? He wanted the 10 because he did NOT want to use the big 58t chain ring that was the alternative - perhaps because it would necessitate undesirable shifting to the small ring or something like that.
04-11-17, 09:06 PM
#25
Senior Member
Join Date: Jul 2009
Posts: 5,945
Bikes: Colnago, Van Dessel, Factor, Cervelo, Ritchey
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 3948 Post(s)
Liked 7,291 Times
in
2,945 Posts
If you're really hell bent on a 10 tooth cog, take a larger cog to a gunsmith and have them machine it for you. I know a few guys that used to do this to get an 11 tooth before they became common. But still, not 100% sure there's enough material to actually achieve it and/or have it strong enough to work.