Securing fixed cog w/o lockring
#1
Securing fixed cog w/o lockring
Suppose I have hub with freewheel threads only. If I use red loctite and wrench the cog on really tight, will it be strong enough to resist backpedal braking? If not, what are other options? I probably can't weld steel to aluminum very easily. But maybe I can drill a hole through the cog lip into the hub threads and run a screw in?
#4
Suicide Hub A rather alarmist and silly name for a freewheel hub used as a fixed-gear hub. Any standard-thread freewheel type hub will also accept a fixed-gear ("track ") sprocket . This is a common technique for converting an older bike to fixed gear on the cheap. Despite the silly name, this is no more dangerous than using a freewheel, as long as you keep front and rear hand brakes installed.
But it doesn't really provide any information regarding what I requested in my initial post. I'm not buying a track hub. I'll just simply get rid of the bicycle and forget the whole project if nothing else works.
The bottom bracket lockring may be helpful, though.
#7
You should do a search using the forum search tool for threads with "suicide hub" in the title to get lots of opinions about whether loctite is sufficient etc. But the quote you have from Sheldon ought to be enough. He thinks it is safe ... if you have two brakes. If you have only one brake it is considerably less safe and if you are riding brakeless then it no, the name is not dramatic.
#10
Your cog is slipping.



Joined: May 2009
Posts: 26,053
Likes: 100
From: Beverly MA
Bikes: EAI Bareknuckle
I'm not using any Loctite but I am using a BB lockring - even though some people on this forum swear it's useless.
Not really sure how many miles are on it but it's the bike I ride in the rain, on quick shop errands, when I'm carrying stuff (as pictured) and during the winter. While I do ride it quite a bit, the longest ride I've ever done on it has been about two miles to the beach pictured on roads with very little car traffic.
Once when I was skidding like a maniac in the parking lot across the street from the shop trying to get the cog to loosen up/fail, I snapped the non drive side crank arm instead (it was just a cheapo crank but still). I'd say the cog isn't going anywhere...
I'll probably throw a brake on one of these days.
By the way: I'm not saying everyone should go out and ride a brakeless fixed gear bike equipped with a suicide hub at maximum speed and busting mad skidz in busy downtown traffic. I'm just saying that in my experience, I have had no trouble and most "reports" of how completely unsafe it is are typically made by people who have never done it.
Not really sure how many miles are on it but it's the bike I ride in the rain, on quick shop errands, when I'm carrying stuff (as pictured) and during the winter. While I do ride it quite a bit, the longest ride I've ever done on it has been about two miles to the beach pictured on roads with very little car traffic.
Once when I was skidding like a maniac in the parking lot across the street from the shop trying to get the cog to loosen up/fail, I snapped the non drive side crank arm instead (it was just a cheapo crank but still). I'd say the cog isn't going anywhere...
I'll probably throw a brake on one of these days.
By the way: I'm not saying everyone should go out and ride a brakeless fixed gear bike equipped with a suicide hub at maximum speed and busting mad skidz in busy downtown traffic. I'm just saying that in my experience, I have had no trouble and most "reports" of how completely unsafe it is are typically made by people who have never done it.
Last edited by Scrodzilla; 11-23-12 at 03:52 PM.
#11
A while back I got the lockring off my bike and after talking with Scrod, spent hours attempting purposefully to force the cog to break free without a wrench and it stayed snug as sin until I gave up and purchased said wrench from Retrogression. I continued to ride without a lockring for 3 days without having it budge in anyway. And I was using an IRD canti on the front for safety; point being, you probably can snug it on their with the right tool and get away with the BB lockring as insurance and be safe as long as you're in control of the bike.
I would never ride brakeless only because with a wife and four kids, my insurance wouldn't pay a dime if they thought I was doing something "dangerous." So I play it safe and always have 1/2 brakes on the Devil.
I would never ride brakeless only because with a wife and four kids, my insurance wouldn't pay a dime if they thought I was doing something "dangerous." So I play it safe and always have 1/2 brakes on the Devil.
#12
Don't be such a ninny.
A friend of mine has put thousands of miles on a bike with a track cog on a freewheel hub and I don't think he's using a BB lock ring. He may be using Loctite, but I think he just tightened the cog RFT. If the cog were to come loose it's not like the bike explodes. All of his bikes have at least a front brake, most with two.
Yes, a proper track hub is ideal, but that wasn't the OP's question.
A friend of mine has put thousands of miles on a bike with a track cog on a freewheel hub and I don't think he's using a BB lock ring. He may be using Loctite, but I think he just tightened the cog RFT. If the cog were to come loose it's not like the bike explodes. All of his bikes have at least a front brake, most with two.
Yes, a proper track hub is ideal, but that wasn't the OP's question.
#13
Senior Member
Joined: Aug 2010
Posts: 535
Likes: 5
Once when I was skidding like a maniac in the parking lot across the street from the shop trying to get the cog to loosen up/fail, I snapped the non drive side crank arm instead (it was just a cheapo crank but still). I'd say the cog isn't going anywhere...
I'll probably throw a brake on one of these days.
By the way: I'm not saying everyone should go out and ride a brakeless fixed gear bike equipped with a suicide hub at maximum speed and busting mad skidz in busy downtown traffic. I'm just saying that in my experience, I have had no trouble and most "reports" of how completely unsafe it is are typically made by people who have never done it.
#14
FWIW I put a cog on a old mtb hub for a snowbeater using red loctite(done proper with clean,de-greased threads and 48 hrs curetime) and was unable to get it off when i didn't like the gearing. Not with a chainwhip,not with the cog in a vise turning the wheel, had to change the chainring instead.
#15
Old fart



Joined: Nov 2004
Posts: 26,345
Likes: 5,249
From: Appleton WI
Bikes: Several, mostly not name brands.
FWIW I put a cog on a old mtb hub for a snowbeater using red loctite(done proper with clean,de-greased threads and 48 hrs curetime) and was unable to get it off when i didn't like the gearing. Not with a chainwhip,not with the cog in a vise turning the wheel, had to change the chainring instead.
#16
Senior Member

Joined: Aug 2011
Posts: 22,676
Likes: 2,642
From: CID
Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers), All-City Space Horse (hers)
Track hubs are surprisingly affordable.
#22
Ugh, ss/fg is so full of contrarians....
I'm using a fixed cog on a freewheel hub with a BB lockring, no loctite. No problems here after a couple thousand miles on the bike. I used this tool to install: https://www.worldclasscycles.com/shimano_chain_whip.htm It works for both fixed lockrings and BB lockrings, both 3/32 and 1/8 chains. Quite handy.
I'm using a fixed cog on a freewheel hub with a BB lockring, no loctite. No problems here after a couple thousand miles on the bike. I used this tool to install: https://www.worldclasscycles.com/shimano_chain_whip.htm It works for both fixed lockrings and BB lockrings, both 3/32 and 1/8 chains. Quite handy.
#24
#25
Senior Member
Joined: Apr 2012
Posts: 211
Likes: 0
From: Minneapolis, MN
Bikes: 1991 Eddie Merckx Corsa, 1991 Cannondale 3.0 Road Race, 2008 Bianchi Pista
I have used the rotafix method with success (no cog loosenings) for >2 years.
I prefer a track hub when convenient, because it's either no more dangerous, or safer. I rotafix the cog with a lockring anyway to ensure I don't strip the threads of my hub. Maybe the lockring is superfluous in this arrangement.
I prefer a track hub when convenient, because it's either no more dangerous, or safer. I rotafix the cog with a lockring anyway to ensure I don't strip the threads of my hub. Maybe the lockring is superfluous in this arrangement.




