Fixed gear cog w/o lockring. FYI



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Luke

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Several months ago I did a Google search on the subject of running fixed gear cogs without
lockrings. There are quite a few threads - some quite contentious - on the subject.

I planned to lace up a wheel using an old Phil BMX hub and install it on my FG messenger bike. After
the wheel was completed, the hub's threads' were lightly greased and the cog was tightened as hard
as possible with a chain whip and installed on the bike. The front of the bike was then wedged in a
corner and I bounced on the cranks as an added measure. The cog didn't budge.

I run a 48t chainring with the 15t cog (bit of a masher here) and weigh in at 175 lbs. I considered
adding a BB lockring - as was recommended by some of the previous posters on the subject - but
*didn't think* :) it was necessary.

And there the matter stood. The setup performed flawlessly for several months, 8 hours a day, 5 days
a week - until a week ago that is. I was riding along at approximately 20 km/h, slowly
de-accelerating by lightly back pedallng when I heard a "pop" and found myself freewheeling. Since
the FG has brakes it wasn't a problem stopping.

I was surprised the cog would unscrew with such little force. Even though on numerous earlier
occasions I had locked the rear wheel by forceful back pedalling, the cog had never once unscrewed.

So why had it now? Maybe the continual vibrations and jarrings of daily use had more of an loosening
effect than anticipated? I'm wondering about how much of a role temperature plays. On the day, or
rather evening, the cog unscrewed the temperature (in Toronto) was -18 degrees Celsius. It was cold!
The Dura Ace cog is steel and the Phil hub body aluminum. Perhaps the two metals' differing rates of
temperature related contraction and expansion factored into the result.

A BB lockring - loctite secured - has now found it's way onto the hub. Of course it's not a true
locking but I'm hoping it's enough to keep the cog tight.

Luke
 
Luke <[email protected]> wrote in message news:<230120032341046366%[email protected]>...

> A BB lockring - loctite secured - has now found it's way onto the hub. Of course it's not a true
> locking but I'm hoping it's enough to keep the cog tight.
>
> Luke

I had two cogs unscrew on my fixed hub-- once right after installing the cog at the base of a long
downhill on which I had exerted some back pressure to attenuate my speed, and once while actually
topping out over a hill. I beleive I had installed the cog on that wheel weeks before the
unscrewing incident.

The first time obviously was due to improper tightening. The second I have no explanation for.
This is in Seattle, so even though it was a couple years ago and I don't remember the temperature,
I can pretty much guarantee it was no lower then 40 degrees F. It just doesn't generally get very
cold here.

Therefore my conclusion, unscientific and faith-based as it may be, is that the cog will
unscrew on its own volition. The lockring and loctite will probably disallow that tendency. But
who am I to say?

Anyone care to ponderate on how the cog unscrewed while going up a hill?
 
>From: [email protected] (Keven Ruf)

>
>Anyone care to ponderate on how the cog unscrewed while going up a hill?

You were riding backwards. Simple. --Tom Paterson
 
Luke <[email protected]> wrote:

: A BB lockring - loctite secured - has now found it's way onto the hub. Of course it's not a true
: locking but I'm hoping it's enough to keep the cog tight.

If you are running a typical freewheel hub then there should be enough room to fit a BB lockring on
the remaining threads. I've done this, using Loctite and so far so good. This has got to be more
secure than 'no lockring, no Loctite' and is a simple matter to set up.

As for why your first attempt unscrewed, what does it matter other than you proved it inadequate.
The chances of your rear wheel locking up are not worth the risk.

Cheerz, Lynzz
 
[email protected] (Keven Ruf) wrote:

>Anyone care to ponderate on how the cog unscrewed while going up a hill?

The only thing I can think of is that the cog stripped when you pushed really hard on it, and the
resulting drop of your front foot stopped the pedal before it came around and got the cog tight
again - so it just "unwound" immediately.

Me, I just ordered a real (though pretty cheap) track hub with a real lockring, for a fixie project.

Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame
 
On Fri, 24 Jan 2003 15:49:29 -0500, Keven Ruf wrote:

> Anyone care to ponderate on how the cog unscrewed while going up a hill?

I imagine it was actually not screwed on tight, because of something fouling the threads or
otherwise causing the threads to bind. Maybe you did something to force the threads loose on that
hill. Then when you crested, you applied moderate back-pressure and it came loose.

Good to see others posting problems resulting in backing off sprockets when used w/o a lockring.
This happened to me once, and I will not ride a fixed cog without a lockring (for me, a real,
left-hand threaded one). Too many pooh-pooh this.

--

David L. Johnson

__o | Do not worry about your difficulties in mathematics, I can _`\(,_ | assure you that mine
are all greater. -- A. Einstein (_)/ (_) |
 
On Fri, 24 Jan 2003 23:21:10 -0500, Tom Paterson wrote:

> Keven Ruf wrote:
>
>>Anyone care to ponderate on how the cog >unscrewed while going up a hill?
>
> Ah, more seriously: What brand cog, hub? I had a cog that had "almost" the right thread on it.
> Weird but true.

Not so uncommon, especially with fixed cogs -- old parts. Probably the hub is English, but the cog
is some weird French size... I have one. It fits perfectly on my old chapo French flip-flop hub, but
not on my Campy hub or my newer Shimano double-sided. You might replace the cog, since that is
easier to do than replacing the hub shell.

--

David L. Johnson

__o | Accept risk. Accept responsibility. Put a lawyer out of _`\(,_ | business. (_)/ (_) |
 
"David L. Johnson" <David L. Johnson <[email protected]>> wrote in
news:[email protected]:

> Good to see others posting problems resulting in backing off sprockets when used w/o a lockring.
> This happened to me once, and I will not ride a fixed cog without a lockring (for me, a real,
> left-hand threaded one). Too many pooh-pooh this.
>
David I had mine come off once and all that happened was that I freewheeled to a stop ...what worse
could happen if you have a front brake?
 
"David L. Johnson" wrote:

>>Good to see others posting problems resulting in backing off sprockets when used w/o a lockring.
>>This happened to me once, and I will not ride a fixed cog without a lockring (for me, a real,
>>left-hand threaded one). Too many pooh-pooh this.

Mike Latondresse wrote:

> David I had mine come off once and all that happened was that I freewheeled to a stop ...what
> worse could happen if you have a front brake?

What if your front brake fails for some reason? Cables break or slip sometimes. I once had a brake
shoe mounting bolt snap on me rendering my only brake inoperative.

If your front brake fails, you'll rely on "resisting" to come to a stop. If it's an emergency (as
most brake failures are) you'll resist extra hard. Could be this is when the sprocket will unscrew
itself, just when you need it the most!

Sheldon "Brakes Break" Brown +-----------------------------------------------------------------+
| When anyone asks me how I can best describe my experience | in nearly 40 years at sea, I merely
| say, "uneventful." | Of course, there have been many gales and storms and fog | and the like.
| But in all my experience, I have never been | in any accident of any sort worth speaking about.
| I have | never seen but one vessel in distress in all my years at sea. | I never saw a wreck and
| never have been wrecked, nor was I | ever in any predicament that threatened to end in disaster
| | of any sort. --E. J. Smith, Captain, RMS Titanic |
+-----------------------------------------------------------------+ Harris Cyclery, West Newton,
Massachusetts Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts
shipped Worldwide http://captainbike.com http://sheldonbrown.com
 
On Sat, 25 Jan 2003 14:10:30 -0500, Mike Latondresse wrote:

> "David L. Johnson" <David L. Johnson <[email protected]>> wrote in
> news:[email protected]:
>
>> Good to see others posting problems resulting in backing off sprockets when used w/o a lockring.
>> This happened to me once, and I will not ride a fixed cog without a lockring (for me, a real,
>> left-hand threaded one). Too many pooh-pooh this.
>>
> David I had mine come off once and all that happened was that I freewheeled to a stop ...what
> worse could happen if you have a front brake?

The chain could get fouled in the wheel.

--

David L. Johnson

__o | Enron's slogan: Respect, Communication, Integrity, and _`\(,_ | Excellence. (_)/ (_) |
 
[email protected] (Qui si parla Campagnolo) wrote:

>Mark-<< Me, I just ordered a real (though pretty cheap) track hub with a real lockring, for a
>fixie project.
>
>Agree with this. There are some really nice but not expensive, flip-flop track hubs out
>there(Suzue). Most of which you can space to 120, 126, 130 and some
>135mm...

I ordered the QR axle for the Suzue flip flop hub - have you had any luck getting that to work with
horizontal dropouts (not slipping)? I figure it's marginal, but I have a few things going for me...

1) I'm gonna use a Campy steel QR
2) I weigh 150 lbs (68kg)
3) My chainring will be a 52, which should limit chain torque (the cog will be a 16, BTW).

Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame
 
On Fri, 31 Jan 2003 22:15:58 -0500, Mark Hickey wrote:

> I ordered the QR axle for the Suzue flip flop hub - have you had any luck getting that to work
> with horizontal dropouts (not slipping)? I figure it's marginal, but I have a few things going
> for me...

I use one with one wheel, and have not have trouble with it since I went to a Shimano QR. I have
used 46, 42, and even 36 chainrings without it slipping. The 36 was for a 2 mile commute-climb.

I just got a pair of non-Q R skewers (allen-key rather than lever) for my other wheel, but haven't
put 'em in yet.
>
> 1) I'm gonna use a Campy steel QR

I had trouble with an old Campy QR on that wheel.

> 2) I weigh 150 lbs (68kg)

I wish

> 3) My chainring will be a 52, which should limit chain torque (the cog will be a 16, BTW).

That is quite a gear, Mark. You're climbing hills with that?

--

David L. Johnson

__o | Some people used to claim that, if enough monkeys sat in front _`\(,_ | of enough
typewriters and typed long enough, eventually one of (_)/ (_) | them would reproduce the
collected works of Shakespeare. The internet has proven this not to be the case.
 
> >Mark-<< Me, I just ordered a real (though pretty cheap) track hub with a
real
> >lockring, for a fixie project.

> [email protected] (Qui si parla Campagnolo) wrote:
> >Agree with this. There are some really nice but not expensive, flip-flop
track
> >hubs out there(Suzue). Most of which you can space to 120, 126, 130 and
some
> >135mm...

"Mark Hickey" <[email protected]> wrote in message
news:[email protected]...
> I ordered the QR axle for the Suzue flip flop hub - have you had any luck getting that to work
> with horizontal dropouts (not slipping)? I figure it's marginal, but I have a few things going
> for me...
>
> 1) I'm gonna use a Campy steel QR
> 2) I weigh 150 lbs (68kg)
> 3) My chainring will be a 52, which should limit chain torque (the cog will be a 16, BTW).

Mine hasn't slipped in eight years with a Simplex skewer so your Campagnolo one will be just fine.

--
Andrew Muzi http://www.yellowjersey.org Open every day since 1 April 1971
 
I had a Ti frame w/ dropouts made from Ti 6-4. That being harder then 3-2.5 it required very high
tension on the QR to keep the axle from slipping. My QR of choice was any old style steel with steel
nuts with real teeth.

That's one reason you don't see horizontal dropouts made with Ti 6-4 anymore.

-Bruce

"Mark Hickey" <[email protected]> wrote in message
news:[email protected]...
> [email protected] (Qui si parla Campagnolo) wrote:
>
> >Mark-<< Me, I just ordered a real (though pretty cheap) track hub with a
real
> >lockring, for a fixie project.
> >
> >Agree with this. There are some really nice but not expensive, flip-flop
track
> >hubs out there(Suzue). Most of which you can space to 120, 126, 130 and
some
> >135mm...
>
> I ordered the QR axle for the Suzue flip flop hub - have you had any luck getting that to work
> with horizontal dropouts (not slipping)? I figure it's marginal, but I have a few things going
> for me...
>
> 1) I'm gonna use a Campy steel QR
> 2) I weigh 150 lbs (68kg)
> 3) My chainring will be a 52, which should limit chain torque (the cog will be a 16, BTW).
>
> Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame
 
On 01 Feb 2003 15:11:44 GMT, [email protected] (Qui si parla Campagnolo) wrote:

>mark-<< I ordered the QR axle for the Suzue flip flop hub - have you had any luck getting that to
>work with horizontal dropouts (not slipping)? I figure it's marginal, but I have a few things going
>for me...
>
>Haven't tried it, we just sell a 15mm Campag or other 'peanutbutter' wrench with the wheelset.
>
>
><< 3) My chainring will be a 52, which should limit chain torque (the cog will be a 16, BTW)
>
>Yowser, BIG gear. I use a 42/16....
>
>
>Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
>(303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

52x16 = 25.5mph @ 100rpm. I would usually pick a gear which gave me an average rpm of about 100 for
racing, or about 90rpm for pottering about. This guy is either fast, a masher, or not owning up to
the 20t spocket on the other side of that flip-flop, which would also be the only justification for
risking a QR, as any other wheel out event takes long enough that time spent getting the wrench out
becomes irrrelevant.

Kinky Cowboy

*Your milage may vary Batteries not included May contain traces of nuts.
 
KinkyCowboy <[email protected]> wrote:

>52x16 = 25.5mph @ 100rpm. I would usually pick a gear which gave me an average rpm of about 100 for
>racing, or about 90rpm for pottering about. This guy is either fast, a masher, or not owning up to
>the 20t spocket on the other side of that flip-flop, which would also be the only justification for
>risking a QR, as any other wheel out event takes long enough that time spent getting the wrench out
>becomes irrrelevant.

Maybe I just built it up with 20" wheels? ;-)

I guess I'm faster than a lot of riders, but I haven't used a bike computer for years so wouldn't
want to make any claims. I suppose I do ride in the mid-20's though since I do spend most of my time
in the 53x16 and spinning 90-100rpm.

Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame
 
"David L. Johnson" <David L. Johnson <[email protected]>> wrote:

>On Fri, 31 Jan 2003 22:15:58 -0500, Mark Hickey wrote:

>> 3) My chainring will be a 52, which should limit chain torque (the cog will be a 16, BTW).
>
>That is quite a gear, Mark. You're climbing hills with that?

That's my normal "around-town gear", and will actually work out better on the hills I climb than a
more traditional (lower) gear, since I like to stand when climbing in a big gear better than sit
while climbing in a "slightly too big gear".

It will also limit my downhill flailing considerably.

Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame
 
On Sun, 02 Feb 2003 23:04:47 GMT, Mark Hickey <[email protected]> wrote:

>KinkyCowboy <[email protected]> wrote:
>
>>52x16 = 25.5mph @ 100rpm. I would usually pick a gear which gave me an average rpm of about 100
>>for racing, or about 90rpm for pottering about. This guy is either fast, a masher, or not owning
>>up to the 20t spocket on the other side of that flip-flop, which would also be the only
>>justification for risking a QR, as any other wheel out event takes long enough that time spent
>>getting the wrench out becomes irrrelevant.
>
>Maybe I just built it up with 20" wheels? ;-)
>
>I guess I'm faster than a lot of riders, but I haven't used a bike computer for years so wouldn't
>want to make any claims. I suppose I do ride in the mid-20's though since I do spend most of my
>time in the 53x16 and spinning 90-100rpm.
>
>Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame

It had occurred to me that you might be a 650c fetishist :) Personally, I don't consider 100rpm to
be "spinning", being pretty comfortable at up to 120, but each to his own. I hit 35mph downhill on
72" the other day, which is definitely quicker than I'd like to be pedalling for long (160rpm+), and
I used to ride my 3-sprocket time trial rig up some fairly steep stuff on 53x15. All part of the fun
of restricting your choice of gears.

Kinky Cowboy

*Your milage may vary Batteries not included May contain traces of nuts.
 
On Sun, 02 Feb 2003 18:04:46 -0500, Mark Hickey wrote:

> "David L. Johnson" <David L. Johnson <[email protected]>> wrote:
>
>>On Fri, 31 Jan 2003 22:15:58 -0500, Mark Hickey wrote:
>
>>> 3) My chainring will be a 52, which should limit chain torque (the cog will be a 16, BTW).
>>
>>That is quite a gear, Mark. You're climbing hills with that?
>
> That's my normal "around-town gear", and will actually work out better on the hills I climb than a
> more traditional (lower) gear, since I like to stand when climbing in a big gear better than sit
> while climbing in a "slightly too big gear".
>
> It will also limit my downhill flailing considerably.

Ah, but that's part of the fun... We all like to brag about how fast we went downhill on our very
low fixed gears, as you have already seen on this thread.

I do prefer about a 70" gear for street riding on a fixed gear, but to each his own.

Is the frame one of yours?

--

David L. Johnson

__o | "It doesn't get any easier, you just go faster." --Greg LeMond _`\(,_ | (_)/ (_) |
 
KinkyCowboy <[email protected]> wrote:

>On Sun, 02 Feb 2003 23:04:47 GMT, Mark Hickey <[email protected]> wrote:

>>Maybe I just built it up with 20" wheels? ;-)
>>
>>I guess I'm faster than a lot of riders, but I haven't used a bike computer for years so wouldn't
>>want to make any claims. I suppose I do ride in the mid-20's though since I do spend most of my
>>time in the 53x16 and spinning 90-100rpm.
>>
>It had occurred to me that you might be a 650c fetishist :) Personally, I don't consider 100rpm to
>be "spinning", being pretty comfortable at up to 120, but each to his own.

I can spin a lot faster, but find my "maximum efficiency" somewhere between 90 and 100. I also
wanted a gear that would preclude someone dropping me because I was spinning 130rpm to keep up. I
figure if I have to spin 130rpm in a 52x16 to keep up, they're gonna get away anyway!

> I hit 35mph downhill on 72" the other day, which is definitely quicker than I'd like to be
> pedalling for long (160rpm+), and I used to ride my 3-sprocket time trial rig up some fairly steep
> stuff on 53x15. All part of the fun of restricting your choice of gears.

Worse yet if I build up a singlespeed MTB to ride on South Mountain. That's - just - wrong. ;-)

Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame
 
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