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New 18t Fixed Front Cog.


Savage

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you dont need to make special tools, you could have just put a freewheel remover compatible spline, thats what people want. the point would have been the fact that your cog would be the only one that was easy(er) to get off. pretty good selling point in my oppinion.

Actually you have less leverage with a freewheel or BB tool than with Chainwhip. The further you are out from the center of the spindle, the more leverage you have. Therfore, since the furthest point out from the center on the cog are the teeth........ chainwhip it is.

It is easiest to free a cog while the crank is still on the bike. As I said before:

1. remove chain from cog

2. remove driveside pedal

3. put pipe on drive side crank arm

4. rotate crankarm/pipe until it is wedged against the ground (i.e. cranks are locked in forward direction)

5. chainwhip on cog, so that arm of tool is parallel to ground.

6. push....... stand on it if need be (or pipe for more leverage).

Leverage is the key.

It really doesn't get any easier than that.

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Actually you have less leverage with a freewheel or BB tool than with Chainwhip. The further you are out from the center of the spindle, the more leverage you have. Therfore, since the furthest point out from the center on the cog are the teeth........ chainwhip it is.

It is easiest to free a cog while the crank is still on the bike. As I said before:

1. remove chain from cog

2. remove driveside pedal

3. put pipe on drive side crank arm

4. rotate crankarm/pipe until it is wedged against the ground (i.e. cranks are locked in forward direction)

5. chainwhip on cog, so that arm of tool is parallel to ground.

6. push....... stand on it if need be (or pipe for more leverage).

Leverage is the key.

It really doesn't get any easier than that.

or simply put two flats on the cog when making them...

1. put cog in vice

2. remove pedal

3. put pipe on crank arm

4. twist ;)

i do know what you mean about the chain whip idea, but i have bent chainwhips and snapped the chain thats on them whilst trying to remove the buggering cogs :@

meh...

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a crappy freewheel tool is no better than a crappy chainwhip, and visa versa. I have had same chainwhip tool for 11 years.

Two flats on the inside side of cog. Now we are making the cog wider, hence we need wider BB. A fair bit of metal would have to be there as most vises do not have sharp edges...... enough to make sure it does not jump off the vise.......... and now you need to ad a vise to the collection of tools.

I do understand what you all are saying, it would be cool looking to have such a set up....just the gains in practical application are not as many as in theory.

Edited by Tim/Trialsin USA
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Shit Paint drawing ahoy:

IPB Image

That's the sorta thing I meant. Easy enough to get a vice on, which'd make it a lot easier to remove, 'cos I - like many others - have obliterated tools trying to get cogs off in the past :P

That is the part that faces the bashring/crankarm..... going to be a bit hard to get the vise inbetween.

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There's a rounded part like that on both sides though isn't there? Or am I being stupid? Either way, there's usually been a section on the BB-side of the cog (as it's on the crank arm) that could be flatted out, from the ones I've seen by other makes?

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There's a rounded part like that on both sides though isn't there? Or am I being stupid? Either way, there's usually been a section on the BB-side of the cog (as it's on the crank arm) that could be flatted out, from the ones I've seen by other makes?

All the trials specific ones only have collar on one side. There is only a certain width you can go before the cog would hit BB. And you want the sprockets to be as close to BB as possible for two reasons.

1. It allows for plenty of space for all sorts of chains to fit with no problem.

2. Chain line on trials bikes already sucks, no need to make it worse by pushing the cog further out.

There are some cogs that have some thread either side of the sprockets..... however, they are for track bikes and are not optimum (for reasons above as well as many not having enough treads to trust not stripping the threads on cranks).

Now, I suppose you could get make it with indentations for BB tool to remove the cog....but those indents are going to fill with dirt, muck and crap.....as well as machining cost (i.e. retail price) goes up.

Edited by Tim/Trialsin USA
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The BB would be less than 25mm away, and in fairness BB extractor recesses don't really fill up with crap, but fair enough, I see where you're coming from...

Correct, optimally you want the sprockets as close to the BB as possible. Therefore, there is not room to ad sufficient sized collar to that side.

BB extractor recesses on the BB don't fill with grime because there is a rotating spindle helping remove a bit of mud. If it were just little holes on the crank cog, I don't see how they are self cleaning in quite the same way as the actual BB. Such little holes on my road bike fill with stuff...... trials bikes can't be less of a magnet for such filth I can't imagine.

Again, I agree with alot of you guys ideas.... just we have not found a magic bullet. Maybe we should make a better chainwhip?!

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say the cog snaps from the threaded coller ? i know its probly not gonna happen but it could, this would leave the coller screwd tight on to the crank

if you just milled two flats on the coller, no need to make it wider then you can use a flat spanner to remove it (Y)

Edited by dave33
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say the cog snaps from the threaded coller ? i know its probly not gonna happen but it could, this would leave the coller screwd tight on to the crank

if you just milled two flats on the coller, no need to make it wider then you can use a flat spanner to remove it (Y)

this guys good, why didnt anyone else think of putting a spanner on there....

good stuff

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marks eno freewheel is curentley in the same state(with 2 flats in it), it snapped my dads vice in half rather than loosening itself. :P i think theyre gonna be rock hard to get off whatever you put on them.

to be honest, the vice snappage was probarbly down to metal fatigue. i dont think it would have broken a newer vice :P

Will

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