On my MTB I have a 24/36 double on the front with an 11-32 cassette. This gives a required derailleur capacity of 33T. The mech I have has a capacity of 33T. All well and good.
I'm thinking about putting a 44T on the front to give a 24/36/44 triple. This means I theoretically need a mech with a capacity of 41T. BUT... isn't this only the case if I was going to use the extremes of crossover, i.e., 44front/32rear or 24f/11r or thereabouts? In other words, if I kept the short cage mech and avoided the extreme chain angles (which I do anyway) will things still work? I just wouldn't use the positions where the mech is either pulled all the way forward or relaxed all the way back.
On my MTB I have a 24/36 double on the front with an 11-32 cassette. This gives a required derailleur capacity of 33T. The mech I have has a capacity of 33T. All well and good.
I'm thinking about putting a 44T on the front to give a 24/36/44 triple. This means I theoretically need a mech with a capacity of 41T. BUT... isn't this only the case if I was going to use the extremes of crossover, i.e., 44front/32rear or 24f/11r or thereabouts? In other words, if I kept the short cage mech and avoided the extreme chain angles (which I do anyway) will things still work? I just wouldn't use the positions where the mech is either pulled all the way forward or relaxed all the way back.
It will work until your brain disengages, and you try to shift to an illegal gear. Then you may regret it. Might work OK if its only the two extremely crossed over gears.
My tourer has one illegal gear, big rear to big front. But I've always avoided that combination on every bike I've owned, so it doesn't catch me out. Small to small is permitted (though only used when brain fails).
I've had a tighter arrangement on my station hack bike (couple of gear at each end of the range were illegal). I got fed up with graunches and near calamities by forgetful shifting. I gave in and bought a cheap long cage rear mech.
On my MTB I have a 24/36 double on the front with an 11-32 cassette. This gives a required derailleur capacity of 33T. The mech I have has a capacity of 33T. All well and good.
I'm thinking about putting a 44T on the front to give a 24/36/44 triple. This means I theoretically need a mech with a capacity of 41T. BUT... isn't this only the case if I was going to use the extremes of crossover, i.e., 44front/32rear or 24f/11r or thereabouts? In other words, if I kept the short cage mech and avoided the extreme chain angles (which I do anyway) will things still work? I just wouldn't use the positions where the mech is either pulled all the way forward or relaxed all the way back.
I would not recommend this. You only have to accidentally go into big/big once (and let's face it we've all done it) and you'll write off your derailleur, your derailleur hanger, and possibly your frame. Not worth the risk.
Thanks both. I think "it will work but isn't worth the risk" is the summary there. As the reason for having a short mech is to slightly reduce the risk of it being smacked against a rock I won't risk it in a different manner - I'll either stick with a double on the front or go for a long cage mech (which I just happen to have spare, as you do)
The frame this will be going on is an Orange P7, and there is no way I want to risk that!
On my MTB I have a 24/36 double on the front with an 11-32 cassette. This gives a required derailleur capacity of 33T. The mech I have has a capacity of 33T. All well and good.
I'm thinking about putting a 44T on the front to give a 24/36/44 triple. This means I theoretically need a mech with a capacity of 41T. BUT... isn't this only the case if I was going to use the extremes of crossover, i.e., 44front/32rear or 24f/11r or thereabouts? In other words, if I kept the short cage mech and avoided the extreme chain angles (which I do anyway) will things still work? I just wouldn't use the positions where the mech is either pulled all the way forward or relaxed all the way back.
You can push a mech's capacity a bit. I think by 8 teeth would be too much, though. You'd have to avoid more than just the extremes anyway.
Quoted message said:
I would not recommend this. You only have to accidentally go into big/big once (and let's face it we've all done it) and you'll write off your derailleur, your derailleur hanger, and possibly your frame. Not worth the risk.
That's a danger if the chain was too short for the big-big. I don't think such terrible things would happen otherwise.
Pete Biggs said the following on 22/04/2007 21:52:
Quoted message said:
You can push a mech's capacity a bit. I think by 8 teeth would be too much, though. You'd have to avoid more than just the extremes anyway.
Yes - the way I ride is to normally sit in the middle ring, and just use the big ring with the smallest 2 or 3 cogs, and the small ring with just the biggest 2 or 3. Usually.
Quoted message said:
That's a danger if the chain was too short for the big-big. I don't think such terrible things would happen otherwise.
The chain would be the right length.
When the new frame arrives, I think I'll just try it with it up on the stand. If I have any doubts though, I'll play safe.
I would not recommend this. You only have to accidentally go into big/big once (and let's face it we've all done it) and you'll write off your derailleur, your derailleur hanger, and possibly your frame. Not worth the risk.
That's a danger if the chain was too short for the big-big. I don't think such terrible things would happen otherwise.
Yup. But if you don't have enough take-up in your derailleur cage, then either it's too short for big-big or it's massively too long for small-small. Which I grant you, is less of a problem - there was a fashion in France between the wars for riding with a very loose chain.
The Conservative Party is now dead. The corpse may still be twitching, but resurrection is not an option - unless Satan chucks them out of Hell as too objectionable even for him.
Pete Biggs said the following on 22/04/2007 21:52:
Quoted message said:
You can push a mech's capacity a bit. I think by 8 teeth would be too much, though. You'd have to avoid more than just the extremes anyway.
Yes - the way I ride is to normally sit in the middle ring, and just use the big ring with the smallest 2 or 3 cogs, and the small ring with just the biggest 2 or 3. Usually.
thats genurally what i do, though with my mountain bike. though i try to predict what's coming so i'm in the right ring.
on the road bike (old mountain bike with marthons) i tend to hold it in the top ring as it zips about well and kingston upon thames area pritty much flat.
