Bicycle Mechanics - Why big jockey wheel ?

Got my new bike today, it's a triban 3. I was looking over it when I noticed the jockey wheel was a lot bigger than anything iv'e seen before. One wheel is the same size as the jockey wheels on my other road bike but the bottom it alot bigger . Its a shimano 2300 derailleur. Is it functional or just a gimmick?

290270

Thanks!

Because the engineers in the Company thought it was an advantage.

You probably need to get the definitive answer from them..

this is a FAQ, but as no one here is in the company.

Amongst the Guesses: Effectively wraps more chain,
and increases the radius of the pulley, so the chain does not bend as far to go around it.

Designers hit the wrong key on the computer?.....Make you think you got your money's worth?.....Who knows what goes through their heads......I'm guessing the bean counters got involved and it's cheaper to make somehow......

Because the engineers in the Company thought it was an advantage.

You probably need to get the definitive answer from them..

this is a FAQ, but as no one here is in the company.

Amongst the Guesses: Effectively wraps more chain,
and increases the radius of the pulley, so the chain does not bend as far to go around it.

That is what I think it just allows more chain wrap with a standard lenght cage for use with a mega range type FW and compact crank.

Someone needs to market ones that look like a slice or orange, lemon or peperoni.

http://www.bikeforums.net/attachment.php?attachmentid=290270&d=1356537648

That is what I think it just allows more chain wrap with a standard lenght cage for use with a mega range type FW and compact crank.

Someone needs to market ones that look like a slice or orange, lemon or peperoni.

http://www.bikeforums.net/attachment.php?attachmentid=290270&d=1356537648

It has a 3 speed crank-set 50/39/30 with sora front mech, if this is any help...

Want something different?
You can go Upmarket to a higher Price Mountain Bike Rear derailleur,
that part was in the build list to keep the price of the bike down, to where you could afford it.

The outer part of the parallelogram is stamped out of sheet metal in one blow.

up at higher price points that part is forged aluminum with a bronze bushing.

it, like an XT read mech, gets close to half of what you paid for the whole bike.

Want something different?
You can go Upmarket to a higher Price Mountain Bike Rear derailleur,
that part was in the build list to keep the price of the bike down, to where you could afford it.

The outer part of the parallelogram is stamped out of sheet metal in one blow.

up at higher price points that part is forged aluminum with a bronze bushing.

it, like an XT read mech, gets close to half of what you paid for the whole bike.

The bike is a road bike, not a mountain bike...

A larger lower pulley increases the wrap capacity of the derailleur without lengthening the cage. As the cage rotates backward taking up slack, the chain wraps around the pulley more. Since the arc of wrap increases, more chain is wrapped around a bigger pulley than a smaller one.

Agreed, larger pulley wheels increase chain wrap capacity. I've read somewhere that it also makes the drivetrain quieter, though I can't remember the source of that info.

FWIW, it's pretty standard now for new derailleurs to come with 11T jockey wheels, where 9 or 10T used to be the standard.

Agreed, larger pulley wheels increase chain wrap capacity. I've read somewhere that it also makes the drivetrain quieter, though I can't remember the source of that info.

FWIW, it's pretty standard now for new derailleurs to come with 11T jockey wheels, where 9 or 10T used to be the standard.

I think we only see them on long cage or wide capacity RDs. Smaller pulleys are still common for short cage versions where capacity isn't an issue.

Now.. 10t is Campag, And 11t is Shimano, DA, etc.. I got a Set of Tacx pulleys,
Spares, Rohloff buys the 10t, for their chain tensioner.

I'm going to try them as an upgrade on my Brompton M3L the chain tensioner on that is 10t too..



I've read somewhere that it also makes the drivetrain quieter, though I can't remember the source of that info.

might have been an opinion expressed here, in which case you may need to take a bit of salt, with that.