Let's talk about jockey wheels

[Yellow Saddle]

Size matters - or does it?

I've seen oversize jockey/pulley wheels on pro team bikes.

No idea if they make any difference.

The likes of Ceramic Speed will tell you big wheels is the way to go.

But as a manufacturer, they would say that wouldn't they?

https://www.sigmasports.com/item/Ce...heel-System-for-Shimano-Ultegra-Dura-Ace/DTH8

The size of a pulley does have an effect on chains and belts. The smaller the pulley, the more flex in the belt and more articulation in a chain. More articulation is more friction. However, since jockey wheels work in the slack cycle of a chain and not under tension, this is neither here nor there, since there isn't much friction in a slack articulating chain in anyway.

The claims in that link you posted are ludicrous. Each and every one of them.

Further, metal jockey wheels are noisy. The best bearing for a jockey wheel is a brass-and-steel bushing. Not a ball bearing.

 

[fossyant]

What YS says. It's all marketing rubbish.

 

[Drago]

I've never had to replace one through wear either, even on some big mile bikes. I've stripped, cleaned and relubed a few, but Jockey Wheels (and idlers) really do take a lot of punishment and seem to just shrug it off.

 

[ianrauk]

Further, metal jockey wheels are noisy. The best bearing for a jockey wheel is a brass-and-steel bushing. Not a ball bearing.

I used metal jockey wheels for a while. They look really nice but bloody noisy. In the end I dumped them and went back to the normal jockey's.

 

[Tigerbiten]

Anybody who's worked with recumbents knows larger power/idler pulleys are more efficient.
And all studies show when sprocket size also drops below around 13 teeth then drive efficiency also drops.
Also resistances increase with chain speed.
I can feel a big increase when I shift into overdrive mode on my HSD and the chain moves 2.5x faster.
Especially if the chain is lacking in oil.
So if you're trying to output over 350 watts at +120 rpm then you well see a slight increase in efficiency using larger jockey wheels.
But for us mere mortals then they're not worth the premium price.

 

[Yellow Saddle]

Anybody who's worked with recumbents knows larger power/idler pulleys are more efficient.

I'm not sure how people working with recumbents will just know this. You need to understand the mechanics of chains and sprockets to understand this.

And all studies show when sprocket size also drops below around 13 teeth then drive efficiency also drops.

What are these "studies" and why the magic number below which efficiency drops? For what chain pitch?

Also resistances increase with chain speed.

No it doesn't. And there is only one resistance and that's friction. What others are you referring to?

I can feel a big increase when I shift into overdrive mode on my HSD and the chain moves 2.5x faster.

No, you're feeling something else.

Especially if the chain is lacking in oil.

Nope, not even then.

So if you're trying to output over 350 watts at +120 rpm then you well see a slight increase in efficiency using larger jockey wheels.
But for us mere mortals then they're not worth the premium price.

Articulation friction has nothing to do with power and everything to do with tension. How do you propose you "see" this increase in efficiency. Chain losses are extremely small and the human body cannot "callibrate" at that scale. A small increase on a small force is not possible to feel.

Us mere mortals don't propose riding at 120+ RPM and then still have any feeling left, nevermind the ability to sense friction.

 

[Mr Celine]

I used metal jockey wheels for a while. They look really nice but bloody noisy. In the end I dumped them and went back to the normal jockey's.

Red ones look fab. And they make me go so fast I can't hear the extra noise.

 

[Drago]

No it doesn't. And there is only one resistance and that's friction. What others are you referring to?

Erm, how about mass and inertia? Sure, such forces are miniscule in a moving drivetrain (or a stationary drivetrain that you want to get moving) when compared to the output a riders legs can produce, but it kinda undermines the only one resistance thing.

 

[fossyant]

Red ones look fab. And they make me go so fast I can't hear the extra noise.

I hope you are using the Sky branded unobtanium superslick grease ! Nothing else is anything near as good.

 

[fossyant]

Erm, how about mass and inertia? Sure, such forces are miniscule in a moving drivetrain (or a stationary drivetrain that you want to get moving) when compared to the output a riders legs can produce, but it kinda undermines the only one resistance thing.

Friction is the main force - you said it's minuscule for the others, so it's not worth debating. Drive chains are pretty efficient as it is, so a super fancy jockey wheel with ceramic bearings will make no difference, that is until you grease it with that Sky Unobtanium grease - makes you go even faster !

 

[raleighnut]

Sky Unobtanium grease

Known as 'Jiffy Lube' ?

 

[fossyant]

Known as 'Jiffy Lube' ?

So long as it has the blue stripe - or you have to pay extra for the 'Ineos' version

 

[Rusty Nails]

I've got a little box of jockey wheels off old mechs in my shed, 'just in case'. Never used them.

 

[fossyant]

I've got a little box of jockey wheels off old mechs in my shed, 'just in case'. Never used them.

Hmm, got boxes of 'stuff' just in case, too, never used them.... time for a clear out ?

 

[overmind]

I've worn out a set (2) of jockey wheels. It looked like the last picture in YS's post. I think it took about 5 years of commuting.

More recently I have been much more conscientious in maintaining the drive train and they seem to be wearing more slowly but that is only anecdotal. Maintenance wise I just give them the odd spray with GT85 and when I am wiping the chain (mickle method) I just wipe the jockey wheels at the same time.

I tend to scavenge old parts from worn-out bikes and use the jockey wheels from old derailleurs when I need a spare.