What is the difference between these pedal bearings?

Can somebody explain to me what the difference is between regular sealed bearings on something like the 105/Ultegra pedals, and the roller bearings on the Dura Ace pedals?
Are there any major advantages of roller bearings? And can both can be overhauled in the same way?

Ultegra Pedal:

Dura Ace Pedal:

Lots of different terminology in the bearing world and different types suit different applications. I’ll let a real mech eng chime in if there’s one watching.

“Sealed” to Shimano means non contact labyrinth seals to keep stuff out, but they’re still loose ball (in a race), and not cartridge bearings (with or without seals. Phil Wood bearings are sealed cartridge ball bearings) which tend to have better seals.

“Roller” bearings are able to handle heavy radial loads (larger contact area over ball bearings). These look like needle bearings (very small rollers). Tapered roller bearings are great in headsets (eg Stronglight, Shimano 600 cartridge), much less chance of brinelling the lower race.

Same overhaul, but roller should give better service for longer. Particularily as the roller bearing replaces a bushing in the Ultegra model.

The ball bearings closest to the crank in the DA pedal also look larger than Ultegra, which is better for load distribution.

pending a response by Blakey I can say the following:

(damn you blakey!!!)

The roller bearings (bottom picture) setup looks similar to the way non drive car wheels are fitted. This setup would have the advantage of increasing the contact area of the bearings and as the rollers appear to run on a taper it should be possible to adjust the pedals for nice smooth running (you should be able to do this to the ultegras but the taper roller bearings will be nicer).

As far as I can tell having never overhauled either type (but having overhauled shimano 525 MTB pedals which appear similar to the ultegra) both would be overhauled the same way.

My experiance with the 525 mtb pedals was that while you can overhaul them they are basically a disposable item. As soon as any play requiring an overhaul is detectable the itty bitty bearings and races are probably shagged. The bearings are also so fiddly that unless you have a problem overhaul is best avoided (unless you are paying a shop do to it in whic case take sadistic plreasure in the act). What I have done though it take 'em apart as soon as i get them and stuff them full of wterproof grease. Dunno if this will have and bearing (hehehe) on ultegra vs dura ace for you, it depends on the price of the ultegra and you intended riding conditions.

Crank bros are similar, they use 1 tiny cartridge and 1 bushing. The Look 4x4’s used needle bearings, much better time between overhaul, and as you replace the entire cart and bushing you eliminate the play.

105 $80
Ultegra $140
Dura Ace $233

Are DA 3x longer lasting than 105?
More to the point, is there any significant difference between 105 & Ultegra?

Hey thanks for the in depth answers Blakey and DaFrog!
I actually have both pedals, and the roller bearings on the DA’s are nice- whether there is a measurable difference while riding, I don’t know.
You give the impression that the Ultegra’s are not very easy to service. I’ve had mine for a couple of years, and I wouldn’t mind overhauling them at some point. Shouldn’t bother?

Yes, I’ve often wondered this myself. They look VERY similar. I believe the Ultegra’s are marginally lighter, but the difference is minuscule.

Of course it’s measurable. But is it significant?

Do you have the exploded diagram for the 105’s? If they also have 2x ball bearings and 1x bushing, then they’re probably the same as Ultegra, with minor cosmetic / weight differences. And at 1/3 of the price of DA, probably the best value for money.

Just checked- it’s exactly the same as the Ultegra ah-ha!

If they still feel smooth the bearings are probably fine. Re lubing with wateproof gease is definately a good idea in my experiance. However the balls are tiny and the whole assembly fidly. there’s actually a very appropriate post on FGG today about rebuilding these pedals.
Unless you have fairly mad mechanical skillz you might want to leave it to the pros

Can you post the link cheers.

theres not to much about specifics just the bit i quoted about the zen like state required to rebuild them.