Fastest coaster brake?

[Archie Sturmer]

Over the years I have pulled apart many hubs with loose balls. The only hubs I find with wear are those which have not been serviced or have been sitting for a long time in the elements.

I also believe the extra balls on the drive side of a coaster hub reduce wear as the load is spread over more balls. The first hub I modified was a Taiwanese or Chinese copy of the Shimano hub. Since the modifications I have not had to adjust the cones to remove play.

What you posted makes sense.
Explains why F&S and Perry hubs have loose bearings in one place, but not in others.
I don't believe that F&S and Perry engineered their hubs with loose balls for the purpose of increasing friction and wear; that would not make sense, (to me).

 

[Schwinn Sales West]

I hot rodded a couple of CB-110E Shimano coasters a while back. I chamfered the edges of the shoes, removed the bearings from the cages on the drive side, added more loose balls and used quality grease. The reduction in drag was very noticeable.

The only purpose for the bearing retainer cage is to keep the spacing of the balls, and you could possibly argue that it makes servicing easier. More balls spread the surface load over more points, but more surface points could increase the surface friction.

Top of the line, groups from Shimano Dura Ace and Campagnolo Super Record used retainers in the bottom brackets and loose balls in the hubs and pedals. Running loose balls versus a retainer is only one or two extra balls different depending on the diameter. I think we are splitting hairs. Not only could you not feel the difference, but I'm also not even sure how you would measure it without fabricating some high-priced gauges.

I think the point we are missing in this discussion is that the driver side retainer is stationary (as in zero friction, zero movement) when the pedals and rear wheel are turning. The inside driver hub retainer only turns during coasting. You actually have only two retainers moving while you are pedaling, the left side hub retainer, and the right-side adjusting cone retainer.

The highest potential to reduce internal hub friction is by looking at the areas of highest friction/drag. Brake shoes and Brake Disk's have lots of drag especially if they were greased. A machined brake shoe cartridge has less drag. The second highest area is in the way the manufacturer designed the clutch assembly, and the retarder spring.

F&S (Sachs) and Perry are both great coaster brake designs. But in my opinion, the ramped roller bearing clutch driver, and the low drag of the lightweight retarder spring assembly of the English made Perry was never topped. If it were made today, I'm certain the cost to manufacture would be very high.

Perry for the win.

John

 

[nortonguy]

What you posted makes sense.
Explains why F&S and Perry hubs have loose bearings in one place, but not in others.
I don't believe that F&S and Perry engineered their hubs with loose balls for the purpose of increasing friction and wear; that would not make sense, (to me).

It would make sense to use bearings without cages to save manufacturing costs, if you do not have to invest in machinery to make bearing cages. Look at what corporations in the USA do, one has recently made their sticks of chewing gum thinner, newspapers get smaller in size, if they can keep from putting a fraction of an ounce in material in any object sold to the public, over thousands or millions of sales it amounts to many tons of material saved and dollars saved in material and labor. Also bicycles probably put a lower stress on ball bearings than any other wheel machine short of a baby-buggy, so leaving out a bearing cage is probably not going to make any difference in reliability. I am just pointing out that spending time and effort removing the bearing cage from a machine bearing is not cutting friction or increasing reliability, it is increasing friction and cutting reliability.

 

[SirMike1983]

The only purpose for the bearing retainer cage is to keep the spacing of the balls, and you could possibly argue that it makes servicing easier. More balls spread the surface load over more points, but more surface points could increase the surface friction.

Top of the line, groups from Shimano Dura Ace and Campagnolo Super Record used retainers in the bottom brackets and loose balls in the hubs and pedals. Running loose balls versus a retainer is only one or two extra balls different depending on the diameter. I think we are splitting hairs. Not only could you not feel the difference, but I'm also not even sure how you would measure it without fabricating some high-priced gauges.

I think the point we are missing in this discussion is that the driver side retainer is stationary (as in zero friction, zero movement) when the pedals and rear wheel are turning. The inside driver hub retainer only turns during coasting. You actually have only two retainers moving while you are pedaling, the left side hub retainer, and the right-side adjusting cone retainer.

The highest potential to reduce internal hub friction is by looking at the areas of highest friction/drag. Brake shoes and Brake Disk's have lots of drag especially if they were greased. A machined brake shoe cartridge has less drag. The second highest area is in the way the manufacturer designed the clutch assembly, and the retarder spring.

F&S (Sachs) and Perry are both great coaster brake designs. But in my opinion, the ramped roller bearing clutch driver, and the low drag of the lightweight retarder spring assembly of the English made Perry was never topped. If it were made today, I'm certain the cost to manufacture would be very high.

Perry for the win.

John

Sturmey Archer periodically considered (and in some cases did) venture into the realm of making single speed coaster brakes. They were unable to compete favorably with Perry and F&S. The Perry brake in particular was popular for many years, being a well-designed brake.

 

[FICHT 150]

The Sturmey Archer SC coaster is a Perry hub. This example is NOS, comes with the typical Perry tools in the bag, but, the carrier is machined to accept Sturmey gears with spacers and retaining ring, same as the other Sturmey hubs. Shown with a NOS Perry B100. The SC has an oil port, this NOS Perry doesn’t. I have a few older Perry hubs that have a port. The Perry hubs also have a threaded gear.
These are well built hubs.

Ted

 

[nortonguy]

The reason that there are no cages in very small diameter bearing applications like pedals and the small light alloy hubs for derailleur type bicycles that also have much smaller diameter balls is that the cage would be so small and light if a needed ball count was kept that it would not be reliable, the cage would have a chance of breaking up and ruining the entire part. There is less friction in small diameter bearings compared to larger ones which have higher surface speeds each revolution. They put the cages on any bearing they can because it is less friction than the balls rubbing against each other in opposite directions, doubling the surface speed of ball against ball. They certainly know how many balls are needed for any given application to bear load reliably, and if it was possible for them to put a cage in they did, not only in bicycles, but in any piece of machinery ever made.