Bicycle Mechanics - Coaster brake with cooling fins

What do you think of this taitanium coaster brake with cooling fins?
http://http://www.flickr.com/photos/21159896@N08/3278818934/

What do you think of this titanium coaster brake with cooling fins?

Well, what IS there to think?
1) that hub is going to be an absolute b*stard to keep clean
2) I think the fins would have done a better job if aligned in the plane of the wheel instead of perpendicular to the axle. As it is it's likely to set up a lot of turbulence around the hub, which won't be able to shift as much heat as a nice laminar flow would have been able to
3) why titanium? It's not that wear resistant, so you're likely to need a sleeve inside the hub. And it doesn't conduct heat as well as aluminum either.
4) coaster brakes are nice from a near-zero maintenance perspective, but hard braking has always been a weakness, both when it comes to modulation and heat build up.You're looking at a mighty narrow customer base if you're trying to find people who really love coaster brakes but whose favourite riding terrain is just a tad too hard for an ordinary coaster brake. In short, if you ride hard enough to need cooling fins on a coaster brake odds are really good that you're also riding hard enough to merit from a disc brake.

do you plan on going down mt. everest with that thing?

I use a coaster brake, and they're okay for what they are. But if you want better brakes, you just use a different established style, no reason to invent anything. That's like inventing a carbon-fiber horsecollar. Where can I buy it, by the way?

I can't think of a good application for that and as stated, aluminum is a far better material for that.

Am I mistaken, or is that an image of a computer model? If it is just a computer model, claiming it's a real hub made from titanium is a wee bit of a stretch, don't you think?

tcs

If Osobikes wants a tarted up, "exotic" coaster, consider Velosteel (http://www.bikeforums.net/archive/index.php/t-69010.html) (also here (http://kogswell.com/siteVELOSTEEL.php)).

Best,
tcs

Elgin built some cooling fin coaster brakes back in the day but they went around the hub, not across.
http://www.firstflightbikes.com/_borders/ElginTwinHub.JPG
from First Flight Bikes.


Coaster brakes don't fade just because the outside of the hub gets hot but because the brake shoes also get hot. Unless you plan on reinventing the guts, I don't see how a titanium hub shell would help this.

As for the fin's, have those been tested for effectivness? I see they might create more turbulance. Also are they tall enough to be effective. Looks like you have just increased the hub shell thickness with some bumps.

If you need testers, let me know. My friends and I do a Cruiser ride with Coasterbrakes down this 16 mile road.
http://i120.photobucket.com/albums/o192/conion1/bogus-1.jpg?t=1234812503

Am I mistaken, or is that an image of a computer model? If it is just a computer model, claiming it's a real hub made from titanium is a wee bit of a stretch, don't you think?

tcs

Yes it is a computer generated image. In other words, CAD drawing.

If Osobikes wants a tarted up, "exotic" coaster, consider Velosteel (http://www.bikeforums.net/archive/index.php/t-69010.html) (also here (http://kogswell.com/siteVELOSTEEL.php)).

Best,
tcs

If you read the thread, the Velosteel apears to be heavier, more expensive and more problematic than the Shimano

Elgin built some cooling fin coaster brakes back in the day but they went around the hub, not across.

from First Flight Bikes.


Coaster brakes don't fade just because the outside of the hub gets hot but because the brake shoes also get hot. Unless you plan on reinventing the guts, I don't see how a titanium hub shell would help this.

As for the fin's, have those been tested for effectivness? I see they might create more turbulance. Also are they tall enough to be effective. Looks like you have just increased the hub shell thickness with some bumps.

If you need testers, let me know. My friends and I do a Cruiser ride with Coasterbrakes down this 16 mile road.

Cmon,
Cool pics!

Well, what IS there to think?
1) that hub is going to be an absolute b*stard to keep clean
2) I think the fins would have done a better job if aligned in the plane of the wheel instead of perpendicular to the axle. As it is it's likely to set up a lot of turbulence around the hub, which won't be able to shift as much heat as a nice laminar flow would have been able to
3) why titanium? It's not that wear resistant, so you're likely to need a sleeve inside the hub. And it doesn't conduct heat as well as aluminum either.
4) coaster brakes are nice from a near-zero maintenance perspective, but hard braking has always been a weakness, both when it comes to modulation and heat build up.You're looking at a mighty narrow customer base if you're trying to find people who really love coaster brakes but whose favourite riding terrain is just a tad too hard for an ordinary coaster brake. In short, if you ride hard enough to need cooling fins on a coaster brake odds are really good that you're also riding hard enough to merit from a disc brake.

Your logic has no place here! It's titanium and it's expensive. It's also probably CNC machined. Jeez. You sound like you know what you're talking about and then you come up with all this... .logic.

It is a CAD model, and a poor one at that. Perhaps a 1st year design student? That's a 10min model for anyone with any proficiency. I bet there aren't even any guts in that model.

Velosteel hubs are quite low end and are found on bottom of the line bikes here in Europe. I have no idea why they are so hyped in the US.

titanium has a crappy thermal conductivity. any coaster brake made with a titanium shell
will overheat, fins or no fins

I've wondered how much of a problem this really is. I do a fair amount of riding on a coaster brake and have never experienced fading or any kind of failure attributable to overheating.

This isn't to say that it cannot happen. Just that it would be a rarity that could easily be mitigated by perhaps using a front brake in addition to a coaster brake.

If overheating is an issue, it may be easier to manufacture some finned aluminum extrusions similar to semiconductor heat sinks, designed to attach to the generic steel coaster brake hub shell that would allow more efficient cooling.

See, They do exist.
http://i.ebayimg.com/08/!BQ7RCm!B2k~$(KGrHgoH-DQEjlLlu3hQBJ7c6,Fbpw~~_1.JPG
Shane

See, They do exist.


Almost everything exists somewhere. The fact that it exists and yet is not common is at least a slight indicator that there are superior designs.

What do you think of this taitanium coaster brake with cooling fins?
http://http://www.flickr.com/photos/21159896@N08/3278818934/
Hipster jewelry.