Bicycle Mechanics - SRAM i-Brakes, what are they?
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Jean Beetham Smith
09-25-04, 02:15 PM
I searched this forum for this topic with no results, but if I used the wrong parameters, sorry.
In a similarly computer illiterate fashion, I can't download the technical manuals at the site
Are these disc brakes with smooth, "stylish" covers to make them more appealing on city bikes, or
are they drum or roller brakes, or are they an entirely new type of braking system? As always, I'm
looking at possible components if I ever do build that custom commuter-tourer.
Dunno, but to me they look like an internally geared hub with a disc brake integrated into them.
09-25-04, 04:25 PM
Sram doesn't say so, but I believe it is a drum brake.
I clicked the link for the technical manual and got a 404 Error Message, i.e. the page doesn't exist.
It seems to be a sort of "modular" drum brake, akin to the Shimano roller brake. Modular, in that they seem easily removed from the hub. Looks like they're looking to make the iBrake a add-on option for their 3, 5, and 7 speed freewheeling hubs.
If you're interested in getting a 72p download of the 2005 gear hub lineup (includes the i-Brake and the more interesting i-Light hub), look here:
09-25-04, 07:38 PM
this is from the 72 page manual, it is intended for use on "Comfort" bikes. yes its a drum brake
• There is a risk of accident if unsuitable forks or
frames are used (see page 55).
• Only 24”/26”/28” wheels are suitable for use.
• The total weight of the bicycle with rider and baggage
may not exceed 125 kilograms.
• The i-BRAKE is not useable for tandems, transport
bicycles, and similar loads.
• The i-BRAKEs must go on the left side viewed from
behind the rear of the bicycle.
FWIW, Shimano's roller brakes have similar specs.
Forks need to be stiff enough since they have a torque arm similar to a coaster brake hub. I don't think they need special bosses like disc brakes, however.
I think Shimano makes a roller brake specifically intended for wheels 24" and smaller. I suspect they'd have to be special ordered.
The couple data sheets I've seen Shimano recommends a weight limit of 100kg. Such weight limits would pretty much rule them out for heavy load bikes such as tandems or cargo bikes.
The use of a torque arm pretty much means that they could only be mounted in a specific orientation.
Jean Beetham Smith
09-26-04, 08:33 AM
Thank you guys, I knew someone could tell me about them, and a special thanks for the link and summary of the technical manual.
09-26-04, 02:57 PM
The tech manual link just has one too many ".pdf"s in the filename. Here the corrected link.
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