A shy person asked:
>
> :> I am interested to know if there is any information available on the load carrying
> :> capacity/rating for bicycle frames. I expect this will vary based upon the type of bicycle eg
> :> Road, MTB, Touring...
I replied:
> : When bicycles are overloaded, it isn't the frames that fail, it's the wheels. With the exception
> : of a few exotic racing frames, any frame will be strong enough to carry any load that won't
> : cause wheel problems.
Risto Varanka wrote:
> A strong carriage is required as well. Some sports recumbents can't take that much load, for
> example see the ratings that Challenge provide for their bikes.
>
> Some recumbent trikes are available in different frame strenghts. (For example Greenspeed and
> Steintrikes.) I gather this basically just means how much metal (extra kilograms) there is on
> the frame.
The original question was about _bicycles_ not trikes, which are an entirely different beast. Trike
design is much less mature than bicycle design.
> The wheels could be just the same. Are trike makers sensible at all?
I guess three well-built
> little wheels can take up quite a load, but you must count the rider in the load too
Actually, _fast_ trikes, such as Greenspeeds are highly stressful to wheels, much more so than
bicycles. This is because a trike doesn't lean in the corners, so there are _much_ higher lateral
stresses on a trike that is ridden above boardwalk speed.
Fortunately, most fast trikes use 406 mm (20 inch) wheels, which are much stronger laterally than
full-sized wheels.
Sheldon "Greenspeed Lust" Brown +-------------------------------------------------+
| There is something fascinating about science. | One gets such wholesale returns of conjecture |
| out of such a trifling investment of fact. | --Mark Twain |
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