Re: Axle Failures
- --- In Geared_hub_bikes@yahoogroups.com, "bikealfa" <mtwils@...> wrote:
>I only do the torque arm fix when the non-turn washers do NOT fit very well. Usually this is done on bikes with vertical dropouts.
> Maybe I have not been following this thread properly, but adding a tourque arm to a non-turn washer still leaves the axle flats as the anti-rotation for the hub and that is pretty small diameter. Maybe the non-turn washers do not work as well in vertical dropouts as in road bike what-we-used-to-call horizontal dropouts?
>There are at least 3 varieties of new NTW made by SA.
> Sturmey Archer still has flats that are smaller than 10mm, and the non-turn washers appear to also be less than 10mm (but I have not measured new ones).
They measure 9.6, 9.85 and 10mm
>I used to braze on a bit of metal to make the non-turn washer fit the 10mm dropout better.Good idea!
>I have also brazed on a piece of metal to make the dropout narrower so I could use stock sturmey axles and washers with no hub mods. The question being - modify the hub pieces which are typically easier and cheaper, or modify the frame so the replaceable parts are stock? Modifying the wing nuts did not seem like a plan, but I found that I could not tourque them enough to keep the axle from moving when standing on the pedals.That last statement is what started this discussion. The current path dependant 3/8" (10mm) axle is just to small.
The 2 companies that have solved the problem are. NuVinci with a larger axle with 10mm flats that fit better in most dropouts and Rohloff with a much larger axle plate bolted to the axle and fixed to the frame.
Personally I like Rohloff's design and would like to see it standarized to every hub. NuVinci's larger axle could also be designed into most hubs but as Neil said, would require the pinions and gears be larger (but with the same number of teeth). The added weight would come with a huge increase in durability. Pinions explode!
One observation I have made is that SRAM gears tend to wear but the bearing races are very durable, whereas Shimano hubs have really good gears but the bearing races wear faster.
The industry needs standards and we need a Bicycle Mechanic's Guild to act as a clearing house for good ideas (like this) and to stop bad ideas like having 200 different rear dearailleur hangers or 80 different headsets!
> Michael Wilson