3 speed hubs

[bikewithmotor]

I was reading a post on 3 speed hubs, where it was jumping out of gear, assuming the hub is in good working order, there is a fix for this on the sturmey archer site. where you modify the lugs with a spring, to keep it in gear.
The AW hubs are the best to use, the SW hubs were known to slip out of gear.
I hope this helps those using the hubs. Further when shifting these hubs you must back off the throttle to allow the hub to shift into and out of gear.

 

[The_Aleman]

Welcome to the forum.

I've been using an X-RD3 for almost 2 years now, with a 4-stroke 49cc routed through it. Instead of the included grip shifter, I use a Sturmey classic trigger instead. I have over 5K miles on it.

The first 6 months or so, I never backed off the throttle when up-shifting. I just clicked the trigger and she slammed home, sometimes full throttle, sometimes just pedaling hard. Down-shifting definitely requires backing off on the throttle, even when pedaling. But I "power-shifted" that thing for a good while. I've never had problems with it staying in gear, nor has it ever jumped out of gear. As with any conventional IGH, cable adjustment is key.

Many of the '60-90's British Sturmeys were problematic. When SunRace took over, they had all of the original tooling sent to Taiwan and found out the tooling was worn out beyond repair. So they got new machines. These Taiwan Sturmey hubs are easily as good as any of the '50's and earlier British Sturmey IGHs.

 

[bikewithmotor]

They must make the hubs super duty if they can take all that abuse, The older SW hubs were made with sloppy clearances and the parts were rough in nature. I had a bike with the 3 speed hub, but I always backed off before shifting it, and never had a gear pop out. The AW hubs might take that, I would not want to try it. Also getting the right shiftier is very important. I would say use only the sturmey archer shiftier and not other brands, because of the different spread between gears. The SW had a lot of problems with jumping out of gear. I assume that the hub you have is a new one, which takes into account for the better shifting. I only mentioned what I did to maybe help others that were having problems with there hubs not staying in gear. the Sturmey Archer Site has a lot of info on the subject, as well as service manuals that can be downloaded not to mention all the parts to repair the hubs. I thank you for the info on your hub, sound very interesting. I would say if you have the money then you should get X-RD3 hub or at least a new one for better shifting and reliability as per the above reply.

 

[The_Aleman]

There are several members using the newer Sturmeys in shift kit configuration. I know of another member on another forum who has the same hub I do running his with a 66cc 2-stroke. He's had his for longer than I have, in fact I bought mine after talking to him about it for a few weeks in 2010. He has at least as many miles on it as I do. Another member here, MotoMagz, has his 4-stroke 49cc running through an X-RD5, basically a 5-speed version of the drum brake hub we're using. So far his seems to be holding up well, too.

While these engines produce more horsepower than pedaling, they do not produce more torque than a human can. If you have 175MM cranks and you weigh 200lbs, standing on the pedals will produce spikes of 150lb/ft or more. These small engines, even with 20:1 gear reduction cannot approach that figure. Early 2 and 3-speed Sturmeys from the 1900s-1920s were sometimes used on motorcycles back in those days, and those engines made a lot more power than these 2-3HP engines we're running. That said, I don't think modern 7 or 8-speed IGHs will last too long with engine power. They have smaller, more complicated innards with more reduction mechanisms. The 3- and 5-speed Taiwan-made Sturmeys seem to be pretty strong tho (and easily rebuildable).

 

[professor]

I am using a SA from an old 60s bike as a jackshaft and had issues with it sliping out of high gear. There was a bit of wear on the internal cross shaped part and the little studs they were to ride against.
I repaired these bits and all is well.
Amazing how tiny the internals are in these hubs.
It would be best to always let off the throttle on shifts to lessen the wear on these tiny parts.