2-Speed, 2-chain Drivetrain: The multi-speed drivetrain consists of a switchable freewheel with two cogs that are each paired with a corresponding chainring via their own single-speed chain.
Riders can effortlessly switch between high gear for speed and low gear for climbing by simply back-pedaling just under half a turn, then pedal forward.
So how does this freewheel selection work
images.jpeg (9.19 KiB) Viewed 2877 times
Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X2, Raleigh 20 stowaway X2, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840, Giant Bowery, Apollo transition.
Trying to visualise this, the low gear freewheel can freewheel when the big chain wheel is driving but when the low gear is engaged the high gear freewheel has to disengage as it's turning too fast so the opposite of freewheeling.
I'm surmising it's some pawl arrangement within the double freewheel assembly.
Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X2, Raleigh 20 stowaway X2, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840, Giant Bowery, Apollo transition.
rjb wrote: 27 Dec 2024, 9:41pm
Trying to visualise this, the low gear freewheel can freewheel when the big chain wheel is driving but when the low gear is engaged the high gear freewheel has to disengage as it's turning too fast so the opposite of freewheeling.
I'm surmising it's some pawl arrangement within the double freewheel assembly.
CVR_1532-768x513.jpg
I thought that, but I now think I was wrong. Looking at the huge great big crank spider, I think the sprockets are fixed, but there's a mechanism in the crank which engages either the big or the small chainring, and whichever crank ring isn't engaged with the cranks, is simply allowed to turn...
'People should not be afraid of their governments, their governments should be afraid of them'
Alan Moore - V for Vendetta
cycle tramp wrote: 29 Dec 2024, 9:00am
...fair enough... I hope they supply the UK with their product as well... i might buy one
Surely this is designed just for these Elephant bikes which weigh a tonne.......slight exaggeration. The only real 'benefit' is that you do not require a front or rear derailleur.
I can't see much use for this product on a 'normal' utility style bike. A bit over engineered and there are much easier ways of getting 2 gears surely. Perhaps I'm missing something.
cycle tramp wrote: 29 Dec 2024, 9:00am
...fair enough... I hope they supply the UK with their product as well... i might buy one
Surely this is designed just for these Elephant bikes which weigh a tonne.......slight exaggeration. The only real 'benefit' is that you do not require a front or rear derailleur.
I can't see much use for this product on a 'normal' utility style bike. A bit over engineered and there are much easier ways of getting 2 gears surely. Perhaps I'm missing something.
Was thinking the same. I'd rather have a 3 speed hub and only 1 chain to clean.
Or why not get 2 separate lightweight single speed bikes, say 9 kg apiece, one with a high gear and one with a low gear. Lash them together with a couple of cross members and struts and jump on whichever one suits for the terrain. This to me is similar engineering.
I used the F&S Duomatic coaster brake hub for PBP03, needing only one cable for a front brake. Germans were quick to tell me that German postal workers used the same hub on their delivery bicycles. The hub gears created by F&S got killed off by SRAM years ago, so Shimano or Sturmey hub gears are the only games in town now.
LWaB wrote:.....Shimano or Sturmey hub gears are the only games in town now.
not quite, in that there are millions of old AW hubs out there. I have recently figured out how one of these might be converted into the hub of your dreams, and two of the options are for fixed/free two speed hubs, with 'high normal' gearing. Looks-wise the converted hub is a bit reminiscent of the old SA 'T' series hubs, but the majority of the hubshell is Al, not steel. This also give very wide-spaced flanges expected to build into even stronger wheels than those built on campag track hubs.
cycle tramp wrote: 29 Dec 2024, 9:00am
...fair enough... I hope they supply the UK with their product as well... i might buy one
Surely this is designed just for these Elephant bikes which weigh a tonne.......slight exaggeration. The only real 'benefit' is that you do not require a front or rear derailleur.
I can't see much use for this product on a 'normal' utility style bike. A bit over engineered and there are much easier ways of getting 2 gears surely. Perhaps I'm missing something.
Very few benefits - no inefficiencies of an internally gear hub, and easier to fix if there is a fault, and the ability to choose both low and high gear ratios... however I mostly cycle on the flats with only a few hills... a flat gear of 56 inches and a lower gear of 34 inches is most appealing
'People should not be afraid of their governments, their governments should be afraid of them'
Alan Moore - V for Vendetta
I used the F&S Duomatic coaster brake hub for PBP03, needing only one cable for a front brake. Germans were quick to tell me that German postal workers used the same hub on their delivery bicycles. The hub gears created by F&S got killed off by SRAM years ago, so Shimano or Sturmey hub gears are the only games in town now.
...er... NuVinci, Rolhoff, Pinion..?
'People should not be afraid of their governments, their governments should be afraid of them'
Alan Moore - V for Vendetta
LWaB wrote: 29 Dec 2024, 11:22am
The hub gears created by F&S got killed off by SRAM years ago, so Shimano or Sturmey hub gears are the only games in town now.
(left unsaid but possibly understandable from context) … for cheap, low maintenance town bikes needing few gears.
I consider 8sp, 11sp, 14sp, etc. hubs to be a different level of complexity and cost to a 2sp or 3sp hub, particularly if you want a coaster brake 2sp or 3sp.
