\agattu Gearing

[oldosc]

There has been some advice on this forum about changing gearing on the Agattu. I have the 20 sprocket (I think the standard one...I so very rarely use the bottom gear I am tempted to change to 19, is there any possibility of having two sprockets that close, on the rear wheel so that a change could be made when stationary (like we changed tyres in early off road days)

 

[stokepa31_mk2]

Hi Oldosc

The standard sprocket is 22 teeth. The standard rule seems to be to drop a tooth for every low gear you never use. I went for 18 teeth and still never seem to use first or second so could in theory drop to a 16 tooth. (battery performance is what stops me). I do not think you could mount two sprockets on the hub if thats what you are getting at.

 

[flecc]

As Paul says, two sprockets couldn't be mounted since there's only allowance for the thickness of one within the retaining circlip groove.

It would be possible to have one made up by having one sprocket as only the outer ring with teeth and a spacer to the main sprocket, the whole riveted or welded together. I estimate the absolute minimum that an engineering company would charge for this would be £50, and it could be much more, so probably not worth it. It would also be necessary to have an additional idler on a sprung arm to maintain chain tension, since the Panasonic motor one wouldn't be suitable for that function.

A more expensive but more sophisticated solution to wider range would be to have a wider range gear hub built in for you, such as the SRAM 9 speed I-motion or the 14 speed Rohloff.
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[stokepa31_mk2]

A more expensive but more sophisticated solution to wider range would be to have a wider range gear hub built in for you, such as the SRAM 9 speed I-motion or the 14 speed Rohloff.
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Now you talking Flecc. I would love to put the Rolhoff in my Agattu. Like you say though it would be v pricey. One day!

 

[flecc]

I just wish they could quiet it down a bit Paul, and preferably stop the middle gear change problem.

My favourite is the I-motion, not as big a range (340%) as the Rohloff (526%) but still much wider than the Nexus hubs.

The NuVinci would be almost silent and slightly wider than the I-motion at 350%, but it weighs 4 kilos.
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[oldosc]

thanks Pretty comprehensive reply...never heard of the other hub types, guess it will pay to develop leg muscles for a bit till the new batterys evolve
Trouble is too many things to do such a short life.
Goin for a ride now north wind is chilly but .....
This is the worst summer I have had here in nearly 4 years..not one day so far to wear shorts...(not lycra )

 

[stokepa31_mk2]

is the I-motion widely available yet?

 

[flecc]

is the I-motion widely available yet?

Some independent suppliers are listing them Paul, but main UK agent Fisher Leisure are listing the hub only, disc brake and coaster brake versions with "shipping not known" against all, so presumably we are still waiting.

They are fitted to some production bikes though, so manufacture is progressing.
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