Did I only imagine I read this.......?

[indalo]

I'm not certain about this but I think I read on a spec sheet somewhere that the gearing on a bike was both internal hub with the addition of a derailleur at the crank. I feel a bit stupid asking but does Shimano or another gear system supplier offer such a thing?

If so, does any major, indeed any, bike maker employ such a system and does it offer any real advantage over one system or the other?......ie, hub solely or derailleur on its own.

Indalo

 

[Blew it]

The Haibike Trekking is fitted with the SRAM Dual-drive, a combined derailleur and 3 speed geared hub. This is especially useful for center-drive machines having room for only a single chain-ring.

The middle ratio on the geared hub is direct, allowing the full benefit of the low losses of the derailleur system. An added advantage, is the ability to shift into a lower gear while the machine is stationary.

 

[indalo]

The Haibike Trekking is fitted with the SRAM Dual-drive, a combined derailleur and 3 speed geared hub.

Cheers for that Blew it! It was only recently I read that but for the life of me, I couldn't remember which bike or which gear system.

Given your description of its workings, I should think it suits the Haibike very well.

Regards,
Indalo

 

[Blew it]

Full description.

SRAM Dual-Drive

 

[flecc]

In effect the three speed hub takes the place of three chainrings at the front, providing the same three ranges of the rear sprocket set. Very handy for e-bikes which aren't able to have triple chainrings for whatever reason, and also for recumbent trikes where a triple front chainring can bring the chainpath too close to the legs.

 

[shemozzle999]

Just like the Brompton 6 speed

 

[andyh2]

The SRAM dual drives are quite pricey. There's a recent (cheaper) one from Sturmey and I think Shimano do one too. Not sure about the comparison of build quality.

Useful for folders too.

 

[jhruk]

Handy for all small wheeled bikes - permits higher gearing without needing over large chainrings. Some 24 speed Dahons using Dual-Drive claim a gear range of 21-114” - impressive for a 20” wheeled bike.

I’m surprised how few folding bike manufactures use it.

 

[kitchenman]

I've got SRAM Dual Drive on my Spirit. Its excellent.

 

[Mussels]

They look good and might slot very nicely onto my 906 if the Alfine hub gives up the ghost, depending of course of the price difference.