Schlumph

[Wisper Bikes]

Hi, I need help!

Has anyone ever tried a Schlumph two-speed, planetary gear-driven crank/bottom bracket system?

If so what do you think?

All the best

David

 

[flecc]

I haven't personally David, but reviews of Florian Schlumpf's three versions have shown it's a bit inefficient, dual chainring much more efficient. It apparently works very well though, but very expensive.

 

[lemmy]

Efficient or not, I want one because it is so beautiful

 

[Graeme]

Is this an indication that you (David) and Wisper have 'seen the light' and are contemplating the switch to crank driven bikes? ;-)

 

[Wisper Bikes]

Hi Graeme you never know, it may happen one day, but not until something really amazing is launched! We are currently looking at very small motors (80mm) that can produce 600W and through gearing but due to problems with ion loss they wont be ready for a while. (Although the engineers we are working with seem have found a solution.)

We are considering the Schlumph drive on a new bike for the 2013 season.

All the best

David

 

[Wisper Bikes]

Hi Tony, thanks.

I tried one out on Monday at the manufacturers and was amazed by the way it felt and drove the bike. I was told the efficiency was very slightly down on a decent derailiure set up but of course this Schlumph is maintenance free and does not require cables to control it.

I agree at nearly £500.00 retail they are very expensive, however they are built like a swiss watch!

All the best

David

 

[flecc]

They certainly look beautiful and are a simple way to double a bike's gear range. I've no doubt the efficiency is far more than "slightly down" on the near perfect efficiency of a derailleur, but the important thing is choosing the correct version.

Since the inefficiency is only when operating through the epicyclic under load, the version chosen should have the epicyclic gear in use in the minority time mode, all the majority time usage in the direct mode unaffected.

 

[Wisper Bikes]

Thanks again Tony, that is exactly what I was advised, the epicyclic gear would be used on the lower of the two gears for hill climbing and pulling away from stationary.

Regards

David

 

[flecc]

Good choice David, minority use of the reduction.

Things are not so clear cut with their speed drive and high speed drive, it being unknown how much time anyone will be in either mode.