Schlumpf Speed Drive

[CptPalmer]

Has anyone giving any serious thought to replacing their crank with a Schlumpf. I really wish I could try one of these out as a trial. My questions center around will I get more speed, how hard would it be to pedal in the higher gear, will it even work on the Stromer etc. The ATS model is priced $300+ so the price point is not to bad. Does anyone have any experience with these cranks?

 

[CptPalmer]

This site should get you started. http://www.ats-speeddrive.com/tpl/all_about.html

 

[Shea N Encinitas]

Will not work on my Dash as there is an axel that sits inside the hub. Tnx for the link I was reading the swiss site. -S

 

[bluecat]

Stromer ceased selling their high speed model after a few months in 2010. Therefore, the need for larger gear declined. Nevertheless, I met a Schlumpf SpeedDrive rider. He told me, riding at high speed was easier (reduced rpm) and shifting gear no problem. As he was a bike mechanic, installation was no issue. Another Stromer rider describes his experience at Stromerforum.ch

 

[Shea N Encinitas]

@CptPalmer So did you decide against the Schlump drive, still on the fence? I could see replacing the triple on a Platinum, pull the left shifter. -S

 

[CptPalmer]

I am still sitting on the fence with this one. I want to make sure the higher top end can be utilized by the motor. The other day was I traveling down hill and I was going 44 and the motor felt like it was in regenative mode. The display also had the >>> on the left side as well and I was pedaling. I need to experiment a bit more to find out what was happening.

 

[MarcD]

IIRC, motor assist will cut around 28mph or 30mph on an ST1 Platinum, so higher gears will only help you increase speed on human power alone (since a 50/11 on 26"x2" wheels will top out around 32mph @ a cadence of 90rpm. To exceed 45mph you would have to be pedaling a 60/11 gear at 110 rpm+. I would guess that the resistance you felt was mostly aerodynamic drag. Once you exceed about 18mph, aero becomes a huge factor in the amount of effort/power required to maintain that speed. It is a major reason why real world experience on my Turbo S shows that I get almost 75% more range @ 18-20mph than at 28mph.