I fitted both the Schlumpf drive and 18 inch wheels to my Strida 5 last weekend. Here’s a picture of the new setup:
http://picasaweb.google.com/2948682/201006#5482733661112080866
The transaction with Schlumpf was very smooth. They don’t have secure ordering capability on their web site, so I phoned them up and provided my credit card number verbally. The package took less than a week to travel from Switzerland to the west coast of the USA.
Installation was very easy, no drama at all. Everything went together as intended and the entire process took less than one hour. Belt alignment is perfect and everything runs very smoothly.
I live in Oakland, California and the weather the past week has been perfect, so I got a few miles in. The combination of the slightly larger wheel/tire combination, lower rolling resistance tires and availability of a higher gear makes the bike much more usable for longer rides. I find myself using the lower gear most of the time, but for nice long flat stretches with little or no incline or headwind it is nice to have that taller gear. The tall gear is somewhat taller than I would like, I have to be going pretty fast before it works for me. It probably would have been more to my liking with the 16 inch wheels, but I did both mods at the same time…
It takes some practice to shift quickly. First you have to position the pedal, which I don’t find particularly instinctive – I have to think about it every time. Then you have to use an unusual movement with your heel, pushing sideways on the crank pin. This takes time, I’m not sure I will ever get to the point where I am “speed shifting”. There is a soft clunk as the gear engages, usually. Sometimes the gear engages with little or no noise. Because of this it is usually, but not always, obvious that the new gear is engaged.
Internal friction of the 2-speed drive is quite impressive. In fact, it is hard to tell subjectively which gear is direct-drive (it’s the low gear). That works for me, since I am spending most of my time in low gear. Once I build up some speed and upshift I can’t really notice any additional drag. Everything runs along quite smoothly.
Overall I am very happy with the Schlumpf 2-speed drive. It is a beautiful piece of engineering and machining and improves the appearance of the bike. The drive itself is remarkably small and compact. I need to practice my shifting, faster shifts would improve things considerably.
http://picasaweb.google.com/2948682/201006#slideshow/5482733304274624386