Sierra

Pogue mentioned Simplex retrofriction shifters in the thread on the SuperCourse and it reminded me of a problem I have. I picked a set of these up recently at a bike swap meaning to use them on the early seventies PX10 that is this winters project. The PX10 frame has no brazed on shifter bosses and the clamp on bosses for the original Simplex shifters have a different(courser) thread than the tension screws in the retrofrictions. I found a set of Campagnolo clamp ons that take that thread but the retrofrictions won't fit on them. I've been watching the retrofrictions on ebay and so far they have all been for braze-on. Did Simplex make them in a clamp on version? Anyone know of some clamp on bosses that will work with them? I tried the local hardware store for the metric screw that would fit the older shifter bosses but it seems it is a non standard thread pitch and they don't have it. Another question on the retrofrictions; what is the deal with the spring in the base of the shift lever itself? I've heard that this is the secret to their smooth operation, but I can't see that it does anything. It just sits in the base of the lever and doesn't engage anything when the lever is slid onto the boss.

USAZorro

Sierra, Simplex absolutely did make clamp on shift levers. They are often on e-bay, and I even own a set (but I have a use for mine). I know someone who might have some available for a reasonable cost. I can give you e-mail if you contact me off the thread.

As for the spring? I don't have that answer.

Sierra

Zorro, are speaking specifically about the retrofriction shifters? I know that Simplex made other clamp on shifters. I have a set on the PX10 now. They are the originals from the Simplex Criterium group that came on the bike. It's the later shifters that are known as "retrofriction" that my question is about. Here is a set now on ebay.

https://cgi.ebay.com/ws/eBayISAPI.dll...sPageName=WDVW

Poguemahone

Simplex made them in a clamp on, both in the classic and open-hole style. I can post photos of both, hold on.

T-Mar

I can corroborate USAZorro's statement that the Simplex retrofriction lavers were available in a clamp-on version. A friend had a set on his Falcon.

USAZorro

Sierra, The person I was referring to as a potential source sold the only set of clamp-ons he was willing to part with. The ones you depicted (well the closed version), is what I was hoping to get from him for a project. I had to settle for a different set he had with shorter levers. The ones you want do show up from time to time.

Sierra

Thanks for the replies and info guys. Now that I know they exist, I will just have to keep my eyes open for them. Anybody know anything about the spring in the lever body? Unless mine has a part broken off the spring, I really can't understand how it's supposed to do anything. It's totally imbedded in the lever body.

Poguemahone

I believe the general concept of the retrofrictions is they give a bit more resistance when you shift to a smaller cog. The spring might have something to do with that. Someone may be along to correct me shortly.

I do know they are far and away the best shifting friction shifters I've ever ridden with. At this point, I have them on four seperate bikes; I upgrade the shifters on my riders as I find the retrofrictions. So the 1972 PX, the 1979/80 PK and PF, and the Trek 560 all ride with them.