Classic & Vintage - Simplex front derailleur limit adjustment?
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How do you adjust the limit on a front Simplex? There is one screw and I can't figure out what it does... The derailleur is not going into high gear.
05-27-11, 10:03 AM
I would imagine that you would loosen that screw for more travel because the screw on the other side is to just hold the cable in place.
But first off try to pull the derailleur arm out with your hand to make sure it isn't just very stiff.
Yes, that's the screw on the front. But, if you weren't having troubles at one time and have made no adjustments, take the little, plastic Simplex cap off the back end and spray some lube in there. I've rebuilt a couple of those (with no success.....the plastic tube clamp kept breaking) and the mechanism inside tends to gunk up with rust.
05-27-11, 10:25 AM
Move the shifter to the forward position and take the slack out of the cable. Loosen the set screw and position the cage over the small ring. The screw you're talking is the high gear stop.
05-27-11, 11:19 AM
After you it it its painfully simple (Simplex)... These are infact great dérailleurs except for the now aging plastic making them unreliable...
05-27-11, 12:20 PM
I'm still using one on my Jeunet. It works fine as long as there isn't a large difference in ring size. It's the fancier one with a chrome clamp and aluminum cap that's incorrectly shown on Velo Base as a Prestige. It has another name, but I can't remember it.
05-27-11, 12:23 PM
the now aging plastic making them unreliable...
That aging plastic, Dupont Delrin I believe, was not dependable right from the start. I have seen several bikes in mint shape because the front derailleur broke early in the bicycle's life. And, previous owners reported the failure as the reason for stopping use of the bike.
05-27-11, 03:08 PM
Delrin is still widely used. There was a huge class action lawsuit after plumbing fittings failed and caused flooding of houses.
How 'bout that........hmmm.
05-27-11, 09:28 PM
The Disraeli Gears website has the instructions for the Simplex Prestige 637 derailleur, the last page of which covers the front derailleur and tells how to adjust it.
See scan 4.
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