Recently purchased an old Hirondelle Manufrance 10 speed, posted pics up here, and many suggested replacing the Simplex rear derailleur~possibly with a SunTour. Happened upon a Simplex SEVEN on a Univega at the local pawn shop for $25. Should I purchase said Univega and make the switch? Or trust that the Simplex will last (barely used). As usual, thanks for helping out a newbie...

I would ride it with the Simplex RD. I've never had any problems with Simplex rear derailer durability altho I've read of others who did. If it breaks or wears out prematurely then replace. Then I'd look for an all aluminum Simplex replacement on EBay if it were my bike.

Agreed......I've never seen a broken one (In person). I've seen and used some that looked absolutely terrible like they had been in constant use for 30 years that still shifted better than my Campy NR......When you upgrade a Simplex SLJ would be awesome.

Only problem I have had with the Simplex "Criterium" type deraillers is that the front deraillers tend to crack around the band area.

No direct experience, but I have twice found old abused bikes with busted Simplex rear derailleurs. That does not really indict them. But, on the other hand I am not sure I have seen more than a handful of broken rear derailleurs otherwise.

jim

Ride it 'til it breaks, but expect it to. I had the Prestige as OE on my Interclub back around '72 and had replaced it by '74 with a Suntour (Vx / V-GT ? whatever their current model was at the time)

if the case is to ride it til it breaks, is it a good idea to get this univega for cheap to have the back-up derailleur? could also prob sell the univega as a single speed i am guessing...

A functioning steel bike for $25 - and a Univega! Buy it. I have a buyer here who pays $100 after the handlebars, shifters, brake levers, and derailleurs are removed.

If the Univega is in good condition and is the right size, I'd test ride it. You just might find out that you like it better than the Hirondelle and not just for the shifting.

Back in the early 70's I broke 2 of these on a Raleigh Record & a friend I still ride with also broke 2 of these on his Grand Prix. Replaced with Sun Tours after that. Can rig the chain on one sprocket & limp home if need be.

Expect the rear derailleur jockey wheels to bite the dust in short order. The Simplex plastic gets very brittle with age, and I've had a couple from the 60's and 70's practically disintegrate. Sun Tour jockeys are replacements that will fit.

Yes...the Simplex shifters work very well but th jockey wheels are prone to breakage.

I strongly prefer SunTour, but there is no reason not to keep using the Simplex units until they die. I have successfully used Simplex shift levers with SunTour derailleurs, but the throw ended up being pretty long.