Fallingwater

I'm restoring this Cycles Elite Sport road bike; the Internet says it's a French model from the seventies. It has 5x2 gears and bottom tube friction shifters.

It requires some work, but nothing too difficult - save for the one big problem that the rear derailer is completely shot. Both wheels have missing teeth, as can be seen in this short video.

I went looking for vintage derailer replacements but found none without insane shipping fees; it was suggested to me that I replace the entire rear derailer with a modern unit like an Altus (with properly set stops), and since it wouldn't be compatible with the antique friction shifter - something about different pulls - get a corresponding modern trigger shifter to mount on the handlebars. This is an option, but I'm considering it a last resort as I'd like to keep the bike as unmodified as possible; I've done a vintage-to-modern restoration already and for this one I'd like the challenge of not changing more than strictly necessary.

While looking for derailers I found on Amazon a set of two Shimano derailer wheels and since they were stupid cheap (€5 for both, shipped) I impulse-bought them, thinking they'd be mostly compatible with the ones on the current derailer. However I've just taken it apart, and found that the wheels it has have - or rather used to have - 10 teeth.

The whole derailer is riveted together. I can't explain the presence of star-driven screwheads; turning them - both the one on the cage and the one that keeps the derailer on the hanger - does nothing other than rotate the whole rivet together. I doubt this derailer was meant to be serviceable. So I brought the thing to the drill press and the bench grinder, shredded the rivets and finally managed to get the cage apart.

This is how it looks like:

The cage together

The cage apart

The wheel removed


Apparently the wheels just ride on simple bushings. The screw, or rivet, seems to be one with the bushing core; I'll have to drill it through or cut it to disassemble the thing and leave a clean hole.

At this point, since the Shimano wheels I ordered have integrated bushings, my plan is to use bolts (and washers to space the wheels correctly, if need be) and nylock nuts in place of these awful riveted screws and rebuild the derailer with the 11-tooth wheels. What I'm wondering is if said wheels are going to be a problem: size-wise they seem slightly larger but not that much, so the chain should still be able to pass through the derailer without fouling.


TL;DR version

Can I swap out the 10-tooth wheels on this derailer with 11-tooth wheels and get away with it? I don't have an easy source of 10-tooth wheels available at the moment, at least not without paying as much for them as I would for a whole new derailer and shifter.

Dave Mayer

This situation cries out for a visit to a bike Co-op. At the shop that I volunteer at, we have a 30-pound bin of similar vintage stuff.

Jockey wheels from old Suntour or Huret derailleurs should work with your old Simplex unit. The inner cage on your derailleur is in poor condition, so it should be replaced as well.

I rode on Simplex (better ones than this) for many many years. The Derelin plastic used is fragile, and becomes brittle with age. And the pivots on these became sloppy quickly - far more quickly than the all-metal Campagnolo units. The drop-parallelogram design always shifted poorly relative to the slant-parallelogram Suntour derailleurs. Finally, these derailleurs have a tiny range; they barely handle a 28 tooth rear cog.

I have a stash of Simplex Criterium and Prestige units sitting in a bin somewhere; would I use these? No way, as a $30 Shimano Altus (or whatever) rear derailleur will function far better. Plus I don't have to worry about the plastic in the Simplex spontaneously exploding, and sending the fragments into my wheel. My recommendation: cut your losses and go with something new.

Fallingwater

Can you use an Altus on a vintage friction shifter? It was explained to me that modern trigger shifters have a different amount of pull as compared to vintage friction ones, so getting them to work right is extremely finicky and might be impossible.

I mean, I too thought it was just a simple matter of pulling a wire, but when they told me that I started having doubts.

Bike co-ops are all closed here because of the Covid quarantine, otherwise that would have been my first choice as well.

alcjphil

Friction shifters are universal. They work with any derailleur

Dave Mayer

How many cogs in your freewheel? Show a closeup of the freewheel and the (right) shifter used for the rear derailleur.

Fallingwater

Five cogs.

Here you go

Edit: it strikes me that you probably wanted to see the number of teeth. Here are pics

Fallingwater

I was told that since the pull is different you might have to move them by really tiny amounts in order to get a modern derailer to work properly, and that gets difficult in the heat of the ride.

I'm fully prepared to accept that they were wrong, and would in fact be glad if that were the case

Dave Mayer

OK. So you have a 5-speed freewheel, and downtube friction shifters that appear to have a relatively small barrel for the cable pull. A modern rear derailleur should work with these shifters, as long as it is not something like a SRAM MTB unit. So a Shimano should work.

If you'd had a 7 speed freewheel, your shifters may have had not enough 'wrap' to cover the entire range of the freewheel. But your 5-speed freewheel is acceptably narrower.

When you are talking about trigger shifters, these are indexed, and will require a lot more planning in selecting compatible parts. Stay with the existing shifters, and get a current Shimano rear derailleur. One that works with a derailleur 'claw' of course.

Crankycrank

You could also get something like this Shimano mech. Already has the mounting claw to fit in your dropout, functions better and and lasts longer than those old Simplex derailleurs and cheap. Not sure what deals you can find in Italy but search the net for best prices. https://www.sunrisecyclery.com/produ...CABEgJ0iPD_BwE

JohnDThompson 

That's if you use friction shifters with a modern cassette, with 9, 10, 11 or more sprockets. The spacing on those cassettes is closer than what vintage friction shifters were designed to use, so a deft touch is needed to shift accurately.

But if I understand your situation properly, you want to use a modern derailleur with a vintage, 5-sprocket freewheel and friction shifter. This should work just fine, probably even better than what that decrepit plastic Simplex derailleur could manage.

steve sumner

the Shimano pulley will not work with a Simplex mech. the Shimano pulleys ran on a 5mm bolt
and Simplex used a 6mm. your rivets are 6mm. if you can't find replacement Simplex pulleys
old Suntour will work as they ran on 6mm bolts. you can use 6mm nuts and bolts in place of your
rivets just be sure to place the bolt heads on the inside so they clear the spokes.

Fallingwater

Perfect.

How would I know if it's compatible with claws?

Amazon has the Shimano Altus RDM310DL for cheap and the Acera RD-M360 for slightly less cheap (seems Acera stuff is slightly better?). In theory I could drill out the rivet that keeps the current Simplex on the existing claw and bolt either of those in its place, but would they fit and work?

Crankycrank

A claw/bracket is used on frames such as yours that don't have a threaded mount attached to the frame. Your Simplex has a claw but is part of the derailleur. Example of seperate claw here which allows you to mount the two derailleurs mentioned above. https://www.modernbike.com/product-2...SABEgLX2_D_BwE

Miele Man

Shimano, SunRace and Suntour all make or made derailleur claws. The part where the derailleur attaches to the claw is threaded. THe derailleurs you are looking at come with that mounting bolt already on the derailleur. You just thread that bolt onto the claw.

To clarify things for you here are some images.

The separate hangers and the unmounted derailleur. Note the threads on the derailleur mounting bolt. Some derailleur hangers are longer than others.


Here are two images of the derailleur mounted on the derailleur hanger. Note thatthe derailleur hanger is missing the small bolt and nut that keeps the derailleur hanger on the frame when the wheel is removed.



You should be able to get a rear derailleur hanger at your local bike shop or a bicycle co-op if there's one open near you.

Cheers

alcjphil

Because it would come equipped with a claw

Retro Grouch 

My first derailleur equipped bike had a Smplex Prestige derailleur. Eventually the plastic derailleur body wore out like they generally do. Everybody I knew at the time replaced them with Suntour VGT derailleurs and loved the performance improvement of the slant parallelogram derailleur.

That's a long way of saying a VGT derailleur would be a period correct replacement. If it ws my bike, that's what I'd be looking for.