Anti-corncob gearing on a Gitane
 

Can an old and less than ideally fit guy in Vermont get over the big hills with a ten-speed double? Yes. Here's my re-geared 1970 Gitane Tour de France. This project started when I picked up an NOS Duopar rear derailleur at an old bike shop yard sale for $4 or something. (And to think that I could have bought another one for the same price! And didn't! Idiot! Idiot!) Anyway, I was going to put it on in place of the Suntour Cyclone that I'd been using since the original Simplex fell apart just because it was French.
But once I got it on there I started thinking, "hey, this thing's supposed to have a huge capacity. I wonder if that's really true?" So I took off the 46-36-26 Sugino on the front, replaced it with the original Stronglight 93 with non-original 45 and 40 tooth rings (thanks to two Bike Forum members who know who they are) and replaced the rear 13-28 cluster with a NOS Suntour 14-18-22-28-38 cluster from e-bay. It was cheap--something like 17 bucks with shipping.
Anyway, it works remarkably well. There are huge jumps between rear cogs, but the closely space front rings provide very nice half steps. Here's what I've got: 86.8, 77.1, 67.5, 60, 55.2, 49.1, 43.4, 38.6, 32, and 28.4. That's a nice low low for my geography and physiology. The high isn't so high, but if I'm already going 25 mph I just have to bite the bullet and coast.
It shifts very well, even in the maximally cross-chained gear combos. Before I got everything adjusted I had a few minor instances of chain suck in front, which still threatens from time to time, but I'm pretty sure that's because the 40-tooth ring is fairly badly worn. I bet a newer one would fix it. Maybe I'll find one one of these days.
Okay, I'll shut up now.

Nice! Great solution and an amazing gear range for a ten speed.

Nice job!

You should be able to climb walls with that gearing.

Somebody recently posted a a link to a new Stronglight 122 BCD 40t ring on a UK site for a decent price. You might be able to find it by doing a search. I wish my Gitane was geared like that. The Super LJ I have on it won't handle more than the 28 tooth big cog I have on it. It's only rated for 24t max!

I did a similar thing on my 12-speed racing bike. Cranks are expensive. Freewheels are cheap. The downside is the steps between the gears, but that's not terrible.

Correct, but tight incremental spacing on the freewheel / cassette is so much more pleasurable.

When we're old, out of shape, and live in the mountains, a rider has to do what a rider has to do!

Great solution. I've done nearly the same over here across the Connecticut River Valley, except the biggest I've found is a 34 tooth cog. Do you have a spare 36 or 38?

I don't have an extra, but they seem to be pretty common on ebay--you can often find a NOS 14-38 for around 20 bucks. Someone on an earlier thread speculated that the same few freewheels go around and around--people buy one, find that they can't make it work, and re-sell it to someone else. The issue is finding a rear derailleur that will go that big. The Duopar works really well, and there's a Suntour model whose name I can't remember that does also--was apparently designed to work with the Suntour freewheel. Others might also work. But you're all set, I think--don't you already have at least one bike set up with a Duopar RD?

I would think that a long cage Deore, 105 or Ultegra RD would be able to handle 38. But, that's just an opinion that I pulled out of my a** (POOMA).

The early Simplex dropouts won't allow you to mount a Shimano derailer.

http://inlinethumb39.webshots.com/43...600x600Q85.jpg

You can tap the hole and grind the hanger to create a stop, but it's kind of a shame to do that.

http://inlinethumb39.webshots.com/43...600x600Q85.jpg

His Duopar fits because he got one with the correct tabbed washer for Simplex dropouts.

[quote=Dirtdrop;9470258]The early Simplex dropouts won't allow you to mount a Shimano derailer.

QUOTE]

Thanks, I learned something. Like I said, POOMA.

Actually, the Duopar is set up for a regular non-Simplex RD. The bike originally came with Simplex mounted with a mounting claw, but when I had the frame painted a few years ago (which I probably wouldn't do again) I went overboard and had the shop braze on an integral derailleur hanger and cable guides. (Something I probably also wouldn't do again.) The only original parts on the bike are the headset, crank, and hubs. The brakes and levers are Mafac Racers that I switched out for the original Competitions during the rebuild (long story, not important.)
By the way, thanks to everyone who didn't make fun of my bar tape. I got it out of the $1 bin at LBS. Unfortunately, it's lasted for years. I'm finally about to replace it, though.

Yes, great memory. I currently have DuoPars on my tandem and on Sporty.

I also have one I'm rehabing that I traded cudak888 for back in June. I plan to run it on my '62 Continental which has 42 & 47 tooth chainrings. I built a 15-34 six speed Suntour Perfect freewheel for this, but a 38 tooth ring would be even better!

Some Gtane TdF's were built without an integral derailer hanger. It seems strange to see a high end 531 frame with a claw, but there are a lot of things about French bikes that seem strange.

I didn't know that Mafac Competitions existed as early as 1970. Peugeot didn't make the switch from Racers until 1974. My Gitane TdF has original Competitons, but I've only been able to narrow its build date to somewhere between 1971 and 1973.

I see you have the optional Campy hubs. You're lucky!

I think the French in general just put together bikes with whatever parts they happened to have on hand that day, regardless of what the spec sheet said. This one definitely had the competition brakes--I still have them in my parts box--and I'm sure that I bought the bike in June of 1970 when I was 16.
I used to not like mounting claws, but now I can see their appeal--they let you use whatever derailleur you want without any structural modifications (That's why I sort of wish I hadn't had the new hanger brazed on, since now I coudn't go back to a Simplex--if for some insane reason I ever wanted to--without unbrazing it.)
I agree with you that it's sort of too bad to re-shape the integral Simplex hanger. Having a bike that came equipped with one is a moral dilemma, I guess, forcing the owner weigh his or her sense of obligation to future bicycle collectors hoping to find a bike with an unmolested Simplex hanger to the selfish personal desire to have a bike that shifts reasonably well.

I agree with your general principle, and I'm the worst at keeping a bike "period correct," but some Simplex derailleurs worked pretty well.

Some work way better than "pretty well".

http://inlinethumb50.webshots.com/38...600x600Q85.jpg
http://inlinethumb07.webshots.com/45...600x600Q85.jpg

I love half-step gearing, but I find I need at least a 2x6 setup to give me wide enough range with small enough progression. I also concur that your 45/14 top is good enough for most applications, although I prefer something a bit taller, such as 45/13, 49/14, or 52/15.

No disagreement from me that Simplex made some good derailleurs, but the one on my TdF was not one of them. I think the jockey wheels were made out of peanut brittle. And anyway, most of the better-quality Simplexes seemed to be short-cage models. I certainly don't think they made one that would work with a 38-tooth cog.

How do you guys figure that? I always figured that what goes up must come down so the steeper the hill on the up side that requires me to use a 30-inch or so gear to climb it needs a big gear to go down the other side at 50-mph. Sure you could coast but what's the fun of that? :)

On my Bottecchia I run 52/40 in front and 14-18-24-30-34 in back for a range of 31.5 - 100 inches.

That's why both of my Simplexes have Bullseye pulleys. I had a Simplex pulley split in half when I was miles from home.

There were some long-cage Super LJs made and I'm watching eBay for one. I don't think it would work with a 38-tooth cog, either. I have a triple on my PX10.

I believe it was the SunTour GT which has the widest gear capability. I've got one sitting waiting for one of my future bikes that will need it.

That's a good setup for pedaling downhill, but it does give you a bunch of duplicate gears. I think you've got a 77.1 and a 78, a 45 and a 46.8, and a 60 and a 58.5. I'm not a gearing wonk by nature, though. It doesn't really matter if you have 7 gears or 10, as long as you've got a range as wide as you need. This is my first venture into half-step gearing, and I kind of like it. But then, I kind of think that pedaling downhill IS fun, especially when I have no choice. "Oh, no, it's not that I'm out of shape or lazy--I'm just plumb out of gears."

I didn't know they were optional--they're just what came with the bike. What are they, Gran Sports? It doesn't say--just "Campagnolo" and some sort of wing-type logo.
It's a very nice-riding bike, though.

Nuovo Tipo, I believe.

Most came with Normandy Luxe Competitions.

Mine is my all time favorite ride, even though it's a bit too small for me.