gitaneusa.com :: View topic - So, I've got this Gitane TdF Professional, early 80's...

verktyg

Lynne,

Here's a link to a 13-28T Helicomatic cassette on eBay:

http://cgi.ebay.com/MAILLARD-HELICOMATIC-6-Spd-Cassette-13-15-17-20-24-28T_W0QQitemZ140200666635QQihZ004QQcategoryZ42332QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

You need a special wrench to remove the ring that holds the cassette onto the hub. They are always showing up on eBay.

Chas.

lynnef

well, that cassette got away. I'm contemplating just replacing some cogs on mine.

Of course, the burning question is how much travel I can get with the existing Simplex derailleurs!

I'm swapping the front 52/42 for a 48/34 (Stronglight Impact compact double).

The current rear cassette is 14-16-18-20-22-24. It does not go low enough.

I'm thinking something like 14-16-20-24-28-32, which gives this:
48 41.2 % 34
14 90.1 63.8
14.3 %
16 78.8 55.8
25.0 %
20 63.1 44.7
20.0 %
24 52.6 37.2
16.7 %
28 45.1 31.9
14.3 %
32 39.4 27.9

or this, which I like better, I think:
48 41.2 % 34
14 90.1 63.8
14.3 %
16 78.8 55.8
37.5 %
22 57.3 40.6
9.1 %
24 52.6 37.2
16.7 %
28 45.1 31.9
14.3 %
32 39.4 27.9

In either case I'd need that rear der to have a capacity of 32T.

verktyg

Helicomatic only went to 28T sprockets AFAIK. I've seen Simplex standard length derailleurs handle 30T and 30T freewheels but not that well when there’s a big difference in chainring sizes.

You will probably need to get a medium or long arm rear derailleur. I would look for one of the long arm Simplex derailleurs that show up on eBay if you want to keep the bike all French. If that doesn't matter then find a late 70s or early 80s Shimano rear derailleurs because they can be mounted on the Simplex dropout on your frame without modification. A Shimano Crane or Tourney rear derailleur will shift fine.

This Simplex long arm derailleur will work but you will have to modify the Simplex gear hanger on the dropout to get it to work:

http://www.velo-orange.com/si440de.html

I'd recommend against some of the later model (post 1984-5) derailleurs because they were designed for index shifting with 7-8-9 sprocket systems that use a narrower chain. It can work but I was looking at trying to keep things simple for you. Your Simplex Retrofriction shift levers don't handle 7 speed+ sprockets that well because of the small diameter barrel that wraps up the cable.

You will also need a new rear wheel or at least a new hub to replace the Helicomatic one you have now. You'll need to check the width of your rear dropouts. The original width was 120mm. Later 6 speed rear hubs are 126mm wide.

Someone may have already spread teethe dropouts to take the 6 speed Helicomatic rear wheel or they may be just squeezing it in. If it's still 120mm wide you can still find 120mm wide wheels and hubs that can use 6 speed Suntour Ultra width freewheels. The 6 speed Ultra freewheels were designed to fit on a 5 speed hub. They show up on eBay regularly in 13-30T or 13-32T.

If the rear triangle has been spread or if you want to have it spread to 126mm, you should have someone with some dropout alignment tools check the alignment of the rear dropouts. Misaligned dropouts are one of the biggest causes of bent or broken axles.

http://www.sheldonbrown.com/frame-spacing.html

http://www.parktool.com/repair/readhowto.asp?id=40

You may also need to get a new bottom bracket to fit your new crank. The old one may not have the proper width to give you the correct chain line.

Chas.

lynnef

I'm not intending to replace the derailleurs or the hub. Or rebuild the wheel at all. I just want to go as big as I can on the freewheel without exceeding the derailleur capacity (which seems to have faded into obscurity).

verktyg

Lynne

Maillard Helicomatic hubs were an early attempt at making a cassette system which would allow fast sprocket changes. The 6 speed versions were available with sprockets between 14T and 32T but 28T is the largest I've seen.

Helicomatic hubs were only made for a few years in the mid 1980s, They're now orphan technology.

http://www.velobase.com/ViewSingleComponent.aspx?ID=ffc06f4f-3bd6-415a-aa66-e4b63e8cac48&Enum=114

http://www.velobase.com/ViewSingleComponent.aspx?ID=1b0c2437-d84f-4fc8-b187-68de658a2a30&Enum=110

As I mentioned in a previous post, you may be able to find replacement sprockets at The Yellow Jersey (608) 257-4737 or Harris Cyclery (617)244-9772.

Personally I've found that ultra low gears on a road bike are counter productive. Gearing below about 30" requires a fairly high pedal cadence to move the bike fast enough to easily maintain balance. This isn't the case with offroad bikes that have different frame geometry.

I still think in inches:

34-24T gear combo is 38.2"
34-26T is 35.3"
34-28T is 32.8"
34-30T is 30.6"
34-32T is 28.7"

A 4" difference in gearing between 28T and 32T is not very significant. If you could find a 28T Helicomatic sprocket then I think that you would have the best compromise of good shifting and adequately low gears. If you find one then remove the 22T sprocket and go with 14-16-18-20-24-28 Teeth sprockets. I've found that most people can take bigger jumps in sprockets at the higher and lower range of their gears.

Chas.

lynnef

It isn't flat here Smile

And 3mph is a speed. I've done it. Not that the Gitane will go anywhere NEAR Clapshaw Hill.

lynnef

I now have a 28t cog and the freewheel remover tool, which I hope will be more used for opening bottles Smile

When I was having the headset removed, the mechanic wondered if all the rusty-looking stuff around the lugs might be the remains of gold paint, rather than rust.

Was gold paint around the lugwork a possibility?

The bike is a heap of french-threaded parts at the moment. I need motivation to clean up the frame.

smilingroadrunner

Hi Lynne,

Yes hopefully the detail painter didn't have too much wine for lunch---but the majority of the Gitane (or at least the early 70's frame) lugs or at least the brazed joint outline were highlighted with a gold pin stripe effect over the basic frame color.

I would assume if the lug union brazing looks good it should be discernible whether it is rusting or detail paint.

I'm sure there are quite a few out there, but your Match blue frame color is not seen too often--as I mentioned in one of my earlier posts you may have to play around blending some of the (I have used TesTors model paint) paints to approach a close touch up. The opaque effect of the Match blue color still should be easier to approach than the clear metallic candy scheme on a lot of frames. I have used the TesTors--Gold paint pens and small brush for the Gold highlighting touch up. As Chas says, a perfect color match may not be possible--but if it protects the small frame scratches that is our goal, If it's not readily discernible from 4-5 feet its good.

___________________
C.A.
Salina, Ks.

smilingroadrunner

Hi Lynne,

I was finishing up some of the images for the decal project and thought this might demonstrate some of the gold detail outlining. Excuse the lubricant residue and grime on the white '70 TdeF frame. It's a future restore project.

___________________
C.A.
Salina, Ks.

lynnef

thanks! I've got the fork in the van; planning to stop by Tammies Hobbies tonight to find some paint. I'm told they have an entire room of model paint. White primer, too, perhaps. And maybe some gold.

The paint job looks a little "brighter" - the biokleen stuff I used removed a bit of the top of the paint. Still rummaging around for some extra-fine steel wool for the chrome. I'm getting some Simichrome as well, to polish up all the parts.

Bike mechanic friend recommended that I replace the caged bearings in the Sugino bottom bracket with loose ones.

verktyg

Remember, touchup is just camoflauge, a little goes a long long way - too much looks worse that the original scratches. I learned that doing photo touchup long ago.

The results shouldn't be noticable from 5 feet.

Good luck,

Chas.

lofter

http://cgi.ebay.com/NOS-Maillard-Helico-Matic-36h-Hub-6spd-Cassette-13-32_W0QQitemZ310017459233QQihZ021QQcategoryZ56197QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

i was going to bid on it but it got too much for me.thats a monster 32t

verktyg

I missed that one. I just bought a NOS 6 speed Helicomatic hub and 13-24T freewheel for $0.99 each on eBay. I would have liked to had that freewheel just for the 28T cog.

Chas.

lofter

it said it was a maillard 700 helio. im assembling up parts for a tour bike.
this would have been nice cause of the 32 for a loaded rig.im going to bid on the long cage derailleur up know Wink

verktyg

lofter,

Check your PMs.

Chas.