1970's French Tandem Restoration Project Advice?!

[pargeterw]

Hello all,

I'm just about to start restoring a 1973 Gitain Gaves Tandem, and have started a blog do document my progress, but, most importantly, to coalesce my inevitably huge number of questions for the tandeming community into one location.

http://gitaingaves.blogspot.co.uk/

I would be eternally grateful if anybody here had time to read the whole thing (it ended up longer than I meant it to...), and hopefully put in a few useful comments?

Thank you!

Will

[Ayesha]

The headset thread will probably be 25 x 1mm, not 1" x 24 tpi ISO thread.

If it is you will have to re-use the adjustable race. If its Brinelled, use caged bearings in the upper race. At least some balls will be rolling OK.
The other three races can be replaced.

Here's hoping the headset is in good order.

[Brucey]

I used to own a 'Globetrotter' tandem which was (I think) made in the same factory as the Gitane tandems. (BTW I see you have spotted your spelling mistake, but tagging the blog with a keyword of 'Gitain' won't be as useful as 'Gitane' I think ).

Since you have a workable set of cranks and BBs I would run those for now and see how you get on. It is easy to get carried away and spend money on stuff you don't need, or that offers but marginal benefit.

I've used quite a few crossover drive tandems and they can get through rear BB units at an alarming rate but this isn't a necessary consequence for all tandems and all crews.

Since 'modern' shifters can be made to work with older cranksets I would suggest an upgrade in the shifting department could be carried out without other changes if required. Note that the correct freewheel is one that is specifically rated for tandem use; not all solo freewheels are anywhere near strong enough.

I do wonder at the longevity of modern narrow chains for tandem use; I have enough trouble getting them to last on a solo these days; my present tandem is still on 7 speed and I'm in no hurry to change.

The 'Atom' rear hub brake should be adequate (i.e. will moderate your speed at least) for hills of about 10% gradient. Ditchling Beacon is steeper than that. New shoes may help; the old ones may be contaminated with oil or glazed. On very long descents with a big load it is a good idea to stop and let the brake cool off once every couple of miles, even with more modern drag brakes. If the rear hub still has a 3/8" axle in it, (and 1/4"balls) look to change it for the fatter version (uses 7/32" balls), as the 3/8" axle is prone to breakage.

What size rims are fitted? There is a fair choice of rims and tyres in some sizes and yes, you can do better than steel rims, even if only because you will have better rim brakes and hook beads that will allow tyres that you can pump up harder if you need to.

Re the BB threading; when the time comes to change them, you can have the old BBcups machined to accept the centre part of a cartridge unit (shimano, edco, etc etc) and then you will be set for the future with relatively low-cost replacements subsequently.

Also; I note that your chainrings are not correctly timed; the front cranks are leading the rears by a small amount. On a five-arm chainset I prefer to use a front drive chainring with a number of teeth ending in a 9,1,4, or 6, since this will allow an almost 'vernier' timing adjustment of the front drive if it is necessary to allow for the slack on the lower run for example. Small front drive chainrings are common, but with a strong crew, I'd advocate larger ones as this reduces chain tension and therefore frame flex etc. Years ago I changed from 32 to 46 and it was night and day different.

HTH

cheers

[pargeterw]

The headset thread will probably be 25 x 1mm, not 1" x 24 tpi ISO thread.

If it is you will have to re-use the adjustable race. If its Brinelled, use caged bearings in the upper race. At least some balls will be rolling OK.
The other three races can be replaced.

Here's hoping the headset is in good order.

Thanks for this - Really helpfull!

We'll see...

[pargeterw]

I used to own a 'Globetrotter' tandem which was (I think) made in the same factory as the Gitane tandems. (BTW I see you have spotted your spelling mistake, but tagging the blog with a keyword of 'Gitain' won't be as useful as 'Gitane' I think ).

Since you have a workable set of cranks and BBs I would run those for now and see how you get on. It is easy to get carried away and spend money on stuff you don't need, or that offers but marginal benefit.

I've used quite a few crossover drive tandems and they can get through rear BB units at an alarming rate but this isn't a necessary consequence for all tandems and all crews.

Since 'modern' shifters can be made to work with older cranksets I would suggest an upgrade in the shifting department could be carried out without other changes if required. Note that the correct freewheel is one that is specifically rated for tandem use; not all solo freewheels are anywhere near strong enough.

I do wonder at the longevity of modern narrow chains for tandem use; I have enough trouble getting them to last on a solo these days; my present tandem is still on 7 speed and I'm in no hurry to change.

The 'Atom' rear hub brake should be adequate (i.e. will moderate your speed at least) for hills of about 10% gradient. Ditchling Beacon is steeper than that. New shoes may help; the old ones may be contaminated with oil or glazed. On very long descents with a big load it is a good idea to stop and let the brake cool off once every couple of miles, even with more modern drag brakes. If the rear hub still has a 3/8" axle in it, (and 1/4"balls) look to change it for the fatter version (uses 7/32" balls), as the 3/8" axle is prone to breakage.

What size rims are fitted? There is a fair choice of rims and tyres in some sizes and yes, you can do better than steel rims, even if only because you will have better rim brakes and hook beads that will allow tyres that you can pump up harder if you need to.

Re the BB threading; when the time comes to change them, you can have the old BBcups machined to accept the centre part of a cartridge unit (shimano, edco, etc etc) and then you will be set for the future with relatively low-cost replacements subsequently.

Also; I note that your chainrings are not correctly timed; the front cranks are leading the rears by a small amount. On a five-arm chainset I prefer to use a front drive chainring with a number of teeth ending in a 9,1,4, or 6, since this will allow an almost 'vernier' timing adjustment of the front drive if it is necessary to allow for the slack on the lower run for example. Small front drive chainrings are common, but with a strong crew, I'd advocate larger ones as this reduces chain tension and therefore frame flex etc. Years ago I changed from 32 to 46 and it was night and day different.

HTH

cheers

Thank you, this reply is amazing.

The BB's (particularly rear) are creaking really quite badly, so I think they do need a replace. I would only swap the cranks if I was sure it would increase the longevity of the BB's to an extent that would recoup the investment. The current ones are in fine working order.

This particular tandem has been in service, with the original BB's for almost 40 years, and they're only just going now. We're not racing competitively or anything, so the feeling is we'll get away with the Velo Orange BB on a crossover?

I agree. We will probably switch to Bar-End shifters, (freeing up the existing shift position for the drag brake, allowing for independent rims). It would be nice to get a Hyperglide cassette onto the back, as it is really jumpy at the moment, and the derailer certainly needs to go, but this will depend on what fits onto the Drum/Hub

I've heard this too, and wouldn't go above 8. I quite fancy something like http://www.ebay.co.uk/itm/New-Shimano-11-34-HG30-8-Speed-Cassette-RRP-19-95-/190718178846?_trksid=p4340.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D11%26meid%3D1678822565410028760%26pid%3D100011%26prg%3D1005%26rk%3D1%26#ht_2002wt_1399 with a proper granny cog, just in case!

So you're saying, keep the drum, but swap the axel inside it?

Rims: I won't be able to measure this till Saturday at the earliest...

BB-Cups: This sounds very interesting, I'll look into it. Thank you.

Timing: As discussed, I won't be swapping the cranks... It looks quite good in the photo, but there is a bit of slack in the timing chain, which when tightened, should solve the problem, I think.

Thanks again!

Will

[Brucey]

I would not associate creaking with a failing bottom bracket; there are lots of things that creak, but not necessarily bottom brackets. I wouldn't be in any hurry to replace the BB units unless they are clearly rather worn when inspected. Forty years is one thing but the tandem may not have gone that far in the time.

I don't know how strong the velo orange BB is BTW.

Note that old style bottom brackets have asymmetric spindles and modern ones usually have symmetric spindles; this means that you cannot always compare the lengths directly. This can cause troubles when buying a new bottom bracket, as the rear one needs to be correct at both ends.

Obviously France is a good place to look for a replacement French threaded bottom bracket. My French isn't great but very roughly;

axe de pedalier = bottom bracket spindle
jeu de pedalier, jeu axe de pedalier = bottom bracket assembly
boite / boitier de pedalier = bottom bracket unit

-which might help when googling.

Note that not all 35 x 1mm bottom brackets are the same; older ones are RH threaded both sides (which means the fixed cup can work loose without loctite IME) but there are others (sometimes called 'Swiss' threaded) where the fixed cup is LH threaded. Some French bikes are, confusingly, Swiss threaded.

Re gearing; you may not have room for more than a standard five or a compact 6 at present, although respacing the rear hub for a standard 6 or a 7 should be possible, don't assume that any more than this is going to be possible without some more investigation. Your e-bay link is for a cassette, not a freewheel; you need a freewheel. See http://sheldonbrown.com/free-k7.html for details. More specifically you probably need a Tandem freewheel, ideally. These have stronger bodies to take tandem abuse; however it seems that such things are no longer readily available new. IIRC the sprockets on a Maillard (or Atom) tandem freewheel are the same fitting as on solos, and of course a freewheel body can be reshimmed and re-used, so it should be possible to re-use your old freewheel if it is a tandem rated one (they are not always marked as such BTW; it is only evident on internal inspection) and you need the strength. You may think you want slick shifting etc offered by a modern hyperglide set-up, but since available parts are mostly meant for solos, they can be broken by strong tandem crews with depressing regularity.

See http://www.tandem-club.org.uk/cgi-bin/db_archive.pl?index (search for 'freewheel') for many discussions re broken freewheels, freehubs, folded cassettes etc etc etc...

If the present rear axle is 3/8" dia. it will need to replaced at some point in the future. As I said before there is a fatter axle that fits into the Atom hub brake; use this. You will need to drill the brake plate slightly. [edit; given that the cones are apparently now NLA, maybe this is not good advice any more. Maybe a better quality 10mm axle would be a better idea.]

If you are a strong crew, I would recommend that you err on the side of strength and reliability when selecting new drivetrain components; fancy-schmantzy-shifters and sprockets are all fine and dandy until you break them. If you use solo-rated equipment, I would suggest that you only do so on recommendation from other tandemists of similar ilk.

cheers

[pargeterw]

I would not associate creaking with a failing bottom bracket; there are lots of things that creak, but not necessarily bottom brackets. I wouldn't be in any hurry to replace the BB units unless they are clearly rather worn when inspected. Forty years is one thing but the tandem may not have gone that far in the time.

I don't know how strong the velo orange BB is BTW.

Note that old style bottom brackets have asymmetric spindles and modern ones usually have symmetric spindles; this means that you cannot always compare the lengths directly. This can cause troubles when buying a new bottom bracket, as the rear one needs to be correct at both ends.

Obviously France is a good place to look for a replacement French threaded bottom bracket. My French isn't great but very roughly;

axe de pedalier = bottom bracket spindle
jeu de pedalier, jeu axe de pedalier = bottom bracket assembly
boite / boitier de pedalier = bottom bracket unit

-which might help when googling.

Note that not all 35 x 1mm bottom brackets are the same; older ones are RH threaded both sides (which means the fixed cup can work loose without loctite IME) but there are others (sometimes called 'Swiss' threaded) where the fixed cup is LH threaded. Some French bikes are, confusingly, Swiss threaded.

Re gearing; you may not have room for more than a standard five or a compact 6 at present, although respacing the rear hub for a standard 6 or a 7 should be possible, don't assume that any more than this is going to be possible without some more investigation. Your e-bay link is for a cassette, not a freewheel; you need a freewheel. See http://sheldonbrown.com/free-k7.html for details. More specifically you probably need a Tandem freewheel, ideally. These have stronger bodies to take tandem abuse; however it seems that such things are no longer readily available new. IIRC the sprockets on a Maillard (or Atom) tandem freewheel are the same fitting as on solos, and of course a freewheel body can be reshimmed and re-used, so it should be possible to re-use your old freewheel if it is a tandem rated one (they are not always marked as such BTW; it is only evident on internal inspection) and you need the strength. You may think you want slick shifting etc offered by a modern hyperglide set-up, but since available parts are mostly meant for solos, they can be broken by strong tandem crews with depressing regularity.

See http://www.tandem-club.org.uk/cgi-bin/db_archive.pl?index (search for 'freewheel') for many discussions re broken freewheels, freehubs, folded cassettes etc etc etc...

If the present rear axle is 3/8" dia. it will need to replaced at some point in the future. As I said before there is a fatter axle that fits into the Atom hub brake; use this. You will need to drill the brake plate slightly.

If you are a strong crew, I would recommend that you err on the side of strength and reliability when selecting new drivetrain components; fancy-schmantzy-shifters and sprockets are all fine and dandy until you break them. If you use solo-rated equipment, I would suggest that you only do so on recommendation from other tandemists of similar ilk.

cheers

Re: Creaking - You're right about this, of course and I won't order anthing untill it's all in bits, but, it has gone a very long way in those 40 years, so it seems likely...

Re: Asymetry - thanks for bringing this to my attention!

Re: Swiss madness - I'm pretty sure this'll be french french, but I'll be sure to make sure : )

Re: Cassette, or not - Deep down I did know this, it just completely passed my by. Thank you again for putting me in my place! The point about a granny on the back still stands, although it does look increasingly unlikely that I'll be able to find such a thing : (

We're not a particualry strong crew, and weigh about 310lb (140Kg) together. The plan is for bar end shifters, which aren't all that fancy, but, I see your point : )

Will

[Brucey]

re freewheels;

for many years this was the dog's whatsits for tandems;

image from here;
http://homepage3.nifty.com/ClassicBicycles/brands/atomtandem.html

Some maillard freewheels tell you what they are on the outside;



or have pawl slots that you can see on the outside;



four holes = four pawls [edit c.f. two pawls for Maillard solo freewheels and many others]. This is a very strong freewheel ratchet. I do not think that you can easily (if at all) buy anything as strong as this new today. Also note that used ones (if shimmed correctly) are stronger than new ones simply because used ones are more likely to share the load evenly between the pawls.

My advice would be that if you have one of these freewheels, you should make a pretty good effort to save it, even if it means rebuilding/reshimming the body, and buying other maillard/atom/normandy freewheels to rob for sprockets. The big sprockets you require do exist, BTW, and are a common fitting to several other freewheels.

Few tandem transmission components can be described as 'bombproof' but this style of freewheel is as close as it gets IMHO.

cheers

[gaz]

From your blog I don't think you've got restoration in mind so much as renovation and dragging it (possibly kicking and screaming) towards the 21st Century.

Looking around the pictures I've no doubt that the rear derailleur is not original, neither are the Stronglight cranks. The rear mech looks like the most basic Shimano Tourney model and you've already identified that it will need an upgrade, the Stronglight cranks are either model 80, 99 or 100 (I don't know how to tell them apart). There's nothing wrong with them, I've got Stronglight 80 crossover on my 90's Dawes Galaxy Twin. Hopefully the pedal threads on yours aren't French, but the 86BCD chainrings are already in the hard to find category.

I accept Brucey's remarks about crossover drives increasing strain on the rear BB but I think you've got bigger priorities.

Braking is clearly one of them. The rims are chromed steel. They do not provide a good braking surface, especially in the wet. IMO alloy rims will make a much bigger improvement than V brakes. Wheel size will be very important before going down this route. If the existing wheels are 700C you'll have no problems. 27" would require the brake blocks to be set 4mm lower, would the Mafac cantilevers offer sufficient adjustment to accomodate this?

The Mafac cantilevers appear to be fitted with Aztec brake blocks on the front and something similar on the rear. These modern compounds are best suited to alloy rims. I do not know whether you can source a better brake shoe for use with chromed steel, something for you to research.

The Mafac cantilevers are designed to work well with your existing brake levers, however I would guess that the brakes could be set up a little better, more here.

Bar-end gear shifters and a friction shifter operated drag brake are an excellent idea.

Whatever you decide to do, take it one step at a time and enjoy the time you spend working on it as much as the time you spend riding on it.

[Brucey]

re the Stronglight cranks;

Stronglight Model 99 were fluted cranks in the classic style.
Stronglight Model 80 the same basic geometry as 99s, but with no flutes and a smoother look.
Stronglight Model 100 look very similar to the model 80, but have slightly more angled crankarms, to give chainstay (and a stepped outer plate front mech) clearance on MTBs.

Both 80 and 100 have 'Stronglight' /'Stronglight 80' /'Stronglight 100' on the cranks. Or nothing. If printed (some are engraved) the number usually rubs off first (it is in the toestrap zone).

IME it is difficult to run a modern front mech (with a stepped outer plate) with 99s. Clearance is greater with the later designs; IIRC Model ~100 has 8mm clearance between the big ring and the crank arm.

edit' Re other things;

your front mudguard stays are fitted to the rack mounts. This is a bit mad TBH. I'd suggest some brackets attached at the lower rack mounts would fix this. The mudguards themselves are rather nice IMHO. Rack mounts? Yes, for a rack like this perhaps;



currently trendy again in the USA, apparently.

Your brakes are short-arm Mafacs; they also did a long-arm version for more power on tandems, but these are like rocking horse poop these days.

Gitanes (and Globetrotters) of this vintage have been known to suffer broken front forks due (apparently) to internal corrosion after chrome plating residues were not fully removed. If you have a chance to flush the inside of the fork blades out through the vent holes, then dry and add rustproofing compound, it wouldn't hurt any.

If you do respray, take as many good photos of the decals as possible; this may help you get the correct decals made up is necessary.

If it were mine, I'd overhaul everything, touch in the paint with a good match, rebuild the wheels with better rims and spokes, fit a new rear mech, inspect the rear axle for cracks, and maybe fit new shifters. Then I'd just get on and use it.

TBH stem mounted shifters are about as handy as bar ends if you ride on the tops or hoods.
If you want to go more modern/convenient, 6-speed DT levers will fit to Thumbies or Kelly Takeoffs and should index reasonably well (but not perfectly) with the present (I suspect strong) freewheel and a suitable rear mech.


cheers

[pargeterw]

Re: Freewheels

Brucey, you are brilliant!

I'll post some pics on the blog once I get everything to pieces, and then we'll really know what's going on... I suspect a lot of regular eBay checking and patience will be in order if it turns out not to be much good?

P.S. I'll probably send a message here every time I add a new post to the Blog, so you don't have to keep checking it (if you cared enough to consider that?)!

Will

[pargeterw]

From your blog I don't think you've got restoration in mind so much as renovation and dragging it (possibly kicking and screaming) towards the 21st Century.

Looking around the pictures I've no doubt that the rear derailleur is not original, neither are the Stronglight cranks. The rear mech looks like the most basic Shimano Tourney model and you've already identified that it will need an upgrade, the Stronglight cranks are either model 80, 99 or 100 (I don't know how to tell them apart). There's nothing wrong with them, I've got Stronglight 80 crossover on my 90's Dawes Galaxy Twin. Hopefully the pedal threads on yours aren't French, but the 86BCD chainrings are already in the hard to find category.

I accept Brucey's remarks about crossover drives increasing strain on the rear BB but I think you've got bigger priorities.

Braking is clearly one of them. The rims are chromed steel. They do not provide a good braking surface, especially in the wet. IMO alloy rims will make a much bigger improvement than V brakes. Wheel size will be very important before going down this route. If the existing wheels are 700C you'll have no problems. 27" would require the brake blocks to be set 4mm lower, would the Mafac cantilevers offer sufficient adjustment to accomodate this?

The Mafac cantilevers appear to be fitted with Aztec brake blocks on the front and something similar on the rear. These modern compounds are best suited to alloy rims. I do not know whether you can source a better brake shoe for use with chromed steel, something for you to research.

The Mafac cantilevers are designed to work well with your existing brake levers, however I would guess that the brakes could be set up a little better, more here.

Bar-end gear shifters and a friction shifter operated drag brake are an excellent idea.

Whatever you decide to do, take it one step at a time and enjoy the time you spend working on it as much as the time you spend riding on it.

I meant renovation, yes. I have changed the blog title to reflect this!

Re: Pedal Threads - They may well be french. They certainly don't take a standard pedal spanner! (I used an adjustable, so I can't tell you off hand what size was needed, but, I don't think there's a problem with the pedals, so I won't worry.) The detail view in the photos (http://i.minus.com/iAONbUIlo301y.JPG) has some writing which I don't know if it is relevant?

Re: Wheel sizes - Being a european version, not US, I'm hopefull that the wheels are 700c, I'll measure them (and everything else) when I get back to the correct part of the country (next week).

Re: Brake shoe compounds - I'll be upgrading the rim, so won't be needing to look into this!

Re: Brake setup - I agree with this, and I'll re-asses the situation once I've got some new Aero Levers.

Re: Brake Controls - I'm glad you think so! Have you tried it?

Thanks for your help thus far,

Will

[Brucey]

a note of caution re brake levers;

most modern aero brake levers are desined to work with dual pivot calipers and these pull a little more cable than your original Mafac levers do. This makes for a long travel brake caliper with a low force, something that you will likely be fighting anyway, so it won't be a good idea to make it worse. The very first generation of aero brake levers were designed to work with single pivot calipers and therefore pull a little less cable. These work better with low MA calipers like the Mafacs. One model that is like this is the Shimono 105 BL-1051, and there are a few others, such as the Shimano 600 Ultegra 'tricolour' ones BL-6401 and various Exage ones.

edit; Re pedal threads; IIRC some Lyotard pedals (possibly French threaded M14 x 1.25mm ones?) need a 16mm spanner on them. If the pedals need to be replaced with British threaded ones, you can usually retap to 9/16" x 20 TPI quite happily; the French thread is a similar pitch and a slightly smaller diameter.

hth

cheers

[gaz]

Re: Wheel sizes - Being a european version, not US, I'm hopefull that the wheels are 700c, I'll measure them (and everything else) when I get back to the correct part of the country (next week).

Don't bother to measure them, simply look on the tyre for a sizing (there will probably be lots of sets of numbers). Your linked catalogue suggests they'll be 27" in which case one of the sets will read XX-630 or 630-XX. If they're 700C it'll be XX-622 or 622-XX. If I were a betting man I'd say the XX will be 32.

[pargeterw]

a note of caution re brake levers;

most modern aero brake levers are desined to work with dual pivot calipers and these pull a little more cable than your original Mafac levers do. This makes for a long travel brake caliper with a low force, something that you will likely be fighting anyway, so it won't be a good idea to make it worse. The very first generation of aero brake levers were designed to work with single pivot calipers and therefore pull a little less cable. These work better with low MA calipers like the Mafacs. One model that is like this is the Shimono 105 BL-1051, and there are a few others, such as the Shimano 600 Ultegra 'tricolour' ones BL-6401 and various Exage ones.

edit; Re pedal threads; IIRC some Lyotard pedals (possibly French threaded M14 x 1.25mm ones?) need a 16mm spanner on them. If the pedals need to be replaced with British threaded ones, you can usually retap to 9/16" x 20 TPI quite happily; the French thread is a similar pitch and a slightly smaller diameter.

hth

cheers

Re: Brake Levers - I was planning on using a "Travel Agent" (linked in the blog) to solve this?

Re: Tapping - I'm not planning on changing the pedals, but, if I do, will this cause an appreciable drop in strength?

Will