Tandem gearing upgrades

[cold_wet_and_tired]

Hello

We've picked ourselves up a tandem off ebay for a bit of fun. The essential first piece of maintenance was to replace the brake pads, which looked like they were the same mid 70's vintage as the bicycle. Now that the vehicle can be stopped we've embarked on some test rides, which are getting progressively longer and invariably end up at a pub.

The remaining improvements I'd like to make are to the gearing: to reduce the lowest gears and to increase the smoothness of the down-shift on the rear derailleur. However, I'm not sure whether obsolescence is going to force us to upgrade the entire drive chain or if we can make modest alterations to what is already there. I've read through Sheldon Brown's article on upgrading gearing as a starting point.

We've avoided any real hills so far, tackling only "undulations", but I think the gearing is too high for us to be able to spin up any extended climbs (chainrings are 52 and 40 and the largest gear on the back is 32). At the very least I'd like to reduce the small ring, but I note that modern chainrings have 5 bolt holes but this one has 6. Are compatible chainrings still available? (Another concern is if the front derailleur will be capable of shifting over a higher range - we'll have to see!).

The rear derailleur is also an issue because it is tricky to change down (up-shifts are perfectly smooth), which is causing me to delay shifting until it's absolutely necessary (or, in fact, too late.) Once in the highest gear, it takes a lot of movement to get it to shift down, by which time it shifts two or three. The internet speaks with some nostaligia for the SunTour Vx, so I'm not sure if the problem is just a change in expectations (perhaps it always was hard to change down?) or if any improvement can be made with adjustments. Sheldon Brown suggests that modern derailleurs are superior to older ones so replacing the derailleur seems like a good idea, but with the market full of options for bike components, what is a good way to select a replacement?

You may have gathered that this is my first foray into upgrading an old bike. I maintain my bikes myself but haven't set about swapping and changing parts before.

I hope all this doesn't make it sound as though we aren't enjoying our new toy. In fact, we are having a great time; I'm just looking now to increase the possibilities of where we can go with it.

[Gattonero]

Chainrings for TA are still available, you've to search for them but something always pops up at cycle jumbles.
Or if you want to replace the whole chainset with something that would use more common rings, is probably a better choice although you may need to replace the BB too with an appropriate length for the new chainset.

For the rear derailleur, using friction shifters means that lots of derailleurs can be used with. If you're not too bothered with modern components, a cheap Shimano Deore rear derailleur works very well with retrofriction shifters

[goatwarden]

If you replace one Bottom bracket then make sure you replace the other at the same time with an identical item. That way your timing chain rings will both be at the same offset and timing ring / chain wear will remain negligible.

[531colin]

Phone Spa for TA cyclotourist chainrings.

[gaz]

Chainrings for TA are still available, you've to search for them ...

TA Cyclotourist chainrings, available from Spa (scroll down) and others. Smallest double inner is 26T, it can also be run as a triple but expect other costs. I've no idea of the capacity of the existing front mech*.

Or if you want to replace the whole chainset with something that would use more common rings, is probably a better choice although you may need to replace the BB too with an appropriate length for the new chainset.

Tandem crossover drive, bear in mind the existing "vintage" TA set will have a resale value.

We've picked ourselves up a tandem off ebay for a bit of fun. ... we are having a great time; I'm just looking now to increase the possibilities of where we can go with it.

Old tandems can have some hard to replace parts. More details and photos could be helpful. If you're having fun on it there can't be much that needs doing.

Those look like steel rims, which don't give the best braking performance in the wet. Most current MTB mechs will cope with a 32T sprocket on a five speed block, if you need to replace the freewheel you may struggle to find anything bigger than a 28T or indeed anything that is strictly tandem grade.

*Edit: TA Cyclotourist / Pro Vis 5 cranks are notoriously incompatible with modern front mechs, doubtless some are fine but many are not.

[Bonefishblues]

Is that the Peugeot I saw for sale recently?

[cold_wet_and_tired]

Thanks everybody. That's plenty of information to get us going. I'll let you know how we get on and maybe even post a photo from the top of the first hill we get up!

Is that the Peugeot I saw for sale recently?

No this is a Motobecane. We went for it because the seller was local and willing to deliver.

Those look like steel rims, which don't give the best braking performance in the wet

We've been fortunate so far as we haven't been caught out in the rain yet.

I rode a bike with steel rims while I was at university - the library was half way down a hill and I remember on one occasion pulling up outside the library only to find myself sailing past into the car park at the bottom of the hill.

[Bonefishblues]

Tbh I'd be looking at the going slower aspect rather than the converse at the moment. Does it have a hub brake in addition to rim brakes?

[RichMoss]

Is yours a Motobecane Inter Club?
You're probably aware of this already - like the Peugeot tandems, it is likely to have some 'obsolete' French standards such as pedal threads,bottom bracket threads, steerer tube diameter. These present a bit of a challenge but are not insoluble.
Useful information on http://www.peugeottandem.co.uk

[cold_wet_and_tired]

We took the bike up and over Cannock Chase yesterday, which is by far our hilliest ride so far. We are learning to share out the effort more evenly on the ascents, especially when we run out of low gears. We made it up though, so I'm not in too much of a hurry to make massive changes.

Is yours a Motobecane Inter Club?
You're probably aware of this already - like the Peugeot tandems, it is likely to have some 'obsolete' French standards such as pedal threads,bottom bracket threads, steerer tube diameter. These present a bit of a challenge but are not insoluble.
Useful information on http://www.peugeottandem.co.uk

Yes it is, thanks for the heads up. I suspected some things may be non-standard but hadn't investigated the details yet.

Tbh I'd be looking at the going slower aspect rather than the converse at the moment. Does it have a hub brake in addition to rim brakes?

Yes. It seems to function well enough (on the understanding that it's not supposed to stop the bike) and is currently operated from the right hand brake lever, with both rim brakes on the left one. I haven't overhauled it (need to do some reading first) but I intend to for piece of mind more than anything. On yesterday's ride I was applying the hub brake first and early on the descents to keep the speed under control and then using the rim brakes as we approached obstacles, junctions etc and for stopping.

[Vorpal]

The rear derailleur is also an issue because it is tricky to change down (up-shifts are perfectly smooth), which is causing me to delay shifting until it's absolutely necessary (or, in fact, too late.) Once in the highest gear, it takes a lot of movement to get it to shift down, by which time it shifts two or three.

I am sure that you have found that with tandems it helps (sometimes a lot) to anticipate the shifts a little in advance of what you would do on a solo bike, especially with hills. I often shift to the bottom gear befreo I start up a hill, even if it means I lose a little momentum, because it ensures I will have the bottom gear when I need it. There is more force in the drivetrain on a tandem, which is part of what makes the shifting go a bit harder & slower. You might also be able to learn to 'let up' a little when shifting, which might help.

Good luck & enjoy the tandeming

[RichMoss]

In case you're interested, there's a couple of pics with brief descriptions in my flickr album (link below) of what I did with my Peugeot.
I started out with a frame, forks, chainset and headset and built it up from there. As I was going to get it resprayed anyway, it was worth getting a bit of brazing work done. Probably the best bit to avoid issues of obsolescence was to get a new 1 1/8" steerer tube on the forks - this makes it compatible with 'modern' 1 1/8" threadless headsets (head tube is already the correct size).
I built new wheels and although I have a hub brake on the back wheel (Sturmey Archer X-RDC w/9-speed cassette), I haven't actually connected the hub brake yet - the Tektro canti brakes are fine (tektro CR 720) - but this is with alloy rims rather than the old chromed steel. I do plan to try the hub brake as a drag brake, probably controlled with a thumbshifter.
I've also put a shimano dynohub on the front, but similarly I haven't got around to sorting the lights yet - deciding on whether or not to fit a front rack.
https://www.flickr.com/photos/8103741@N03/albums/72157670123143056
It is a lovely bike to ride

EDIT: I've just re-read your original post and see you've replaced the brake pads - given the apparent age of the bike, as a precaution, I would suggest replacement of cables too.