A customer of my bicycle shop brought in this vintage tandem that they wanted restoring and I thought the project would make a good Instructable.
The new owner of the tandem used to go on regular holidays as a child to the same place in Belgium and would borrow this tandem and cycle around the area with his brother.
On returning to the same place for a holiday over thirty years later he discovered the tandem unused from when he last visited and decided to bring it back to England and get it working again.
This isn't a restoration in the sense that everything is going to be original and vintage, but instead we're going to update the tandem and just get it working as a great bicycle to have some fun on.
Step 1: See What You've Got!
The first step of anything like this is to see what you're dealing with.
This project was made a little more difficult because another mechanic had started to strip the tandem and then given up. So I was initially presented with the frame, a couple of odd wheels and a box of bits.
Luckily the major unique parts of a tandem, the bottom brackets and cranksets, were still on the frame untouched.
At some point in the history of this bicycle it had had a pretty brutal red paint job, which was flaking and starting to peel in places. So a full strip and repaint is going to be necessary, but before we get to that stage we need to make sure the basics are going to work.
Step 2: Sort Out the Wheels.
The original wheels had completely rotted to bits. The previous mechanic had picked out a couple of wheels that they thought would suit the tandem.
The rear wheel was a modern 26" wheel with a Sturmey Archer hub. The hub includes internal 3 speed gearing and a hub brake. This wheel also has an aluminum rim and stainless steel spokes.
The front wheel was an older 26" x 1 3/8 wheel with a steel rim and galvanised spokes.
Apart from the fact that the two wheels were different sizes I was worried about the braking power of a caliper brake on the steel rim. In the wet steel rims loose a lot of their braking power. With a tandem, YOU NEED GOOD BRAKES!
After a few weeks hunting on ebay, I managed to find a modern Sturmey Archer 26" front wheel with a hub brake and an aluminum rim. An exact match for the rear wheel.
This means we've got hub brakes front and rear and we even have the option of a caliper brake at the front, which should mean we'll have excellent brakes once the tandem is finished.
A couple of chunky Schwalbe Marathon tyres and some nice new tubes and our wheels are looking great.
Step 3: Sort Out Mudguards.
The previous mechanic who had half started the job had found a pair of old steel mudguards that they thought would suit.
But the mudguard eyes on the tandem were in very strange places. So I sourced a pair of Velo Orange stainless steel mudguards that had very flexible fittings. I bought these and made sure they fitted with the wheels before sending the frame off to get blasted and painted.
Step 4: Strip the Tandem
Sorry! I seem to have lost the photos from this step.
Basically take the tandem apart. One bit at a time. Even though this tandem is old, we believe 1930's, it came apart easily... Good quality steel and well put together in the first place.
When you take things apart put nuts back on bolts, cable tie anything tricky like a headset so that it's all in the right order. Put everything in zip lock bags and label them. Take photos. Draw diagrams. Although you'll think you'll remember how it came apart, you never know how long it might be at the painters.
When you're left with a frame, a pair of forks and a bunch of stuff in zip-locks bags, put all the bags in a box and write 'TANDEM' on the side...
Step 5: Paint Job!
We had our frame and forks sand blasted, hot zinc undercoated, finished with a British racing green top coat and several coats of lacquer.
Our frame was old and when it got blasted it looked pretty pitted. But it was strong steel and purely a visual thing. The owner of the tandem was happy for it to look pitted and old. The other option would be to get the filler out. But that would have been a lot of work.
Step 6: Put the Headset and Forks Back Together
The first part of any bike build is to attach the forks to the frame which means putting the headset together.
I had to reuse all the old parts of the headset, as there's no chance of finding a replacement. But I never reuse old bearings. The headset bearings were big, but a standard size. Don't try and compare bearings by holding them up next to each other. You either need a proper bearing gauge (local bike shop) or a good pair of (digital) calipers.
Our headset went back together nicely and when finished was pretty smooth.
Step 7: Attach Wheels and Mudguards
As we had already tested our new wheels and mudguards in the frame and forks, this was fairly easy.
As we're using hub brakes both of our wheels have a brake arm, which needs to be securely attached to the tandem, to stop the hub rotating. These clips come in many different sizes and we had to try a few as our tandem has some odd sized tubes. But they're fairly cheap and any local bike shop that has access to Sturmey Archer stuff will be able to get them for you.
You also need a cable stop clip for the Sturmey Archer gears if you have them, like our tandem did. Again these come in a variety of sizes and again you should be able to get hold of them from your local bike shop.
Step 8: Rebuild Bottom Brackets, Replace Cranks
The next step was to put the bottom brackets back together.
Sorry. I lost these photos as well.
Basically look at your photos and diagrams from when you took them apart and reverse the procedure.
Again I used new bearings in the bottom brackets, everything else had to be the old stuff. The bearings in the bottom bracket were massive, a size that hasn't been used for quite some time. But as my bike shop is cool, I had some and put new bearings in.
This tandem has a cotter pin crankset. I used new cotter pins. I'd also done a DIY black paint job on the cranks, as they looked a bit tatty.
Step 9: Seatposts and Handlebars
The owner of the tandem had splashed out on two new Brooks saddles.
It took some measuring, guesswork and trial and error to find the two seatposts that fitted this tandem. They were odd sizes in the end.
I reused the clamp which holds the handlebars for the person at the back, on the seatpost for the front.
Turns out both sets of handlebars were very odd, the stem clamp diameter was 23.5mm. I only found one pair of bars on the internet and they were about £170. So another DIY spray paint job later and we're reusing the old bars.
Step 10: Final Touches
So now we've got the frame, forks, wheels, mudguards, seat posts, saddles and handlebars in place. It's time to tie it all together.
Which means new chains. We used some top quality single speed chain, ended up using three chains to make up the lengths. The front bottom bracket was adjustable to get the chain tension. Our rear dropouts were horizontal to allow us to get the chain tension at the back.
It also means cabling up the brakes and gears. Sturmey Archer hub brakes need a specific adjuster barrel and cable end stop. Again any local bike shop that deals with Sturmey Archer will be able to supply these.
You need a gear shifter to work with your hub gears. In our case we had a new old stock 3 speed Sturmey Archer shifter.
You need brake levers, we re-used an old pair of Wienmann ali brake levers.
You need grips. We bought new black cork grips. We had to cut down the front pair to work with the bars and brake levers.
Step 11: Gotchas!
Apart from the crazy stem clamp size for the handlebars there were a couple of other things that caught me out for this build.
You can't buy Sturmey Archer gear cables long enough for a tandem. I ended up wedging a normal gear cable into the Sturmey Archer shifter. It seemed to work, only time will tell.
The cranks were incredibly thin. The thread on the pedals quite long. The extra pedal thread that stuck out of the back of the cranks caused trouble. Snagged the chain, chipped the paint. In the end I got out the angle grinder and smoothed them down. And then did another DIY paint job.
There were no cable stops built into the frame. The frame had crazy sized tubing. So in the end I used quite a lot of cable ties.
Step 12: Finsished!
This thing shifts. It's also a bit scary. I'm not a big fan of tandems but I think we got it right with this thing.
The hub brakes are good, stop it fast.
The gearing is good, and that was a stroke of luck. I was expecting to have to try a few different sizes of sprocket on the rear hub. But we were lucky and got it right with what was on there.
All in all. A pretty freaky bike.