My home-built tandem trike
Technical description:
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Over Summer 2000 I took the tandem on a tour, visiting Spokesfest in Leicester and Cyclefest in Lancaster. Read all about it here:
Tour index
--- Tour page 1
--- Tour page 2
--- Tour page 3
Then in late 2001 I lent the trike to two sisters and a brother who wanted to take it across the USA for a charity ride. It was modified by Mike West of Specialbikes Ltd to take a Kettwiesel trike attached to the rear swingarm, making it into a five-wheel triplet. Luckily, it managed to survive the trip (and their 58mph top speed) without breaking :-) and is now back in the UK. You can read all about the Campbells' adventures on the machine here:
http://www.pedalpowertrio.com
Three large JPEGs of the hitch built onto the back of the trike to tow the Kettwiesel can be seen here:
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Close detail
The final chapter in my ownership of the tandem was pedalling it over to Cyclefest 2002 in Lancaster, where its new owner, Luke Stephenson, was waiting for it. I hadn't been riding it for a while, and needed the space - and Luke will give it the TLC it deserves. Now to start planning Mark II... things I'd change include:
- Clean up the chainline to avoid at least three of the pulleys used in Mk1, and avoid conflicts between chain and rear seat in certain positions.
- Reduce wall thickness for rear and swingarm sections, and increase it in the front sections, especially between cross-beam and front seat, where there's most stress... this should safely save a bit of weight.
- Rethink the way the sections join - Mk1 was a pig to get apart :-( and also, the exposed bolts somewhat limited the seat adjustment.
- Think more about luggage capacity from the start - it was a bit of an afterthought on Mk1
- The rear suspension element was unsuccessful, using a home-made shock from an exhaust bushing. Either simple lump of rubber or a commercial MTB shock would be better.
- Consider using a rohloff mid-drive system: increases complication a bit but avoids a very long derailleur cable to the rear.
- Buy in modern kingpin assemblies with ISO disk mounts, so I wouldn't have to make adapters for the Hope disks...
- Use bronze bushings or ball bearings for kingpins and handlebar pivots, instead of messing around with plastic ones which wear out fast.
- Use a 48-spoke rear wheel (preferably with disk brake) from the start
- Where aluminium is used, get it anodised or something to prevent corrosion.
- Use a proper BB shell with threads in rather than bodge it with a 45 degree mavic-style chamfer as I did on mk1 - making getting spares on the road a nightmare.
- Revise clamping of rear BB eccentric so as to avoid water ingress.
- Revise seat attachment clamps so that paint isn't damaged when adjusting
- Revise steering geometry to avoid very heavy action at full lock...
There's probably more...
I also gave a talk about the tandem at Cyclefest 2002; you can see the slides I used here.
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