In case anyone hasn't noticed, I've been posting on the Folders topic about a Brompton which I've been repairing / restoring for a friend.
https://yacf.co.uk/forum/index.php?topic=124758.0So having posted that project, I thought I'd post some maintenance / upgrade work I'm doing on my trike.
I built this trike 12 years ago and since then have put somewhere over 25,000km on it. Friends nicknamed it The Beast as at over 50kg, it's the heaviest bike/trike they've seen.
It's built from 3 kids 24" bikes and originally most of the parts came from those bikes, even the gear shifters.
Over the years I've changed and upgraded only a few things, but most of it hasn't changed much. It originally had a leather office chair, but that disintegrated pretty quickly when it got wet, so I replaced it with a folding sun lounger. The brakes were the most significant change about 3 years ago, I welded on the brackets to convert it to disk brakes. It's amazing how much better it is now it stops when I want it to, particularly with over 50kg of momentum!!!
The gears and drivetrain need some significant maintenance and while I'm at it I'm finally upgrading the bottom bracket bearings. The old loose balls lasted only a few months between adjustments, so I decided external bearings and a Hollowtech crank should be the answer. I want lower bottom gear too, but didn't want to compromise the top gear, so with the new smaller main chainwheel I needed smaller freewheel top sprockets. That's plural, because it has 2 rear freewheels, one in the middle and one at the back. With 7 gears on each, that makes 49 gears!
Today, I got the old bottom bracket apart, which needed some heat due to the thread lock. I managed to get the new BB bearings and crank in place too and removed the mid shaft and gears.
As I'm finally getting around to improving the gearing, I decided it's also time to straighten the mid shaft. I made it from a rear wheel hub, which I cut in half and welded a tube between the halves. I had no lathe then, so aligning the parts was a bit hit and miss. Anyway it was a bit wobbly but worked. A couple of years or so ago one side wore out. Amazingly the bearings carved their way through the bearing shell!!! So I only had a spare front wheel hub at the time and I needed it fixed, so I welded that on. The bearings are smaller, but it's been working fine and that end is welded on nice and straight.
I 3D printed some plates to fit the front chainwheel, as can be seen. I think I'll do the same for the mid shaft chainwheel.
So that's where I am, mid shaft in the lathe, just measured with a dial gauge about to cut and reweld straight!
Here's a few pics...
The boot takes 2 crates of beer...