Whooeee! It all seems to work.
Having overhauled my old red 2003 Brompton and re-installed the Juliane Neuss recumbent kit, with a single chain drive to replace the old belt and chain setup, I’ve ridden it round the block and it all seems to work. Some detail work to do yet to get it running smoothly and make it fold properly but I think I’ve crossed the big hurdle of getting a chain drive to work.
The overhaul started with stripping the bike down to treat the rust patches with Kurust then paint with Hammerite Gloss in a cheerful yellow colour. The paint isn’t perfection but it’s pretty good for a backyard aerosol job, Hammerite gloss paint is very forgiving.
Then I refurbished the rear hinge which had seized up (having been previously worn and wobbly), cleaned up and lubricated everything else, removed all the gubbins associated with the belt drive and moved the mountain drive to the boom.
The scary bit was fitting a long chain. Would the Brompton Derailleur cope with it? Would my plan to use chain tubes to route the chain and allow it to fold work? A great deal to go wrong.
The bare chain was never going to work as the bottom section clashes with the front wheel but installing some chain tubes on a lash-up basis dealt with that and some fine tuning of the way the tubes were fastened to each other and the frame led to an installation that seemed to run OK on the maintenance stand.
That wire thingy on the upper chain tube came with the tube but I’ve ordered a more sophisticated “floating tube” gadget
Here’s the front end
And here’s some real magic. Having taken the bike off the stand, without thinking, I flipped the rear wheel under into the parked position
Could have been a disaster, I wasn’t paying attention at all, but see how the chain tubes keep everything under control. I need to make that top one splittable (we do that on our Hase Pino, it’s not rocket science) and I think I should be able to fold and unfold the chain and keep it all taut enough. I’ll probably make the bottom tube a long split one as well.
A few other details, here’s a clamp with a piece of stud used to hold the Mountain Drive torque arm steady. Thanks to Simon Koorn for suggesting how to do that.
Those pedals are some cheap folding pedals but I’ll probably fit a Brompton folding pedal on the left and a cage pedal on the right.
For anybody not familiar with the Juliane Neuss design, here’s how the boom mounts on the head tube.
I need to work on the gears, there’s an occasional skip which is probably due to fitting a new chain to worn sprockets, but I’d bought some new sprockets precisely for that purpose. It’s set up with SRAM narrow range 6-speed which goes well with the Mountain Drive to give 12 equally spaced gears.
However I have a spare Brompton Wide Range (BWR) hub and I’m probably going to fit that instead, when I first tried out the recumbent I felt it needed higher top gears as the steering is a bit twitchy and pedalling at a high cadence at speed was quite scary. On gentle downhills it gets up speed very fast so I want to take advantage of that. But I’ll leave it with the narrow range setup until I get used to it and everything working, the BWR requires a new set of learning to sort out the overlapping ratios between upper and lower range on the Mountain Dive.
Also for some reason the brakes are really not working well, I’ve got used to really good brakes on my newer Brompton, I think the front caliper on this one is the same as the current ones so I’ll experiment with better pads. I have some Swiss Stop Greens in the drawer and they are supposed to be excellent.
And you’ll see it has Kojaks, my first set. Well it is a bike for racing and I won’t be using it much for urban utility cycling.
So now I have two weeks to do the fine tuning and get my recumbent reflexes working, at the moment steering a straight line is not really working, especially at lower speeds. “Abeillaud”, a member of the french speaking Brompton Forum, has organised a recumbent team for the Brompton World Championships and Juliane herself will be riding with us so I need to make a decent job of it.