Author Topic: Recumbent trike (hopefully folding)  (Read 10628 times)

Recumbent trike (hopefully folding)
« on: December 19, 2015, 09:16:39 pm »
I've wanted a Windcheetah ever since I saw one in the Richards Bicycle book aged 10 or something!
Then at the start of this year I discovered AtomicZombie, and started on the process of building a StreetFox (but with disk brakes, 20" rear wheel, and a few extra modifications, including a fold in the middle). This isn't necessarily a "bodge", but there are a few along the way! I'll update this thread with my progress so far - I've not completed it yet, but I've made a lot of progress!
This is what it's supposed to look like when done:


This is what I started with - the bikes in the top photo were knackered and free, but the suspension bike cost a whole £15:
20150114_185607 by duncancmartin, on Flickr
20150118_183431 by duncancmartin, on Flickr

So, off came the rear triangle - this will be used almost entirely as is.
20150124_124346 by duncancmartin, on Flickr
But the rest of the frames didn't survive so unscathed - here are the headtubes and the pivot for the rear triangle (angle grinders are great!):
20150124_141729 by duncancmartin, on Flickr
And here they are all cleaned up with the chopped up forks to go with them:
20150125_135603 by duncancmartin, on Flickr
At this point, I decided (don't know why) that I needed significantly more travel than could be provided by the crappy shock that was on the kids bike, so this arrived:
20150124_160615 by duncancmartin, on Flickr

And then it was time to do more than buy things and chop them up!
More to come......

Re: Recumbent trike (hopefully folding)
« Reply #1 on: December 19, 2015, 09:35:02 pm »
I also got myself some BMX wheels for the front ones - lots of spokes, 14mm axles to stop them bending when held on one side, and both rear wheels so I can screw a brake disk adapter on.
20150127_183729 by duncancmartin, on Flickr
Box section steel - 1.6mm wall, 40mm square. I got 6m, and I think it was about 40 quid! I ended up using a little under 3m, so I've got enough to make another if I want! I used a holesaw to cut the end of this one so that I can weld in the pivot for the rear triangle. Originally I actually just made a hole with steel at the end so it was extra sturdy, but when I put the pivot point in the hole I didn't have enough clearance at the back for the triangle to attach! So I binned that idea and just did it the way the plans said, relying on the welds to hold...
20150221_105332 by duncancmartin, on Flickr
Held in place so that it can be welded in properly...
20150221_105420 by duncancmartin, on Flickr
Ugly (but sturdy) welding:
20150221_115344 by duncancmartin, on Flickr
20150221_120606 by duncancmartin, on Flickr
Cleaned up a bit on the grinder:
20150221_121715 by duncancmartin, on Flickr
Here's the suspension mounting plates that I chopped off the donor bike:
20150222_162303 by duncancmartin, on Flickr
Then they got welded on (after guessing exactly where they should go so that the seat back wouldn't foul he shock)
20150228_165219 by duncancmartin, on Flickr
And here's them and the pivot point in use.
20150228_170658 by duncancmartin, on Flickr
This was all done by the end of February, so that was actually reasonable progress so far. Then things slowed down a bit...

Re: Recumbent trike (hopefully folding)
« Reply #2 on: December 19, 2015, 09:59:08 pm »
The next bit of the process is to create and attach the backrest:
20150301_161152 by duncancmartin, on Flickr

At this point I realised that the threads on my wheels would be rotating in opposite directions, so if I attached a screw on brake disk mount to the right hand one it would unscrew whenever I tried to brake! After a little thought I figured I'd just bolt the screw on addapter to the hub, so I drilled these holes:
20150328_144304 by duncancmartin, on Flickr
And bolted the disk and screw on adapter through them:
20150328_172102 by duncancmartin, on Flickr
I wasn't convinced that this would be effective, but it's been done on other AZ trikes, and apparently it works. There's some threadlock on the threads, and it's done up really tight, so this is more belt and braces than seriously stressed bolts, but we'll have to wait and see how well it stays put...
I also got some 15mm (x 50m) bar, and then drilled 14mm holes for the axles to go through:
20150228_165118 by duncancmartin, on Flickr
Here's the practise go I had at welding the spare one onto a chopped  remnant of the fork crown.  This bit was quite tricky to get the angle good, and also it's a really stressed weld, between a 15mm bar and a pretty chunky bike part (the wall sizes were probably 5mm thick). I turned the welder up to power setting of 7 (out of 8), and bashed the hell out of the test piece. I managed to hold the bar in the vice and hit the fork crown so hard that I bent the 15mm thick bar (without breaking the weld)!
20150314_122412 by duncancmartin, on Flickr
More to come in a bit when my laptop is charged!
Cheers
Duncan

Re: Recumbent trike (hopefully folding)
« Reply #3 on: December 19, 2015, 10:26:32 pm »
 :thumbsup:
If it ain't broke, fix it 'til it is...

woollypigs

  • Mr Peli
    • woollypigs
Re: Recumbent trike (hopefully folding)
« Reply #4 on: December 19, 2015, 11:25:32 pm »
This looks fun :)

Re: Recumbent trike (hopefully folding)
« Reply #5 on: December 19, 2015, 11:55:45 pm »
Thanks guys. :)
Battery charged, on with the story...

After a couple of months break, I started on the cross boom. This is where those head-tubes you saw earlier ended up. I used the holesaw again to get the right camber and caster angles. Before chopping out the ends of the tube, it looked like this (note industrial MIG welder and crap pillar drill in the background):
20150504_162902 by duncancmartin, on Flickr

With the headtube balanced in the right place it looked like this:
20150504_165356 by duncancmartin, on Flickr

And then finally welded up and cleaned up with the flap disk, it looked like this:
2015-09-27_04-00-53 by duncancmartin, on Flickr
At the point where I'd done this on both sides, I discovered something really irritating - when I had been welding the headtubes on I'd fired a couple of bits of welding wire straight through the gap, and now there was something rattling around inside the tube, and there was no hole to get it back out of! After much thought I drilled a small hole in the middle of the boom, and tried to magnet the rattly bits out.  That failed dismally!  :( Eventually, I got some double sided tape and stuffed it through the hole - shook the tube up and down a lot, and managed to capture the loose bits on the tape! they even came out of the hole again afterwards! :)

Then there was a big gap where I got sidetracked into other projects like constructing a set of replica Roman auxilliary shields (that's another thread entirely!). Eventually, I got back to this and realised I had to work out where the boom should live. I couldn't follow the plans, because they call for a v shaped boom, but I'd decided a straight one would be easier! :) (And also because I figured it would create more of a compact shape if folded.)
So I mocked it up and experimented a bit:
2015-09-27_04-01-26 by duncancmartin, on Flickr

When I'd finally decided it was good I tacked it and welded it in place.  As you can see, my welding is getting better:
2015-10-11_06-38-00 by duncancmartin, on Flickr

I'm still not 100% sure the boom is in the right place, so I'm not going to add any extra re-enforcing gussets until I've ridden it and made sure the backs of my legs don't clobber it where it is! I added seat mounts next - that was relatively straightforward:
2015-10-10_08-13-47 by duncancmartin, on Flickr
and then ground the welds flat so that the seat base would sit properly:
2015-10-11_06-37-08 by duncancmartin, on Flickr

Finally, with the frame in reasonable shape, I used a nylon clean and strip disk to remove all the surface rust, and brushed some grey primer on to stop it coming back (another unusual use for a toe-strap - I should add it to the list on that other thread!):
2015-10-11_09-27-48 by duncancmartin, on Flickr

That brings us up to the start of December, but I've made some progress this month again, so I'll have to add that tomorrow...
Cheers
Duncan

clarion

  • Tyke
Re: Recumbent trike (hopefully folding)
« Reply #6 on: December 20, 2015, 10:03:36 am »
Looking good so far.  Keep us posted!
Getting there...

Torslanda

  • Professional Gobshite
  • Just a tart for retro kit . . .
    • John's Bikes
Re: Recumbent trike (hopefully folding)
« Reply #7 on: December 20, 2015, 02:42:28 pm »
Homebuilding is fun! Redshift got me AZ's book many years ago. (It could've been my 40th birthday.) Reading it showed us what we got wrong when building my first recumbent and allowed me to refine (really?) the design (and that's not the right word, either!) and ended up with this . . .



Haven't yet attempted a trike. Way too much going on with castor/camber and Ackerman/centrepoint besides having to make the right side mirror the left . . .

PS If you still find yourself wanting a Windcheetah, I've got one for sale . . .

VELOMANCER

Well that's the more blunt way of putting it but as usual he's dead right.

Re: Recumbent trike (hopefully folding)
« Reply #8 on: December 20, 2015, 05:21:41 pm »
I don't have the book - I just bought a pack of 6 plans for $36. I'd love a Windcheetah, but I fear it's about a grand more than I can afford! I've sent you a PM just to confirm. I've never even ridden a recumbent or a trike, so it's a bit of a step in the dark!

Anyway, back to the story. I got hold of a crappy folding bike, and then I chopped it up for bits:
20150504_174943 by duncancmartin, on Flickr

I eventually got around to sticking the front wheels on, so it ended up on it's own wheels like so:
2015-10-23_08-56-30 by duncancmartin, on Flickr
2015-10-23_08-56-46 by duncancmartin, on Flickr

I had some 3mm plywood hanging about, so I cut out a couple of pieces and bonded them together for the seats: 2015-11-01_05-07-27 by duncancmartin, on Flickr
Then I drilled holes and put T nuts in and screwed them to the frame to see how it would work. Followed by some CAD (cardboard aided design) to see how the fold would work if it folded over the top like an ICE trike.
2015-12-11_09-51-37 by duncancmartin, on Flickr

I've since thought that I might fold the back wheel underneath instead, because that would put the joint in compression rather than tension. It would also mean that I could put the pivot point where the seat meets the backrest, which is probably the point that would cause the shortest overall package. HP Velotechnic fold that way, and their fold looks very easy to do. I need to do some more CAD to see how that would actually work!

I got some foam from Hobbycraft and cut it to the right shape for the backrest and seat base:
2015-12-04_10-09-17 by duncancmartin, on Flickr

And so I painted the bases:
2015-12-12_05-55-08 by duncancmartin, on Flickr

Last weekend I strapped the rear triangle to the back of my fixie and took it to the Broken Spoke Workshop to replace the bottom bracket (with a really short one that came with a Truvativ crankset)
2015-12-13_07-41-16 by duncancmartin, on Flickr

And now we're almost up-to-date - this weekend, I chopped the arm off the crankset so it will work properly as a jackshaft. I'm going to run the middle ring to the freewheel, and then the front chainset to the inside ring of the jackshaft.  Crankset mutilation:
2015-12-18_10-07-27 by duncancmartin, on Flickr

2015-12-18_10-07-38 by duncancmartin, on Flickr

Then I put the triangle back onto the bike, so that the rear end is essentially finished. After that, I stapled some vinyl over the seat foam - it's quite good on the top but pretty scraggly on the bottom. I figure I'll sort the bottom out once I've actually tried riding on it and I'm happy with how comfortable it is:
2015-12-18_10-07-52 by duncancmartin, on Flickr

And finally, I made the clamp bits to attach the front bottom bracket to the main boom (it moves along the boom to adjust for leg length).
2015-12-19_04-59-17 by duncancmartin, on Flickr
Became this:
2015-12-19_04-59-41 by duncancmartin, on Flickr
Became this:
2015-12-19_04-59-53 by duncancmartin, on Flickr
Now I need to weld the plates to the BB shell either side of the main beam and put bolts through to allow it to be clamped. I'm really frustrated that the bottom bracket I ordered hasn't turned up despite getting an email from Royal Mail saying that it had been delivered! >:( But I want to chase the threads in the BB shell before I install the bottom bracket properly (after I've done the welding), so I'll have to wait until the Broken Spoke is open again (I don't have my own BB thread tool).

So now I'm up-to-date.  I doubt much is going to happen over Christmas, but we'll have to see how it goes.
The remaining really difficult bit is welding on the brake/steering arms. They need to be parallel to the ground, and to the brake disks.  I've been putting that off, but there isn't much else left on the critical path to riding it!
Cheers
Duncan

Kim

  • 2nd in the world
Re: Recumbent trike (hopefully folding)
« Reply #9 on: December 20, 2015, 05:58:04 pm »
I've never even ridden a recumbent or a trike


This is made apparent by:

Quote
Then I put the triangle back onto the bike, so that the rear end is essentially finished. After that, I stapled some vinyl over the seat foam - it's quite good on the top but pretty scraggly on the bottom. I figure I'll sort the bottom out once I've actually tried riding on it and I'm happy with how comfortable it is:
2015-12-18_10-07-52 by duncancmartin, on Flickr

Neat though it is, you're going to find that horrendously sweaty.  Especially if you do the whole seat in it.  But don't worry too much until you're happy with the rest of the trike, seats usually need a bit of tweaking anyway.

Pond filter foam seems to be a good cheapskate alternative to Ventisit.


*returns to watching with interest*   :thumbsup:
To ride the Windcheetah, first, you must embrace the cantilever...

Re: Recumbent trike (hopefully folding)
« Reply #10 on: December 20, 2015, 06:09:28 pm »
That's what the plans call for - I'm making enough changes to fundamentals that I'll stick with the plans for the rest if it makes life easier! It was super cheap, so if it gets binned at some point then that's fine.
*off to google ventesit*  ;)
Cheers
Duncan

mmmmartin

  • BPB 1/1: PBP 0/1
    • FNRttC
Re: Recumbent trike (hopefully folding)
« Reply #11 on: December 21, 2015, 10:16:46 am »
Astounding imagination, excellent skills, superb implementation. Was going to post pix of my efforts at adding a pocket and some reflective strips to turn a normal cycling gilet into Something To Amaze, but am now feeling completely outclassed and inadequate. I mean - getting metal to melt and stick to metal? I can't do that.
Besides, it wouldn't be audacious if success were guaranteed.

Re: Recumbent trike (hopefully folding)
« Reply #12 on: December 22, 2015, 03:19:48 pm »
Great thread, just come across it.
Keep at it.
If you ever need any tube bending, especially 40 mm box, give me a shout, I have the necessary dies.
Welding, fabrication and light engineering available to forum members.

Re: Recumbent trike (hopefully folding)
« Reply #13 on: December 22, 2015, 05:08:56 pm »
Great to see somebody enthusing about home building. Your posts made me laugh though - all those old scrap bikes, pictures of saw off headsets, workmates, talk of angle grinders and some serious heavy duty mild steel tubing. I could almost smell the ground steel in the room and hear the buzz of that MIG welder going on [what are you using out of interest?] when I was reading your description. Takes me back.

I've never even ridden a recumbent or a trike, so it's a bit of a step in the dark!

That's what happened to me and I ended up building 11 of the damn things in the end! [Rode some respectable distances on a few of them too].

Looking forward to seeing the finished thing. It's looking tidy. Brad's put together some good bikes [I really liked his very first one, The Marauder]  and it's a good idea to work from plans that are known to work - you'll learn a lot and it will save a lot of messing about.
I'd be amazed if it's your last  :)
Garry Broad

Re: Recumbent trike (hopefully folding)
« Reply #14 on: December 22, 2015, 08:19:54 pm »
If you ever need any tube bending, especially 40 mm box, give me a shout, I have the necessary dies.
Thanks, I may take you up on that when I get to the next one! :)
The welder is one I got to try car restoration (ended up getting rid because it was far too large a project). It is a secondhand Murex Tradesmig I got from a welder repair guy. It weighs a ton, and the stitch functionality doesn't work, but it's solid and reliable and produces good welds. I've got a 3 year lease on a argoshield gas bottle as well.
Welder by duncancmartin, on Flickr
I taught myself to use it by trying and then posting on the migwelding forum and then trying again!
I'd like to learn TIG - I had a go on a car resto course I went on, and I've got a cheapass scratch start box, but it takes the tiny little Argon canisters and so it would cost a fortune to get good enough to use it.  I should just buy a lift start (or even an HF start) model with a proper adapter for a decent sized gas bottle, but that's real money, and eats into the project budget!
Not sure what the next one is going to be... :)
Cheers
Duncan

Re: Recumbent trike (hopefully folding)
« Reply #15 on: January 02, 2016, 11:02:47 pm »
I added the bracing for the bottom bracket today.  The plates I had cut previously were too short, so I had to make some more. 40mm holesaw, angle grinder with a cutting disk and some 4mm sheet created this:
2016-01-02_01-57-08 by duncancmartin, on Flickr

I lined everything up thus:
2016-01-02_06-13-43 by duncancmartin, on Flickr

and welded the plates onto the BB shell.
2016-01-02_06-14-02 by duncancmartin, on Flickr
The welds were crappy and blobby because I forgot to clean the paint off the shell before tacking the plates on, but the joins seem pretty sturdy.  Maybe a little too sturdy - the cardboard I used to space my joint for welding clearly wasn't correctly placed and the front edge is a bit on the tight side! Still, nothing a bit of brute force and ignorance can't fix. I cleaned the welds p a bit, so it all looks a bit better now:
2016-01-02_07-47-22 by duncancmartin, on Flickr
2016-01-02_07-47-10 by duncancmartin, on Flickr

All that remains is to mark it up and drill some holes for the bolts that go under the main boom. Oh, and recut the BB threads, so the BB can be trial fitted...
That would leave me with just the pulleys and tensioning to fix to have all my propulsion bits sorted - I really should get on with the steering/brake arms soon! :)
Cheers
Duncan

Re: Recumbent trike (hopefully folding)
« Reply #16 on: July 29, 2016, 09:39:36 pm »
Progress on this today.  I cut and drilled some brake caliper mounts (2mm steel), some steering tabs (4mm steel - took forever to drill the holes!) and also drilled the holes in the bottom bracket assembly.
This is what all those bits actually look like:
2016-07-29_06-32-41 by duncancmartin, on Flickr
Hopefully tomorrow I can weld them on - once that's done I'll only need to sort out the tie rod (and I've got the bits) before I can had an unpowered roll down the hill!  ;D
Cheers
Duncan

Re: Recumbent trike (hopefully folding)
« Reply #17 on: July 30, 2016, 06:14:04 pm »
Much more progress today. I had originally cut out the brake supports according to my cardboard templates, but when I came to actually attach them with the brakes attached, I realised I had to modify them a bit! Still, I eventually fettled them until they fitted well enough and then I welded them up.  I then realised that the steering tab wouldn't fit in the right place on the right hand one, so I had to cut some extra out of the brake mount (not a problem - it was just a quarter of an inch on the end). After that, I measured it twice, and welded on the steering tabs.
IMG_20160730_174924 by duncancmartin, on Flickr
The welding isn't quite as pretty as you would like (though some of it's not too bad), but it's strong enough:
IMG_20160730_174939 by duncancmartin, on Flickr
IMG_20160730_174950 by duncancmartin, on Flickr
Once I've made dinner (and these things have cooled down), I'm going to put these back into the frame and try to work out how long the tie bar needs to be - then I can weld on the bolts for the track rod ends. At which point, adding the wheels, the brakes, and the handlebars (oh yeah, and the seat back) will allow me to try a roll down test. :)
Cheers
Duncan

Re: Recumbent trike (hopefully folding)
« Reply #18 on: July 31, 2016, 06:39:02 pm »
I've not managed to have my first ride (roll) on it yet. :(
However, I have made some real progress - the steering link bar is all welded up (including adding a squared off part in the middle that I can turn using a 13mm spanner to open/close it) and installed...
Plus the cranks and pedals are on. :)
Welding the nuts on the end of the steering rod is really helped by the groove in the workmate:
IMG_20160731_152429 by duncancmartin, on Flickr
I think she needs to grow a bit:
IMG_20160731_171159 by duncancmartin, on Flickr
Waiting in the garage for the next session:
IMG_20160731_173009 by duncancmartin, on Flickr

Now for the downside - the reason I didn't get to ride it is because I couldn't fit the brakes.  Sure, I could slot the brakes over the disks and then bolt them on, but when I did that, the wheels wouldn't go round properly! Aside from needing shorter bolts (they hit the disks if I do them up fully), the alignment isn't quite there and the calipers rub on the edge of the disks.  I'll get some washers with the bolts, and I'll have to make the brake holes into slots. Once that's done, I should be able to roll.

The next steps are to get some chain (I reckon I need 3.45m or thereabouts), a (cheap) derailleur to put some tension into the return side, a chain tube, and a round groove pulley (so I can route the tensioned side). Oh, and some brake and gear cable for the rear mech/brake. I think that's all the pars I need to make it actually usable, and fitting them is mostly a matter of regular bike mechanics rather than complex recumbent engineering!
Cheers
Duncan

Re: Recumbent trike (hopefully folding)
« Reply #19 on: August 01, 2016, 12:33:13 am »
Duncan, this is fascinating!

Re: Recumbent trike (hopefully folding)
« Reply #20 on: August 13, 2016, 09:34:15 pm »
As often with this build, 2 steps forward and some head scratching!
I got some chain and hosepipe last week, and the pulleys arrived in the post. Today I got some bolts, so I was in a position do get on with the trike again. :)
I have finally got my brakes into a reasonable position.  They both have a little intermittent rub, but I'm blaming that on the disks not being 100% round!  It'll be annoying if it stays like that, but for getting it on the road and testing it, I'll put up with it! :)
IMG_20160813_203928 by duncancmartin, on Flickr
I also installed the pulley. I got some M10 bolts with shoulders on, and then I realised that I needed to space the pulley off the main boom. I cut down a piece of the 12mm tube I used for the steering rod and put it over the bolt as a sleeve. Then I worked out where it needed to go, and I welded it on. :)
IMG_20160813_203945 by duncancmartin, on Flickr

Then I was trying to work out how much chain I needed (I got 3, and I need to use about 2.5, but it's how many links the .5 is that needs thinking), and I realised I had a problem. Because I'm using a jackshaft I need to add a tensioner for the return chain section, and I figured I would use a rear mech I have lying around. Because of how it works, I need to add a mount about an inch away from the beam - I figured adding some extra box section to the side would make it straightforward. But if I do that, then the box is in the way of the top (drive) section of the chain.
The way that I was thinking of mounting the rear mech:
IMG_20160813_204859 by duncancmartin, on Flickr
The problem with the drive section of the chain:
IMG_20160813_205205 by duncancmartin, on Flickr

I could make the box bigger (or offset it somehow) and run the drive part of the chain through the box. I'm not sure if  that would be a good solution though, time for some thinking!
Cheers
Duncan

Re: Recumbent trike (hopefully folding)
« Reply #21 on: August 14, 2016, 05:56:06 pm »
I have a cunning plan.  :) Instead of welding a piece of 40mm box alongside the existing main beam, I can weld a 20mm box across the bottom of the main boom, and put a piece of plate on the end (with a captive nut welded to it). That will give me enough clearance for the drive part of chain, while still giving me a reasonable point to mount the derailleur on. :)
Clearance:
IMG_20160814_165325 by duncancmartin, on Flickr
Mounting point:
IMG_20160814_165318 by duncancmartin, on Flickr
I'll have to wait to cut, drill, and weld the end piece though - no garage time today.
Cheers
Duncan

Re: Recumbent trike (hopefully folding)
« Reply #22 on: August 20, 2016, 05:10:28 pm »
It rolls! And it stops! And the pedals (sort of) allow you to make it go forwards!   
I welded a nut into some 20x20mm tube, and then welded that to the underside of the main boom:
IMG_20160820_110920 by duncancmartin, on Flickr
Then I attached the derailleur to it, sorted out the chain length and turned it up the right way:
IMG_20160820_120004 by duncancmartin, on Flickr
Finally, I put handlebars on and the brake levers onto the bars, and tried to ride it! It worked! Unfortunately it was in the biggest gear it has, which was rather hard to pedal, and the derailleur I'm using for tensioning is kinda twisted so it doesn't do what i is suposed to and keep everything in line. I was able to ride it down the street, but coming back up what is only a slight include proved too much! Anyway, here it is after the maiden voyage!
IMG_20160820_115958 by duncancmartin, on Flickr

I then went to a local bike shop and got some gear cables and outer - I've now sorted out the rear derailleur using a spare thumbshifter, and used another one for a parking brake using the V that was on the back wheel. That seems to work pretty well, but it was hard to take pictures of these bits! It started to rain halfway through these fixes, so I couldn't try another ride on it afterwards. Before I do any more I need to bolt some hooks to the garage wall so that I can hang some of my bikes up - without doing that I will have to carry it in and out of the garage, and it's a heavy old beast! So DIY to do first, and then fine-tuning of the trike! Not sure if I'll get any spare time this weekend, but I've got Monday Tuesday and Wednesday afternoons, so hopefully I can make some progress this week and get it working properly before the end of August (I'm away next weekend so can't work on it or ride it then)!
Cheers
Duncan
PS - yes the brake cables need significant shortening (and the left hand one has much more travel than the right one, which needs to be sorted so I don't end up with too much brake steer), but it's still in dry assembly/proof of concept stage at the moment. There are loads of other bits I need to do before it's finished including (but not limited to): sort the seat out, fix the derailleur tensioner, improve/shorten the handlebars, add grips, shorten the front wheel axles on the outside, tweak the brakes, install a front derailleur (and shifter), shorten the main boom (I reckon it's long enough to fit a 7 foot person with some space to spare)band add chain tube(s) where needed. There is also the possibility of converting to under-seat steering if I don't like the tiller style, and obviously the original plan was to make it foldable. Damn, for a second then I thought I was almost finished!!!  :-X

Re: Recumbent trike (hopefully folding)
« Reply #23 on: August 24, 2016, 09:50:53 pm »
There's good news and bad news!
The good news is that I've sorted out the issues I was having with the middle derailleur (not helped by the fact that if I have the back chain on the big ring and the front chain on the middle ring, then they clash with each other), and got the rear derailleur indexed properly. I then got to ride the trike up and down and up and down the road.  My neighbour also had a go!  :thumbsup:
Here's a still (note the slope and the handbrake holding it):
IMG_20160823_162403 by duncancmartin, on Flickr

There's even a video (horribly shaky, due to being taken by my 7 yo) but I can't work out how to upload it to flickr - I think it's just too big!

The bad news is that while I was riding it, I realised that the crank alignment was horrible (this picture should show that the chain is parallel to the main boom, except for where it goes along the chainset, where the front pints outwards):
IMG_20160823_162941 by duncancmartin, on Flickr
IMG_20160823_162923 by duncancmartin, on Flickr
On more serious examination, I discovered a crack in the weld holding the bottom bracket to the left hand plate (as seen from sitting in the seat). 
2016-08-24_09-03-47 by duncancmartin, on Flickr
Obviously this will need to come off and get re-welded (and for that I'll need to remove the cranks and the BB). I'm not sure if I need to remove it and then completely re-weld it, or can I get away with straightening everything up, cleaning up the old welded joint where it failed and then welding it again, or need to disassemble and go back to bare metal and 2 separate pieces. I remember (you might even be able to find it on this thread) that I forgot to clean the BB shell properly so the welds were ugly - I thought they were strong enough, but I guess they weren't and that's why this has happened.
I also need to sort out the tip on my MIG - I think it's a bit old and warn, which means that sometimes the wire just pushes the torch away from the thing you're trying to weld! It's also a bit splattery. Not going to help with making strong welds...
Anyway, at least I have proof that the concept works. The only bit that concerns me is how low the tensioner for the front chain run goes - I'm bound to catch it on a speedbump at some point. It's necessary if I want to run gears at the front though and there's nowhere else to put it (unless I guess I flip it completely and run it where my left ankle would go?). Does anyone have bright ideas about how to make this less vulnerable?
Cheers
Duncan

TheLurker

  • Goes well with magnolia.
Re: Recumbent trike (hopefully folding)
« Reply #24 on: August 25, 2016, 06:40:58 pm »
*cough* zip tie *cough*  :D

S'looking good thobbut.
Τα πιο όμορφα ταξίδια γίνονται με τις δικές μας δυνάμεις - Φίλοι του Ποδήλατου