Just finished home built SWB

The latest project - finished at last. It’s taken quite a while to finish this off due to this dam PMR which is affecting my wrists/elbows/shoulders /neck. As I can’t ride my MTB anymore I decided to build another recumbent two wheeler. I built this one as quick as I could so I could ride again - took me over a month as I can only use my hands/arms for very short periods. I have another on the drawing board and will be sending off for hubs, rims, deraileurs, shifters, crankset, spokes, rims, disc brakes, etc, shortly. When I'm able I'll put together another with all the new parts - could be quite some time though before I have use of my hands again. The new one will have a 27.5 rear wheel and 20" front, the frame will be basically the same except stretched a little and the rear forks will be slightly smaller section tube. For this build I scavenged parts from a recumbent trike I built about 10 years ago, the stripped trike frame now hangs from the shed roof, a rather dusty and forlorn sight now.

The rear wheel stayed basically the same except for the axle I had to shorten slightly complements of a slight build mistake on the rear forks: I tend to measure once and cut and weld twice as opposed to the more common approach - I’m different what can I say. The front wheel was made up using the spokes and rim from the trike but laced to a standard front bicycle hub I had lying around..

I turned up a Bottom Bracket with a 24TPI internal thread from a piece of 38mm tube I had lying around, LH thread on one side and RH thread on the other. Unfortunately the bottom bracket warped a little when I welded it to the frame but, judicious use of a panel hammer and running a threaded bearing cup in and out a few dozen times freed up the thread again...
From the same stock I turned up and threaded a half bracket for the intermediate cassette and welded it to the frame. The internal thread on the older cassettes is the same thread as the bottom bracket bearing cups so a bearing cup was screwed into the cassette and the cassette screwed into the half bracket The intermediate cluster gives another four ranges handled by a modded front derailleur I mounted under the seat, Shifting is handled via an extension thumb tab welded to the modded derailleur.
The headstock I turned up from a solid lump of 38mm stock bored to take standard bearing cups. As the boom and bike frame are welded front and rear of the headstock and the headstock takes most of the bike and riders weight the middle section of the headstock I left fairly thick so It wouldn’t warp or bend.

Drop bars sit atop a 450mm riser which slips inside a modded BMX fork. As the handlebar riser is quite long I had to clamp it from the bottom of the fork using a standard riser slash clamp and a short 8mm allen head screw.
Brakes are simple side pulls and not very effective. I turned up a couple of nylon bushes for a pair of old stem mount shifters I had, welded backing plates with cable mounts to the handlebars and routed all cables through cable tidies I turned up and welded to the frame to keep things neat.

Front derailleur is GSX, and the rear is Deore, both quite old and way past their prime. Crankset is 52/36 from memory and the rear cassette is a 13-26 5 speed with an intermediate four range cluster in the middle. Due to the 20” rear wheel I had to swap and change cogs on the intermediate cluster to gear everything up a little. This set up gives me a slightly lower range than my MTB and a range slightly higher than the same bike. I mounted a couple of pulleys I turned up from nylon atop the boom for chain routing and also mounted a derailleur long cage in front for front chain tensioning. All up I think there are 2 ½ chains. The bike weighs around 14kgs, the same as my MTB.
The frame is made from 30mm x 1.5mm RHS duragal, that‘s all I had to hand otherwise I would have used black.. Headstock is set at 70 degrees and wheel offset at 45mm, unfortunately the trail isn’t optimal making wheel flop more noticeable than I’d like and the steering is rather responsive. When I get around to it I’ll increase the wheel offset by another 10mm, that should give me less wheel flop and trail and make the bike a little steadier at speed.
Seat height is 450mm and bottom bracket height is 600. Seat back angle is 45 degrees, I find anything less gives me a sore neck.

I've found this bike incredibly comfortable, my weight is spread out evenly over seat back and seat proper, the bars come easily to hand and as there is no pressure on my wrists/arms longish rides are easily accomplished. Only real problem I have is using the shifters and brakes, the PMR has made me very week in the wrists/hands and I have trouble on occasions. I think I might have to send off for the new cycle parts a little sooner than I anticipated and install them on this bike in the interim.

 

Very nice but I can't image that seat being comfortable like you mentioned. Is there additional padding that goes on the seat?

 

Seat comfort.

No the seat has no padding. I've found what makes a seat uncomfortable, for me at least, is where the spine rests against a hard surface. If you look at the picture you'll notice the centre section is cut out so the spins doesn't contact the seat back, also at 45 degrees body weight is evenly distributed between seat back and seat proper. If the seat back angle was less then there would be more weight resting on the back, more upright and more weight would rest on the rear end Either side of the spine is muscle, put simply muscle is a very good natural padding material, so for me I find it very comfortable. In my trike post you'll notice the seat back is in two distinct parts, bent to fold around the body with a little lumbar support. I used this seat for around 10 years and although my rides have never been long at around 25-30klm not once in the 10 years I used it did I get a sore back or suffer chaffing. If it ain't broke, why fix it. Eventually when I get around to building a new bike with new parts I'll probably follow the same seat design - when your on a good thing?
PMR, yep that's it, a real PITA. Unfortunately rather than the normal areas I suffer it in the wrists, forearms,elbows, upper arms and shoulders as well as the more usual neck area. Probably as a result of an infection I got after an elbow arthroscopy.
As for measuring once and cutting twice; well. I'm a diabetic so when I'm in a building frenzy I tend to not notice my BGL when it gets low, confusion sets in and I tend to make mistakes, and of course my favourite excuse - I'm old.

 

Intermediate cluster detail.

The intermediate cluster is a freewheel 5 speed cluster, I used the freewheel cluster because they thread straight onto a bottom bracket bearing cup (no idea what thread cassettes have).

The cog closest to the frame is a 20 toother, outboard of that is a 26 toother and the chain is moved between these two cogs via a front derailleur in the same fashion as a normal derailleur on the crankset. These two sprockets drive the rear wheel. You’ll notice another mistake here, I welded the derailleur mount too far away from the cluster which made gear changes difficult so I added an extension.

Outboard of the 26 toother is a 24 then a 20 and then a 14, these are driven by the front crankset. The 24 is really only a spacer to keep the drive and driven chains from clashing. It can be used but only as long as the drive chain is on the inboard 20 toother; realistically though, I just can’t pedal that fast.

The front drive chain normally stays on the 14 tooth sprocket and intermediate gear shifts are done via the inboard 20/26 toothed cogs. If I need a crawler gear I can move the chain manually to the outboard driven 20 tooth cog but again you have to pedal awfully fast.

Top gear is very tall and only useful on a long flat roads, Bottom gear (using the 14 tooth intermediate driven sprocket) is low enough to get me up all the hills I’ve encountered and there are plenty around where I live! Not a wide spread of gears but the bikes/trikes were made on the cheap with what I had in my workshop - next one will be a little different to that: Deore and Tiagra cycle parts, indexed thumb shifters (deore and Tiagra) and BB7 mechanical discs mounted on Deore hubs laced to 20” front and either 27.5 or 29 rear rim (yet to work out ratios).

I‘ve no idea how commercially available recumbents with 20” wheels handle gearing (presumably internal hub gears) but the cycle parts I used were what I had to hand and as it turned out have worked very well. In truth I’ve never even seen a recumbent bike or trike except for pictures on the web, and of course mine, so I had to be creative in the design/building process.

Hope my description makes sense, if not two pictures must be worth at least two thousand words!

 

How many usable gears do you get with the intermediary setup?