Prototype hack together surprise

J

jonrev

After some time with a delta trike I completed last year I decided a trike was really not ideal for my location. I think it was as much my own attitude of 'being in the way' of other traffic that made me uneasy but whatever, I decided I wasn't comfortable taking up so much of the width of the narrow lanes while traveling so slowly. I felt I was being a nuisance to local traffic! I felt guilty! I felt uncomfortable! I also wasn't brave enough to take to the faster main roads where large and fast vehicles are always in a hurry and I would feel like roadkill waiting to happen.

I decided I would have to resort to a two wheeled bike again. I got out my old Coventry Eagle mountain bike and fitted a little 250watt front wheel hub motor and went for a ride. I actually enjoyed it to my surprise but my backside didn't so much. I had a massive saddle which came with a bunch of bike stuff I bought a while ago and the extra padding helped a lot. Things were looking up and I started thinking about other ways to improve comfort.

The obvious way was to go for a more recumbent riding position so I sketched out a rough shape for a semi-recumbent bike to build. I hadn't ridden or even seen one before so I decided to use much of my delta trike parts and steel to mock up a ridable testbed so I could finalise the design before spending too much effort building the final bike.

Two weeks later I had what looked like a monstrosity taking up a good part of my workshop. Made from a hotch potch of bits and pieces glued together very roughly into a shape which seemed to fit me- more or less. I didn't really want to be seen actually attempting to ride the thing- that's how horrid it looked. So I decided to give it a very quick coat of paint so at least it looked slightly less awful. I found a part tin of silver hammerite and splashed it on. The paint ran and dripped and it looked even worse. I then found a part tin of some Lidl metal paint in a greeny colour and spalshed on a coat of that on top. The green separated on top of the silver and left large blotches of semi-hammer effect. It now looked like a bad attempt at a camouflage effect. I stood back for another look then stood back some more and decided it was...........interesting!!

A few tweeks, manually find a gear ratio that felt about right (no shifters fitted), a couple of chain guides and an ill-fitting front brake and it was ready to go.

And I really rather like it. Of course it's not usable but it feels quite good and stable to ride. Seat back position is wrong and so are handlebars which I need to swap over to a remote rather than tiller style. I haven't decided if I should actually put more work into this one or start the next but either way I am happy that I will be able to have a bike I can actually ride without too much discomfort and feel fairly safe on both lanes and main roads. A small triumph?

John
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Well I decided the monster was not worth too much more energy or time so I started a replacement using a couple of frames I had about. I wanted full suspension as my local lanes are pretty poor and my delta showed me just how nice a suspended bike can feel. Front is obviously no problem and I have a selection of forks to choose from. Rear is a bit more awkward.

The front half of the bike will be a sturdy frame from my collection which appears to be a slightly lengthened variety. Not sure what this style is called but seems to be a version of a cargo bike of some kind. I am using a rear triangle from another cheapo steel bike for the suspended rear section. I've left the bottom bracket in place and made a pair of suitable brackets welded to the rear horizontal chainstays of the front bike. The pedal axle of the rear bike will fit between these and become the rear suspension pivot. This seems to work nicely so I've welded a few strengthening pieces to beef up the front bike rear section to add stiffness before I cut away the excess frame sections. Problem will probably be the chain line clearance but it's a job to see exactly how the chain will run at the moment- we'll see.

My intention at the moment is to cut down the front bike seat tube and make a rack out of tubing from there and over the rear wheel. I should then be able to fit a comfy seat further back and lower to get closer to that semi-recumbent ideal I'm after. Not too low as I like to be high enough to be visible but low enough to get the pedals froward effect and get some of the weight off my 'personal unsprung rear end'.

This may all end in tears but it will be an interesting project and a learning experience. Pics show the beginning of fixing the two bikes together.
I'll put up more pics as things progress.


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A bit more work on the oddity and now I'm not sure how much I like it- or not! It has some good points and overall it's worked out ok but it also has some less likeable bits.

I want full suspension so that made things a bit more difficult to start with. Brad's 'Wildkat' LWB recumbent is far more elegant and easy on the eye but I'm a fat so and so and I also want to be able to carry a reasonable load, plus it will be an E-bike so felt my bike needed to be strong rather than elegant. Some fussy bracing of the rear section was to ensure it won't collapse despite hacking away a fair bit of the original frame to reduce the height of the rear section.

I really think the bottom bracket should be moved forward up the main tube a little way for a more recumbent riding position but will wait till I can do a test ride before making that decision. I am also thinking about welding on a crossbar between steerer tube and seat tube to form a front triangle for added strength plus a place to mount the battery. Another thing is I'm thinking that a 26" front wheel might be better. I've got front suspension forks and an electric front wheel. Drawback could be that I then couldn't move the bottom bracket very far forward as it would probably mean the pedals would be too close to the wheel!

All this makes my brain hurt at times and my brain isn't working as well these days as it is. As example I spent some time adapting the seat with a saddle post so it neatly slid up and down the rear seat tube for height adjustment. I then made up a bracket so it was fixed at the front and stood back to admire my handywork. IDIOT! The saddle was now fixed at the rear to the unsprung section and front to the sprung section Doh!

Ah well the dog enjoys being outside with me and is not a critical companion so we're happy enough. I'll load up more pics as and when.
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A bit more done now and a first test ride. I think everything is about where I want it to be now. The seat is as far back as I can easily put it and it is pretty nice to pedal in this position. I would ideally have placed it further back and lower in relation to the pedals to give a more recumbent position but it does feel quite good as it is. For the short ride I took it all seemed to work well and the saddle was nice and comfy.

I still find the tiller steering very strange though. All is fine till you need to turn fairly sharply such as when doing a U turn in the road when everything feels most unnatural. A bit like riding an upright trike where you feel the bike wants to go in a different direction to the rider. I dare say, like riding an upwrong, it will feel better with practice??? If not I can always change to remote steering but I'd prefer not to as It will add complication and probably take up some real estate that I'd rather keep clear for a mount for the battery pack.

I strapped a battery on the crossbar for a trial run. I actually hooked up both the PAS and brake cut-offs for the first time on this setup. I hadn't used either on an ebike before and was quite impressed. On maximum assist I was holding 27-29 KPH for both runs along my lane with steady but not exhausting pedaling. This is exactly what I need for now so I can get the exercise I need without risk of a coronary and still eat up the distance for a worthwhile ride.

More refining and fiddling ahead but so far so good...ish.

John
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I really didn't like the tiller at all. anything but a straight line just felt horrible. I still think I could have grown to feel more at home with it but in the end I set about fitting remote steering.

I had a headtube unit from something in the 'stash' which was really lightweight and clearly not intended for bike front forks. Very thin tubing and welded to a piece of equally thin box section. Almost a perfect fit as it was and strong enough for my needs so I welded it just in front of the top of the seat tube of the front frame. This seems to put it in a fairly good position and feels pretty good and way more natural to use than the tiller. It also doesn't take up much room so, if necessary, I could still sit a battery on the crossbar. I am now making a new battery which will slot in to the space below the crossbar filling that empty space and will be nicely out of the way.

I haven't fitted a front deraileur and don't think I will. Apart from the fact that it will be a bit difficult to mount to this particular frame (at least for me it will) and I don't think I actually need the extra gears. Norfolk is pretty flat with the only slope worthy of the name 'hill' is some way the other side of Kings Lynn to me near the Sandringham estate. I can think of no reason I would want to head in that direction at the moment so am not in need of a vast range of gears. Once I get to use the bike regularly I will decide where I want the chain to run on the rear gear cluster and jut put it in place by hand. Then I can use the front three ratios. To be honest I don't have a lot of experience with these mechanisms and it takes me forever setting up a reliable change on just the one set.

This bike is intended only for local pottering and runs to the local coop store for provisions when needed. If in the future I decide I'd like to be more adventurous I'll build something with 'longer legs' perhaps.

As an aside S...., my local Evri parcel delivery lady (who is a real gem), asked me if I had a bike for sale that would suit her. She has a sister who has just got herself a bike and they wanted to do a little cycling together. Now S.... is disabled with some sort of muscular distrophe type
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weakness and struggles a little even doing the parcel deliveries so I was a little sceptical that she'd manage a bike easily. Since I didn't have a ladies framed bike anyway I asked if she wanted to try the upright trike which I would happily give her for nothing if it would work for her. She was delighted and asked if she could try it up the road. I explained that it felt really odd till you got used to it and she'd need to practice. She climbed aboard and managed one turn of the pedals before veering across the lane and into the field. She decided she didn't want it! I told her she could sell it and buy herself a standard bike with the money but she didn't commit and hasn't been here to deliver since. Ah well if she doesn't want it when I see her next I'll put it up on Ebay.

Sorry pics and text are a bit disjointed but I can't seem to reposition the text/pics.

John
 
Very nice!
Let me know when you consider this to be "done", and I will snag a few photos to try out the new Builder's Showcase forum. I am going to do this manually as the last gallery almost took down the site due to its size. Just going to randomly find finished rides to post, or do it by request.

Cheers,
Brad
 
Hi Brad. Not sure when any of my builds are actually 'done' as I never seem to be completely happy with what I have. I either want to do alterations or just start again. I guess that's the same for most of us on here- the fun is as much the building as the using. Once the battery is done I'll be doing more riding and decide if more fettling is on the cards. I keep looking at the bottom bracket and thinking about moving it up and forward into the little triangular space or maybe mount it further forward under the downtube. I need a few miles of riding to decide which is difficult right now as my confused senior citizen dog gets really panicky if he doesn't know where I am.

BTW I think I'll go for your plans offer as I still regularly refer to the plans I have and to your BBBonanza book for reference when I'm building and it will be a good way to support the site in the absence of a 'donations' system.

John
 
Finally got the battery built and boxed. I made it so it's a good snug fit in the frame. It has a pair of brackets fixed at one side and a pair held on with bolts into rivnuts on the other. Nice and firmly held but two minutes to remove with an allen key. Other little bits done and now sitting waiting til I can get away long enough for a proper trial run.

Pulled out another bike I'd been working on a while back and got that one finished pretty much. It's a standard frame except for an added crossbar and alterations to move the saddle rearwards a little. Battery is one I bought recently but it won't fit in any nice tucked away places so it has had to become a 'feature'. It sits on top of the crossbar and butts against an upright addition to it. The pack is designed to be strapped in place with the supplied velcro webbing straps and works nicely.
First impressions on the 100yds or so up the lane and back is that it's rather nice to ride. The hub motor wheel is a 700c so I had to buy a tyre for it since I had no tyres of that size. It's still only 250watts but feels really good and is almost silent.

Now I'm really looking forward to putting both bikes through their paces.

John

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Been a bit difficult getting time to concentrate on bikes for a while. Things have happened and Ben has had problems so time has been short but have managed a few hours on and off. I haven't been able to get more than 100 meters or so from the house so really not been able to get much of an idea how the long bike actually performs but I decided I'd try positioning the pedals further forward. I wanted to be able to revert to the original position if the move didn't work well so I left the original BB in place and welded a second one as far forward and as high as I could easily get it.

As in the pics it is about as far as I dare place it without major surgery. Just enough clearance between foot and front wheel. I thought I'd need to move the saddle forward but so far I've tried it 'as is' and can manage well enough. I can actually lean against the seat back while pedaling now which feels nice. Legs are extended as far as I feel comfortable but again I haven't been able to ride far enough to make a final judgement. No great problem if I decide to move the seat once I've ridden a bit more.

I'm now in the process of changing the top chain guide roller and probably adding another to take up slack in the chain return path. The extra length does tend to make the chain droop more and I think extra support will make it less likely the chain will jump off a sprocket.

Overall I am really liking this odd bike of mine. Each 2 minute run up the lane and back brings a smile to my face. The electric power works like a charm and on a sunny day like today it's a real treat to be effortlessly gliding along at 20mph just gently pedaling. Reminds me of my teen years and my BSA Bantam except there's no noisy engine buzzing away and no vibration at all- just bliss!


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I needed another project to keep me busy and also had the Lifepo4 battery pack I made a while back which didn't fit into either frame I currently had. So I made another frame specifically to house the Lifepo4 pack and built around it.

I wanted to make it as simple and unfussy as I could so in true Brad style used box section steel and as far as possible used the simplest structure I could come up with which was strong and would house the battery plus allow full suspension. It is a pretty utilitarian thing but I quite like it.

As usual things became a bit more complex once I started adding necessary steering etc but still not too bad. Dimensions are much like the last one and pedaling position is nice and relaxed. It will use another 20" powered front wheel and I'll use the PAS and brake cutouts as on the last one.

One difference is that I decided to use a geared hub rather than deraileur gears which I don't get along with too well. I've been looking out for a 26" wheel with an IGH fitted on Ebay but have found nothing yet and I have never laced a wheel before. I know of no Bike workshop near enough to get to and back in a time my old dog could be expected to wait without going into panic mode.
Then I found a local chap on my Freecycle who had two 26" bikes to give away which both had SA three speed hubs. A quick dash and I had two usable IGH wheels plus lots of other bits to play with. It would have been nice to find a wheel with more gears but three is enough for my terrain and my cycling style for now.

I got the bike to a rideable state today and took it for a quick dash up the lane. I had previously decided the oversized saddle would need to be replaced with a more comfy seat but it actually felt pretty comfortable so will leave it til I can give it a better tryout. Riding position also feels just about right so it's now ready to have the electrics installed.

So a third bike I can't really try out properly at the moment!!

I think my next project will be a similar style but with 'a hub motor as a non hub motor' using an intermediate layshaft . I have a 500w hub motor from a 26" wheel going spare and will probably build something around that. Something to get my teeth into and stop me going stir crazy :) My biggest problem now is that my workshop is getting really crowded with bikes and bits and tools. The trike and various bits have now gone out to the rear lean-to and the greenhouse is also used as a shed and cat home. So far I have resisted the temptation to use any part of the house for storage?

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Nice looking bike and a useful to boot !

On a SA 3 speed some of the input sprockets are dished , this means you can put 2 on together and using a rear mech give it a 2 speed into the SA hub if you are in need of some gear range ?

Paul
 
Thanks Paul that's useful to know. Right now I don't think I need more gears than the 3 the SA hub has. All my lanes are pretty flat and no hills in my area to worry about. Only thing I'm thinking is that I might run out of leg speed at full tilt. It was pretty close with the deraileur setup on the last bike but I was using the second largest gear on the front set so still had some leeway there.

As I said I can't really go for a long enough run to try out the bikes properly at the moment. A 100yd dash really isn't far enough to give a proper feel for how it's all performing. I don't know how long Ben has left but he still loves being outside wth me atm so I'll just have to keep building and leave the testing till later.

John
 
I had to go to see my GP today. Seven and a half miles and although I usually take the car so I get here and back asap Ben had spent most of the morning asleep so I decided to go by bike to give the latest iteration of my semi-recumbent a tryout.

Conclusion is that it's pretty darned good. The saddle is really quite comfy and pedaling position is just right once I get going. Starting off is a wee bit wobbly as I find it a little hard getting my second foot on the pedal without looking down to position it. It's certainly not as natural as with a standard frame bike and once or twice I pedaled off with my right leg and then missed the left pedal completely and ended up pretty much at a stop before getting sorted at which point the bike was wobbling all over the place till I got some momentum going again. Add to that is the fact that first gear is too high and needs a real shove for the first few turns of the pedals up to walking pace before I can relax and pedal comfortably. If I use the electric power after that first shove there is no problem but I really would like to be able to use just pedal power if I want to.

No doubt finding the second pedal will come with practice but the high gearing is a problem I would like to sort out. Pulling out of a junction which has a slope up to the road was a bit scary and only the fact that the bike was powered up and I stabbed at the throttle when I lost that second pedal saved me a very embarrassing topple in the middle of the road.

At the other end of the scale third gear is just right and at 28-30 kph it's a perfect cadence for me to assist and excercise my legs.

The second of the IGH hubbed bikes has a larger sprocket on the rear wheel so I could swap it over and try that one. It is quite a bit larger (I haven't counted the teeth yet) so my worry is it may spoil that third gear ratio. I also have a few smaller front sprockets I could use to reduce the ratio so I will check them too.

I like the idea Paul suggested about using two sprockets on the hub and using a dreaileur. Not sure how practical it might be especially since the originals are the thicker ones which use the wider chain. I'm not sure this chain would work with a standard deraileur would it? Conversley the alternative front sprockets are the narrow type for deraileurs- would the wider chain be happy running on these? Any suggestions would be welcome.

Overall I am pleased as punch with this bike and really enjoyed my ride today. Ben was awake and yelping when I got home and left me with a fair bit of 'clearing up' to do but he was ok as soon as I appeared and we spent the rest of the afternoon in the workshop as usual. Plenty to do and lots of projects to keep me busy.
 
Just for information I replaced the front sprocket (46 tooth) with a slightly smaller one (42 tooth) and it has made a noticeable difference to my wobbly starts. Top speed pedaling is still manageable and probably helps me to give worthwhile assist to the motor. The setup actually seems to top out at a smidge under 30kph. No problem getting to 29.8kph but need lots of help to rise above that speed. No problem for me as that's plenty fast enough and only likely to be used on long straight bits of road.

The front sprocket I had is actually part of a cluster from a defunct bike so is of the narrow variety. The chain seems to run ok on it and showed no signs of being unhappy but does seem to be a little bit more noisy. A fair bit of clicking seemed to be evident but to be fair I was listening hard for any sign of problems so maybe being picky about something I would not have noticed otherwise. Is it deemed acceptable to run a narrow sprocket with a wide chain?

Made a stupid booboo on the short test ride today. I had fitted a very poor rear view mirror as a temporary measure so I can see what's about to hit me up the backside as I veer around across the road looking and listening for problems. I seem to remember many moons ago I could actually turn my head around far enough to look behind me but not now. If I really try hard I can catch a quick glimpse but sort of sideways and not though the lenses of my glasses so not well enough to be sure nothing is after me. Anyway this hopeless mirror seemed to not line up to give me a rear view so I stopped and spent some time fiddling and pushing it about till I forced it into a position where I could see. Set off again and the motor would not cut in at all either with PAS or the throttle. Cursed the Chinese for making such crap and pedaled back to the workshop. Spent a while pulling all the wiring out of the controller box and checking all the joints and reseating all the plugs- no joy. Decided I had a blown box or motor and was about to dismatle it all when I noticed the right hand brake lever was being partially pulled on by the mirror where I'd forced it over. Not enough to apply any braking but just enough to kill the motor power (as it's supposed to) Doh!

I'm thinking now that I will dismantle Semi-recumbent Mk2. I really haven't got room to store any more bikes (luckily the upright trike sold on ebay last week so that's given me the rear patio area back). This new bike is much more pleasing to the eye and nice to ride so it's a keeper. I also have the lightly modded frame and my old Coventry Victor conversions so space is at a premium. I'd sell the Coventry but I doubt I'd get enough to cover the motor conversion and battery pack so will try to hang onto it for now. Can't decide exactly what to start on next. I just wish I felt happier riding a trike round here but I know it just wouldn't get used as I don't feel comfortable on these roads so I'm looking and planning again and thinking mid drive but not sure yet.
 
Jonrev

This explains how to get 2 gears on a SA hub , although don't watch if you are feeling sleepy !


The different chain types are 3/8th and 1/2" [ this being single speed ] this is the horizontal gap between the rollers.

Most cheap chains you can buy claim to be up to 8 speed as that is the largest screw on cassette made.

You don't need expensive stuff I have ridden 1000's miles on kids SIS rear mechs and they perform great , oh and friction shifting is also bullet proof [ helps I can see the cassette from the driving seat ! ]

9 - 10 - 11 - 12 speed all require ALL the components to made for that speed or greater so we get into expensive parts for no real gain ?

A general purpose 7 speed is usually 14t - 28t , a 10 speed 14t - 28t just has more gears between low and high but no more range.

Paul
 
Hi Jim,
That's a nice clean frame build much like Brad's Wildcat LWB. Lightweight as well compared to my efforts. My problem is that I want full suspension to help cope with my local lanes. Badly potholed and cracked where farm traffic is constantly moving about and badly repaired with a few splodges of tarmac plonked on the worst holes. Add to that the desire for electric assist and my tendancy to overbuild and I end up with a pretty weighty frame.


My other hangup is that I don't want to be too low compared to other traffic. I like to see and be seen so seating position is higher than ideal for a full recumbent. At this height I'd need the pedals to be way up high and I'd be bit top heavy- (I have a very slight personal weight excess!!). Still I have a bike which is pretty similar to the Wild cat riding position now.
Overall I am pleased with my latest bike as I managed to simplify it so very little extra bracing was needed and it turned out pretty 'clean' and not too heavy.

Did you go on to build more bikes? Do you have pics and descriptions you can share?

Paul,
Thank you for the vid. I managed to stay alert all the way through. Wasn't sure which of us would fall asleep first- me or him! I did learn things I didn't know and good to see the double sprocket conversion actually being done.

My limited previous experience with deraileur equipped bikes when I was a young'en was using the friction type changer which I always found simple and easy to get working. These modern indexing types give me more trouble. I think my big mistake was that I dismantled several bikes and added the bits to the parts collection I bought a while back. All deraileur stuff was lumped in together with no attempt to keep bits matched. Now I have problems getting a rear cluster, front cluster, rear hanger unit, front hanger unit and handlebar changers to work together.

I will look out a pair of those dished SA sprockets and see how I go.
Thanks again
 
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