Building a Quadricycle...

[irw]

Right- First off, apologies for not updating over the past few months, I haven't actually done that much work on the quad mainly due to the day job and trying to plan my wedding.

Anyway, Here are the latest updates & photos!

Bottom Bracket Initial Design (friction hold in within the frame)

The amended design, as implemented on the stoker's side, uses a wider hole and a slightly larger gauge of aluminium tubing to help provide space to bolt it in place. Photos to follow. I think, once the quad is in a fit shape to ride a few miles, I'll pop along to a local welding shop and get them to weld the BB's into place in the rectangular tubing, as this is the one area of the quad where I am struggling to get things nice and snug and immovable.

The Seats

Currently each seat is made up of a welded steel right angle frame (salvaged from a piece of scenery that was being chucked at work) with a couple of sheets of 18mm ply attached and some thick foam to save a sore bum. In their current guise, these seats probably add about 5-10Kg each onto the weight of the bike, so I'm looking for ideas to reduce this. Probably in the form of proper recumbent bike seats!

Gears

I have gone for the axel-mounted style rear derailleurs, quite simply because it's really obvious where they need to go, although because of the angle they sit at, removal of the derailleur(s) is required to take the rear wheel(s) off. Pictured here (pilot side) prior to the chain being run through. I haven't got as far as front derailleurs yet, mainly because of the slight movement that still exists in the BB's. Since I took this photo, I've actually drilled out a bit more so that the rear wheels sit higher up in the metal now, to help with the chain path, so to fit the derailleur on, I've had to angle grind off the tip of the curvy section at the top of it.

Steering
Pictured below is an experiment which took place whilst trying to work out the steering linkage, from the shaft to the wheels. I'll follow up in the next few days with how the final linkage looks.

Because of how the steering column aligns almost exactly with the front right wheel, I couldn't use the same design found on a number of other quadricycle models I have come across in my research. It took a bit of thinking outside the box, and a bit of good old Technic Lego to come up with the final design.

And here's another picture of the steering column prior to handlerbars being fitted:

Brakes

No Photos as of yet, but rear brakes have been fitted to both rear wheels. I intend to get hold of some dual-pull brake levers so that both rear brakes can be operated on one lever, and both front brakes on another lever.

Testing

Well I'd been waiting for this moment for a long time- I finally got a second set of brakes fitted once I found out that the LBS round the corner from me stocked 3m brake cables, and I set out across the road to Morisson's car park (after closing time, so it was deserted).

This is the most compehensive testing so far, everything else has just been out of the garage and up and down my small driveway.

It Works!!!!

Is that the recumbent smile I've read so much about on these forums?!

My tests today have shown that I seem to have got the Ackermann geometry pretty much spot on (well, at least, when I realised yesterday that I was reading Peter Eland's spreadsheets upside down it is now spot on! ) and the quad's turning circle is about 5m[sup]2[/sup] for a full 360 (although this should only be attempted at low speeds as I found out when I nearly tipped myself!)

The second attempt to get into the car park (On the first, the chain came off the front chain ring due to BB movement so I had to take a quick left turn off the round about!):
[media]

[media]http://www.youtube.com/watch?v=hFAc4bLZXCQ[/media]]View: http://www.youtube.com/watch?v=lGKcBidqDvY[/media][media]http://www.youtube.com/watch?v=hFAc4bLZXCQ[/media]


Now I was having so much fun I got a bit carried away, and on returning home, forgot I was still on a test ride, and took the turn into my driveway a little on the fast and sharp side, and managed to bend the rear wheel out of shape . Yes, I know, you told me so!

So, can anybody recommend a couple of sturdy rear wheels which take a standard cassette, and where to buy them? Should I be thinking something along the lines of this? (although one of the FAQ's on that says it does not accept a cassette)

 

[irw]

It would appear that I can't post more than two youtube videos in one post, so here's a few more of the testing!

Trying a high-speed sharp turn:
[media]

]View: http://www.youtube.com/watch?v=WDaMzpnxZxo[/media]


And trying the brakes out:

[media]

]View: http://www.youtube.com/watch?v=_CpgEH62Ods[/media]


Like I say, if anyone knows where I can buy some suitably strong rear wheels, please let me know, as I can't do any more testing until I replace the one I broke!

 

[bikepete]

Nice work! Glad my steering spreadsheets were useful...

Re seats: might be worth a look at the bottom of this page:

http://www.zephyr.nl...p?pagina=winkel

also

http://www.zephyr.nl...agina=zittingen

If you can bend plywood something similar might be possible - otherwise just 33 Euros for an untrimmed seat. Needs some supporting hardware too of course.

Re wheels: I would probably have recommended 20" (BMX) ones if starting from scratch - these come as strong as you want, even up to 48 spokes, for not silly money. Usually just single speed though if you get BMX ones, so you'd need another gearing solution. You can get 20" wheels with cassette hubs too (for folding bikes, recumbents etc) but usually not cheap nor usually as strong...

Looks like you could fit 20"-ers in your chassis without probs - would lower it too which would improve stability...

If you're sticking to 26" I'm not sure there's an affordable extra strong solution if you stick to cassette type hubs - they're so strongly dished that lateral strength is low almost irrespective of spoke count and rim strength. You could possibly get stronger wheels by using singlespeed hubs i.e. no dish - but this is unlikely to be particularly cheap either.

 

[bikepete]

BTW, whereabouts in the country are you? If there's a bike recycling operation within striking distance they would be an ideal source of cheap wheels etc for experimenting.

EDIT - looking your profile it's Lichfield, which appears to be 30-odd miles from Leicester. which means DOWN TOOLS NOW and get ye to Cyclemagic!

http://cyclemagic.org.uk/

http://www.velovision.co.uk/cgi-bin/show_comments.pl?storynum=932

Hilldodger on this forum is one of the people who run it.

 

[irw]

BTW, whereabouts in the country are you? If there's a bike recycling operation within striking distance they would be an ideal source of cheap wheels etc for experimenting.

EDIT - looking your profile it's Lichfield, which appears to be 30-odd miles from Leicester. which means DOWN TOOLS NOW and get ye to Cyclemagic!

http://cyclemagic.org.uk/

http://www.velovisio...pl?storynum=932

Hilldodger on this forum is one of the people who run it.

Thanks for the tips Pete, It's actually on 20" wheels at the moment!

Ian

 

[irw]

Thanks for the tips Pete, It's actually on 20" wheels at the moment!

Ian

D'oh...It would appear I have made a schoolboy error and thought I was using 20" wheels as that is what the rims are. I went to Halfords today to buy one of the BMX wheels that I linked to above and turns out I actually had 24" wheels. (To be fair, the ebay auctions in which I won the original donor bikes had them listed as 20" wheels.)

Anyway, all is not lost as the cassettes from the original donor bikes will go on the BMX wheels, I just need to adjust the positions of the rear wheel suports slightly to sort out alignment.

I've also had a think about the seat situation, after looking at the links that Pete supplied, and it just so happens that work want to get rid of some old conference chairs (formed plywood!).

I think this has to be one of the more interestingly shaped things I've ever had on my rack! (The new wheel can be seen attached to the side of the rack!)

 

[irw]

Right- I actually finished the Quadricycle back in October, but now that I have my wedding and our theatre's big annual show out of the way, and I've got some time off, here are the photos documenting the last few months of the build!

Continuing where we left off:

01/08/2010

The new formed-plywood ex-conference room chairs, mounted, with pre-drilled locating holes, giving a fore-aft movement of about 8":

Close up of the rear-right brake set, now moved to align with the new 20", 48 spoke BMX wheels:

Bottom Bracket Mark II:

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23/08/2010
An overall shot of the quad, now with both sets of handlebars attached, and with both bottom bracket mounts converted to BB MkII:

You can just about make out an elasticated carbon-fibre tent pole that is wedged into the front wheel arch, and the rear wheel support, this was just there whilst I was musing about a fairing shape! During test rides around about this time, we discovered that BB mount MkII was just as unsuitable as Mk I, so a Mark III was called for!

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31/08/2010

A bit of angle-grinding later, and here is Bottom Bracket Mark III:

This modification on the bottom bracket mount proved absolutely rock solid! The wheels on the donor bikes may have been white-elephants, but a lot of other bits are coming in useful!

New chain-pulleys to get the chain-line in order!

After a test ride with the pulleys like this, the forward of the two (on the right) was raised up and mounted directly to the level of the 1" square steel spacer bar to get the chain running a bit straighter, and lower the forces acting on the mount. The original idea behind having it as low as possible was so that the seats could be set further forward, but in practice, the seats should never have to go far forward enough to interfere with the chain as it is now.

First tester-coat of paint on the frame:

It was around this time that the then soon-to-be-Mrs. IRW started thinking seriously about using the quadricycle as our wedding transportation, we had been joking about it for a while, but were not sure how the build would go, so I stepped up a few gears to get it finished in time for the big day on the 22nd of October.

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06/09/2010

The painting coming along nicely:

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19/09/2010

And a little bit more:

The steering linkage/handlebars has been sprayed in gloss black Hammerite, with the frame in blue Hammerite.

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19/09/2010

With the paint-job pretty much complete, and all integral parts re-assembled, I took the quadricycle the one mile trip into work so I could weigh it on the counterweight flying system:

At this point, it weighed approximately 65Kg

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14/10/2010

With the wedding fast approaching, and the soon-to-be Mrs. IRW away at her parent's house in Bristol, I took the opportunity to build a special 'wedding carriage' seat:

I knew it was worth keeping the frames from those conference room chairs, and that bit of set that provided the original seats! In the above picture you can just about see the padded faux-leather covers I salvaged from some skipped office chairs that I have attached to the ply wood seats.

Here is the passenger seat with it's wooden base in position:

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17/10/2010

Here you can see the quad sitting on my drive-way, with the passenger seat padded and covered in a similar material to the seats:

You can also see the new mud-guards that I whizzed up as a means of wedding-dress-proofing the passenger seat!

Carol testing her seat!:

You can also see the front lights mounted on each front wheel arch in the above photo. There are two matching rear lights on the back.

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22/10/2010

The big day arrived, and the best man got to my house to find me still tinkering in the garage!

Myself(left) and Steve, my best-man cycling the quad to the church:

And with Carol on the back, going from the church, via Freedom Cycles (the brilliant & helpful LBS where I bought most of the new parts) to the reception venue!

And finally, me locking it up outside the reception venue!

And that's it for now! Carol and I have been out a few times over winter, mainly just to work and back. I'm waiting for some nicer weather to go further afield!

Ian

 

[mickle]

Brilliant!

 

[Keith Oates]

Says it all Mickle!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[germanicdogman]

that is fantastic

 

[Arch]

Wow. I missed this thread somehow, and when I read the first posts I thought, oh, he'll never do it, then I realised it was an old thread, and saw the progress.

Just fabulous!

And especially fabulous that the new Mrs irw was happy to use it for the wedding. There's a marriage that's going to last!

Well done, and congratulations!

 

[irw]

Thanks for the positive comments everyone!

Arch, you may have missed it because up until yesterday it was in the 'Know How' section.

Obviously now it's come a bit further than 'How should I build this?', so I asked the mods to move it to here!

 

[Night Train]

What a fantastic build. I also missed it and I began reading thinking it was January this year. Doh!

Have you seen this blog? Quadracycling in Ottawa.
I found it very inspirational but they seem to have stopped writing now that they have 'his and hers' Catrikes.

 

[irw]

What a fantastic build. I also missed it and I began reading thinking it was January this year. Doh!

Have you seen this blog? Quadracycling in Ottawa.
I found it very inspirational but they seem to have stopped writing now that they have 'his and hers' Catrikes.

Thanks NT, I have seen their blog, I've got it bookmarked in fact!

 

[irw]

Well its been a good while since I last had reason to get the quad out, and that's partly due to moving jobs/house in April- I just don't know the local area well enough to feel confident with it round here yet!

However, now that I'm settled in here, and with Leicester Skyride looming on the 28th of August, I've cleared some room around it in the garage and am making some adjustments to make the quad a little more 'user friendly'.

Since it was completed, the seats have been awkward to adjust, requiring the use of two spanners to undo the nylock nuts and bolts that held them to the seat beams, and also requiring the use of a squeezy clamp to hold the inside edge down to the central beam. After a day or so of thinking, I got the angle-grinder out today, and have started cutting some 'slots' that match the bolting positions on the seats so that seats can be slid into position after loosening off the new wingnuts and spring washers that will hold them still.

In this photo, you can see the new driverside rear slot, towards the right hand side of the picture, you can see the old holes that would have held the front of the seat down. There is now a slot here as well, and also one in the central beam (You can just see the inner rear seat bracket of the stoker seat up centre).
You can also see in this picture what made me adjust the chainline to how it is in the wedding pictures! I've still got the bracket on as I'm going to straighten it out, pop another pulley on it and use it as a pickup to take some of the sag out of the return run of the chain.

More updates to follow!

Ian