The Ratrike Thread

[Night Train]

I don't think I have done a thread on the Ratrike, the build has been dotted about on other threads so I thought I would bring everything together and include the current modifications.

The Ratrike started off life as a KMX with a broken back and much wear and tear.

The first job was to strip it and repair the broken back. I took some measurements of the wheelbase as it stood and worked from there.
My steel stock in my workshop is considerably heavier duty then trike material and so I paid a visit to the scrap yard. The thinest wall thickness tube I could find was a post from a child's bunk bed. Only snag was that it was 2" round and the KMX was 50mm square.

No problem, use just the Land Rover no1 special tool and bash the round to square.
Then I welded the tube in place.

Now normally bike and trike frames would be brazed, mig or tig welded. I only had an arc welder with 3.2mm rods more suited to 6mm plate, still, what could go wrong?

The frame had a very slight twist after welding so a big lever and a strong bench vice sorted that out.

The rest of the trike was reassembled with new cables but the same old chain. The chain had a couple of twisted links which were removed. The deraileur was missing a wheel but my spares box yielded one that was a close enough fit. I could only find one bolt in my scraps bin that fitted but it was, and still is, 60mm long. I will cut off the excess one day.

It the sat for a year or so while I pondered how to set up the brake calipers.

I then had to offer of a ride out with Arch and so I set about preparing the Ratrike for the road. I figured the brakes and got them working. The back one had a stripped thread in the clamp so the cable inner was slipping. An easy fix with an electrical connector block to anchor the cable.

I needed lights and a flag and mudguards.
Another visit to the scrap yard produced a cheap 'Argos' type telescopic clothes rack.
That gave me a telescopic flagpole, a place to mount lights and a coat hook!

For the mudguards I found some off cuts of hardboard which I glue laminated together using the front wheels as a mould.

I added a backing board to give a mounting point and then cut up the scraps of the KMX backbone to make the supports.

That meant the kingpin bolts on the steering was too short. I replaced them with some M10 studding and nylock nuts top and bottom.

I then met up with Arch to do a run but still needed a flag. I had an ancient cycling tabard which I took with me and, after fixing Arch's hand cranked Singer sewing machine, I converted the tabard into a flag.

We then did a ride across the Solar System with the obligatory cake stop.

So now I have a working trike I started to build a trailer, there is a thread on that one so I won't go into it here.

Today I decided to get a few more bits done.
First a front light mount. I needed to replicate a handlebar mount just above the BB and with a bit of digging about the scraps bin I found a metal leg bracket from a cupboard which I cut up and bolted to the BB stem.

I also fitted a bike computer and a bell. The bell was easy, I put it on the left grip so it can be flicked by thumb or finger while riding. The computer was a bit more fiddly.
I decided to mount it on the left side mirror stalk. That meant building up the thickness with bit of inner tube until it became bar thickness.

The wire is run inside the grips and then follows the rear brake cable to the back wheel. The cable needed to be extended as it could not be mounted on the front forks as instructed.

Fitting the magnet took a bit of thought, there being no wire spokes to clamp it to. I drilled a small hole in the web of the plastic wheel spoke and fitted the magnet there.

That left a bit of a problem. The instructions require the sensor to be about 3mm from the magnet!
I extended the magnet by bolting a long bolt to the spoke web and then screwing the magnet to the end of it with a lock nut.
The sensor was then fitted to a spare headlight mount clip which was then screwed to the rear fork.

I then fitted a luggage rack to the back. I had the choice of a 20" rack or a 26" rack. The 20" rack wouldn't clear the brake caliper so I bent the stays on the 26" rack to fit.

Next on the list is the rear mudguard. I had borrowed one from my Marin but there is now another bit of hardboard being laminated together in the workshop. At least I will have matching ones front and rear.
And then a tow hitch.

 

[Arch]

Well done on the additional improvements, I look forward to seeing them sometime!

The whole computer thing is impressive, I get frustrated enough trying to get the clearances right on a straightforward set up!

It's all getting very Mad Max!

BTW, if anyone wonders about that pic of the two trikes outside the pub, as far as I know mine isn't expecting the patter of tiny tyres, so they must have behaved themselves.

(And I do like that image on the tabard flag. Very Death Star...)

 

[Night Train]

The Ratrike now has a tow hitch.

I took some inspiration from this one.

http://www.fleettrikes.com/gallery.htm

It is single sided as the rear forks have a brake caliper above on one side and a deraileur below on the other side. That made it difficult to have a symetrical attachment on both sides.

It is made from a leg from one of those stacking tables that used to be in schools. I found one in a skip a few years ago with bent legs and so I had it fo rthe metal.

It is fixed underneath the fork with three rivet nuts and M8 bolts.

The hitch is the Ransomes Vergecutter hitch.

This is the trailer drawbar that fits it. More on that in the trailer thread.

I have fitted the rear mudguard but no photos yet. It and the front ones have been sprayed white as I had a tin of road marking paint lying around and I have run out of matt black and silver.

 

[Night Train]

I finally got the white painted mudguards fitted on again.

It looks like it should have NYPD on the side and flashing lights.

It has the panniers too.

They are the old ones off my Harley and are expandable.

 

[3tyretrackterry]

whats the weight of the whole thing like in comparison to others i built my own trailer using school table square tubing and i have various mods on my trike nothing like yours though. i tend to over engineer so i am curious bearing in mind that if you are using trike for touring then the pre luggage weight may have a bearing on how much stuff you can take

 

[Night Train]

That's a good point.
When I have a moment today I will quickly do a weight check on the wheels and see. I doubt there is much weight saving, even using aluminium on the trailer and hardboard for the mudguards, relative to the whole thing.

 

[Night Train]

I have added rubber 'O' rings to all the moving parts of the hitch both on the trailer and the Ratrike to ease the sloppiness and add some damping as well as keeping grease and water apart.

I also took the chance to weight them.

The trailer weights in at 16kg with the cover.

The Ratrike weighs in at 26.6kg with the panniers on. The rear wheel carries 10.6kg while each front wheel carries 8kg, obviously without me on board.

 

[Night Train]

OK, the panniers weigh a little too much, at 3 kg I can do better, or at least lighter, somehow.

I put my new purchase to use today and fitted the bar ends. They allow the mirrors to move further outboard for trailer towing.
Left side gets computer and bell.

Right side gets....

What's this? Another lever?

I fitted a triple chainring 28/38/48 tooth. It was the biggest I had in the parts box. There was a 4 ring chainwheel but that was only a 46 top and silly small granny ring.
To change gear I tried the 'throw it across' with the chain sleeve but that just resulted in throwing the chain right off, more often then not.

So I pinched the front mech of my hack bike on the basis it never uses the smaller rings anyway and found a friction shifter in the parts box.
The shifter went on the bar end but the three positional adjustment holes gave bad, worse and worserer positions on the bar end. So I drilled a couple of extra holes to move the lever 90deg from the usual range of movement.

The front mech had nowhere to go as the boom doesn't have a mech tube to fit it to, and is aluminium and so I couldn't weld one on.

Well, a bit of oak and a lathe comes in handy sometimes.

The oak mech post is screwed to the light bracket with three wood screws. It has had a coat of furniture wax to keep some of the elements off it.

I then went though my stock of cables and found that I dodn;t have a long enough outer nor inner. I went to Wilkinsons and bought (yes, I had to buy a new bit!) a new inner for 97p and then cobbled together two bits of outer that were the right length together. I used a short bit of plastic pipe cut from a brake bleeding kit to join the two outers together and then a bit of adhesive lined heat shrink over the top to keep it sealed. That gave me a usable cable for the front mech.

So now I have 21 gears.

The rear mech complained a bit at the limits of chain length but I eventually tracked it down to a bent hanger that was also stopping me from getting top gear. With a bit of leverage with a long adjustable spanner all is now well and I have full use of all the rings and all the cogs.

 

[TheDoctor]

That is some highly sophisticated bodgery going on there, mate!!
I particularly like the turned oak front mech mount.
Appalled at the 97p for a new cable though. What's wrong with string?

 

[Night Train]

Appalled at the 97p for a new cable though. What's wrong with string?

Believe me, I did think about it.

I was thinking of a big lever on the boom with a direct connection to the mech and a Land Rover 'red knob' to operate it but I am thinking about weight.

 

[BenM]

I am thinking about weight

If you don't have them all ready, after a few miles of powering your "rat" you will have legs like tree trunks!


I think you should have pursued the direct connection + big lever for the changer and ignored the few extra grams!


I am thinking of adding a couple of extra rings at the front of the Orca... which either requires me to get a new boom or bodge. I am thinking bodge so your mech post is a bit of an inspiration.


Keep on with the photo journal - it is fascinating.


B.

 

[sheddy]

How are the wheel arches made waterproof ?

 

[Night Train]

If you don't have them all ready, after a few miles of powering your "rat" you will have legs like tree trunks!

Cheers.
The extra gears are to prevent needing legs like tree trunks, or even like Spandex's!
I do have strong legs but I need to get used to spinning rather then out and out strength or I will damage my joints.

How are the wheel arches made waterproof ?

Only with paint and water proof glue. The front ones originally had a coat of shellac sanding sealer but now both have a been sprayed.
I'm not expecting them to be properly waterproof just enough to survive each trip at the moment. I'm not much of a wet weather cyclist anyway so it is more to keep the occasional puddle and dog poo from splattering me.




I went to work on the sewing machine again today and made a pair of pannier bags. They are as big as will fit just so that I don't have to scrunch everything into little balls, 16" wide, 6" deep and 18" high when open. The top scrunches up to keep some weather out and stuff will need to be in plastic bags for proper weather proofing.

I took the Ratrike out for a short shake down run earlier this afternoon, only a mile round the block to include a few junctions, left and right turns and hills. I threw a load of tools in the panniers just in case.

The front mech manages to throw the chain right off the big ring but fetches it back on again. Stopped and adjusted that.

Then a bit of chain slap in bottom gear on the granny ring allowed the chain to catch, and lodge, on one of the bolts that holds the headlight bracket on. I had to remove the chain ring to release that. I then milled a domed headed bolt on the lathe to replace it (at home afterwards, not at the side of the road, that would have been too amazing even for me!).

The rear mech doesn't index very well, it hunts up and down some of the adjacent cogs and the detent to hold 1st doesn't anymore. Not sure what to do about that, it could be just too knackered.

The mirrors needed to be folded to be as low as possible to prevent the view being obscured by arm signals.

I think the left side pedal, or more likely the crank arm, is slightly bent.

The front brakes appear to be dragging a little I think.




I then hitched the trailer on and did the run again. I put a few kg of weight in it but it wasn't noticable at all.

Had a friendly wave from another cyclist.

A van driver shouted out "Is that a bike????" and gave me a thumbs up.

A load of secondary school kids pointed and laughed as they walked home from school.

A playground full of primary school kids ran to the fence to calling out "Corrr!, look at that!".



During both runs traffic gave me a very wide berth, which was nice though it could have been in the same way that people move away, as you approach them at a party, and then pretend to be busy doing something else.

I have put it all away for now as I will have to get some rest before an evening at the theatre set building.

 

[Arch]

I went to work on the sewing machine again today

Wow, I used a bike. What sort of average speed do you get on a sewing machine?

It's looking good. And a little bit mad. But mostly, cool.

 

[Night Train]

Wow, I used a bike. What sort of average speed do you get on a sewing machine?

It's looking good. And a little bit mad. But mostly, cool.

Cheers, Arch.

On the subject of average speed, over the test run I got an average of 6.9mph with a momentary peak of 18mph. Not too bad given repair and fettling stops.