Refurbishing my bike trailer

[Gareth]

During the days running up to my Christmas break, I spent a few minutes each lunchtime practicing my newly found pipe bending skills on lengths of scrap hydraulic pipe.
I just the love the aestethics of engineering pieces with circles, sweeping radii, and equalateral triangles, especailly if I have designed and made it myself.
6 months ago I would have never been able to produce multiple bends maintaining an accuracy in all 3 dimensional planes; plus or minus (+/-) 1 mm and plus or minus (+/-) 0.5 degrees.......... Time and experience makes perfect.

The following 3 photos show my practice efforts at making a section of space frame containing 120 degree angled bends. Unfortunately the lengths of available scrap pipe that I had to hand would only make sections one bend short of my requirement for the side space frames that my new single wheeled bike trailer will be made up from.

Going for it with the pipe bender.

[/img]

Putting in the last bend: That's 10 mm outside diametre galvanised steel hydraulic pipe with a wall thickness pipe of 1.5 mm. It requires approximately 20 kg/metres of force to make the bends, and the handle of the pipe bender is only 300 mm long. So that is in excess of 60 kgs of force that I am having to put on the handle for each bend.

[/img]

A few grunts and five or so minutes later, my practice piece is done.

[/img]

I now have sufficent lengths of 10mm hydraulic pipe for my new single wheeled bike trailer curtesy of Stauff ltd. Over the next few days I will be completing the refurbishment of my original bike trailer, and then bending up sections and components for the new one.

 

[Gareth]

Alas, I have still not completed the refurbishment of my orignal bike trailer, there is only the top coating of paint to apply and then reassemble the componants. Being self-employed in the middle of a recession has meant that I am actually working longer hours; an average of 60 per week. I have to take the work while it is there because I do not know where the next job or contract is going to come from. A new lady in my life has also meant that I have been out wining and dining, etc. in what little sparetime that I have.

However, during lunch breaks, I have managed to bend up the majority of the hydraulic pipe that I am using to make the single wheel bke trailer that I want for pleasure cycling days out and picnics this summer.

I have now bent up the major componants of the single wheel bike trailer's space frame. The photos show them laid out on my living room carpet, and over the next few weeks I will braze them together to make a Monocoque space frame type chassis: that means that each componant shares the stress loading of the one's next to it, and evenly distibutes the loadings throughout the frame work.
The rectangles are 750 mm long X 400 mm wide, and I have used 10 mm outside diametre (uncoated) steel hydraulic pipe throughout. This single wheel bike trailer has been specifially designed and diamensioned to carry two cool bags (or one large cool box), a large Kelly Kettle, and the cyclist's spare waterproofs, etc. The maximum designed carrying load is 25 kgs with a built in >| 200% overload capacity (25 kgs+ 25kgs+ 25kgs= 75 kgs). So far I have ustilised an overall linear length of 8.4 metres of hydraulic pipe.

[/img]

[/img]

[/img]

Just a quick mock up of the componants, to see what the single wheel bike trailer frame will sort of look like, including the load that it is designed to carry: two Thermos cool bags and a large Kelly Kettle.
Hopefully this picture will give you some perspective of the size.

 

[twowheelsgood]

Hi Gareth,

Interesting thread. I'd thought about doing something like this too.

Both your new and orignal trailer look hugely over-engineered to me, especially as the design target is to carry only 25kg. Indeed your orginal trailer looks like what you see in Europe as a moped trailer.

25kg is only about the limit of what you can carry on a pannier. You could easily accomodate that load by adapting (strip it to the chassis) one of the better constructed kiddie trailers which are easy and cheap to get second hand.

I actually picked up a secondhand vitelli camping trailer, which is a serious bit of kit that is designed to carry 50kg (twice what most are designed to do) in a kind of basket arrangement. Itself only weighs 8kg all in. (In fact I'm rather pleased as it was £300 worth for £40...) I'd look into this kind of design and use the tubing as a "chassis" frame only. I think those side pieces are just unecessary weight - but they look cool. You also don't necessarily need a high side frame if the things inside are bagged or boxed - you just bungee them down.

It actually looks bigger in the flesh and has a load area of about 90cm*60cm - so easily enough to carry what you wanted. The basket appears to be 3-4mm steel rod.

You also have to think about a coupling which in itself be expensive and how to mount the wheels. If you use bike wheels (like a bmx), you'll need to support both ends of the axle (again more weight), whereas trailer wheels have a thicker axle and hub and can simple be attached to the outside.

As for painting - don't bother for the price of a few large tins of hammerite, you can get a powder coat if you shop around. The finish will never be satisfactory and you'll be forever touching in spots with paint. My trailer was made in 1992, is powder coated and is not exactly "as new" but is still neat and serviceable after 15 years.

 

[Gareth]

I'll bet that you lot had thought that I had forgotten about my Bike trailer, and it had become an abandoned project.

Well, you were not far off the mark; working hard on the Ocean Observer, meeting Lois and forming a new relationship, and my new virgin plot allotment have consumed a lot of my time recently. But last week I had the opportunity to finish the rubbing down to bare metal and repainting my two wheel bike trailer at long last; it's only taken me 9 months to get around to it.

Anyway last week I got the paint on, and over the weekend I actually managed to reasemble the trailer. As it was me, one incident, and one technical problem arose.

The incident:

I spent all of Thursday painting: One coat of Hammerite Primer undercoat, one coat of Hammerite Smooth dark blue top coat, and one coat of Hammerite Dark blue hammered finish paint. Because I live in a smallish ground floor flat without a garden, I chose to undertake the work in my internal hallway. Suspending the bike trailer from a piece of timber resting on the toilet, and bedroom door frames. All well and good in theory, but damn well dangerous in practice.

I had opened all of the five windows and the internal doors in my flat to allow ventilation, but there was no wind, and therefore no draught. At approx. 5 pm, Lois found me passed out on the sofa. I had stopped for a cuppa after finishing the third and final coat of paint, but had not realised that the paint fumes had built up. I was awoken abruptly by Lois, and dragged outside into the fresh air, and it took a good few minutes and a little "mouth to mouth" for me to return to my senses. So if it says use in a well ventilated area on the tin, follow that advice, and if possible do the painting outside.

The problem that has arisen:

Originally, 10 years ago this Bicycle trailer was designed and built to be towed behind a fixed frame mountain bike on 26 inch diameter wheels. My Falcon Explorer has 700c diameter wheels fitted, and therefore the the trailer's drawbar is not long enough to fit to the seat post; my chosen towing point. I now have to make a new bracket to fit onto the rack of my current bicycle, and it may be another couple of weeks before I am tearing about Norwich with the trailer loaded with my shopping, gardening tools, etc. following behind me.

The bike trailer hanging from the door frames and the first coat of red-oxide primer on:

[/img]

This will give you some idea how small my place is; Who else do you know who keeps their bicycle in their living room:

[/img]

[/img]

The smooth finish dark blue topcoat on:

[/img]

The hammered Blue topcoat on:

[/img]

The bicycle trailer frame paintwork finally completed:

[/img]

The bicycle trailer refurbishment is now finished, there is just the towing point modifications on the bike luggage rack to do, and the subsequent photos to take and post when is complete.

From this, nine months ago:

[/img]

To this, today:

Note; I have fitted my two drinks bottles for the photo.

[/img]

[/img]

 

[mickle]

Wicked.

 

[Amanda P]

Hmm. Wait till you see mine... just off to the powder coaters next week with it.

It has a spaceframe design not unlike a Moulton and not unlike this

http://i105.photobucket.com/albums/...er single wheel/singlewheelbiketrailer008.jpg

Two wheels though. Built from steel tube scrapped by StarTubes at Elvington, all brazed construction (no nasty blobby welds). It doesn't have those mudguards that Gareth's has.

It may be up for sale at the York rally....

 

[twowheelsgood]

That looks pretty good to me Gavin. The electric blue bidons are a neat touch!

I "almost" enjoy shopping since I got the trailer and it's strangely satisfying to take the recycling from the house and get a week's food in a single journey without going near the car.

My design was basically similar to the Vitelli which I was extremely lucky to find at that price but the basket would be fitted around one of those large PVC storage boxes you can buy in B&Q for waterproof, removeable transport and storage.

I'd never actually ridden with a trailer before and was extremely impressed at how comfortable and stable it was compared to loading up the pannier past what was really sensible.

How much was the powder coating uncle phil? I was quoted £25 but the colour would have to be "whatever large order we were doing that day".

 

[Amanda P]

I haven't taken it to Hutchinson yet. I would be surprised if it came to more than £30.

I pay cash and I don't ask for a receipt, so it's possible that I'm getting a 15% discount...

Fair choice of colours though. I'll just get it done more quickly if I'm happy with satin black or whatever colour another large order is!

 

[TopCat]

Nice trailer Gareth. Just goes to show what a little TLC can do.

passed out on the sofa?

I think you painted indoors on purpose so you'd get mouth to mouth

Tom

 

[Gareth]

A lot of people have asked me about the hitch that I use on my now 11 year old home-built bicycle trailer. So I have recently taken a few photos of it for you all. I use a 10 mm industrial ball joint assembly, often found on the connecting rods of process machinery. I made up a suitable fixing arm for the ball joint from a length of 16 mm diameter steel bar, mitred it, welded it to a piece of 4 mm thick mild steel plate, and utilising 8 mm diameter stainless steel socket head bolts, flat washers, and nylock nuts;

A brief recap:

The trailer just afer I had refurbished it about 18 months ago:

and recently ready for action on a charity shop run:

The components laid out before final fitting on to my bicycle's frame:

Fitted into position:

Note; that it has left sufficent room to accomodate my bike lock under the saddle:

and finally with the trailer hitched up and ready for a utility run:

Note; the additional piece of chain and the padlock that I have included. This gives me some additional security when the bike and trailer is left outside of a shop or parked up on the city cycle stands, and also as an extra safety device if the trailer should ever jump the hitch when I am towing a load, etc.