Another picture of the wooden bicycle, the PLYCYCLE.

So, another pretty picture of the finished wooden bike.

Fixing and Gluing... Well epoxying.

   I got to a point of no return, having got all the metal work finished, the final laminating of the main frame was upon me.

Prepping for the final epoxy fix on the main frame.

It meant a lot of guess work around the amount of resin I would need to mix up for the job, and in the end I was slightly short and had to do a hasty additional mix. The west system epoxy I have been using has been great, really easy to use at every stage. I put in the metal head tube and bottom bracket sections after the initial 'wetting up' and from there there was no going back. It was just lining it all up and clamping it into position, then cleaning down any excess epoxy after clamping from around the metal parts that I would nor be able to sand back later.

 All clamped up, just need to wait for it to go off.



Head tube with decal, fixed in, no going back.

I also managed to get the back end all lined up, and fixed with epoxy the day before. It was slightly less nerve racking, although I don't know why because technically it was harder. However it all worked out. I had drilled small holes in the inside of the metal drop outs where they join the hanger to allow excess epoxy to squirt out, as the fitting with the wooden frame was too tight at the join to let it out. It allowed me to put plenty in and not worry about a dry join. When I was fixing them together I measured from the center of each stay where it joins the frame, to the end of the drop out to get them centered. I also delicately popped the wheel in to see how it lined up, it was good.

Back end all epoxied together.

Next steps are to fix the main frame and back end together, to have THE WHILE WOODEN FRAME  together as one for the first time. Then to do final shaping and sanding ready for the posh yacht varnish I have procured.









Drop outs....

I set about getting the drop outs to fit the stays. First I had to cut the stay down to allow the metal section to centre up. Slightly nerve racking as it is a one way event. So measure check, measure check then cut, carefully. I got the top ones bang on, but the bottom ones were still a smidgen too long and had to have a screw drivers shaft with taken off, it was a precise measurement, and worked a treat.
So having got the metal work mostly in shape the thing to do was offer it up. The main adjustment needed to make it all fit was to thin the wood back on the stays. In cutting the stays back, the length of the stay that fitted the tube had shortened, so a quick bit of rasping and they all fitted well.

 Drop outs mocked in, with wheel.

When it all came together, it fitted better than I had expected, so well that I could pop the wheel gently in and see it all there for the first time. All good news, but the point of all this apart from seeing if all the planning would actually work, was to spot bond the metal components with acrylic adhesive so that I can give it all to my colleague Lew to braise up. But I ran out of time, that will have to wait, but its all there ready.

Drop out mock up detail.

Once I get the metal work done I can start the final phase of the project, final bonding, shaping and fine sanding followed by varnish. It all seems possible now.

Today I also spray painted the head tube, so it will be ready for bonding into the main frame. All I need to complete that is the transfer with the PLYCYCLE logo and some spray lacquer.

Reamed!

I collected the reamed and faced head set from Argos cycles at lunch today. On the outside it looks just as it did before, but look inside and the evidence is clear.

Head tube and fin with primer coat.

Head tube faced and reamed inside.

This week I also need to pop back with the forks to get the crown reamed to fit the headset nicely, its a while you wait job at Argos cycles.

But now I have the head tube working I can get on and do the final lamination of the frame.



Fitting the metal work.

I really felt like I have made a step forward with the coming together of the metal parts and the main wooden bike frame. So what did I do? Well.... I split the frame into its two halfs and inserted the metal pieces to daw around them.

Bottom bracket lined up for marking.



I then routed out inside the markings to allow the plate sections to neatly sit between the two halfs of the frame. I also cut some slightly deepersections in the center of each plate to allow some extra epoxy to create a plug. The plate will have some holes drilled in it eventually to allow the epoxy to bond though.

Botton bracket fitted.

Head tube fitted.

At the mement the pieces are fairly loose fitting because of my relative inexperience in this type of building. I think that the epoxy resin will help me out here.

The next few steps are fiddly and there will be no aparent progress, as in new parts. Its just bonding, and tweaking to get the rear stays to fit. Rear drop out parts are in the post, and will heavily influence how the back end of the bike turns out.

Got lots done.

A bit of progress. Firstly I cut some rear stays and tacked them onto the main frame. The main reason for doing this was to ascertain whether the crank would clear the bottom stay. I am pleased to say it does. See the vid.

Crank clearance test.

The other reason for tacking on the stays was to see if they lined up and would actually fit. They did, so I made four more. Each stay will be made of three layers of the 12mm birch ply.

Rear stays all cut.

I spoke to the resident mechanical engineer at work about giving me some help with the fabrication of the bespoke metal fastenings. He had a great idea about how to connect the stays to the drop outs. I had always been worried about weakening the stay by drilling it, his suggestion was to make the end of the stay round and slot it into a metal tube that in turn would be welded to the drop out. I like it, quite simple and will maintain the strength of the stay.

After my last post, I did get the epoxy I wanted, even if I did have to cycle to the other side of town. I bought a small kit of West System Epoxy to learn how to use it. So the first thing I did today was to mix up a small amount (30ml) and have a go at laminating three strips of off-cuts. I found it easy to use thanks to the very clear instructions. I haven't gone back to see how strong it is but I am confident it will be fine.

 Epoxy Resin test.

But the big job today was to split off the two outer layers of the main frame and to reduce weight by cutting out as much as I dared. The idea being that when the outer layers are laminated on top it will create a box section and maintain strength but loose weight, as the frame is really quite heavy at the mo. 

Drilled out.     

     Shapes cut with jig saw.

                        

I drew on the shapes I wanted then drilled out the main cavities. I then trimmed out the remaining bits with a jig saw. What I didn't do was weigh the frame before and after, but it has made a huge difference. I like the look of it. My son asked why the whole frame couldn't look like this. Its a good question, I think it would look great, but I don't think it would be strong enough. I think the box section idea is vital, as I think the frame would flex too much if opened up like this. Also I would have taken more care on the cutting had that been the plan. Next time maybe.

 Just the curve around the back wheel, head set groove to drill out and the rear stay shaping to do to complete the wood work. Metal work next. Then fix it all together.

Using Bike CAD

Having been all excited about materials and getting started, it dawned upon me to focus a little more on the actual design of the bicycle. Bicycle design can be just a few sketches on paper, like I did below, but I thought I would have a crack at Bike CAD an on-line bicycle design tool. It is set up with some basic templates for most bicycle styles that are then 100% customisable. So I went with a road frame and entered my hight and

chose some parameters, below is what came out. I have a geared bike and a fixed gear bike and I enjoy both for different reasons, but as you can see here I have gone for a single speed design, mainly because for my first complete build it will be easier.
Bike CAD is set up for steel framed bikes so I am looking at this for basic measurements and geometry. I found it really useful to be able to type in different seat post angles and see the changes to all the other angles straight away. No doubt this will evolve, but I like the basic simple shape of this bike and I hope it will be possible for me to adapt this into wood with out too many changes to the frame geometry.