2014 and still going strong!

It is the end of September 2014 and I have been riding the Plycycle all summer and it is still going strong. Since completion in 2011, I have had to replace the forks as I originally bought cheap ones and I stripped the thread on them. Other than that it is all great.

It is a pleasure to ride, even in hilly old Bristol.

Plycycle - wooden bike out in Bristol 2014.

Another picture of the wooden bicycle, the PLYCYCLE.

So, another pretty picture of the finished wooden bike.

Moving on.

So I made the change to the head tube angle, this will have to be it, there is no going back now. Unfortunately during the fitting and reshaping of the wood, I pranged the paint on the head tube really badly. I have had to rub it back and repaint it, which is a real shame as It was a good paint job and the head set was fitted so I have had to spray over and around the installed headset which is not ideal. But i think it will be fine.
If I hadn't messed up the head tube paint, I could have resined the main frame together, but that had to wait, will be the next job, then i can do the final shape and sand.
Rear drop outs are sprayed in the shiny green colour, just need lacquering, then I can resin the rear set together.
I also spotted a pair of leather handlebar grips on eBay, couldn't resist.

The fix?

      I have had a good look for some replacement forks second hand, and there are some nice ones out there but I cant use them because I have made the head tube on the plycycle longer than average. All the second hand forks are cut down. I don't want to 'fork out' for a new set, so I am going to work with what i have.

How did the front get so out? Well... The head tube is longer (for strength binding to the wood) and therefore lifts the front of the frame, and the forks are slightly longer (off the shelf and cheap) and although individually these extras don't seem like much in the end it is about 3.5cm of lift. Enough to radically move the front of the bike away from what I had in mind.

I put the photo of the bike into photoshop and measured and analysed and this is what I think.
with the forks I have I will never get the top of the frame horizontal with the ground, I can handle that, just. As for the relationship of the front wheel to the main frame, I can play with that a bit. Luckily there is plenty of room to adjust the angle and position of the head tube mounting. So I propose moving the head tube back and steepening the angle. This will take the top of the frame further from the horizontal but I think will bring the bikes proportions back together.

Looking at the angle change in photoshop.

Hopefully I can make the tweak easily enough, and then it really is put it together time.

Sanding and shaping.... Again.

This weekend I have spent time working on the wooden frame again while the metal parts are being braised. It seems like a while since I have actually worked on the frame.
I spent some time refining the shape of the taper into the rear wheel, first making the curve closer to that of the wheel and then tidying up the actual taper. I am not aiming for perfect lines as I have always wanted this to be clearly hand made, however I am also wanting to create something I will be proud of. If I had unlimited time I am sure I would refine and remake parts until I was truly happy. Isn't that always the way?
Anyway I have been using a cutting disk on an angle grinder intended for the light shaping of mild steel. However my father in law tried it on wood one day when we were restoring my wife's Morris Minor, not only did it work, it worked really well, and best of all did not over heat or clog up. It also only leaves light ridging that sand out really easily. I will use this for the final shaping of the frame once it is bonded into one.

Another job I have started is the chocking up of the bottom rear stay, having cut out too much from the main frame. Luckily I took out 12mm, so the fix was as simple as bonding in another layer of ply.

Rough shape bonded on.                                        Sanded into shape.

I roughly cut the piece and bonded it into the stay, making sure to align the bottom bracket fin slot. Then when it had cured, I set about working it back. I spent a relaxing hour in the back garden just slowly sanding it. I am sure I could have set about it with a power tool or a quicker hand tool, but I just got into the sanding. It was quite relaxing, therapeutic I'm sure. Anyway, I got it to a place where it will fits well enough to be ready for the final fitting. It will then require more sanding to make all the shapes fit more neatly where it buts up to the main frame.

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.

Name.

I think this bike will be called the 'Plycycle', and in order to represent this on the head tube I have knocked up a logo to go with it.

In other news the drop outs are coming on, getting to grips with the metal work.

Drop outs work in progress.

The next stage is to line up the frame accurately and tack glue the drop out components in position ready for braising. Inside they are scuffed ready for fixing to the frame. I just have to decide what adhesive I will use. I was planning to use the same epoxy as everything else, but I have been given some acrylic structural adhesive, that may just be a bit better. I will do some tests.



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.



Head tube.

While trying to move things on I thought I would have a go at assembling the front end of the bike. Stating with the head tube I proudly got out the head set, lined up the pieces and offered the top bearing cup up to the head tube. It didn't fit. Not just in a small way, there was just no way it was ever going in. For those of you who are reading this having made your own frame from scratch, you will now be realising how green I am to this.
I was worried that I had bought the wrong size tube or head set or both. On double checking, I had the correct ones.
I decided to swallow my pride and put in a call to the guys at Ceeway where I had bought the tubing from. They were very patient with me and explained all about reaming.
Reaming. The tubing is sold with an internal diameter that is slightly too small for the headsets. This is because as the frame is braised, distortions occur and the tubing is often not as truly round as it should be. So when the braising is complete, the frame is 'reamed and faced' to true it up and cut it out to the correct size for the head set.
So my head tube needed reaming. The tools I needed were easy to find but very expensive, so a quick web search brought up Argos racing cycles, bespoke frame builders and restorers, who are fairly local to me. I nipped over one lunch and they were more than happy to do the job for me for a fraction of the cost of the tools. Perfect. I pick it up next week.

Frame tacked together for dropout measuring.

In addition to the front end shenanigans, Lew and I have been mithering about with the drop outs. The actual drop outs have been bent to match the angles of the stays. Lew bent the stainless drop out sections with an oxyacetylene torch. The next step is to make the tube fittings to fit the wood. As mentioned below, we have revised the plans for this a couple of times, and we think we have now got a simple and effective way forward. The only recent change in plan is in how to physically join the drop out plate to the tubing. Normally a simple butt would be used and braised together. However because of the over sized tubing I need to accommodate the wooden stays, a butt was not going to work as well as we thought. It would need an insert made, and that is just too much machining for this project. so we have decided to try and squeeze the ends of the tubing into an ellipse using a jig, to take the shape of the drop out and make the braising more straight forward. Lew is testing this weekend, I will reveal the out come soon.

As you can see above I have put the frame together slightly more formally in order to get the drop out angle was right. I found that by the bottom bracket I needed a wedge, as my initial measurements had been wrong. Nothing a bit of resin and a bolt cant mend.

It was also an opportunity to start putting some of the bolts into the frame. The first being the bottom bracket ones. These now go thought the metal fin inside the frame and it is rock solid. When the frame has its final lamination (when the head tube is done) It will re-enforce it again.

I also need to start thinking for a name and a badge to put on the front.

Not much to show, but still going.

Its all in the title. Again, not much to show, but I have been doing little bits and pieces. Truing up the frame cut outs for the stays and the stays themselves. However the biggest focus of the build recently has been the fabrication of the metal rear drop outs. We have angled the drop out brackets to match that of the stays so the actual drop out plate runs parallel to the frame and therefore true.
I hope to have something to fit to the wooden frame soon, as that will push the build into the final phase.

Metal work, works!

   I have in my grubby hands two pieces of metal work greatness. Lew ( the engineering man) made the parts up for me from my card board templates. I had stock head tube section and a standard blank bottom bracket shell from Ceeway, which I bought back at the start of the wooden bike build in order to measure up to. As the wooden frame came together and I understood more clearly where and how the metal parts would need to fit, I was able to discuss the detail with Lew. He then made a jig to hold the plate at 90 deg' to the tube as he braised them together.

Head tube and fin fixing.

    Hopefully this shows how I intend to sandwich the fin between the yet to be laminated wooden layers that make up the wooden bike frame. The Head tube has a wedge shape to it in an effort to increase its holding strength in the frame, it may well be bolted through as a precaution too.

Bottom bracket with fitting fin.

      With the bottom bracket, we decided to take the fin all the way around the shell. Originally I had intended to have the bottom section of the bracket shell exposed with the fin similar to the head tube. But then I decided to surround the shell with wood, and after discussion with a couple of engineering types it seemed a good idea to get as much strength into the bottom bracket area as possible. It seems obvious, but the stresses going through this section are huge, especially if I go fixed gear or single speed with the bike. Gearing it will drasticly reduce the loading, but I don't really want that.

   Next I need to paint the bits that will be exposed to the outside, while leaving the bits bare that will have direct epoxy resin contact.

   I have also just ordered  from Ceeway, two blank stainless track style drop outs and some 22mm tube to make the rear stay/drop our connections. I had hoped to use the left over head tube but it was just too big at 31mm diameter. Ceeway is just a treasure trove of frame building bits.

   On the wood working front, I hope to have the stays shaped soon and if the weather is warm enough I will have a go at the first stage of bonding the four frame layers into two halfs.

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.

Poxy epoxy.

I went to get some epoxy resin today, but the shop didnt have what I wanted. So I will have to go to the place I know has it but is the other side of town.
If I can get some resin then I can start testing with some off cuts for the laminating process. Seeing as I have never done any epoxy based bonding, I think it best not to experiment on the actual frame.
I also held up a wheel to the frame today to work out the rear stay lengths. I think I will have to cut into the rear curve that follows the wheel contour as I am going to have to bring the wheel about an inch closer to the frame than I had originally thought. Its not a problem at all, I had just got used to how it was looking and the cut will change that shape.

Rear hub...

So, I said back in the beginning that this would be a fixed gear bike, and so it probably will be. But my attention has been drawn to an amazing hub gear from Sturmey Archer. It is a two speed kick change back pedal brake hub. Yes a bit of a mouth full but its amazing. No cables! Just kick back to change between the two gears. There is a free wheel, but put in a back pedal and it is a traditional American style brake. I love the fact that it will need no cabling. It is £70 for the hub only, which as nice hubs go is not that much, but in truth is probably more than I want to spend on this project right now.

It would be nice though.

I've got wood.... plywood.

So I finally made it to the wood shop to investgate ply wood for my bike. Robbins timber, in south bristol are set up to supply the boat building and mending trade, so have a very good stock of hard wood and marine ply. I was only going to have a look, but one thing led to another and I came home with a half sheet of building grade 25mm hard wood ply. It is less than half the price of marine grade which has no air gaps between laminate layers, this does have strctural / strenght implications, but for my prototype I will be fine using this for the frame, rear stay, well i am not so sure.

The lovely lovely timber yard.

My new piece of 25mm hardwood ply in the van.

Wooden bike - in miniature.

It is not a great thing of beauty, but this model has really helped my see where this is going. I cobbled it together in lunch break at work and then shot it on a green screen set down in one of the studios, on my phone. Perhaps I should have spent more time on it and shot it with a proper camera, but really at this stage that is not the point. I really wanted to see the shape of the frame in 3D. I tacked a print out of the bike design onto some foam core card and set about cutting it out. The foam core is not quite to scale, too thin for the main frame and too thick for the rear stays, but it is good enough to get the idea. Oh yes and I used square section brass for the forks...... Remember, cobbled together.

I made the forks too long on the model and it really makes a huge difference to the intended design. The bike now looks unbalanced, squat at the back and lanky at the front. I dont think it is worth changing the model at this stage. I like the model and I think I may make another, proper scale version at some time in the future. 

Bike design progress.

I was just looking at the Renovo site in more detail and noticed that they have the curved frame line around the rear wheel to shorten the rear stays as I have proposed I'm my last design. I am quite pleased as it means that I am doing something right in my bike design process.
There can't be many bike shapes that have not already been put out there, especially in the standard frame geometry that I am following.
Yesterday I thought it would be a good idea to make a model of my wooden bike design. Just made out of foam core and bits and pieces, it will be near as possible a scale representation of the design below. It's nearly done, I will post pics when it's ready.

Plywood.

Today I started swatting up on plywood for the frame components of my wooden bike. I am lucky that in Bristol there are a couple of very good suppliers, who stock a variety of hard wood ply in most thickness's. I have based my design around 25mm ply, so that is a given, what is not so cut and dry is the wood base of the ply. The one I have my eye on is a 100% mahogany ply. The only problem with that is the cost, £168 per 8x4 sheet. Too much for a test project, maybe if the proof of concept bike works I can make another with the expensive wood. So the question is, what else is out there. Well the main wood in cheap ply is spruce, a soft wood, which although lighter, I have ruled out because I don't think it will be strong enough in the high stress parts of the frame in the longer term. So that leaves other hard wood options. The one that seems best, affordable and made to high standards is birch ply. It is the most commonly available high quality ply, both my local suppliers carry graded birch ply from rough and full of knots to architectural grade.  Best of all, birch ply usually comes from sustainable forestry, something that is harder to to be sure of with the more exotic hard woods. The really good stuff is about £45 a 8x4 sheet, I think this is what I will go for.

The bottom bracket....

I had initially hoped that I could hide the bottom bracket mounting inside the wooden bike frame with a single metal tongue filleted between the two halfs of the plywood frame.  This may still be possible, but I am worried about the amount of torque that will have to go through this fixing, as it is one of the most mechanically stressed parts of the bike. My plan at the moment is to use a two metal mounts that sandwich the wooden frame. This will defiantly be stronger, but I also want to keep the metal work hidden as much as possible. If I can find a way of making this work then that would, of course be best. I had best get the sketch book out.

Bike design, next step.

I took the BikeCAD image below, with its acurate angles, (but designed with a steel frame in mind) and copied it in illiustrator. This llowed me to start plying with the proportions of my wooden bike design. It is amazing how fast little details acumilate and have a knoc on. For example, the only way to maintain the geomtry of the frame that I designed in BikeCAD, and add material for strenght, is to
increase it into the central frame viod. This in turn makes the botom bracket fixing point rather out on a limb, very low down. So that needed tweking and beefing up and so on. The above is by no means the answer, but it isthe first time I have seen what the shapes may actually have to look like. This will (I hope) evolve as I add detail and the inevitable probems arise.