PLYCYCLE

Take a look at the finished bicycle here.. www.plycycle.co.uk

Friday 29 April 2011

I started again. Wooden bike frame MK2

I did it, I started again. The wooden bike frame had got to a point where I had to make a decision, as I explained in the last build post. It just didnt feel right. So I umm'd and arr'd and eventually I jumped into my van and went to a new ply wood supplier. Avon plywood. They were brilliant. I talked it over with the man there and we decided that I should go with Birch ply, my original plan. I bought a sheet of 12mm birch ply and set to work.
Having done it once the second attempt at the wooden bike frame came together much faster. In a couple of hours I was back to the same place as the first frame.

Work in progress.


I took the opportunity to make an amendment, I noticed that there was possibly not enough space for the seat post to slot in and maintain enough strength, so I extended this in the new frame.
The first most striking difference apart from being much lighter in colour, is that bitch ply has many more possibly twice as many laminate layers as the hard wood ply in the same cross section, this gives it a very different feel. The birch is also easier to work on. The look as the curves are worked in is much more striking (see the video) and I have a much better feeling about this build. 

Old frame MK1 darker - New frame MK2 lighter.


The main reason for loosing confidence in the last frame was the amount of air gaps between the laminate layers. Looking this over with the fella from Avon ply, he thought it was just bad luck on my first sheet of 25mm hard wood ply. However, the new wood has no voids yet. This gives me renewed confidence, as I was hatching all sorts of plans to inject epoxy resin into the voids in the MK1 frame.

Just seen this has uploaded sideways, sent from my phone, didn't check it, didn't keep it, that'll teach me.

As you can see in the vid, I have now got four layers of ply wood in the frame. This will mean two extra fixings of epoxy, but will make the cutting out of the middle two layers for weight reduction much easier as I would have had to use a router on MK1. I can just use a large hole cutter on the two matching middle sections.

I am really glad I started again, I feel much happier about it now, even if I have had to spend on a new sheet of ply. I learnt a lot on MK1 and know that MK2 will be better.

2 comments:

  1. I have used laminated birch ply to make longboards. They hold up great. We even did a 3mm laminated board with some pretty tight curves. You've got me thinking!
    Dixon

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  2. Good work…unique site and interesting too… keep it up…looking forward for more updates. carbon clincher wheelset

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