Friday 11 January 2013, 4pm

I’ve been quiet on the blog, but busy in the shed. I started work on the kingpins for the front suspension. Here’s some components.

The small black (primed) tubes were hanglider tubing (7075 aluminium) and the larger tubes (internally primed) the more common 6061. The smaller tubes will be the kingpins themselves, while the larger ones will be the front wheel axles. I’m using unidirectional tape and two diameters of carbon sleeve. I was planning on using 4 layers of uni and three of the small tube on the inside of the kingpins and 4 layers of small tube and one layer of larger tube on the outside, in two infusions. The problem was that the fibre was packed so tightly inside the smaller tubes that I couldn’t draw the resin through, so I ended up putting all the carbon inside a piece of electrical conduit (16mm ID). The resin takes a long time to make its way through and just made it before the resin jelled. I used a piece of half inch wooden dowel in the centre of the axles, which was drilled out afterwards, to make the axles into tubes.

The axle used 2 layers of small sleeve, 4 layers of uni, 5 layers of small tube and 3 layers of large. Here’s how I pulled the carbon through –

and the dowels –

axles ready for infusion, kingpins ready for failure –

Second attempt at kingpins, ready for infusion –

And the infusion setup with gravity assist –

The trimmed components –

And with the conduit and dowel removed -

The conduit was turned down until very thin and the rest removed with a knife, the dowel was drilled out.

I also started work on the bottom bracket / cross-shaft mount. Here’s a jig I made up using a scrap of 17mm formply –

And the components being glued in place on the frame tubing (once again 7075 from a hanglider – powder coated as it corrodes easily) -

The upper tube is the bottom bracket, the lower the cross-shaft bearing mount and the frame tube (62.7mm OD) has been covered in fibreglass tape. And here it is after bogging, ready for infusion -

I’ve done some fancy embossing and made the distance between the mounting tubes longer, as I realised that my feet were going to hit the cross-shaft (woops!).

I also finished off some components –