Rims

Last time I mentioned that I was going to start work on the rims. Now, whilst this statement was true, I may have misled you slightly in that I didn't tell you that I already have the blank rims. A company in Christchurch makes hollow rims for antique machines and they had already made me a set in return for some pin striping that I'd done for them.

Their method is simple and produces very strong, medium weight rims. Two tubes are rolled to hoops, one hoop of a very slightly smaller diameter than the other. The smaller hoop is then cut in half around it's circumference to form the inner part of the rim, this is welded to be a closed loop of a U section. The larger hoop is now nestled into the U section and MIG welded around the circumference on both sides. The excess outer half of this hoop is then cut off and the welds dressed off. The rims end up slightly heavier than they need to be and are a bit functional but getting them made has saved some time. For future projects I'll make myself a proper rim rolling machine, I'll probably replace these rims then.

You can now see the relative sizes of the wheels, 

very different from the contemporary high bicycles.

The first job is to mark the locations of the spoke holes. As I mentioned before, I'm using 50 spokes in the front wheel and 30 in the rear.

I made up a full size template of the rims with the spoke locations

marked and simply transferred the marks across using a square.

With a hollow rim of a fairly thin gauge it is important to ensure that the spoke head or nipple is properly supported so that it doesn't pull though in use. Two methods were used, the first was to drill through both parts of the rim and support the head in a counter sunk part of the outer surface, immediately under the tyre. The second method uses a curved washer or profiled support to prevent the tensioned spokes pulling through. 

The current rims are more like the Roadster profile. 
I'll eventually make some more like the Racer

The curved washers used on Westwood rims are for the same purpose.

I'll be using the first method, a counter sink can be easily achieved by drilling a small hole and using a centre punch to produce the shape required. A little practise in some scrap gave me the size of hole to drill and the weight of the hammer blow to end up with a decent counter sink with a hole of roughly the correct size for the spokes. This approach does have the added complication that the holes have to be drilled at the correct angles rather than just radially through the rim, so I made a simple jig to hold the rims whilst drilling.

I had to move the drill press down to the floor as I 

didn't have enough clearance above it to the ceiling. 

First centre drill every other hole and then flip the rim over to do the other side.

Then drill the small pilot hole through both layers of the rim, 

this has to be done very carefully and at the highest drill speed as the second 

surface is convex to the drill and it will wander and break very easily.

then using a supporting block under the rim, hammer the counter sinks 

into the outer edge using the newly drilled holes as the centres.

Finally put back onto the jig and drill through at the correct size for the spokes.

Then clean up both rims ready for painting. 

I hadn't decided on a colour for the bike and had assumed it would be some sort of deep red (naturally). I asked the advice of my wife (resident soft furnishings and interior decor expert), she immediately vetoed me and said it has to be black. She even got one of my catalogues out to prove the point. She is of course correct, wives always are, it will be black with either red or gold pin striping. My favourite paint has always been Tekaloid coach enamel. The formulation changed from linseed oil to Alkyds at some point but it sprays and brushes on equally well, most people are surprised when presented with a deep, even finish to learn that it has been applied by brush. Tekaloid can be cut and polished back when completely dry to a high lustre. It is an entirely appropriate finish for an antique cycle. Sadly, of course, I cannot obtain Tekaloid in NZ. Resene, however, sell an old fashioned alkyd gloss enamel of a similar type. It has a high VOC value so I suspect it will not be available for too much longer. I've been spraying it with a breathing mask in my spray booth (an old, disused outside loo) with good results. Depending on the weather, I'll try and get a few coats on this week.

In the meantime. I'll start work on the spokes.

In other news, I've just entered Le Race again. I haven't done it for a couple of years now and it will be interesting to see how an old, lardy retro grouch manages. I don't think I'll be troubling the judges this year.