Looking good !

As you may know if you have been following this blog, I have been faced with many hurdles since starting this bike and living here in Japan makes this build a lot harder and longer than it would have taken me back home in New Zealand. But things are looking good now as even with some American solid tyre tied to the front rim with bits of string and some nice British tyre tightly fitted to the rear wheel I have been able to make a very good mock up of the frame and the required angles needed to achieve an authentic looking replica ordinary. Many builders over look this vital step and either have no rake at all to the front forks or too much and I've seen some replicas where the gap between the backbone and the front wheel is huge, not only does this look bad but seems like the builder didn't really care what the finished bike would look like. Yes building an authentic looking ordinary is not a simple task but if you take your time you can build something that you will proud of and a bicycle that will be admired as well. I spent several hours making sure the backbone to front wheel spacing was perfect and only when the overall bike looked perfect I stopped working on it. The above photos show the results I achieved today and it would not have been possible with my favorite power tool the mighty Makita power file. The next step is to have the bearing housings fixed up so the C clips fit perfectly and after that the entire frame can be welded together.

Yoke & Backbone

This morning when I arrived at the bike shop I cut the backbone to the correct length and then with a hand file slowly filed down the top of the steel round section that fits inside the backbone. By working slowly and testing the fit several times I was able to achieve a nice tight fit and then once I was happy with it, I then drilled two large holes in each side of the backbone so that the inner steel round section of the yoke can be welded. As well as welding the two side holes there will also be a lot of welding required at the front of the backbone and yoke so overall it will be held in 4 places which will give it the required strength needed as this section holds the entire weight of the rider and keeps the frame together. Later on once all the welding is completed I will have a lot of filing and cleaning to do which will entail the use of the Makita power file, standard hand files and a lot of sandpaper. To achieve a nice clean fit it's important that the overall finish is perfect and if we decide to nickel plate the top of the yoke the entire area has to be free of any pitting or imperfections as they would show up easily when plated. Pictured above are a few photos I took of the backbone with the yoke/ steering pin connected.

The backbone is ready for cutting

Today I spent the morning searching for 40mm C clips which turned out to be quite rare in Niigata city and ended up driving 30mins out to my old home town of Shibata where there is a great home center / pro shop which had the size c clips I needed. I discovered that when the brass bearing housings were made they were not perfect as even though the sealed bearing is a nice fit the C clip does not fit into the grove, this should have been checked by the machinist who turned them up on the lathe / milling machine in the first place. The 40mm C clip is too thick to slide into the grove provided. The only way to fix this problem is to have the bearing housing machined so that the C clip holds the sealed bearing tightly in place with no sideways movement at all. Apart from buying some C clips of the correct size I also bought two strips of black coated angle iron with pre drilled holes to act as a straight line gauge to keep the frame in line. This is most important when getting the entire frame welded together and for figuring out the required fork race, backbone spacing etc. So this afternoon I have worked out how much is needed to be cut from the top of the backbone and I'll do that over the weekend at the bicycle shop and file the yoke to make sure it's a nice tight fit inside the top of the backbone. Apart from that a few holes will be drilled in the top of the backbone so it can welded together. I'm so happy to have finally got to this stage and the fork rake and backbone to front wheel spacing looks fantastic as well.

Bearing housings

The other day when I did a mock up of the frame I discovered that the slotted cranks that I had custom made could not rotate on the hub shaft due to the shape of the brass bearing housings. The top section on the housings has a slight outward curve which caused the inside face of the slotted crank to hit it. So at work I put the brass bearing housing in the vice and used my favorite power tool the Makita power file and leveled the outside surface of the brass bearing housing so that it was flat. Overall the bearing housing is quite wide so that is part of the problem, but now it should be fine. The cranks and the bearing housing with be close maybe 2 - 3mm but once held in place securely the housing will not be able to move so should cause no problems at all. My next job is to find a new pair of C clips which are the same size only thinner to hold the bearing firmly in place. Pictured above are the front bearing housings

Front forks

Yesterday at the bicycle shop I cut the forks to length and drilled some holes in the bottom and the top of the fork blades to allow them to be welded onto the dropouts and the steering head legs. The overall fit was perfect but only bolting the front forks onto the bearing housings would tell if they are the right length. So after dinner last night I fitted the bearing housings to the hub and put the forks on and with the backbone held tightly to the 18mm wooden blocks it showed that the steering head was sitting 5mm to high !. I had a feeling this might happen so today I have the following jobs to do at work.

1. Cut 5mm off the bottom end of the fork blades or the top - which ever comes off easy as I put them together so they fit tightly.

2. Sand the outside face of the brass bearing housing flat as because of it's current shape it does not allow enough room for the crank arm to rotate

3. Drill a weld hold in the side of the rear forks on what would have been the steering tube

After that I need to purchase another large c clip that actually fits in the groove at the back of the bearing housing, the current c clip is the correct size but it's to thick to fit correctly which in turn does not hold the bearing tightly in place. Once the front fork and the bearing housings are looking good then I can cut the top of the backbone to the correct length. Pictured above are a couple of photos of the front forks.

Frame mock up part 2

I have just returned from the home center near my house with some 18mm tick wood which I then cut into shorts blocks and taped it to the backbone. The above photos show the correct angle of the backbone once welded together. I would have preferred the rear wheel a little closer to the back of the front wheel but the backbone radius does not allow a closer fit, but it still looks very nice and once I get the front forks cut to length I can then decided the rake of the forks and where to cut the top of the backbone. After that there will be some cleaning to be done on the frame and then we'll be ready for welding the frame together.

Frame mock up

As I'm still waiting on the solid 3/4 inch English tyre to arrive I thought if I tied the American style tyre to the front wheel I could them work out the space from the wheel to the backbone and the length of the front forks. I have now figured out the length of the fork blades and will cut them to length at the bicycle shop this weekend and drill holes in the ends of the fork blades so they can be welded onto the bearing dropouts and the steering head. Basically I'll mock up the entire frame with everything fitting tightly and once I'm happy with the angles and that the frame is in line only then will I get it welded together. Pictured above are a couple of photos I took this morning of the frame mock up, I think I can get a better fit to the backbone by placing some wooden blocks the correct thickness in between the front wheel and the backbone as this space is often too big on most replica's so therefore needs to be a nice uniform close fit with the rear wheel slightly tucked under the front wheel.