Saturday, January 30, 2016

BSA Hornet Brakes, Cables & Forks

I have reached a good breaking point on the Interceptor and must shift gears to take care of my other bikes. The 70 BSA needs de-coking and re-timing, the Norton head gasket is leaking, and the Hornet needs tweaking.

Bikes safe and warm for the winter. 

Although the Hornet ran great last summer I did uncover a few areas of opportunity to improve its performance. The front brake works alright but is not what it should be, the forks leak a bit, and the cables are all too long.

I disassembled the Hornet front end and checked the brake shoe wear. Contact was good but could be better. I had taped sand paper in the drum and rotated the brake plate while working the shoes out. I found it difficult to get the tension adjusted right.  After dwelling on this for a while I came up with a method to make this process easier. A reversed wood clamp provided the adjustment necessary to lightly sand the shoes. The clamp was opened up as the shoes were worked in.

An easy method of fitting brake shoes. 

The brake cable is the Barnett variety with a coil at the brake arm connector and is longer than necessary. This was shortened and the factory adjuster, which was re-plated with my Interceptor parts, was put back on. The feel is greatly improved. Combined with better brake shoe contact I should have brakes back to 100%.

The brake cable fit with a ferrule and frayed. 

Brake cable soldered and ready to fit. 
The throttle and clutch cables received the same treatment and work much better now. 

Next it was on to the leaking forks. They were disassembled and fitted with 9/32 thick x 1 5/8 ID o-rings below the fork seals. This is not shown in the parts book but there is room for one. I have read the factory used string in this space but none came out when the forks were disassembled. Most of the oil was coming from the bottom damper bolts which were sealed (not very well) with an aluminum washer.  I put silicone sealer on the bottom of the damper rod mount and around the retaining bolt head. I think this will do the trick.

One last bone of contention is the new fuel cap which leaks slightly. I cut a 3 mm cork gasket to replace the rubber one which came on it. The rubber seal distorted quite quickly which was probably caused by the crap put in our gas here. I put an o-ring in its place which is a bit dodgy for a detailed restoration. Cork should seal well and not deteriorate like the original seal.

The new gasket formed to the opening well. 

The bike is finished but I will have to wait to try everything out.

On to the Norton. A bit of a leak from the push rod tunnels I think. 

Sunday, January 24, 2016


After repairing the painted parts they were taken to Precision Motorcycle Painting in South bend Indiana. I used them on my Hornet and was very pleased with their work. They are not cheap but they know motorcycles and are perfectionists which I am willing to pay for. Pictures of an original tank were provided as well as a photo of all parts to keep things sorted out when it was time to pick them up. I have found this to be a good idea as many parts come and go from suppliers and it is not hard to get things tussled.

An OEM paint stripe purchased from a supplier in England was provided for color matching and pin stripe width.  Tank decals were also purchased from the same supplier. The decals were much darker than the paint stripe and also thicker than the original tank script. In addition I was concerned gas would easily damage them. For these reasons the decal was used to make a paint mask and they were painted on to match the stripe color. The stripe was painted with black pinstripes being applied by hand. 

All of the other parts were sprayed as well. I know many people use powder coating with good results but I have heard of fails and I have not used that method yet. Maybe on a future build.

Saturday, January 9, 2016

Finishing Aluminum Parts

The aluminum bits on the Interceptor were in good shape overall but corroded and scratched. They still had the original factory finish which gave me a good guide for polishing. 

Original state......good shape but in need of refinishing. 

I don’t like to remove more material than necessary when polishing as voids in the castings may pop out. This happened on my transmission cover & had to be repaired with low melt temperature rod. Starting out with the highest grit paper that will remove the largest scratches, usually 320, a progression of papers is taken to 1200 grit. Each grit is applied 90 degrees to the previous one and a rubber block is used to minimize dips and waves. The parts then move to a stationary buffing wheel where sanding scratches are removed. Rubbing compound is worked by hand for the final gloss. I use “Semi-chrome” or “Mother’s Billet” for this final step. I find that working with paper keeps the degradation of the surface to a minimum, although it is a lengthy process. 

Filling a 3 mm void which came out of the casting during sanding. 

There was small black spot to start which opened up quite rapidly. 

Pit filled and case polished. A small pit remains but overall it looks good. 
I am afraid to polish any further as it may expose more voids. 

Finishing complete, with the exception of the transmission inner side cover.  
It will be polished when it is rebuilt. 

The brakes had hardware riveted in place. They were left in place and painted to replicate CAD.

Another diversion....The Hornet forks are dripping from the damper rod bolts and fork seal retainers....time to disassemble and reseal. On with my quest for a somewhat leak free BSA ...... I thought engine may leak but after 400 miles or so but it is sealed up pretty good.