Refurbishing brake drum surfaces           December 2016

Reclaimed brake/clutch surfaces

A few photos of items I've recently had metal sprayed to restore the brake drum surface to the original dimensions (skimmimg has a limit).

Photo 1. 2 New Hudson brake drums and a pressure plate from a single plate clutch.

More about vintage and veteran motorcycles to come.

Back from the scrap heap

1930 New Hudson brake reclaimation

Photo 2 a 1930 New Hudson rear brake drum. This should be a nominal 7 inch (177.8mm) diameter brake drum. When it came to me, the drum rang like a bell! The drum was about 7 1/4 inch (184mm) dia and the wall thickness was minimal. I thought this would end up as scrap, as I wasn't prepared to reuse the brake with such a thin wall.

The specialist melts 2 feed metals (stainless steel and copper) together in specific proportions, and blows it using compressed air, to the base surface. The 'filler' metal mix is then turned/ground down. You may notice a coppery sheen to the rebuilt surfaces. I've already had the 1931 350 New Hudson running on metal sprayed drums with new bonded shoe linings, and the brakes are very good!

 

Gouged out clutch plate

Clutch plate

This clutch pressure plate from a 1922 Moss lightweight gearbox/clutch was very rough, having suffered a lot of metal to metal contact in it's earlier life. I could have machined a new plate from solid, but the 'teeth' would have to be filed manually, or maybe laser cut.

I thought a better way was to refurbish the original with the metalspraying process (which is primarily used to resurface huge textile machinery rolls instead of replacement). This enabled additional thickness to be laid down, to increase the rigidity of the plate.

Petrol tank rubbers                                        February 2017

Collection of tank rubber photos

The 1931-33 New Hudsons have tank rubbers with quite complex shapes. The left side is quite bulky but hollow, to mimic the shape of the right side which encompasses the hand gear change gate. With time and UV exposure, the left side sags badly and the right side splits on the concealed mounting plate.

I sent my best distorted pair along with 2 petrol tanks (350 and 500) down to Dial Patterns for moulds to be taken. These were then reworked to correct the distortion and both tanks checked for 'fit'.

Then 25 pairs were slowly poured (3 stage process to eliminate air bubbles). 4 pairs were supposed to be for my bikes, but every single pair has gone to other owners! The material chosen for the new rubbers is much better for wear than some others on sale, but we found that the odd splash of rain resulted in grey/green spots as they absorbed moisture (although they turn black again as they dry out). Soon sorted with a coat of tyre black paint.

Another smaller batch has now been ordered, but this will be the last batch.

More vintage and veteran motorcycle restoration topics to come.

Tank Rubbers available again                            July 2017

The last ever batch of 1931-33 New Hudson tank rubbers have now arrived. 15 pairs made, 4 for my bikes, 3 to Austria, 1 to India, 1 to Norway, 1 to Warwickshire. The rest are still available at £100 a pair plus postage. Not cheap compared to commercially available rubbers, but these are a superior, longer lasting material, and small batch manufacture.