Recently I’ve been working on this Herse tandem number 109 99. It probably dates from the early 1940’s and was most likely upgraded and re-painted by Herse around 1947/8. It has posed a number of questions in how to deal with certain condition problems. In particular, the front derailleur has been cut off and the question is how to replace it without causing damage to the original finish of the bike. The front and rear racks are very rusty and pitted and are not suitable for re-chroming, and the rear drum brake is in a poor state.
The front hub is an FB – ITALIAN no less! Herse turned the flanges off and riveted on his own very large duralumin flanges. There are 18 rivets each side, corresponding to the spoke holes of the original 36 hole hub, but the new flanges were provided with 40 holes to make for a stronger wheel for the tandem. The spokes are Trois Étoiles non-butted tandem spokes and the rims Mavic. The papillons are Bell bronze, a stronger option for the tandem than the usual alloy version. Spokes and the steel centre part of the hub were cleaned with a brass brush and then various grades of wire wool. The aluminium parts were polished by hand using 00 wire wool, followed by 0000 wire wool and polish together – either Solvol Autosol or Simichrome. I prefer not to disassemble where possible, and this makes for a lengthy and sometimes awkward process, but with results that respect the originality of the bike. I also dislike using a polishing wheel because I prefer a slightly satin-like finish, rather than highly polished. Also, the wheel can destroy detail and leave an uneven surface. Final polishing is done with Solvol Autosol.
Similarly the chainsets were all polished by hand using the same 2 grades of wire wool, and polish, after initial cleaning and de-greasing with cellulose thinners. I always use thinners outside, and take the usual precautions considering its volatility and other dangers.
The same techniques of hand polishing were used for the Lefol brake levers and Cyclo 5 speed Derailleur. Note the Herse modifications of the right hand brake lever, beautifully crafted, to apply both front and rear rim brakes together, whilst the left lever operates the rear drum brake. The Derailleur has also been modified by drilling the shafts and providing oilers to properly lubricate the moving parts.
As far as the frame was concerned, it was quite a challenge due to the presence of many scratches and small rusty areas. The frame is never going to look immaculate, the aim being simply to make it presentable. I chose to do a minimal amount of touching in of paintwork. After initial cleaning of the oily bits with paraffin, I rubbed the rusty areas lightly with 0000 wire wool, treated the rust with a neutraliser, then cleaned the rest of the paintwork with Renaissance Pre-Lim, a very lightly abrasive compound. This removes any remaining dirt and grime, preparing the surface for the final polish. It is very important to keep away from the lining and lettering, which can be done by carefully working up to the lines with a single finger inside the cleaning rag. Pre-Lim can leave a white residue in the rusty bits, so I clean this off with car brake cleaner, a quickly evaporating solvent. Some touching in was done, but I tend to wipe off much of the paint before it dries, only leaving small amounts in the scratches or damaged areas. This darkens the area without leaving a too obvious patch of new paint. After that the final finish is two or three coats of Renaissance Wax, which brings back the shine very much to its original look. The original finish is nowhere near as glossy as modern finishes, which is why refinishing never looks quite right.