Cleaning alloy cycle components

I was doing some internet searching in relation to a bike I had to work on for the Springhill Cycle Collection. The bike, an early 1970s model, had been stored in less than ideal conditions and the alloy components were showing signs of surface corrosion - not been cleaned before it was stored. The components were a Spanish copy of Campagnolo and in parody of the great Roman cycling god, the copies were named after the ruler of the Greek Olympian gods, Zeus. Frank Berto in his tome 'The Dancing Chain' doesn't rate Zeus components. Zeus components were never very common in this part of 'the oul sod', so to get a bike equipped with Zeus is unusual. The bike is local, has been ridden and used judging by the layers of dirt and wear to the parts. Anyway to return to the point, the large flange hubs are not Zeus and turned out to be of Japanese origin. I haven't seen photos of this particular model of hub on the web.

However, here at Methuselah Towers I have a confession to make. I haven't bought a news stand cycle magazine in 10 years and don't frequent internet forums, so therefore cannot claim any kind of expertise other than experience. So I have to defer to the 'experts' on the web, who advocate using various grades of abrasive papers and buffing wheels to polish alloy components. Personally I would have grave reservations about such an aggressive approach, as I have experience of alloy components such as Campagnolo and Stronglight cracking and failing. I also don't agree with re-polishing old alloy to a very high surface shine, far removed from the original finish. To me it detracts from the originality of the parts/machine and can, in my humble opinion, be a case of 'over egging the pudding'.

I prefer a more subtle approach, one advocated by a long forgotten source. I was told to use a brass brush to clean alloy and then wipe the surface with oil. I now prefer to use WD40 or an equivalent solvent, on a soft cloth or a bit of kitchen roll, to wipe the burnished alloy. The brush will get rid of the surface bloom and expose the nature and extent of any surface pitting and corrosion. A decision can then be made about re-polishing if deemed necessary. It is surprising how much the brass brush will clean up the alloy, whilst still leaving a sympathetic finish to the metal. Where the corrosion is not too deep it can be polished out after cleaning, using Autosol and a soft cloth. A final clean with a silicone based car polish will give it the final seal as you have in all likelihood removed the original anodised finish. I have tried to show a few before and after photos to illustrate the point. The Maillard small flange hubs are ones I rescued from the scrap bin of a cycle business. 

Remember that you will need to keep an eye on your repolished alloy as it will now be more susceptible to corrosion as the anodised coating has been removed!

Frozen handlebar stem

I bought a 1982 Hirame Model 48 SUMA bicycle frame a couple of years ago on e-bay, which came complete with a frozen handlebar stem. Hirame were made by Kuwahara, from Osaka, Japan and imported into the UK in the early 1980s, by the now defunct bicycle business Evian (G.B). The frame had been used as a winter bike, judging from the nature of the corrosion and all the gear tunnel braze ons and rear gear hanger had been removed from the frame. It was no longer in the original paint. My frame is not from a top of the range machine built with Ishiwata tubing. It was my intention to restore the bike to as near original as possible, with all Japanese parts. The frame originally had full chrome forks and rear dropouts. The difficulty was how to remove the original alloy stem which was stuck in the frame due to galvanic corrosion? I intended to try and save the stem if possible. It would be easy to cut the stem and melt the seized part out of the steerer tube with a gas torch. I had done this in the past and read of various methods on web forums, of how to remove the stem, but all involved the destruction of the alloy stem. I preferred to try a different method. Making sure that the expander bolt assembly was in the stem and tightened up, I up-ended the frame and hung it over a drip tray. I then poured a product called Plus-Gas, down the steerer tube, leaving a small reservoir above the expander bolt and left the frame for three weeks, refilling from the drip tray as required, adding some new liquid each time. Once the liquid had finally drained out of the steerer tube, I then righted the frame and inserted a front wheel into the forks. I then released the stem expander bolt and inserted a used, salvaged, long steel riser MTB handlebar into the stem to try and turn the stem.

It gave easily and with a little effort, levered out of the frame. There was much evidence of galvanic corrosion, especially in the slot at the back of the stem above the shaped expander nut.

I cleaned the alloy with a brass brush before using a metal polish. There was a linear crack spreading horizontally, each side of the circular hole at the top of the slot designed to prevent cracking!

I would guess the damage maybe occurred when someone tried to remove the stem, whilst it was welded in through corrosion, prior to the frame being sold. I am disappointed that the stem is not safe to re-use, but it was worth the effort to try and remove it in a non destructive fashion.  I have learned something along the way.   I don't know if this method will work in every case, but I will certainly try it again in the first instance, to try to remove a stem without damage, before resorting to a more destructive method of removal as a fall back position.