Hi

Well, the dangers of rummaging around on EBay late at night... I've acquired an ancient, very heavy but well made tandem frame locally for not much money. Found the number ST24 under the front bottom bracket which, having done a bit of research, could suggest it's a Sun frame made in 1951. Whatever it is, it seemed like a good candidate to get back on the road, takes 26 inch wheels, so no problems there, frame and fork crown drilled for caliper brakes (no worries, we're in Cambridge and all the hills left years ago), even the rather lovely Brampton eccentric bottom bracket shell appears to take, after careful measurement, using the digital vernier caliper I finally had an excuse to buy, a 'standard' 1.37" x 24 TPI adjustable bearing cup (the fixed cup being integral with the shell) rather than the unicorn-like Chater Lea 1.45" which were often fitted to tandems back in the day, I believe. Furthermore, all of the bearing surfaces are in a fair ride-to-the-pub-but-stay-away-from-the-alps state (bottom bracket and headstock grease nipples to thank for this I think) and I can get hold of cottered axles and chainrings to make a reasonable approximation to the single sided drive I believe may have originally been fitted. All good, or so I thought, however, on closer examination with a wire brush, I discovered some bright spark has drilled a hole through one of the fork blades several inches up from the axle mount, no idea why, maybe for a drum brake reaction arm? To my mind, this makes the fork somewhat unsafe... though the hole appears to have been drilled in antiquity (several of the coats of paint appear to have been applied after it was done) and previous owners must have been quite happily hooning around on it in this state, not me however.... So, back to EBay and purchased a 'vintage tandem fork' on the off chance it might fit and miracle of miracles it does (steerer tube about an inch shorter than the original on, but this, surprisingly, wouldn't have been a problem), but, you've guessed it another (maybe the same..) bright spark had drilled a hole in one of the fork blades on this one too, his time at the top... Right, time to forget authenticity, would it be OK to use a modern decent quality mountain bike fork as a replacement? They appear to be much stronger than the delicate, graceful originals, but appearing and being are two entirely separate things.. the forks on my tandem trike are even thinner and more graceful than the holey vintage bits and yet seem to tolerate the huge side loadings the trike generates, so clearly size/thickness is not necessarily a guarantee of strength. Yes, there'll be numerous issues with steerer lengths/ threads/fork angles, bearing sizes etc to keep me out of said pub, but would mountain bike forks, in principle, be up to it? Phew, thanks for your time, off to measure some ball bearings....