I bought two new old stock Lotus frames a while back.
One from eBay, the other from a bike shop.
Both appear to be the same frame, one in dark blue, the other in green. Both with LOTUS script on the tops of the seat stays, both have sloping crown forks, and both have Lotus decal headbadges, but both came with a metal headbadge and two rivets?
Both use a recessed seat clamp bolts, both use recessed caliper nuts. Both have Champion #1 decals. Both have Shimano forged dropouts and are 63cm, with 126mm rear spacing. Both frames have down tube shifter bosses and both use a 27.2mm seat posts. Each frameset weighs just under 5lb.
The shop owner that I bought the one from seemed to think it had been ordered to replace a customer's wrecked Supreme frame but they sent the wrong size and it never got returned. The one from eBay came from a guy that said he bought it at a bankruptcy sale in a lot of items, and knew nothing more about it.
Now here's the kicker, the rear brake bridge is mounted so far up the seat stays that even with a 27" wheel that the caliper needs to be about 60cm reach or so. Of I use a 700C, a set of long Dia Comp Center pulls would work but there's no way to mount a cable hanger with a recessed seat bolt.
The fork had the opposite problem, a 27" wheel with a 1 1/8" tire only clears the top of the fork by about .040", a larger tire wouldn't fit. Plus, I can't find a short enough reach brake caliper? I've got a super short set of Shimano 105 calipers, but even they won't adjust up far enough to match the rim. With a 700C wheel, it looks normal and I can run a normal 49mm reach caliper, like the Dia Compe 500s I was planning on using.
I'd rather run 700C wheels, but I have both sizes here I can use.
I need to figure out the brake caliper vs. rim size deal.
If the rear brake bridge was lower, I'd be fine, but it's even mounted high for a 27" rim, and out of reach for a 700C. There’s not much difference between the two rims but the braking surfaces are about 15mm different overall, or about half the width of a brake shoe. I don’t mind running two different length calipers, but I want them to be the same type and series.
If I run 700C wheels, I won't be able to find a long enough rear caliper, unless I find a way to mount a cable hanger. It looks to me like the rear is made with 27" in mind, and the fork is made for only 700C.
Also, installing a 27" wheel with tire requires deflating the tire, it hits both the seat post and the front bar between the chainstays, a 700C bare fits in but will clear with a 25mm tire. Was there some type of caliper that I don't know about that would fit something like this?
Second, does anyone know what was a super low stack height headset from the 80's? I was going to use a Shimano 105 or 600EX headset and there's not enough fork threads. I have an old steel headset from an old Trek that works, but just barely, but I'd prefer to use something lighter.
I was also wondering if just using a different fork would solve my wheel size problem? I need a steer tube about 244mm long to use the better headset. (As well as allow me to use a 27" wheel and still run my Dia Compe 500 brakes.) I have one Champion #2 all chrome fork here, but its a plain stamped type crown, which would look odd on this bike. But it may be my only option?
(Sorry for the long first post but I wanted to keep it all in one place).