CRANKSET:
O.M.A.S. Corsa (modified) - post 1968 Campagnolo Record compatible 144 mm BCD - 42/52 Clear anodized and factory "drilled" aluminum alloy chain rings / no inner reinforcement webs / 52 tooth ring without chain "roll off" pin - 170 mm Clear anodized forged aluminum alloy arms / 9/16" x 20 TPI pedal threads / 22 mm x 1 mm cap threads - O.M.A.S. model 804 dust caps (omitted) - O.M.A.S. model 166 aluminum alloy chain ring bolts - model 900/SS "Big Sliding" Corsa : O.M.A.S. crank bolts and washers - Black anodized aluminum alloy - M8 x 1.00 x 20 mm bolts with 15 mm head / M8 flat washers : grouped model 167 : stainless steel protective pedal washers ... [Although they were distributed through O.M.A.S. and indeed bear their distinctive logo, these crank arms are actually based upon forgings made by Sakae Ringyo (SR) - just as were those late 1970’s to early 1980’s proprietary Raleigh cranks as well as the earliest version of the MAVIC branded SSC cranks dating from 1978 through 1988. In each of these instances, unfinished SR Royal crank arm forgings were sent along to those respective companies where they were machined, ground, polished, etched, and anodized to preference. This makes perfect sense if you think about it inasmuch as a full fledged forging operation requires a HUGE capital investment and ongoing expense - one that simply could not be justified by the likes of O.M.A.S., MAVIC, or Raleigh given those products that they offered requiring same. On the other hand, Sakae Ringyo, which has a history dating back to 1912 even though it was effectively re-incorporated immediately following the aftermath of World War II only to eventually be purchased by Japanese steel tubing manufacturer Mori Industries in 1989 and combined with the remnants of Maeda / SunTour when Mori assumed the assets and liabilities of that company in mid 1990 to form SR SunTour, was a massive company offering a diverse range of forged goods, many of which were not even cycling related. They were also the largest producer of bicycle crank forgings in the world at that time (...they would later slip to number two after Shimano got into the game forging their own wares at a newly re-dedicated Taiwanese facility). SR easily had the capacity to service any additional volume that the three aforementioned comparatively small companies might possibly generate on their own - and to do so many, many times over. As for the O.M.A.S. specific version of these cranks, just like their contemporaneous Campagnolo counterparts they have a 144 mm BCD, use a standard 22 mm x 1 mm cap threading, and they even bear a striking physical resemblance. But there are subtle differences too. The edges of the crank arms themselves are more rounded than the Record arms, the decorative fluting is both wider and deeper and its edges are finished differently, and the tabs at the end of the crank spider where the chain ring bolts pass through are not squared off but rather have been rounded. As for their respective weights, a bare vintage Campagnolo Record drive side crank arm (...no rings, chain ring bolts, or dust cap) weighs in at 254 grams whereas its O.M.A.S. counterpart tips the scales at 261 grams. But before anyone jumps to the conclusion that a mere seven gram difference might somehow be of any significant advantage, consider if you will the fact that vintage Record cranks have a reputation for too often cracking at the apex of their spider along the stress riser whereas the SR forging, in any of its various guises, was and still is generally acknowledged as being virtually bullet-proof in this regard. The earliest O.M.A.S. branded model 800 and 900 cranksets came fitted with aluminum alloy chain rings which were essentially the same as the SR Royal-5 having inner reinforcement webs like their Campagnolo Record / Nuovo Record contemporaries. By the year 1981, however, O.M.A.S. had diversified their product line to include alternatives featuring both lightened chain rings (...their 800/S and 900/S models) as found on the SR Royal-5 SL and which were quite similar to the Campagnolo Super Record offering, as well as "special" lightened chain rings (...their 800/SS and 900/SS models) where not only the inner reinforcement webs had been removed but the rings themselves were given the factory "drillium" treatment in common with the SR Royal-5 ESL and Apex AX-5DLASL models of cranksets. In each of these cases, the chain ring bolts provided were chrome plated steel and not the optional O.M.A.S. aluminum alloy ones I have seen fit to employ here. And in keeping with those other examples of such minor flourishes to be found elsewhere on this particular Pino Morroni bicycle, the fluting and logos on the face of these O.M.A.S. crank arms were given the decorative Black paint infill treatment. I will also freely admit to fitting aftermarket and non-standard stainless steel pedal washers to help protect the anodized finish on those alloy crank arms. The original crankset which came mounted on this Pino Morroni was a Gipiemme Cronosprint model 100BA Bagarre featuring Black anodized 170 mm arms and 42/52 Gipiemme light alloy chain rings.]
