Originally Posted by
mitchmellow62
I think we're on the right track but I don't totally agree with Hondo6. The original crankset looks to me to have riveted chainrings. It also has no labeling. I'm doubting it is Campagnolo. Also, putting the crank on a shorter spindle than spec would move the crankset inward and produce the opposite change in chainline than described. I do think that the 300ex crank is probably on the wrong bottom bracket spindle but I think its too long. At any rate, changing to the correct bottom bracket (115mm for the 300ex according to Sheldon Brown) will fix the problem(?).
You appear to be correct re: the original crankset being rivited. I hadn't examined the photo at higher mag and had assumed those were bolts.
Interesting about the disconnect here in spindle length for the FC-A300. Per Velobase, the original BB for the 300EX groupset was the BB-A450. Other sources say that later Shimano switched to a cartridge BB (BB-CS10 or BB-CS11, if I recall correctly).
The BB-A450 was produced in 2 versions: 113mm spindle for 68mm (English) BBs, and 115mm for 70mm (Italian) BB shells.
https://manualzz.com/doc/53868814/sh...-exploded-view
Haven't checked spindle lengths for the later cartridge version that Shimano switched to, but I've seen at least 1 for sale that had a 115mm spindle for an English BB. So at least that length was made.
My guess - and this is only a guess - is that Shimano found that a 115mm spindle worked equally well with both and later changed their recommendation re: spindle length. That would be consistent with my own experience; I'm running the 300EX groupset (less the groupset's BB and hubs) on an older bike with a 68mm BB (English), and as I recall it currently has a 115mm generic cartridge BB in it. Works fine with 115mm; I'd guess it very likely works acceptably with 113mm too. Can't recall what the original BB was (bike documentation didn't say what type was installed and I don't recall now).
You could well be correct about the spindle being too far out vice too far in; that's hard to tell from the OPs photos and description. The rear view photos of his bike with the Shimano crankset installed don't really show the distance between the crank and the BB that well. Mine has what I'd estimate to be a 5-6mm gap based on poorly-calibrated eyes. (smile)