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I have and old schwinn HS. .....probably 86 or 87. 68mm bb and i have some shimano fc-mt60 triple cranks. According to Sheldon that triple crankset should be 122.5mm. Thats what i put in. A brand new shimano sealed un55 122.5mm bottom bracket.

with no front derailleur on the bike should the bike want to run in the smallest gear in the front or the middle ring? Right now with no front ring and the smallest cog in the rear it wants to sit right in the middle of the large and middle chain ring and jam in there. Makes no sense. It seems like the spindle is too long? I would think a mt60 would be around the same era and work great. I am not sure what is going on here.

I hope to get it sorted out. This thing has rollercam brakes and is going to be a great commuter.

88Tempo

It's probably trying to climb up onto the big chain ring.

The way I understand it is that with a triple up front the middle ring should line up with the middle cassette cog as closely as possible.

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i suppose i can try to put a spacer or 2 under the drive side to see if that helps. It just seems odd. I thought maybe i had the wrong size spindle but i even pulled it and checked. I did throw a 9 speed cassette on the rear and i am in the smallest ring in the back and it is really really close to the chain stay/dropout but not rubbing or touching. Perhaps that is closer to what the old 5 speed would have been thus throwing off the chainline outward a bit causing the chain to wait move inbetween the chainrings up front in a neutral spot. Strange......though.....firist time ever seeing that.

88Tempo

This is part of what Sheldon Brown says on the subject.

On a bicycle with a sprocket cluster, this is the chainline to the middle of the cluster. With a single chainwheel, this should match the front chainline, to equalize the chain angle for the inner and outer sprockets. With more than one chainwheel, the front chainline could be shifted a few mm inward or outward depending on how the chainwheels are to be used. The article about chainline with derailers covers that topic at length.

https://www.sheldonbrown.com/chainline.html

https://www.sheldonbrown.com/chainline-multi.html

TenGrainBread 

FYI a 1986 or 1987 High Sierra had a 6 speed freewheel stock. 1986 had a 14-32 Suntour freewheel with a 28-38-48 SR triple crank.

With no front derailleur your chain should not be shifting in the front unless the chain is really being pulled diagonally in the rear.

122.5 sounds like the right length. On Velobase that is the only listed length for an MT60 bottom bracket.

Did you coldset the rear dropouts to accommodate the 9s hub? If not done evenly that might affect chainline.

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The frame has been cold set and appears straight. Ill take some measurements. I pulled the cranks and spindle back off to take some measurements there and it is correct. at 122.5. I might try a spacer or 2 under the drive side cup lip.

I have yet to find the shifters i want to use. I want thumbies that will go from friction to 9 speed indexed. I will probably use them mainly friction. I am really eyeing those microshift thumb shifters with the ratcheting mech. They seem to be well liked.