Originally Posted by
FrancoSuisse
Front is 47-50, but the 28 tooth rear freewheel is about all the Gran Sport can handle. I had to leave a little slack in the chain. Even with a frame indent, the 47 chainring runs a few millimeters from the frame.
The dropouts have soft rounded edges as though cast, but are not precision.
As for what is "stock" on these bikes -- I remember in 1962 a dealer friend ordered two dozen Legnanos from Avenia and was able to spec them, component-wise.
Nice bike. I have posted about my 64TdF previously here also. I was only able to comfortably get a 14- 26 Suntour perfect 6 speed rear in mine. As you state, I had to leave chain slack so as to allow the Gran Sport RD to have enough slack to get the big/big combo too. It was stated to me by veterans of half step gearing to not ride in small/small or big/big which makes sense. The Gran Sport was at limits of adjustment of both high and low, but it does get all 6 gears. The 3 tooth shifts to the 23 and 26 tooth gears are not as crisp as the 2 tooth shifts, but worth the tradeoff. Your bike also looks to be the larger frame size as is mine. It is really too big for me, but these old Italians are not easily found, so one works with what they have. I put a shorter handlebar stem on mine.
5th gear slack, I wouldn't use small and 6th
Suntour Perfect 6 speed. 1 washer moved from left side to right and axle recentered so 14T misses the RD mounting bolt.
I find it interesting also that your bike like mine lacks the oval at the seat post. Most have that. Mine has no tubing sticker, but Falck has been mentioned. Do you think yours came originally with fenders?
Are your wheels 27"? I copied this ad from another poster that I found interesting.
Mine looks and sounds like the top one
I was happy to get the 14-26 on mine as the 14-22 5 speed that mine came with was too tall for me. I am 62. I will need to investigate the 45/42 gearing that PhilBob57 mentioned. Flatlands here too. I didn't pull my BB, as it was adjusted to perfection and I didn't want to risk damage to the cotter. The 3 speed guys pour oil down the seat tube. I made a slightly runny lube of grease and 80/90 gear oil and put down seat tube. I had to push it to the bottom with a dowel. Laid bike on side for a day and rotated pedals. After a couple days of this, I saw traces of lube from the BB. Repeated on the other side. Not really proper, but BB adjustment and bearing feel was perfect and I wasn't going to risk cotter damage. This bike won't be ridden thousands of miles so good enough. A very interesting and unique find and project. Have fun and keep us posted.