Originally Posted by
Happy Feet
I'll check the stem but admit I took it out for a 35km ride today to see how it ran and decide on a gear combination I like.
THE STEM IS DANGEROUSLY TOO HIGH!
Sheldon Brown forever damned AVA brand stems as
Death Stems! I've never seen an AVA stem fail but the sand cast PIVO brand stems are/were the
real death stems, especially the ones produced during the early 70's Bike Boom.
The stem on your bike is probably old enough that it's better quality but before I ever got back on that bike I'd pull the stem, also the fork and carefully inspect both for cracks.
Stems should be inserted at least 75mm-80mm (3") into the steerer so the expander is below the threads on the steerer!
Here's an example of an extremely poor quality Bike Boom era PIVO stem. Note the flaws in the quill - it's supposed to be 21.9mm diameter but measures ~20.0mm in the mid section.
More importantly, note the crack at the top of the expander slot!
This is what happens when the crack spreads. You are left hold the detached bars! It happened to me!
When the stem is tightened with the expander section in the threaded area of the steerer, it can also cause a crack in the threads. The sharp V shape threads are perfect for creating stress risers.
French style steerer with a flat in the treads for the lock washer.
British/Italian style steerer with a slot milled in for the lock washer.
Back in the early 70's I had 2 stems fail while road testing customer's bikes plus the top of a steerer break off. I was EXTREMELY lucky in that I was able to safely bring those bikes to a stop.
So unless you like to meet new people like orthodontists, plastic surgeons, neurosurgeons, etc. I suggest that you take my recommendations seriously rather than being concerned about the looks and gears of the bike!!!
One other suggestion, file, drill or grind a small round area at the top of the expander split in the stem to prevent stress riser cracks from forming. I do that to ALL of my stems that don't already have them.
REPEAT - The stem should be inserted 75mm-80mm (~3") into the steerer to get below the threaded section.
Also, your bars are probably 36cm or 38cm as was the fashion back then.
Originally Posted by
Happy Feet
The chain line is terrible with lots of front rubbing and skipping under pressure in both low and high chain rings. It only confirms my desire to make it a single speed.
Figure on bikes like this as having 8 usable chainring/FW combinations. The cage on the Simplex FD can be bent a little and properly aligned with the chainring but... those old Simplex Delrin derailleurs are far more than prone to breaking.
Originally Posted by
Happy Feet
The chain rings are 52/30-something that are riveted together. If I don't want to destroy it (I like to keep parts I take off in case someone else wants to restore it later on) I'll have to swap it out for a period correct (in appearance) replacement. However, That big chain ring (also the one connected to the crank) is too big!
The chainrings are probably 52/36T. Those crank arms most certainly have a 50.4mm BCD (Bolt Circle Diameter) which was an industry standard for decades. TA Pro 5 Vis (Cyclotourist) and Stronglight 49 chainrings will fit but you may have to play around with the mounting bolts.
TA "Outer" chainrings are available in 40T from Peter White Cycles:
https://www.peterwhitecycles.com/ta-chainrings.php
This BF thread discusses TA Pro 5 Vis (Cyclotourist) in depth.
Specialties T.A. Cyclotouriste (a.k.a. Pro 5 Vis) History/Info
Originally Posted by
Happy Feet
I have read that persnickety French axles won't take English cottered cranks. Is it so in this case and, if so, are there any easily sourced standard cranks that will fit? Something in the 35T or so range.
If you want to forsake a period correct look, VeloORANGE sells square taper sealed bearing BBs. That allows you a wide selection of cranks to choose from (and don't believe all the bull pucky about ISO, JIS and other spindle tapers - if it fits, it works)
Here's a Flickr album I put together in a hurry back in 2011. Read my descriptions under the photos. I should update it - someday.
https://www.flickr.com/photos/282672...57627678462359
I personally would be far more concerned about the stem than the looks... we don't like to loose members on BF!
verktyg
