Originally Posted by
T-Mar
In the first post he says it's a 28.5mm seat tube with a 25.4mm post, indicating imperial tubing and hi-tensile steel.
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Danj54 wrote
"The tubes are 28.5 and 25.4mm." I didn't see any mention of seatpost diameter. 25.4mm seatposts were used on gas pipe French bikes up through the mid 70's (25.0mm, 25.3mm and 25.8mm too).
Originally Posted by
T-Mar
It also had an English threaded BB shell. However, the serial number format is consistent with later Motobecane/MBK. Do you know what year they switched to imperial tubing and English threading?
T-Mar, I don't know that they ever did. All of my French bikes from throughout the 80's have metric tubes (4 Motos, 6 Gitanes, 5 Bertins, 5 Peugeots and 1 Mercier).
Some have British threads and use 22.2mm stems but there's no logical time line as to when the switch from metric threads took place.
My 1986 Bertin has metric Reynolds 531 tubes with French threads and my early 90's Bertin has metric Reynolds 501 tubes with British threads.
I'm in the middle of replacing the headsets on my 1983 Peugeot PSV-10 (metric) and the 90's Bertin (inch) so my measurements are very fresh. Dug through my box of headsets looking for a metric Stronglight A9. Only had British so I got one coming from eBay.
In the late 70's we started seeing Peugeot U-08s with British FWs and pedals, even a few with British BBs, even 1-2 with Swiss BBs coming into our shop for service - we didn't sell em, only worked on em (looking back, they could have been Canadian made or assembled).
I have a 1974 Gitane TdF that came from OZ. It has British threads with metric tubes. Probably made for the Australian market.
Is it wrong... Or just French???
Chas.