At the Co-op I have been working on an old Gitane Mixte. It is low end, with the usual Delrin Simplex derailleurs and cottered steel crank. Yesterday we put on a pair of aluminum 27” wheels to replace the steel ones. After we got everything adjusted, I took it for a short ride in the parking lot. To put it mildly, it Did Not Feel Right. The front end felt as though the wheel wanted to flop from side to side. I have ridden quite a few bikes (including French bikes from that era) and have never come across that. I did not have a lot of time to look further at the frame but since yesterday I have been wondering if the fork was a poorly chosen replacement. When my client comes back in, I want to measure the trail and the frame angles to see if I can spot anything amiss. Can you kind folks suggest anything else I should keep my eye on?

Thanks, unterhausen. I have a mid-70s Peugeot with low trail so I know what you mean. When I first rode the Peugeot, it was obviously different but not that hard to get used to. But this Gitane feels waaaay different. I’ll take some measurements when I get the chance. That should help diagnose what is happening.