Simplex clamp on gear shifter bracket - which bolts?

teraffic

Retro Newbie
Hi there, thanks for any help you can give.

I bought my gf a Carlton Courette mixte; she doesn't get on with downtube shifters or drop bars, so I'm converting it to flat bars and shifters. Sacrilege? Anyway. I got some shimano downtube cable stops, only to realise that there are no bosses on the downtube; the shifters were band on. Not possible to dismantle enough to use them for the cable stops, so I bought the below simplex piece. The supplied shimano bolts are just a tiny bit too big;
they go on for a couple of turns into the simplex and then jam. Everything I look at is either too big or small. Any thoughts on what bolts these would take? Or should I try and tap a new thread??View attachment 560840View attachment 560841 View attachment 560839
 
Hi there, thanks for any help you can give.

I bought my gf a Carlton Courette mixte; she doesn't get on with downtube shifters or drop bars, so I'm converting it to flat bars and shifters. Sacrilege? Anyway. I got some shimano downtube cable stops, only to realise that there are no bosses on the downtube; the shifters were band on. Not possible to dismantle enough to use them for the cable stops, so I bought the below simplex piece. The supplied shimano bolts are just a tiny bit too big;
they go on for a couple of turns into the simplex and then jam. Everything I look at is either too big or small. Any thoughts on what bolts these would take? Or should I try and tap a new thread??View attachment 560840View attachment 560841 View attachment 560839
Hi, I think the Simplex bolts are a different thread from the Shimano ones. Probably French threads.Can you use the screws from the original down tube shifters?
 
teraffic -

Your attachments didn't come up so I am assuming you are trying to fit older Simplex retaining screws to the modern Shimano clip. Older Simplex levers used a now obsolete metric M5 x 1 screw thread compared to the modern M5 x .8 which is probably what Shimano is using. Perhaps get a thread gauge and check? If you tap a new thread you may not have enough "meat" to retain the new bolt. There is related info here: https://peugeotcoursepb12.wordpress.com/tag/retrofriction/
 
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