1977 Carlton Corsa renew

[FR7]

The Corsa I started work on it in January, tho I was going to change it to a ten speed I didn't know that I needed a bigger bottom bracket does any one know the size for a double ring
Iam trying to upload pics but it won't let me I'll try later

 

[Spokesmann]

You would probably need a slightly longer BB spindle.