So there is this bike that I want to buy: a 56 c-t seat tube and 55c-c top tube mint '84 gianni motta. Super rad bike. The only problem is that I'll need to change out the handlebar to a more modern fit (larger and flatter on top) and will need to accomodate my long torso (no easy task!). I have found that with the vintage bikes, I can't find a bike that "just fits".
I think it is the seat tube angle. Since I don't have the bike in front of me, does anyone know the seat angle of the gianni motta "personal 2001)? I'm thinking about changing out the campy seatpost to an easton with 40mm offset (right now it has a 20mm offset) to acheive the 60-40 weight ratio and also possibly changing to a longer saddle. If i do that then it doesn't affect the 125mm original stem length and I THINK I will be comfortable.
Is there any problem with rigging the seatpost to accomdate my long torso? I have sat on the modern felt bike and it fits like a glove (I took its measurements and am using them to rig the motta) I am tempted to look around more but I'm not sure exactly what I'm looking for (a shallower seat tube angle?) because I still want a (preferably vintage) racing/performance oriented bike...a comfortable one, that is. What should I do?
U said "I took its measurements and am using them to rig the motta" but what measurements? the angles? u have to different bikes there... u cant adjust the position traying to trick the angles with the seat and the stem, because u wont find the right position ever.
Well what u have to do is take the measurements related to the floor, for example from the floor to the top of the seat, then the front of the seat how back is related with the center of the BB (always use center of the BB OK??? i think make a lot of sense), then from the front of the seat to the front of the stem, then fron the floor to the top of the stem and so on... put them in a paper ok?. I think u got the idea. Try to reproduce those measurements in the MOTTA, thats all u have to do. If the motta is smaller or bigger than the FELT for sure u will have to change the stem or something anyways.
The angles will give u only how soft or how the handling it will be. So u cant compare one bike to the other one or try to find the match in the other bike because no matter how u move the seat and stuff the ride it will be different anyways. For sure u'll be able to transfer all the measurements to the Motta but I bet the ride it will be different and u'll have to get used to it anyways.