Time trial frames: Extended Seat Tubes benefits?
- Thread starter angusross
- Start date
Old Ned
Old School Grand Master
I don't really think there's a benefit as such, just a different way of building a low-profile time trial frame compared to a sloping top tube style. I've known riders have long seat tube extensions and very short seat pins but this does limit the size of rider who can use it. It's a bit like the current vogue for 'seat masts' on modern 'knitted soot' frames. At least the one you show does have a 'reinforcement' between the seat and top tubes. The overall seat tube length c-2-t could be slightly longer than you would use on a 'normal' frame.
Is the frame yours? It's nice.
Is the frame yours? It's nice.
Old Ned":3b0saznu said:
No unfortunately its not mine!
The reason being is I am looking at a TT frame with a extended seat tube. the center to top is 58.5. Not sure about C to C but I normally ride a 51-53 C to C. the top tube is the right size (52.5) its a low pro frame with 700c wheels. Just trying to figure out if its a ok size for me. I imagine my seat pin will end up being quite short and wanted to know if that is a problem..
It's done for aerodynamics. They're trying to do away with the turbulent air created by the binder bolt. The seat masts of today actually succeed but the extended seat tubes didn't.
I suggest you get the c-2-c height for standover reference. The c-2-t would just have to be a little less than your current BB to seat rails measurement. just to make sure you can get your post and seat on.
I suggest you get the c-2-c height for standover reference. The c-2-t would just have to be a little less than your current BB to seat rails measurement. just to make sure you can get your post and seat on.
Extended seat tubes don't fix the aerodynamic problems of the binder bolt because there is still a collar and binder bolt sticking out unless your seat is slammed all the way down to the top of the extension.
As for weight, yeah I guess you could save a good number of grams cutting your seatpost shorter but I'd still not go all that short. Although the frame pictured above has a reenforcing gusset most do not. If there are no gussets the stress points are the same as on a standard frame and require the minimum insertion point to be down at the top of the top tube.
As for weight, yeah I guess you could save a good number of grams cutting your seatpost shorter but I'd still not go all that short. Although the frame pictured above has a reenforcing gusset most do not. If there are no gussets the stress points are the same as on a standard frame and require the minimum insertion point to be down at the top of the top tube.
