seat angles



Phill P

New Member
Jul 9, 2006
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I'm beyond frustration!

My current bike has a 72.5 degree seat angle, and I have the seat right back on the rails. I've been professionally fitted and don't have any knee problems.

How ever the problem I do have is there are very very few bikes out there that have a 72.5 degree seat angle, and I don't think I could get this position with a 73, and besides it would through off the handling.

I don't think there is anything freakish about my leg lengths, so why are the large frames out there all with 73degree+ seat angles? How are people getting correct leg geometry with these bikes??

I have a very small list of non custom bikes out there that have a 72.5degree seat angle, anybody else no of any?
 
Phill P said:
I'm beyond frustration!

My current bike has a 72.5 degree seat angle, and I have the seat right back on the rails. I've been professionally fitted and don't have any knee problems.

How ever the problem I do have is there are very very few bikes out there that have a 72.5 degree seat angle, and I don't think I could get this position with a 73, and besides it would through off the handling.

I don't think there is anything freakish about my leg lengths, so why are the large frames out there all with 73degree+ seat angles? How are people getting correct leg geometry with these bikes??

I have a very small list of non custom bikes out there that have a 72.5degree seat angle, anybody else no of any?
The seating angle varies not with the bike model but with frame size. Most manufacturers specify slacker seating angles with bigger sizes. For example, a Lemond would start at 75degrees for the 49-50cm size and by the time you reach the 59cm size and up they'd spec it with the 72.5degree seat angle.

There is no one formula for all. Even a big bike with a steep seating angle can be compensated with a seat post with an offsetted clamp or one can move the seat on its rails further back, etc. etc.
 
The seat cluster to BB difference between 73 and 72.5 degrees is only about half a centimeter on a 57 cm frame.

It would help to know what size frame you use.

If you use a larger frame then finding a 72.5 angle would not be difficult. If you use a 57 cm or smaller frame then it would be hard to find a modern racing frame with that slack of a seat angle.

You might want to check your KOPS position.
 
I currently ride a 60cm top tube, but its a bit long for me dispite being 6'2 (187cm)

And yes I know seat angle increase with sizes, but not that many brands have less than 73deg even on thier largest frames.

What I'm really looking for a 72.5deg angle (or even 72) with a 580-585 top tube and long 200mm head tube. Current bike is 72.5, 600mm top, and 200mm head, but its too long for me. 900mm insteam, but poor lower back and hamstring flexibility means I don't streetch out enough. Already shortened the stemm too (before you ask)

Cinelli and Leggera are the only brands that seem to fit this (and azzurri but I'm giving up on that idea)

Adding more set back on a frame with a steep seat angle would upset the weight balance that the frame was designed for. As I said I'm at the limit of the rails for my current bike, so would be way over the back of a frame with 73deg.
 
Phill P said:
What I'm really looking for a 72.5deg angle (or even 72) with a 580-585 top tube and long 200mm head tube. Current bike is 72.5, 600mm top, and 200mm head, but its too long for me. 900mm insteam, but poor lower back and hamstring flexibility means I don't streetch out enough. Already shortened the stemm too (before you ask)
Size 60 Cannondale Six13 and CAAD8: seat tube angle=72.5 head tube=19.2 Top tube=59.0
Merckx 58: seat tube angle=72.4 head tube=19.8 top tube=58.3
Merckx 60: seat tube angle=72.0 head tube=21.1 top tube=59.0
 
Giant TCR Advanced Teams have the 72.5 angles in their medium-large and large frames. Top tubes are in the range you want, but head tube is a bit short. Remember they are a compact frame.

06_geom_tcr_adv.jpg
 
but look how short thier head tubes are!!!

Would need about 5 spacers to get it to the correct height!
 
Phill P said:
but look how short thier head tubes are!!!

Would need about 5 spacers to get it to the correct height!
I just added the Merckx stats to my earlier post. Merckx has always used a slacker geometry and it looks like it would fit your needs.
 
Wish I could afford a merckx...might as well go custom.

Will go have a look at thier range anyway (and buy a lotto ticket)


mmmm AXM......