I have a question about Cyclocross frame geometry. I have noticed lately that alot of the seat tube angles are getting slack. For my size frame the two cross frames that I am looking at (Specialized and Salsa Chili) have slack 72* seat tube angles. It would seem to me that for cross racing a 73 or steeper seat tube angle would be beneficial. Any thoughts, opinions or input would be appreciated.

Are you looking at a large size frame, 58cm or greater? Most frames have 73 degree seat angles, for example, Redline, Kona, BMC, and Ridley. These frames are in the 54 to 56 cm size. The big questions is frame size. Do you get a one cm or two smaller frame and depending on your terrain, might need to consider BB height.

I currently ride a 58cm Cannondale cross bike with a 59 top tube and 73 seat angle. I am looking to move my Cdale to a pit bike and get a tricross or salsa chili but the comparable size has a 72 seat angle. I tested a tricross and felt that the geometry was really lax.
Maybe it is just in my head. I mean does 1degree of seat tube angle really make a noticeable difference?
Are you looking at a large size frame, 58cm or greater? Most frames have 73 degree seat angles, for example, Redline, Kona, BMC, and Ridley. These frames are in the 54 to 56 cm size. The big questions is frame size. Do you get a one cm or two smaller frame and depending on your terrain, might need to consider BB height.

I currently ride a 58cm Cannondale cross bike with a 59 top tube and 73 seat angle. I am looking to move my Cdale to a pit bike and get a tricross or salsa chili but the comparable size has a 72 seat angle. I tested a tricross and felt that the geometry was really lax.
Maybe it is just in my head. I mean does 1degree of seat tube angle really make a noticeable difference?

Boy, bicycle geometry is a huge can of worms. Just one degree could make a huge difference if it wasn't right to begin with. You could make it up with a seatpost that has a different setback...maybe. But then again, at that frame size, slacker seat tube angles work a lot of the time. Depending on the riders femur length,shoe size,crank length etc. Do what I did,spend $100 and get a fitting at a good bike shop. Take your old bike with you. It will be the best $100 you will ever spend!

towerscum

I agree. I do need to get a good fit. I have been fitted twice at two different shops but each time was not very thorough. And at no charge what do I expect!! Anyways, at my size frame the slacker angles seem to be pretty common . When I look at geometry of cross bikes though it does seem to be all over the board. Specialized and others as 72, Cannondale and others at 73, Van Dessel at 74 I believe.
So I was just wondering what peoples opinions were on the angles. I thought a steeper seat tube angle would be better for cross racing do to the quick bursts. But then again not all cross bikes are raced.
Boy, bicycle geometry is a huge can of worms. Just one degree could make a huge difference if it wasn't right to begin with. You could make it up with a seatpost that has a different setback...maybe. But then again, at that frame size, slacker seat tube angles work a lot of the time. Depending on the riders femur length,shoe size,crank length etc. Do what I did,spend $100 and get a fitting at a good bike shop. Take your old bike with you. It will be the best $100 you will ever spend!

towerscum

Samuel, you stated that you currently have a Cdale cross bike. Any reason why you don't want to get another Cdale cross bike/frame? Do you not like your current cross bike? The reason I am asking is because most racers have two cross bikes so that they can change bikes during a race. Therefore, it makes sense to have two identical bikes.

Your seat angel dilemma can be rectified by getting a frame with the same angle as your current bike. Also, I think that a slack seat angle is not good because with a cross bike you need to put your weight more forward through turns to get the front wheel to bite.

Good luck

Samuel, you stated that you currently have a Cdale cross bike. Any reason why you don't want to get another Cdale cross bike/frame? Do you not like your current cross bike? The reason I am asking is because most racers have two cross bikes so that they can change bikes during a race. Therefore, it makes sense to have two identical bikes.

Your seat angel dilemma can be rectified by getting a frame with the same angle as your current bike. Also, I think that a slack seat angle is not good because with a cross bike you need to put your weight more forward through turns to get the front wheel to bite.

Good luck

VHR2518, Thanks for the reply's. I have an optimo cross bike. I love it. I can get a great deal on a tricross or salsa but may just have to buck up and pay regular msrp on a new c-dale as my back up bike.
Samuel, you stated that you currently have a Cdale cross bike. Any reason why you don't want to get another Cdale cross bike/frame? Do you not like your current cross bike? The reason I am asking is because most racers have two cross bikes so that they can change bikes during a race. Therefore, it makes sense to have two identical bikes.

Your seat angel dilemma can be rectified by getting a frame with the same angle as your current bike. Also, I think that a slack seat angle is not good because with a cross bike you need to put your weight more forward through turns to get the front wheel to bite.

Good luck