Triathlon - Can someone explain this one to me?

This is another - please help me grasp TT/tri geometry thread (just warning you up front)

I've seen tons of threads about TT vs. Road Geometry. I think I must be missing something. Until I can afford a dedicated tri bike, my roadie will have to suffice. I just ordered a tri saddle, after enduring the torture of an Olympic tri in the aero position using my road bike with clip on bars. Here is where I am confused. I know the Tri geometry has a steeper seat angle, shorter top tube, and greater distance from the BB to the end of the fork (see http://www.bikesportmichigan.com/bikes/difference.shtml). Soooo... if the optimal postion for the sake of argument (and I realize opinions differ) is a knee over pedal spindle scenario, what would be the benefit of a tri specific forward seat post, a la the profile design fast forward? It seems that I would not want to move forward to the point that my knee was past the spindle. What am I missing here?

Here is where I am confused. I know the Tri geometry has a steeper seat angle, shorter top tube, and greater distance from the BB to the end of the fork (see http://www.bikesportmichigan.com/bikes/difference.shtml). Soooo... if the optimal postion for the sake of argument (and I realize opinions differ) is a knee over pedal spindle scenario, what would be the benefit of a tri specific forward seat post, a la the profile design fast forward? It seems that I would not want to move forward to the point that my knee was past the spindle. What am I missing here?

The forward seat post allows you to be in a more forward and aero position, as if your bike has a steeper seat angle.

The knee over the pedal spindle (kops) method doesn't apply for a TT/Tri position. That traditional method just gives you a starting point for fit for a road bike and is sensible but there's no scientific evidence to support it either. You should do what's comfortable for you.

This is another - please help me grasp TT/tri geometry thread (just warning you up front)

I've seen tons of threads about TT vs. Road Geometry. I think I must be missing something. Until I can afford a dedicated tri bike, my roadie will have to suffice. I just ordered a tri saddle, after enduring the torture of an Olympic tri in the aero position using my road bike with clip on bars. Here is where I am confused. I know the Tri geometry has a steeper seat angle, shorter top tube, and greater distance from the BB to the end of the fork (see http://www.bikesportmichigan.com/bikes/difference.shtml). Soooo... if the optimal postion for the sake of argument (and I realize opinions differ) is a knee over pedal spindle scenario, what would be the benefit of a tri specific forward seat post, a la the profile design fast forward? It seems that I would not want to move forward to the point that my knee was past the spindle. What am I missing here?

your knee being forward is a consequence of your hips being more forward and thus a greater portion of your body mass being over the pedals for the downstroke...thus more power for TTing. The shorter wheelbase and forward position make handling the bike more difficult than a more traditional roadie. The designs are task specific.

I say ride what you got! I can hammer most fancy types I luv nothing morte tha to pound some tool ona 3K tri specific bike and my old school 8 speed Ti Eddy Merckx....
That being said a steep seat tube does impact hip position yadda yadda and thus make one more "quick"

Its not so much that you are forward, but rather that the bottom bracket is back. To get your head well down into the aero position you bend more at the waist untill.....you can't breath. By rotating the feet aft, you keep the angle between your chest and legs at the top of the pedal stroke at a more managable number. This is the advantage when using the bike for Time Trial work. The additional advantage for Tri work is that you ease the workload on some of the leg muscles that you will use for the run when the bike stage is over.

I am going to go out on a limb and challenge you to find anywhere in TD's article where he stresses the importance of KOPS. I haven't read the article in years but I don't think you will find anything in there that stresses KOPS.

Since you are reading up on this, go to Slowtwitch and read up on tri-tt fitting, they have an entire series of articles. It is pointed out in one of them that KOPS isn't a concern in your TT/Tri fit.

So, no problems.

I luv nothing more than to pound some tool on a 3K tri specific bike on my old school 8 speed Ti Eddy Merckx....


Sounds like someone has some envy issues to work out.

Thanks for the great response! Let me see if I follow by summing up:

1. KOPS does not really apply for TT/Triathlon
2. Using a forward seat post would give me a more "tri-efficient" position on the road bike, and make it a bit easier to breath when aero.
3. The main obstacle would be perhaps less accurate/predictable handling (My bike is rather longish, so maybe this would not be such a big deal? 60cm Trek)

If I'm clear with this, I think the forward post sounds like the way for me to go.

Hey pally, I'm just saying do nto forget the reason why we ride. I luv new high tech stuff as well but if you are like a me a working stiff with kids and all that jazz you cannot always afford to buy what ever is new and pretty...I bought my Ti Eddy Merckx thinking it was it for me, then carbon became the new Ti....lighter faster better now I am stuck. My bike maybe old school but the Quads are cutting edge baby!!

and yes I am jealous.
Peace out yo!

My favorite tool is the dictionary (http://dictionary.reference.com/). I failed spelling in the 8th grade and have been lobbying on behalf of the dictionary ever since.

In the Chicago tri I passed a guy riding a Cervelo P2 on my Raleigh grand prix w/clip ons. As I passed him (~21mph) while I was flying by at ~24 mph he shouted out..."great time!"

I'd never call him a tool.

btw, your bike is still about $1k more expensive than mine.;)

Sorry if I offended you and your dictionary skills.
Ride and Have fun.....I was once passed during a Mt Bike Biathlon by a kid wearing sneakers and no suspension.....I have a Specialized full suspension and Sidi's.
Humble is as Humble does

Don't get me wrong, I still love my alu Trek, and actually have no desire to switch to another roadie, even a full carbon job (though I wouldn't turn one down). Pain is my big motivator. I did fairly well in my olympic tri. The bike is my strongest leg, and so far I think I pass more than I'm passed. I've passed the tricked out rigs, and I've likely been passed by the likes of vintage steel. What's getting me is that knife in my back that strikes after about 20 miles in the aero position, not to mention the numbness in other areas. If a new seat and seatpost will take care of that, and maybe spare me a few seconds to boot, I may just need to sell some toys in order to make that happen.

thehammerdog, I hear ya, wife, kid1, kid 2, job, mortgage. Main thing for me is to stay fit long enough to enjoy the first three and outlive the last two. :D

http://www.cervelo.com/content.aspx?m=Engineering&i=TriBikeFit

http://www.cervelo.com/content.aspx?m=Engineering&i=TriBikeFit

Good post.........thanks