Can anyone help me understand the different between TT and Tri bikes? It seems that the seat angle is a big difference, TT bikes leaning closer to road geometry and Tri bikes being more forward, but what does that do for you? Any good articles out there on the matter that you could link me to? Thanks
The theory of the tri bike is that that steeper angle saves your hamstrings for the run. But the TT’ers don’t have to run afterwards so it’s not an issue. Also the road racers want to keep their TT bikes at similiar seat angles to their road bikes since that’s what they’re used to.
All kinds of theories and speculation about which is better but nothing has ever really been proven either way.
No expert here but in the tri world I would say they are the same but if you want to be UCI legal then a tt bike leans towards road geometry
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This is a myth. There are very, very few road racers nowadays who have the same saddle position on their road and TT bike. Most have the saddle further forward on their TT bike. As opposed to a generation ago, riders train on their TT bike enough now that they can get used to a different position, and the benefits are large enough to warrant two different positions. In the case of Team CSC, all 25 riders have a differnt saddle position on their TT bike than on their road bike, some of them close to 77 degrees seattube angle.
It’s funny that two bikes built for (somewhat) similar purposes (timed bike races) can be so different.
Triathlon bikes can be anything one would use in a triathlon for the bike leg. That being said, the “tri bike” classification was made in the late '80s. Before Boone Lennon made that funny loop of tubing, a tri bike was no different than a road bike; though some guys were using TT bikes, which typically had a large rear wheel and a smaller front wheel, along with pursuit bars. But Empfield had designed a bike from the aerobars back, which the seat angle happened to make you run better off of the bike (amongst other things).
The line got blurred for awhile, as some guys were using steeper angled TT bikes until the UCI Nazis deemed that a seat nose not 5cm rearward of the BB was illegal. But I think the rule is silly, as many end up going on the nose of the saddle, which makes them sit well over that 5cm mark.
The tri bike thing has gotten blurred, as well. Some are going slacker and slacker, as slack as 75 degrees, and still call themselves a tri bike. One would call that multisport geometry to be correct. What about the three Cervelo tri bikes (out of their tri line)? They can be anything from 74-79 degrees, depending on the clamp orientation and saddle rail adjustment. A Softride can be any angle you want, as well as the Titan Flex bikes.
Tri bikes are anything that is used in the bike leg of a triathlon, and a TT rig is anything used in a TT, as long as it meets within the scrutiny of the UCI Secret Bike Police.
"…some of them close to 77 degrees seattube angle. "
How do they manage to keep the nose of the seat 5 cm behind the BB with such a steep seat angle?
With an eye toward the confusion posed by the original poster. . .Perhaps we need to settle on different terms than Road, TT, Multisport, and Tri when describing geometry. While most of the “old faithful” on this forum and others might know the intended differentiations. . .what is the relative newbie to think with all the conflicting data? You tell them tri-geometry is greater than, say, 76 degrees, and then they see someone like Bjorn Anderson or LVL riding at the top of the sport in relatively slack angled bikes. Does that mean they aren’t on tri-bikes?
Bunnyman put it best. . .“Triathlon bikes can be anything one would use in a triathlon for the bike leg.” That pretty much covers the gamut of seat angles. For any given prospective triathlete, “tri-geometry” is that geometry that works best for them. (NOTE TO THE DIURETIC FORUM DEBATERS: this discussion isn’t meant to open the can of worms regarding which geometry is best for triathlon. . .simply clarifying the semantics of the debate. . ) Is my Talon SL NOT a tri-bike because it’s at 75.5 degrees and the nose of the saddle is 5cm behind the BB? My bike is a tri bike because I use it for tris. Any straight TTs I do are mainly for training and testing purposes.
The most confusing term is “multisport.” As opposed to triathlon? C’mon folks. You and I know the implied difference, but joe or jill newbie likely uses those terms interchangeably. Tell them to get a multisport bike and they think that means slapping aero bars on whatever it is you’re riding.
Of course, in deference to our moderator. . .steep angled bikes can certainly be termed “triathlon-inspired geometry.” But to drop the “inspired” implies to many out there that anything other than steep is NOT tri geometry. . .and hence. . .not the “best” for doing triathlon. The corollary to that argument would be that the person isn’t really a serious triathlete until they own, ride, and race a ~78 degree bike. We all know that to be untrue.
Therefore. . .
I vote to drop references to specific events or sports in reference to the geometry of bikes. . .simply refer to slack, mid, and steep angled geometry. We could endlessly debate where the specific cutoffs are, but they are roughly, as commonly referred to on this forum. . .
slack = less than or equal to about 74 degrees
mid = between 74 and 77 degrees
steep = greater than 77 degrees
(Slowman probably defined them more exactly somewhere on this site and I’ll defer to him regarding any differences, but the general principles are there)
" Tell them to get a multisport bike and they think that means slapping aero bars on whatever it is you’re riding. "
Ha ha. You just made me think of the local weirdo who put Carbon Strykes, mirrors, DH fenders, streamers, flashing LEDs, and bar ends on his full suspension mountain bike.
EXACTLY! Who are we elitists to tell him that isn’t a tri-bike? It may be slow, heavy, fat, dorky, geeky, and overblown (yet somehow cool in a non-conformist-hey-at-least-I’m-out-here sort of way), but its still his TRI-BIKE!
We’ve all seen 'em.
Except this guy goes around town with his trailer in tow and picks up aluminium cans with this bike!!!
If he were to do triathlons with this bike, then I would maybe snicker a bit, but think to myself “this guy has much larger testicles than even my rabid, rabbit nuts to race on such a doofy bike”.
"…some of them close to 77 degrees seattube angle. "
How do they manage to keep the nose of the seat 5 cm behind the BB with such a steep seat angle?
They are one of the very few teams with a bike sponsor that understands the rules 100%.
Other bikes are built than the P3, because not everyone can afford to spend that kind of money on a bike. At gulf coast, I sure passed a lot of P3s on my cheap Tequilo, and I’m not even that fast of a cyclist (usually average about 20-21mph).
----->Trent
Setup. . .I ben set up like a motherf****r!
But does he wear a helmet?
“They are one of the very few teams with a bike sponsor that understands the rules 100%.”
What exactly do you mean by that? Either the seat is 5 cm in back of the BB or it isn’t. Are you referring to morphological exemptions?
can’t we just save ourselves a lot of time and effort and start calling tri-bikes “trikes”?
There are several things WITHIN the rules that allow riders to get their preferred position while other riders who would like to obtain those same positions are not aware exactly what the rules allow them. We have of course every intention to keep it that way.
What exactly do you mean by that? Either the seat is 5 cm in back of the BB or it isn’t. Are you referring to morphological exemptions?
They have long legs.
Keep the saddle exactly 5cm behind the BB, and compare the seat angle on someone with a 75cm inseem and a 92cm inseem.
Scott
Heres my take on this, at one time tt bikes were set up like road bikes, then aero bars arrived, i built my first tt frame before aero bars, but it has a steaper seat angle then the road bike i was using,people found that using aero bars you tended to wind up on the nose of the sattle so this is where i belive the steeper seat tube angle comes from,i know how slowman invented the tri bike ,wetsiut,swiming and running and all sorts of stuff but there were all kinds of builders making tt frames who never heard of the work slowman was doing,i have two tt frames both steep a 78degree road and a 76 degree road and i never run,
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Uhh. . . it has to do with where they place the bottom bracket in relation to the rest of the bike. . .and how that relates to the position. . .and balance. . .
Oh forget it. . .Gerard can explain it. Its obvious to me, just by looking at Cervelos, what he means, but much harder to put into my non-engineer trained words.
Uhh. . . it has to do with where they place the bottom bracket in relation to the rest of the bike. . .and how that relates to the position. . .and balance. . .
Well, no. You are talking about things you can do to make a bike work (i.e. be balanced, handle well) at different seat angles. You only need 2 pieces of information to figure out seat angle…BB to saddle height, and saddle setback(or set forward…) from the BB. There is nothing special about a Cervelo that allows the CSC riders to ride steeper (the touted advantage of the Cervelo is that it allows people to ride steeper and still have a bike that works…) Very tall riders have an advantage under the UCI rules in that they have a much larger range of seat angles they can ride at and still be legal. Wether or not that is an advantage that translates into an advantage on the road is another question.
Scott