Road Bike versus Triathlon Bike
- Thread starter kdelong
- Start date
At a very rough level, a triathlon bike will have much more emphasis on having good aerodynamics, which is obtained to some extent at the expense of some additional weight. This is due to the fact that most triathlon bike courses will have limited hill-climbing, and are therefore more speed-oriented, where better aero really helps. ("Triathlon" bikes are really time-trial bikes, for the most part.)
In addition to using tubing that is more aerodynamic (flattened, blade-like down tubes, for example), you will also see such aero "tricks" as enclosed or hidden cabling, "carved out" seat tubes where the front of the rear wheel is really tucked into the back of the seat tube, brake locations that get them more out of the air flow (especially rear brakes in unusual locations), etc.
In terms of geometry, dedicated time-trial or trathlon bikes will have full-time aero bars, and not just clip-ons. Going along with the aero-bar riding position, the seat tube angle is significantly steeper than on a road bike - 76 or even 78 degrees, versus 72-73 degrees for a typical road bike. (Some multi-use bikes will have reversible seat posts, to allow changing the seat-tube angle.)
All of these aero improvements add a bit of weight (especially true in the case of aero wheels), so whereas a high-end road bike will be under 15 lbs, a comparably equipped and priced triathlon/TT bike might be a couple of pounds heavier.
Some road bikes are starting to incorporate some aero elements, such as blade-shape downtubes, more aero forks, etc. Felt and Cervelo have been doing this with some models, and the Ridley Noah has a bunch of neat little aero features, including slotted forks and seat stays, intended to produce better airflow.
In addition to using tubing that is more aerodynamic (flattened, blade-like down tubes, for example), you will also see such aero "tricks" as enclosed or hidden cabling, "carved out" seat tubes where the front of the rear wheel is really tucked into the back of the seat tube, brake locations that get them more out of the air flow (especially rear brakes in unusual locations), etc.
In terms of geometry, dedicated time-trial or trathlon bikes will have full-time aero bars, and not just clip-ons. Going along with the aero-bar riding position, the seat tube angle is significantly steeper than on a road bike - 76 or even 78 degrees, versus 72-73 degrees for a typical road bike. (Some multi-use bikes will have reversible seat posts, to allow changing the seat-tube angle.)
All of these aero improvements add a bit of weight (especially true in the case of aero wheels), so whereas a high-end road bike will be under 15 lbs, a comparably equipped and priced triathlon/TT bike might be a couple of pounds heavier.
Some road bikes are starting to incorporate some aero elements, such as blade-shape downtubes, more aero forks, etc. Felt and Cervelo have been doing this with some models, and the Ridley Noah has a bunch of neat little aero features, including slotted forks and seat stays, intended to produce better airflow.
In addition to the comments above, dedicated Tri/TT bikes tend to have:kdelong said:
- Steeper seat angles to facilitate the forward positioning that opens up hip angles while riding in aero bars
- Shorter top tubes to allow the rider to maintain a structural position with upper body weight well supported by forearms at a fairly steep angle when in the aero bars.
- Shorter head tubes to allow substantial seat to aero bar pad drop without having to go to a steep drop stem.
- Changes in wheelbase and front end geometry to make the bike more stable with far more weight on the front wheel than a normal road setup. You can take a road bike and mount a fast forward style seatpost, a short stem and aero bars but it tends to be real squirrely when you weight the front end so much which gets even worse when steering with your elbows.
Those are the big geometry changes and then you get into stuff like tubing shapes and curved seatposts to make it more aerodynamic but the big stuff is how you'll fit on the bike and what it'll feel like when you ride it.
-Dave
What constitutes a "triathlon bike" is a grey area.
Essentially, triathletes want to do the same thing as cyclists when on the bike: they want to go fast.
The formula for this doesn't really change if you decide to swap your knicks and jersey for a tri suit.
What does change is the rules for racing, and the fact that a triathlete needs to get comfortable on a bike right after a hard swim and also transition quickly and comfortably to a hard run after the ride.
Rules depend on what you are doing.
In draft legal events (sprint or olympic distance) the preference is to use a normal road frame with drop bars and clip-on aerobars. The saddle usually ends up forward to provide a comfortable position on the aerobars and to allow a good range of movement of the hip. Riding in a small groups and the closer race courses largely negate the need for a time trial bike.
For ironman distance (as far as I know), drafting is illegal so there's no need for drop bars. The courses are also long and extremely non-technical, so they lend themselves to the use of a time trial bike with steeper seat angle to allow the rider to sit low on the aerobars in relative comfort for long periods.
So a triathlete will ride a TT or road bike depending on conditions.
Generally a "tri" bike is merely a TT bike branded as such for marketing purposes to appeal to that market.
A good example is the old Cannondale Ironman, which obtained a lot more fame from being ridden in Tour/Giro prologues and TTs by Mario Cipollini (accompanied by an appropriately ridiculous paint job) than it did under any triathlete.
Essentially, triathletes want to do the same thing as cyclists when on the bike: they want to go fast.
The formula for this doesn't really change if you decide to swap your knicks and jersey for a tri suit.
What does change is the rules for racing, and the fact that a triathlete needs to get comfortable on a bike right after a hard swim and also transition quickly and comfortably to a hard run after the ride.
Rules depend on what you are doing.
In draft legal events (sprint or olympic distance) the preference is to use a normal road frame with drop bars and clip-on aerobars. The saddle usually ends up forward to provide a comfortable position on the aerobars and to allow a good range of movement of the hip. Riding in a small groups and the closer race courses largely negate the need for a time trial bike.
For ironman distance (as far as I know), drafting is illegal so there's no need for drop bars. The courses are also long and extremely non-technical, so they lend themselves to the use of a time trial bike with steeper seat angle to allow the rider to sit low on the aerobars in relative comfort for long periods.
So a triathlete will ride a TT or road bike depending on conditions.
Generally a "tri" bike is merely a TT bike branded as such for marketing purposes to appeal to that market.
A good example is the old Cannondale Ironman, which obtained a lot more fame from being ridden in Tour/Giro prologues and TTs by Mario Cipollini (accompanied by an appropriately ridiculous paint job) than it did under any triathlete.
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