The most critical element in selecting a bicycle is the fit.
Start by finding a quality bike shop and get measured by a trained bike technician. Fitting tools such as a Serotta Size Cycle (you’ll need to wear your bike shoes and cycle clothes for the fitting) may be available. If you can’t find a shop with a Size Cycle, then have the technician do a fitting using some type of fit kit.
Once you are on a fitting cycle, and even when you are on your bike confirming the fitting, the bike technician will check a number of spots critical for good alignment. For example, with your crank parallel to the ground, a plumb bob from the front of your knee should line up with the leading edge of the pedal.
After spending about 45 minutes on a fitting cycle, with plumb bobs hanging from my nose, knees, shoulders and other body parts, I learned that certain frames worked for me while others did not. For example, neither a Pinarello nor a Trek had the right dimensions for my body, but the Serotta, Colnago, and QR worked for me. I opted for a Serotta, and love the bike. The important thing is that I was able to make a decision based on my precise needs and dimensions. Through the fitting, I was able to fine-tune and coordinate saddle-stem-handlebar-aerobar positions, and it has paid off in both cycling efficiency and comfort.
Don’t get caught up on particular frame manufacturers and preferences until you have gone through the fitting process and know which frames will work for you. For example, Trek used to be known for an unusually long top tube and from the fitting I learned it was the wrong bike for me.
Also, different manufacturers measure their frames in different ways. In measuring seat tube length (which is the most common size reference, such as when you read about a 56cm bike, or a 59cm bike), some manufacturers measure from the bottom bracket to the top tube, others from the bottom bracket to the top of the seat tube. So again, the issue is the geometry of the particular bike, and not some preconceived notion of the right size bike for a person.
Many triathletes use road bikes adapted for triathlon conditions. This includes the addition of aerobars. Aerobars are critical – they make a huge difference in comfort and aerodynamics. When doing your bike fitting, make certain the technician knows you are going to use aerobars, because this will impact the stem length and the saddle position, along with other alignment elements.
A final note on frame size: Your body size is a critical factor in selecting the material for the frame. Many riders find smaller frames made of aluminum to be uncomfortably stiff. (The older Cannondales were known for their stiff frames, so the Cannondale riders tended to be large folks – you would rarely see a smaller person riding a Cannondale in a stage-race length event. I’m 5’6”, and I found that a Cannondale in my size had such a stiff frame that it felt like my fillings were shaking out of my mouth. They’ve improved and now even have a series of compact frames for smaller riders.)
You can often negotiate a package deal with a bike shop, and bear in mind they will often swap components on a bike that is already made up. That can be particularly helpful if you are looking for a more custom set-up, such as a time trial handlebar with aerobars and bar-end shifters. The same goes for chainring and cassette sizes. Depending on your strength and the courses you ride, you might want to consider a 39-52 chainring combination. If you are very strong and you ride and train in a flat area, consider a 53-42 or even 56-42.
On the groupo issue (complete component groups such as Shimano Ultegra), the industry slogan is “Shimano wears out and Campagnolo wears in.” The Shimano will probably feel better than Campy on the test ride; the Campy will shift better six months to a year later. (I bet I can start a lot of controversy with this comment.)
I have used Shimano SPD, Time and Speedplay pedals, and highly recommend the Speedplay but are used with success. Years ago, when I was first starting out, a friend in the business lent me Shimano M535 pedals and shoes. They are mountain pedals, very resilient, but very heavy (and look awful on a sleek road or tri bike). On the other hand, for my first season, they were free, and that is a hard price to beat.
Like frame sizing, the most critical issue with any pedals is getting a thorough, professional fitting. Go to a good bicycle shop and work with an experienced salesperson. A proper fitting is not only critical to effective power transfer, but also to prevention of injury. Clipless pedals affect the stress on the knees and ankles, because they limit the rotation and placement of your feet on the pedals. Get a full fitting – several items must be in correct alignment. The cleat should be under the ball of the foot (fore and aft position) to transfer the power and stress through the ball of the foot, while maintaining the knee in the proper position. Also, the cleat must be positioned so that the foot is in the correct lateral position on the pedal (close to the center line of the bike, which is known as the Q factor, without rubbing a chainstay or putting excess pressure on your knees). The cleat and pedal combination changes spacing between your foot and the pedal bed, and therefore you have to check that your saddle is at the correct height for your leg extension at the low point of the crank rotation, and that the leading edge of the knee is over the ball of the foot when the pedal is parallel to the ground. While you are getting the cleat fitting, you can also probably get the bike technician to check out and adjust your position on the aerobars.
Beware of inexperienced technicians!
I was in a hurry to replace worn-out cleats once, and did not go to my regular shop. When I got on the bike, I found I couldn’t unclip my shoes. The bike technician had installed the cleats backwards and reversed the left and right cleats! (Fortunately, I was able to reach down and loosen my shoes so I could get my feet out and leave the shoes on the pedals.)
With good cycling shoes, Speedplays provide a very stable platform, even when standing on the pedals. Speedplays are best known for their wide range of rotational movement (less stress on the knees and ankles). Also, they are very lightweight, work from either side for ease of clipping in, and look cool! Speedplays clip in on either side; Time and Look both clip in on one side only.
A critical issue is the fit of the shoe – Time makes a good line of shoes, and they work perfectly well with Speedplay pedals. Avoid shoes that require lacing – a velcro strap is idea for triathlons. These shoes are not as convenient as SPDs for walking – you do tend to tip back like a drunk penguin, but if you are not walking far in them, it is worth the trade-off.
Finally, clipless pedals are absolutely fantastic for increasing cycling efficiency. They are also extremely comfortable, and it is very easy to forget you are clipped in. Everyone falls once. When my cycling coach warned me, I dismissed the problem, thinking, “Hey, I’m a smart guy. I’m not going to do something so stupid as to forget to unclip.” Third day out with the pedals, I was a bit distracted pulling up to a traffic light, and just as I stopped moving, over I went. I looked like Arte Johnson on the show Laugh-In, who always fell over on his tricycle. P.S. – A few weeks later a friend bought clipless pedals. I shared with him the warning, he said, “Sure. How stupid do you think I am? I’m not going to forget about the pedals.” Twenty five miles into the ride, while stopped at a traffic light, I reminded him of that statement as he brushed himself off after his fall. You’ve been warned. Gentle landings.
