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View Full Version : What Kind of Bike Should I Buy? (Or: Is This Bike Any Good?)



Rahzel
07-02-08, 10:46 AM
There are a lot of questions on this board that go something like this: "I'm new to triathlons, what kind of bike should I buy? I have $XXX to spend." Or, "I found a deal for bike YYY, is $ZZZ a good price?" Or, more simply, "Is bike QQQ any good?"

This post will try to answer many of these types of questions.

First, I want to talk a little bit about the difference between a triathlon bike and a road bike. The primary differences are (in addition to the fact that a tri bike is usually ridden with a bullhorn base bar + aerobars):

- seat tube angle
- chainstay length/wheel positioning relative to bottom bracket
- tube shapes

"What is 'seat tube angle?'" This references the angle that the seat tube makes with respect to (more or less) the ground. On a road bike, this angle is usually 73 degrees (+-2 degrees). On a modern tri bike, this angle is usually between 76 and 78 degrees, with the general consensus among experts such as Dan Empfield (the inventor of the triathlon bike), being that for most people, 78 degrees, or even 80 degrees (though few bikes are manufactured with a STA of 80 degrees) is optimum. "Why is a steep STA optimum?" There is lots of research (check out the tech archives at http://www.slowtwitch.com) that demonstrates two things: (1) steepening the STA allows for your hips to "roll" forward, flattening your back and creating a more aerodynamic position (the farther backward your seat is, the higher your torso has to be to keep your thighs from hitting your torso). (2) steepening the STA has been shown in many athletes to lead to faster run times, by sparing key running muscle groups on the bike portion of the triathlon.

"Why do I care about wheel positioning and chainstay length?" In the aero position on a triathlon bike, your center of gravity is decidedly farther forward than on a road bike. If a tri bike had the same wheelbase as a road bike, the tri bike would be very "twitchy". Most tri bikes, to create good handling, bring the rear wheel in very close to the seat tube, often necessitating a "seat tube cutout" (this has aerodynamic benefits as well), and move the front wheel out towards the front of the bike even more. This is usually accomplished by decreasing the head tube angle, and/or installing a fork with more trail.

"Why do I care about tube shapes?" Well, to be honest, aerodynamic frames are pretty far down the list of "things that will make you go fast". You'll do much better by improving your position, buying a tight-fitting race suit, an aero helmet, and race wheels. However, within your budget, you may as well buy a bike that is constructed with aerodynamics in mind. Look for thin head tubes, teardrop-shaped down tubes, a seat-tube cutout, and an aerodynamic seatpost.

This is just a summary of what makes a tri bike different from a road bike. For more detailed information, check out the tech section of http://www.slowtwitch.com - Dan Empfield has created a tome of detailed information on this subject, and this is basically just a summary of his research.

Okay, now that you know the main differences between a tri bike and a road bike, it's time to figure out what's the best bike for you on your budget. The answer is:

The best bike for you is ALWAYS the bike that fits you the best.

Buying a bike with a steep STA and aero tubes is great, but if you buy the wrong size (or even the right size in the wrong brand) you'll regret your purchase down the road. It may take you five years to realize that you bought the wrong bike, but you'll be jonesing for a new one regardless.

To ensure that you purchase a bike that fits you correctly, I recommend either getting a F.I.S.T. certified fitting from a bike shop near you. You can also learn about how tri bike fitting works by checking out the great resources (http://www.slowtwitch.com/Bike_Fit/index.html) that Dan Empfield (the pioneer of the F.I.S.T. system) has provided over on slowtwitch.com.

Now that that is out of the way, let's talk specific bikes and specific budgets. Keep in mind that the bikes listed here are a sampling of all the bikes available on the market. They also have a personal bias, no matter how much I'd like to remove it. I'll say up front that my personal bike is a Giant Trinity Alliance, and I recommend it to everyone I meet. I'm also biased towards bikes that sell heavily in the United States, because that's where I live and that's what I know about the best.

I am also personally biased towards recommending bikes with a steep (78 degree) seat angle, for the reasons I mentioned above in the discussion of seat tube angles. I also have had extensive personal experience riding steep, as well as numerous personal discussions with other riders that ride steep as well. However, since personal experience isn't scientific evidence, I feel obligated to mention this as a personal bias.

Also, remember that if you have a X dollar budget, you'll only be able to spend, say, X MINUS two hundred on the bike. The other two hundred should be spent on important accessories, such as aerobars, a race skinsuit, clipless shoes/pedals (if you don't already have those), a helmet (aero if you can afford it), etc. Down the road, consider an investment in some race wheels. You can spend anywhere from $500 to $5000 on these, and that's the topic for a whole another thread :)

Also consider the following: if your budget is on the low end of things ($1000 or less), many tri bikes available from discount retailers like Bikes Direct are adequate, but will leave you wanting more if you decide to stick with triathlon in the future. It's counter-intuitive, but your best bet on a low budget is usually to hold off on buying the tri bike (buy a road bike with clip-ons instead) until you're sure that you really want to invest in a tri bike. Then, when you're ready, you can spend a good wad of cash on a really nice bike that doesn't need to be upgraded in two years.

IF YOUR BIKE BUDGET (after accessories) IS:

$500 or less: buy a used road bike. There are no new road or triathlon bikes in this category that will be satisfactory for hard training and/or racing. Additionally, at this price point, road bikes have more "value" than tri bikes--you'll get a lot more road bike at this price level than you will tri bike. As of July 2008, look for 9 speed components of Tiagra level or higher. Remember to purchase clip-on aerobars for $50-$100 to complete your ride. In the USA, you may be able to find an inexpensive used road bike in the following brands: Trek, Cannondale, Specialized, Giant, Felt. An additional option for wrench-heads is to purchase a cheap frame (such as a Leader frame) and build it up with a component groupset.

$501 - $1000: buy a (better) used road bike or entry-level new road bike. There are no new triathlon bikes that are currently sold in the USA at this price point, except for inexpensive framesets such as the Leader frame or some Bikes Direct models. Additionally, at this price point, road bikes have more "value" than tri bikes--you'll get a lot more road bike at this price level than you will tri bike. As of July 2008, look for 9 or 10 speed components of Tiagra or 105 level or higher. If you're buying a road bike, remember to purchase clip-on aerobars for $50-$100 to complete your ride. In the USA, you may be able to find an inexpensive used road bike in the following brands: Trek, Cannondale, Specialized, Giant, Felt, Cervelo.

$1001 - $1499: buy a lightly used entry-level triathlon bike or a nicer new road bike. Buy the tri bike if you (a) already have a road bike OR (b) are sure that 95% of your rides are going to be solo rides and that you will primarily be racing triathlons and not road races. Otherwise, buy the road bike and put clip-on aerobars on it. In the USA, here are some good tri bikes that will sell in this price range lightly used:

- Cervelo Dual
- Cervelo P2K
- Quintana Roo Kilo
- Felt S32
- Some of the older Trek TT/tri bikes
- Cannondale Super Six Slice Si or whatever they called that bike

$1500 - $2000: this is one of the sweet price points in triathlon bikes. All of the major bike companies make great bikes at this price point. Component groups will vary, from Ultegra/Dura Ace on the Cervelo down to Sora/Tiagra on the Giant. Frames will usually be aluminum, but contain aerodynamic shapings. The key here (and with any bike purchase) is buying the bike that fits you. Remember to check out the seat tube angle of the bike, how long the bike is (known as "reach"), how low or tall the bike is (known as "stack"), and if all of these things fit you. Generally, if you want to ride steep and fast, you'll want a high STA, lower stack and perhaps more reach (if you're a man especially). Anyway, here are some of the popular bikes that sell at this price point:

- Cervelo P2 SL
- Trek Equinox 5, 7
- Felt S22
- Quintana Roo Kilo/Tequilo
- Kuota K-Factor
- Giant Trinity Alliance A2
- Specialized Transition (the lower models)

$2500: this is the other sweet price point in triathlon bikes, thanks largely to Cervelo's introduction of the 2008 P2C at this price point, which forced other bike manufacturers to quickly become competitive at this price. Expect aerodynamic carbon fiber frames, Ultegra and Dura-Ace components, durable (but not aero) wheels and a stellar ride at this price. Mandatory reading, for purchasing a bike at this price, is Tom Demerly's excellent review (http://www.bikesportmichigan.com/reviews/2500wars.shtml) of four tri bikes (Cervelo, Felt, Kuota, QR) at this price point.

- Cervelo P2C
- Trek Equinox 9.0
- Felt B12
- Kuota Kalibur
- Giant Trinity Alliance A1, A0
- Quintana Roo Seduza
- Specialized Transition (the mid-range models)

$3000 - $4499: If you've got more than three grand to spend on a bike, in my opinion you should seriously consider purchasing a bike in the $2500 range, and investing in some good quality race wheels with the difference. However, this is only my opinion, and there are many bikes sold in this price range that are great (and that may fit you better than the bikes at $2500), including (but absolutely not limited to):

- Cervelo P2C (Dura-Ace version)
- Trek Equinox 9.5
- Felt B2
- Scott Plasma
- Cannondale Slice
- Titanium bikes by companies like Litespeed
- Kestrel Airfoil
- Argon18 E112

$4500+: The triathlon "superbikes" all sell for $4500 or greater, starting with the Cervelo P3C (and soon, the P4C). Remember to buy the bike that fits you, and if at this stage no bike feels absolutely perfect, buy a custom bike (you can afford it).

- Cervelo P3C/P4C
- Trek Equinox 9.9/9.9SSL
- Felt DA
- Specialized Transition (the super-duper version)
- Kuota Kueen K
- Scott Plasma II
- Argon18 E114

Note: Almost all of the bikes I have recommended (with the exception of all of the Trek and Scott bikes) are designed around a 78 degree STA (the Trek and Scott are designed around a 76 degree STA).

Disclaimer: my recommendations of specific bikes are based on my limited knowledge of the United States triathlon market. If there's a bike that you like that I forgot, let me know and I'll add it to the list! If a bike isn't on this list, it probably means I just forgot it, not that it's a poor bike. I don't want this to be an exclusive list, and I apologize in advance if I've neglected your favorite bike.

Tom Stormcrowe
07-02-08, 11:03 AM
Stuck!

Triguy
07-02-08, 03:18 PM
Well Done, but I need to add a 76 degree reaction...

Reason to be open and accepting of 76 degree STA:

1. It isn't always more aerodynamic. Yeah, a flat back looks cool, but when your seat is around 78-82 degrees, it is significantly higher(1+cm) than if it were around 76. This means that as a whole your body is sitting higher in the air, meaning a flat backed steep position is often less aerodynamic than a slightly rounded more slack position. Check out the FA positions on biketechreview.com. Secondly, having more weight on your front end often requires wider arms and shoulders. Long ago Lances aero gurus agreed that getting narrow had big gains with less negatives on power and comfort than getting low. For an N=1 perspective, I brought my seat back 4cm and down accordingly, my power files suggest no change in aerodynamics but my crotch neck and power files sure thank me.

2. Muscle balance. When I run(yes I am an "efficient" FOP runner), my muscles are used fairly evenly. My hamstrings as much as my quads. This is the way running should be done and if you're doing it the right way, you should be using your muscles evenly on the bike. Steep riding causes an excess in use of the quads. A slacker STA(76ish) promotes balanced muscle usage, which should produce more power and allow better pacing for better running.

I don't think Steep or slack is right or wrong. It's an individual choice. I think however that right now steep is a fad and as with any fad, it's leading to misinformed decisions and consumer pressuring.

Rahzel
07-02-08, 03:42 PM
but when your seat is around 78-82 degrees, it is significantly higher(1+cm) than if it were around 76.

No, it's not. The difference in seat height when you move 2 degrees forward is very small (less than 1/4cm), assuming that the distance between the pedals and your measuring point on your saddle stays constant. Do the geometry for yourself.


This means that as a whole your body is sitting higher in the air, meaning a flat backed steep position is often less aerodynamic than a slightly rounded more slack position.Do you have aero data to prove this?

Check out the FA positions on biketechreview.com.Frontal Area isn't everything. There are many, many more considerations than just frontal area alone. For example, the angle of your arms with respect to vertical.

Secondly, having more weight on your front end often requires wider arms and shoulders.This is not true, not even "often". The weight distribution on the front end and the width of the aerobar pads are independent variables.

Long ago Lances aero gurus agreed that getting narrow had big gains with less negatives on power and comfort than getting low.This N=1 example is not a good one, because Lance had a back problem that prevented him from getting very low. All the gurus who have done scientific studies agree that for most triathletes, the solution is to get as low as you can (comfortably), then as narrow as you can (comfortably). I don't have a source off the top of my head for this contention, but I'll find one if you want.

For an N=1 perspective, I brought my seat back 4cm and down accordingly, my power files suggest no change in aerodynamicsOf course your power files won't show (or even suggest) any change in aerodynamics! Your power meter doesn't measure aerodynamics! Admittedly, one puts out less power in a more forward aero position, but the aerodynamic gains more than make up for it.

but my crotch neck and power files sure thank me.The fact that your crotch and neck hurt when you move forward suggests an improper fit, not any inherent flaw in a forward position.

I don't think Steep or slack is right or wrong. It's an individual choice.I think riding steep is right, and riding slack is wrong. It is a choice, but if you ride slack you may be making the wrong choice. I have scientific evidence to support this contention. Unless you can provide scientific evidence that supports riding at 76 degrees over riding at 78 degrees, we'll have to agree to disagree.

Source: http://www.slowtwitch.com/Tech/What_science_says_of_seat_angles_222.html

Triguy
07-03-08, 05:50 AM
No, it's not. The difference in seat height when you move 2 degrees forward is very small (less than 1/4cm), assuming that the distance between the pedals and your measuring point on your saddle stays constant. Do the geometry for yourself.

Frontal Area isn't everything. There are many, many more considerations than just frontal area alone. For example, the angle of your arms with respect to vertical.

This is not true, not even "often". The weight distribution on the front end and the width of the aerobar pads are independent variables.

This N=1 example is not a good one, because Lance had a back problem that prevented him from getting very low. All the gurus who have done scientific studies agree that for most triathletes, the solution is to get as low as you can (comfortably), then as narrow as you can (comfortably). I don't have a source off the top of my head for this contention, but I'll find one if you want.

Of course your power files won't show (or even suggest) any change in aerodynamics! Your power meter doesn't measure aerodynamics! Admittedly, one puts out less power in a more forward aero position, but the aerodynamic gains more than make up for it.

Source: http://www.slowtwitch.com/Tech/What_science_says_of_seat_angles_222.html

Actually the two biggest aero gurus in the bike world believe in slack(75-77) riding, Steve Hed and Jon Cobb, I was fit by one of them.

If you don't realize that a person can back calculate aerodynamics from a power file you don't realize much when it comes to utilizing a power meter. Do you own one?

Triguy
07-03-08, 07:12 AM
All right I have another free minute or two....

I did the calculations, and my saddle dropped .75cm when I moved my seat from an approxiamate 81 to 77. In the middle of both our guesses.

Lets get one thing strait, CdA is how aerodynamics are measured and it is Coefficient of drag multiplied by Frontal Area. Or alternately, drag force at a certain speed. Your suggestions, angle of arms(which effects frontal area), is not in the measurement of Aerodynamics(it's not Cd, and it's not A) its a variable in position aerodynamics and an important one that has an effect on both Cd and A.

Frontal area is huge in the world of aerodynamics, because it's the one variable anyone can measure! This is because the human body's position on a bicycle will have a coefficient of drag around .6-.7(and in general smoothe rolled in shoulder, and a low head position help the most with this), this is large but an unmeasurable variable(unless of course you have time and a powermeter). However, frontal area can range in great amounts, as much as 15%(about the same as Cd). However, to measure my FA all I need is black clothes and a white background and a little time.

You know whats great about what Steve Hed and Discovery's findings about Lance? It's not N=1 anymore. They have applied the principles to Ekimov, Leipheimer and many of the High Roads team members. All of whom have great success at time trials, many of whom can get lower than lance but first, they get narrow.

As far as my steep riding position, I ran fine off the bike with it. Usually top run split but the ability to sit on ones ass bones instead of ones taint is a much finer choice.

________________

You know why I think I'm right? I say it's up to the individual. You say we all should be doing things the same way, which even Dan Empfield doesn't say. I think more consideration should be given to the bike-run combination than what works for most people. People should consider their run first, what fatigues on them easily and what muscles are they using in their stride. If people get big time hamstring fatigue running, great power away at 80*. However, if you do a track workout and your quads are screaming at you, maybe you want to save that part of your leg for the run and move your seat back.

mrmcmasty
07-03-08, 10:11 AM
So... I hate to be the new guy to bring this one up (actually I don't but it seems polite to say so) but this is supposed to be a sticky on which bike people should buy when getting into the sport, and while I enjoyed the discussion on seat positions, I don't even own a bike yet and I am still interested to know more about which bikes people prefer and why.

You are both obviously very into riding and possess a rather in depth body of knowledge in regard to cycling. I'd like to hear your take on what kind of bike a new rider/newbie to tri's should look at when making a first bike purchase.

I have come to the understanding that which bike is not nearly important as how it fits and how comfortable you are while riding. More important is getting familiar with the bike and then if you get seriously into the sport, buy a great bike! (but thats an opinion formed in about weeks worth of reading and a total 140 miles total logged on a borrowed bike)

Rahzel
07-03-08, 10:14 AM
Actually the two biggest aero gurus in the bike world believe in slack(75-77) riding, Steve Hed and Jon Cobb, I was fit by one of them.

If you don't realize that a person can back calculate aerodynamics from a power file you don't realize much when it comes to utilizing a power meter. Do you own one?

To be fair, I do not own a power meter, and upon further thought I do now see how one can calculate drag from one's power numbers, provided that one is able to accurately measure speed on several runs over an identical course!

In any case, it seems we will not convince each other, but in this particular instance that's fine. This is, after all, a resource to help triathletes decide what bike to ride. I believe 78 degrees is better, you believe 76 degrees is better. Fortunately, this isn't American politics so people can choose what's best for them! (and two tiny degrees seems to be what separates the two American political parties these day anyway yuk yuk yuk)

As a bookend to this debate, I will say this: I have obviously written my original post with a bias towards 78 degree seat tube angle bikes, which i fully admit to. Triguy, if there are any 76 degree angle bikes that you feel I should include on my list, please let me know and I'll put them on there! I know of several 76 degree bikes (and one 74 degree bike, the Kestrel Talon) that I left off the list, but mostly because those are European bikes and I don't know a lot about them (or how to buy them in the U.S.)

I have a strong opinion on this matter, but I don't necessarily want that to shine through on the original post. Again, let me know how you feel I can improve the original post and I will do so, in the interests of inclusiveness :)

senatorw
08-24-08, 09:00 AM
Excellent sticky. Now can you please just do one on the Look v. Speedplay, which pedals threads (true, mostly in the roadbike forum)?