I am going to try and keep this at least a little bit high level, since this is a topic that you could probably write a thesis on if you wanted to. Also I am not planning on covering general bikey type info here, I wrote something about buying a road bike the other day here:
Buying a road bike
Most of what I said in there holds true for tri bikes as well.
So on to tri bikes specifically. Why would you bother?
Well usually for a couple of reasons:
- Aerodynamics
- Comfort
Okay so for most people the first thing when they think of a tri bike is the aero benefit. 'This thing is going to make me fast because I will have so much less drag'. 'I better sell bike X and buy bike Y because they released a white paper that showed it has 2.7% less drag when the wind is blowing at 14 degrees at 17km/h'. People usually think things like that.
So first thing, yes an aero bike will make you faster. The design of them has inherent advantages over a road bike, such that if you are in an aero tuck, you will have less drag. Simple as that. It is engineering and therefore correct.
Beyond that, do you need to worry that Trek uses Kamm Tails and Scott uses truncated aerofoils. You can if you like, but you don't really need to. They are the shapes they use to describe their aerodynamic tubes by the way (just in case you were wondering). It is probably enough to know that most manufacturers have this aero bike thing pretty sorted. Over the last few years we have seen aero bikes gradually begin to look more and more a like. Place the silhouette of a Cervelo P5, over the newest Trek Speed Concept, over a Scott Plasma and you will notice only minor differences in frame shapes. As a result the differences between the main brands can be measured in the order of 1 or 2%, and in some cases less than 1%. They all have their differentiators, but they are minor. Once you have decided to get a tri bike, then you have made a pretty significant aero gain. After that you are talking small differences.
So what are some of the things to consider. Firstly cost. Generally the more aero the bike, the more it costs. All the major brands save their best and fastest tech for their top tier models. It gradually filters down, but by then they will usually have a new latest and greatest tech to keep you reaching for your wallet. So cost, figure out how much you can afford and look for a bike that fits your budget. Be aware that entry level in tri bikes means something different to entry level in road bikes. Very few manufacturers make a cheap tri bike. Most of them start at around $2000. I think the manufacturers make an assumption that if you are looking for a tri bike then you have done a bit of training and a bit of racing and have made the decision that this is something you want to spend some money on. I think that is probably a fair assumption. If that doesn't describe you, if you are brand new to tri, haven't owned a bike for a while, haven't ridden for a while, then I would suggest getting a road bike. Nothing worse than owning an expensive specialist bit of equipment which you suddenly realise that you don't want (well war and poverty etc are probably worse, but you get what I mean).
When you are choosing your budget, keep in mind what I said above. The major aero advantage comes from the fact that you are on a tri bike. After that it is icing. Yes for an extra $1000 you might be able to get a bike that tests show will save you 28 seconds over a Half Ironman. But if you don't have that $1000 then don't be tempted to compromise on what you can afford. Yes, if you can afford to and are willing to spend more, then sure do so, the bike will be quicker, probably...
That brings me to a couple of other points. The amount of drag something has is proportional to how fast it is going. Therefore, the faster you are going the more drag you have and the bigger the advantage an aero bike is going to give you. Without wanting to sound harsh, if you are pottering along at 26km/h in your Half Ironman, then it isn't going to matter too much what sort of tri bike you are on, the differences between them will only add up to a minor change in the amount of drag you have. If you are booting along at 42km/h, then it becomes a bit more of a big deal. Yes a tri bike will be more aero than a normal road bike and therefore, you will be quicker, but the difference will be smaller the slower you go. The same goes for the differences between brands of tri bike. So be honest about your capabilities. If you are at the slower end of the scale, then probably don't spend all your time reading all the white papers and all your money on the latest and greatest. You are probably going to get as much advantage from something further down the price range as you would from that top of the range $12000 aero beast.
That brings my next point. Something in the realm of 65% to 80% of your drag on the bike comes from you, the rider. The rest is the bike. So if you are talking about a 1% difference between two bikes, you are really only looking at 1% of 20%, so about 0.2% of overall drag. Not a lot then. The point being that if you aren't able to hold a good aero position on the bike, then you are losing most of the benefit of that bike. If this is the case then it is probably worth have a good think about whether you really need a tri bike. Perhaps getting aero clip ons for your roadie might be a far cheaper option. Every race I see people on their very aero tri bikes (sometimes expensive ones) sitting up with their hands on the elbow pads. If this is you, save your money, the tri bike is doing you nothing. Also if this is you and one day you have somebody clip you on the back of the head during the race saying 'Get a clue', that is probably me. Once again be honest about your capabilities and buy a bike that matches them.
Next point and it also relates to capabilities. Bike complexity. These days, in order to get super aero, the top bikes are becoming more and more integrated. That means cables running through handle bars and through stems, integrated stems, underslung rear brakes, the list goes on. Nearly all of these items are harder to work on than their non aero equivalent. The top aero bikes are a pain to work on, simple as that. Some are less of a pain, but we are talking degrees of painfulness here. To give an example, when I had a Cervelo P5 it would take me about 20 minutes to remove the handlebars to pack it for travel. Back in the day it used to take me about 2 minutes on my old P3. On the P5 I couldn't adjust the height of my stem, I needed to take it to a bike mechanic for that and then it still took them half a day or so. I knew somebody who when they ordered a P5, deliberately went for a marginally less aero non integrated set up, to save themselves the pain. Not a bad option, the bulk of the aero gains are in the frame anyway. Brands like Specialized and Quintana Roo deliberately design their tri bikes to be easy to work on. They reasoned that for your average Joe it was more important to be able to pack it up with 10 minutes and an Allen key than it was for Joe to save 10g of drag by having a fully integrated cockpit. Not a bad idea. In summary, if the extra aero of a top bike isn't going to make much difference to you in terms of speed, save yourself the pain and money and go for a less integrated, simpler, cheaper version. The current Cervelo P3 is a great example of a bike that does this, super aero, easy to work on and a reasonable price. A very nice balance.
And finally getting to my last point (I think). Fit. Possibly one of the most crucial bits. No point having the most super duper aerotastic bike in the world if you can't comfortably hold an aero position on it. As I said above, most of the drag on a bike comes from you. If you can't get aero, then there is no point to having the bike.
The other thing that people forget is that not only does a tri bike allow you to hold a more aero position, but it should also mean you can hold a position that will then allow you to run better off the bike. One of the major geometrical differences between a tri bike and a road bike with aero clip ons is the amount of space between your thighs and your chest when in the aero tuck. Basically you aren't as scrunched up on a tri bike. This allows you to be more comfortable when you ride, utilise muscles more efficiently and get off the bike feeling better. If you aren't getting that extra room on your tri bike, then you are losing one of the big advantages of getting a tri bike, you might as well save yourself the money and put clip ons on your road bike.
So when you are choosing a bike, give it a ride, make sure it fits you. If it doesn't, even if you had you whole heart set on that bike, then look at something else. These days tri bikes are pretty good in terms of adjustability. Cervelo pride themselves on the fact that any of their bikes can be made to fit any person (they aren't far off either). Early 'super bikes' that first played with full integration were notorious for their lack of adjustability. Basically if you weren't one of a couple of body shapes, forget it. These days they are a lot better. So depending on the make of the bike you are looking at it shouldn't necessarily be a big issue, but it is a very important one and one you need to get right.
So I think that is about it for now.
So to summarise:
Be honest about your budget and look for a bike that fits it.
Be honest about your capabilities and look for a bike that best matches your ability.
Be honest about your mechanical prowess and look for a bike that suits your ability.
And finally, get a bike that fits you.
Hopefully that has been helpful.
Great article - helping me choose a tri bike as I read this.... Thank you
ReplyDeleteI am glad it was helpful Clayte. I hope you have been happy with your bike choice since then.
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