How Do I Buy a Bike for Triathlon?

By Neil Melville

Although perfectly possible to do a triathlon on any old bike there is no doubt that you will enjoy your training and racing more and you could be minutes faster and find the going easier if you had something a bit more suited for purpose. If you have been racing already you will also realise that there are a lot of exotic and expensive beauties out there but when you try to hunt one down the choice becomes even more bewildering. I can't tell you which bike to buy but I can cut through the jargon and, because I have been through this same process twice, once with a £500 budget and once with £1500, perhaps I can help you understand the choices you will have to make.

How much do I need to spend?

Before I can answer that you need to first ask a different question...

What do I get for my money?

Answer: a combination of four things – Frame material and workmanship, wheels, groupset (gears, chain, brakes, cranks etc), and then finishing kit (saddle, seatpost, bars etc). The idea of thinking of a bike as the sum of its parts is important because, for example, my bike has a good frame, pretty good wheels but has an average groupset found on many bikes at half the price. Many bikes below £1200 will keep the price down by using relatively low quality finishing kit. Don't let this bother you though; remember that with bike-buyng you are mostly getting what you pay for and as long as the most expensive items (frame and wheels) are as good as you can afford, other stuff you can either upgrade or replace when it wears out. Lets think more about what you are buying...

Frame Material

What you want in a frame is lightness and stiffness, a light frame takes less energy to move uphill or accelerate, but stiffness is as important. If you imagine riding a bike made from copper pipes, all of your pedaling efforts would simply bend the frame from side to side and next to no energy would be left to move you forward. As you took corners at speed the front of the bike would flex and make steering less positive. The other extreme would be a frame made of cast iron – very stiff but getting the thing to move against gravity would not be a lot of fun. So, bikes aren't made out of copper or iron, in order roughly of cost they are made of cheap steel alloys (often referred to as Cro-moly), aluminium alloys, expensive steel alloys, titanium alloys and carbon fibre.

That's not the end of the story. Although many consider carbon or titanium the ultimate, a carbon frame may not be as light or stiff as an aluminium or steel frame at a similar price. Another example, aluminium is 3 times as light as steel but it is softer so aluminium tubes usually have a greater diameter to achieve the same strength. A quality steel frame can be made from smaller tubes with thinner walls and end up just as light.

Bottom line – don't get hung up on frame material.

Why isn't one aluminium/steel/carbon frame the same as another?

Of greater cost than the actual material is the workmanship and design used to produce it. Whatever material is used, they are made of hollow tubes, and to make these tubes lighter still they will vary in the thickness of the material used along their length, thinner where less strength is needed, thicker where stiffness and strength are more important. This process is done by double or triple "butting" the tubes. Alloys capable of remaining strong as tubes get thinner and lighter are expensive and take time and skill to produce. The designers and engineers will compensate for using thinner, lighter tubes too by shaping them into different combinations of round, oval, even square cross section, but producing these thin, strong, shaped tubes with varying thickness costs. Remember that a frame designer isn't just trying to achieve lightness and stiffness but also good handling; how well the bike handles at speed and how fast you can take corners on it.

My first car was a Morris Marina with a big engine; it had loads of power but if you got to any kind of speed, the steering wheel started to judder and the car hopped around the road. If you think that you don't go fast enough for handling to matter then consider this – to make my Morris move I just had to press on the accelerator but if you slow unnecessarily for bends, you have to use the power of your quads to get the bike moving again. Or if the bike doesn't feel comfortable at speed and you can't take advantage of the downhills then you'll have to put in more effort somewhere else to get back the ground you lose – probably on the uphill following the hill you're descending! So on a twisty, turny, undulating course the stiffness and lightness of your frame will let you power up the climbs and out of corners, the handling will let you take the corners and downhills faster.


Because wheels are a pretty big component, accelerating their rotating weight is a significant proportion of the energy you expend, consequently you can spend over £1000 on wheels alone! However, if you are trying to compare two bikes you want to look at the hub (centre part) and the rims for an indication of wheel quality. The hub should be of an equivalent quality or better to the groupset being used and if it isn't that's an indication that cheaper wheels are keeping down the cost of the bike. Difficult to do a comparison of all the different rim manufacturers but Mavic are most commonly used and their 2004 product list (in ascending order of quality) is:

  • Rims: MA3, CPX22, CPX33, Reflex, Open Pro
  • Wheels: Cosmos, Ksyrium equipe, Ksyrium elite 650, Ksyrium elite 700, Ksyrium ssc sl, Ksyrium ssl sl tdf, Cosmic Carbon

In addition to more traditional looking wheels, the reduced spoke, deep rim look is now fashionable even for mid range wheels. These theoretically result in a lighter wheel which has reduced air resistance but a good traditional wheel made of lightweight materials can still be lighter for the same price. If looking at a bike with this type of wheel, ask advice for how good the wheels really are. At the cheaper end of the quality market you may find that cheap (and nasty) tyres get used to keep the price down. Cheap tyres can be false economy when you consider that they may cost you £20 each to replace.


The better groupsets are better engineered so that shifting between gears is smooth and positive. Because of this you will often find that bikes below £1500 use more expensive parts for important functions e.g. better rear derailleur than front or good crankset and cheap brakes. The materials used are lighter and harder wearing and consequently more expensive, those at the cheaper end may use more plastics and steel. Again this is significant; if you are buying budget and putting in a decent mileage then expect to be replacing most of your harder working components within a couple of years. No bad thing because you can use this to buy cheaper and upgrade as you need to. But don't forget about the extra weight you will be carrying in the meantime – the difference in weight between just the cranksets, brakes and derailleur on Shimano Ultegra and Sora is 300g.

The two main manufacturers of groupsets are Shimano and Campagnolo. Historically, Campag was what everyone aspired to if they could afford it. Today, it is widely acknowledged that Shimano has caught up and Campag is more competitively priced. Campag groupsets are still significantly lighter than Shimano equivalents and you will still find bike shop staff who will regard my comments here as blasphemy! To help you compare, here are the two manufacturer's 2004 groupsets in order of quality.

Shimano Campagnola



Shimano describe 105 as the first "road/racing enthusiast's" groupset in their arsenal. Veloce is it's approximate equivalent from Campag. On bikes around the £500 mark, Tiagra and Sora will be found in part. You can identify the parts used as the groupset name will be written on them.

Finishing Kit

You have bought a nice frame but if you were a lightweight obsessive you could spend as much again on carbon fibre bars, seatpost etc. Of course most off-the-shelf bikes don’t give you the choice and this is often an area where cheaper and heavier stuff gets shoved on to keep the price down. Nothing you can really do about this other than pay more money for custom builds BUT what is important is that when it comes to fitting the bike to your body shape, you may well want to swap for different width bars or a different length stem. If you are doing this it will save you money to make these decisions pre-purchase, you may even convince the kindly shopkeep to exchange these items for free or upgrade at a discount.

Your choice of bars may influence what you buy. I bolt on tri bars to a traditional bar but I rarely use the dropped position except when scaring myself going downhill too fast. I would be better off using a true aerobar.

OK. Good. So how much do I need to spend?

What is your budget? With bikes you pretty much get what you pay for. Be careful though; a £2000 bike isn't twice as fast as a £1000 bike, but you will definitely enjoy riding it twice as much. But any bike twice the cost of anything you have ridden before will feel twice as good. That said, I'm going to suggest that you start thinking at the £500 mark (although a sale or second hand bargain might take this down quite a bit).

For £500 you will get a double butted frame with Shimano's Sora entry level quality groupset, probably with a 105 rear mech. (mechanism/derailleur). An aluminium bike will be lighter than a steel one at this price but you will be looking for a steel 'cro-moly' fork as it will absorb road vibration giving a more comfortable, smooth and controlled ride.

As you climb towards £1000 you can expect a carbon fibre fork and lighter weight frames with shaped tubing for better handling and stiffness, the groupset will be better engineered, shed the plastic and give a smother shift and better wear; first full Shimano 105 and then part Ultegra. Bikes above £1000 will be a real quality investment usually with an Ultegra groupset and perhaps fancy reduced spoke wheels.

For £1500 you will either be looking at lighter more aerodynamic wheels or you could be spending the money on a Titanium frame instead, some argue that it's the ideal frame material. Weight is also shed by finishing the bike with quality bars, seat posts and other finishing equipment.

Somewhere towards £2000 the first Shimano DuraAce or Campagnolo Record equipped bikes appear. Still feeling flush? In that case splash out on a carbon fibre bike. As I said, you get what you pay for but even an entry level bike is going to feel fantastic compared to anything you have ridden before. If you can scrape together an extra couple of hundred, you will notice the difference but don't forget to save some of your cash for shoes, clipless pedals, tribars because not only do these things make a much bigger difference to your speed and energy expenditure than a lighter groupset but chances are you can haggle for a discount if you buy them at the same time as the bike.

Getting the right size

This is crucial, and becomes more so the more time you expect to spend sitting on it. There are two simple traditional fit tests:

  1. Stand-over height. Stand over the top tube and lift the bike off the ground. There should be at least a two inch gap between the wheels and the ground.
  2. Top tube length. With your elbow touching the nose of the saddle, do the tips of your fingers just touch the straight part of the bars?

However there are a number of reasons why you should be wary of using just these two tests or believing any sales assistant that declares a bike a perfect fit on the basis of them without seeing you on the bike.

Firstly many bikes have ‘compact' frames with slightly or dramatically downward sloping top tubes. Some argue that the smaller resulting frame is stiffer and lighter, but this is only true only if the longer seat post required is not heavier than the bits of frame it replaces. From the manufacturer's point of view, a compact frame means more people pass the stand-over height test and they can get away with making a smaller range of sizes! What this means for you is that a 54cm frame from one maker may be a good fit but you can't say that the frame size you need is 54cm for all models and manufacturers. The top tube length test is clearly not going to work if you have short arms and a long back!

So how do you know if a bike fits you? The cheapest option is to seek the advice of a shop assistant knowledgeable about road biking and ideally time-trialling who will look at you sitting on the bike and suggest how the saddle should be raised, slid back or angled on its rails, whether a longer stem is needed and what height the bars should be. Their guidance will help you appreciate what a good fitting bike should feel like. You can fast track this by going directly to a shop with a sizing jig – this is a frame which can be altered in every dimension and angle. By doing this you can expect good advice on the dimensions of the bike you are looking for. You will pay for this service but often the cost is refunded if you buy a bike from that shop. Some shops even use the measurements to customise the bike they sell to you. An alternative sizing method that will give as good results but will not give you the same feeling of what a good fit should feel like is computer based sizing. The output is a diagram showing the dimensions of your ideal bike, its then up to you to wander the shops with a tape measure! The perfect, and so more expensive solution, is to use the Bikefit service (its like the other measurement services but additionally looks at your riding style and is a much more in depth process. The result is a perfect fit for the bike you own or the bike you want.

An important consideration when it comes to fit is what you will be using the bike for. In most triathlons, you ought to be spending a significant portion of the race on your tribars (more about tri specific bikes shortly) which places you in a more stretched out position. If too bent double in this position you won't be comfortable or pedal efficiently.

Being very short presents a big problem because bike design is constrained by the size of the wheels. The seat tube and the top tube both have to be a minimum length to accommodate a standard 700c wheel. A bike that is too big or a custom build is not your only option, but you are going to need to seek out manufacturers which equip their smaller frame sizes with the smaller 650 wheels. Trek is one that I know of (I have a 5' sister), there may be others.


Do you need a tri bike?

Genuine tri bikes have their own geometry; shorter top tube, more vertical seat post designed to position you forward over the tribars in a comfortable aerodynamic position. This position is also advantageous for bike to run transition because it encourages the use of similar muscles. More of your body weight is over the bottom bracket so the maximum power you can put into pedal strokes is supposed to be greater (think of the difference in the gear you can push when you stand on the pedals to climb a steep hill). I say supposed because the other argument is that the more relaxed angles of a typical road bike allow a greater average power to well trained cyclists because the hamstrings are able to play a more active part in turning the crank through its entire cycle (efficient pedaling is an even use of muscle power throughout the turn). Because the frame's steeper angles absorb less vibration and push you on top of the bars more, tri bikes are less comfortable for long days in the saddle at the contact points of bars and saddle.

Some real life examples: Spencer Smith has switched between road and tri geometries at various points in his career dependant on sponsor and what bike he was most used to riding. Jodie Swallow will be using a titanium road frame for the hilly Athens Olympic course.

A bike built for tri will also come equipped with appropriate wheels and finishing kit which can save you money compared with later deciding to replace these bits on a more standard road bike. So in answer to the question, “Do I need a tri bike”, the answer is "No" but a tri bike will be faster for the distances and the nature of triathlon racing. How about these bottom lines:

  • If the primary reason you are buying a bike is to participate in multisport (triathlon or duathlon) events and do solo training rides – buy a triathlon geometry bike.
  • If the primary reason you are buying a bike is to participate in group rides or races – buy a standard road bike.


Out shopping

By now you should have a goodly portion of the jargon you need, a few ideas about what you are looking for and the ability to look at two bikes side by side and have the beginnings of an idea of how to compare them. It is impossible for me to recommend one shop over another, because although you will get a greater number of more knowledgeable staff at Sigma cycles or Condor, Evan's will have a bigger range of bargains, and your small local dealer may surprise you because although he sells mostly mountain bikes to pay the bills, he was in fact British time trial champion in the 80s and has a couple of real beauties at the back of the shop, the time to give you some excellent advice and will throw in shoes and helmet if you flash your quads and keep him talking. The tri specific shops in London are Bike & Run and Tri & Run but all the shops mentioned here will do at least one tri specific bike. Remember that Serpentine members also get discounts at some of these shops.

Remember that even the best bike shops have staff who won't be knowledgeable about your specific needs as a triathlete. Make sure you at least ask for help from someone who rides a road bike. Ask him/her about the relative merits of different options, what you would get if you get if you spent a bit more or less. Ask them what would be the first thing that they would upgrade as a test of their knowledge and an indicator of the weakest link on your intended purchase!

Do not. I repeat, do not be intimidated. It's their job to serve you and if they can't do it well then go to someone who can.

Buying Second Hand

This can be a real source of bargains – often in great condition. The knowledge that I have aimed to give you here should tackle at least some of the worries you had about being sold a lemon. Good sources of quality second hand bikes are the classified section of Cycling Weekly magazine, the Triathletes-UK website and the British Cycling website. If buying second hand, what you need to watch out for is the less obvious signs of wear because if you end up replacing worn components sooner rather than later that could easily add a hundred quid to the price. Here are some of the things you want to ask about or check:

Part Cost
Tyres £20 each Look for obvious signs of wear and cuts

£25 chain

£30-£60 cassette

£15-£30 chain ring

When the chain wears the rear cassette needs to be replaced too. If the chainrings are worn too the potential cost is quite high. If the chain has done more than 1000 miles (less if not cleaned or ridden in wet weather) then chances are it needs replaced.
Brake/gear cables £20 Check for cracks in the plastic and frayed cables
Frame Don't buy Look for dents in the frame and cracks in the paint around the weld points

Can I buy a bike that I can commute on and train/race with?

Only you can answer that one.

The two tasks are so different that I want you to buy two bikes. You already know that you can race triathlon on any roadworthy bike and you might be able to guess that a fast, light race bike is less than ideal for central London commuting than something with a stronger frame and wheels and better stopping power. That fast bike will be so much more fun to go training on though especially if it hasn't been coated in road muck for five days a week. Go into a bike shop and ask this question and they will point you to the new breed of street bikes – lighter frames and wheels than an equivalently priced mountain bike but with MTB style V brakes. You could make it faster for racing by fitting narrower tyres and a tri bar but it will still be heavier than an equivalent race bike.

If you didn't want the faff of changing tyres a step up would be to buy a second set of wheels. If price is the issue then how about buying a race bike for racing and training and a second hand bike for commuting? If you are concerned that you aren't going to love triathlon then another alternative might be to buy a mid priced bike for this season and sell it at the end with the intention or replacing it with something better next year.

Good luck!