Shawn asked me to re-post this article from the old forum, it has some very good advice (from a guy who has a sub 19min '10' to his name). I've had to copy it from the original source and amend it a bit so it may not read exactly the same as the previous version but it's well worth 2 minutes of your time.
Here are some little tips to get you steaming past people on the bike as you cut through the air like a very sharp aero thing...
Aerodynamics
Most of a riders problem when reaching speeds of over 20mph is overcoming aerodynamic drag. If you envisage an aircraft's wing, it's that kind of thing you need to be thinking about, cutting through the air smoothly not creating any eddies or swirls of disturbed air behind you as you go, as these form low pressure wakes which try and suck you backwards.
Lots of people don't understand the importance of aerodynamics whilst cycling, and it applies to everyone, regardless of ability. In fact, if you're a slower cyclist, then you have more time gains to make by improving your aerodynamics, as the top end cyclists have to increase their power much more to make the same difference as the relationship between power produced and time isn't linear.
Rider position
This is the biggest part that play in the aero game. People telling you that you have to buy a new bike, get new this and that otherwise you can't possibly hope to be any quick are unfortunately misguided.
Here's a little test: kneel down in front of your bike, facing it head on. It's quite thin. This is what the air sees. Now imagine a rider on it, and you can begin to see why making the riders body position as narrow/thin as possible because much more important than aero frames or whatnot!
Aerobars
Aerobars are a must, they can be had cheaply off eBay for about £20-30, and will allow you to not only rest your arms in a comfortable position, but will also bring your arms inwards, reducing your frontal area and therefore aerodynamic drag. Do not tilt your aerobars downwards, if anything tilt them up a tiny amount, or keep them level, otherwise they act as a big scoop which directs the air into your chest rather than around your body. On a road bike with clip on aerobars, you probably want to use some that are a bit shorter than normal, for example Profile Jammer GTs, Vision clip-ons, ITM VIPs or Oval clip-ons. On a dedicated time trial bike the angles are slightly different, and you can get away with longer extensions as the saddle position will be a bit more forward. I use long extensions and an upturned arm position: experiment and see what works. It might not be that comfy to start with, but the more you practice on them the easier it gets. Copying someone’s position off the internet might make you look good but you may not be able to get the power out in that position. Make small and measured changes as opposed to one big change.
Helmet
The second biggest gain to be made is through the use of an aero helmet. There is a bit of a stigma attached with these, as they do look kinda funny, but are hugely important in aero terms. Get one that you can touch the tail to your back with - if you ride with the tail sticking up then the aero gains aren't as good. eBay is again a good place for aero helmets, look for helmets such as the Giro Advantage, LAS Chrono, Limar/Lazer Chrono, Louis Garneau Rocket, Met Pac VII, Bell Meteor and Spiuk Kronos. There are others but these are pretty good, especially the Spiuk and Bell. An aero helmet is more important than your bike frame or rear wheel, something to bear in mind …certain helmets suit certain styles of rider and back position. For me the RALTECH is king for aerodynamics, for others it would stick up and disrupt the airflow.
Wheels
The front wheel is much more important than the rear, as it hits the air first. Ideally you want a wheel with a very deep rim (over 50mm) and few spokes, the perfect example being a HED Trispoke which has a deep rim and only three spokes, each of which are shaped like an airplanes wing to cut through the air better.
However, you don't need to go all carbon everywhere, as there are certain wheels out there that are fairly aerodynamic, but not that popular as they're not the latest brand etc. If you can find a front Mavic Cosmic, or Campagnolo Shamal, preferably with 12 spokes then these are great to use. Also a Shimano WH-R535 or 545 (where there are 14 spokes, but are attached to the rim in pairs) have equally as good aero benefits, as do Rolf Vector Pros. These crop up on eBay all the time as people splash the cash on the latest wheel from Zipp or Planet-X without really knowing why. Older carbon wheels are still worth a look, such as Zipp 440s or Zipp 530s, HED Deep/CX/Aero/Alps, and Mavic Cosmic Carbone SSC. Corima 4-spokes are pretty good, Spinergy 4-spokes are okay, trispokes that actually say "Trispoke" on them are also good, but avoid "Spin" trispokes at all cost.
The rear wheel should ideally be a disc wheel. Before you start reaching for the shotgun and heading for the local bank, there are other options to consider, of which the best is a wheel cover. This is basically a piece of plastic that covers up the spokes on your rear wheel, turning it into a smooth surface for the air to pass over. They don't look as fancy as an all-carbon disc wheel, but in a comparative study in a wind tunnel have been found to have near identical aerodynamics to a Zipp disc. People don't believe this (usually after they've bought the Zipp disc), but it's true. I've used one and it's great, plus you don't mind so much if you drop it, whereas an £800 disc tends to get carried everywhere on a cushion with an army of slaves. Disc covers cost only around £100.
Great pieces of kit, and they save you a packet.
Tyres.
Tyres make a fairly big difference too, due to the rubber compound used in their construction and their shape and aerodynamics (honestly!). If a tyre has no tread pattern it does not mean it's bad in the wet, and lots of knobbly bits and grooves do not mean better traction. We're not mountain bike racing here!
If you are using clincher tyres (so a tyre and inner tube), then get yourself some Michelin Pro 2 Race or Vittoria Open Corsa Evo CX, and put Michelin Latex inner tubes in them. The special inner tubes are important, and you can lose up to a minute over 40km with the wrong type of tyres. If you can find them, I use Veloflex Record tyres, but the puncture resistance isn't great, and they're rare and expensive. If you are using tubular tyres (ie. tyre and tube all in one, mostly reserved for fancy carbon wheels), then Vittoria Corsa Evo CX pumped up to about 140psi are a good bet, any higher than that and you're wasting your time. Clinchers should be pumped up to about 120psi.
Frame, gears and bits
Having a fancy bike frame is just about looks really, and you get extra bonus points for wacky designs on it. A bike frame that fits you is the major important thing, there's no point having a £10000 frame if it's too big or too small! If you can find one with tubing that is shaped like an aircraft wing (ie. non cylindrical) then that's great, but not something to worry about over the categories above. Equally the gears/brakes/shifting mechanisms just save weight the more money you spend, so sticking with your Shimano Sora and Campagnolo Xenon gears isn't slowing you down. If people start talking to you about "crisper shifting" or a "smoother action", then just beat them over the head with your disc cover.
Summary
It's often worth having a look to see what the top cyclists and triathletes are doing in terms of positioning and things, but sometimes they get it wrong as well. If you go on the internet there's all sorts of debates ranging around about the best and fastest kit to buy, but if you've only got that 20 quid that you saved from last week, get yourself a set of aerobars, get into a nice aero position, and smile all the way to the finish line.
Good luck in the crazy world of TT and don't be put off by the old guy with the assos suit and the Cervelo laden with Zipp. When you beat him, he will be gutted.
