There are few more important metrics to consider when setting up your bike than how and where you sit. Obviously, the saddle is the physical where, but it's precise positioning, and in particular, its height, has a direct effect on the power you can apply to the pedals and your fundamental comfort while riding. The two issues are connected, so here's how to get it right...
Our guide below shows you what we believe is the best method to set your saddle height. We've included a list of the tools and materials that you will need to complete the job and in some cases where you can buy them. If there are others that you prefer then feel free to let everybody know in the comments.
Tools & Materials
1. Seat post. Adapting the saddle height to suit your personal physiology is relatively easy thanks to seat posts which slide up and down the inside of the seat tube. The seat tube is connected at the bottom bracket to the cranks where your power is transferred to the bike. Setting the saddle height measurement will depend on your personal measurements from crotch to foot.
2. Finding the truth. There are many old wives tales, arcane theories and mathematical formulae to give a to-the-millimetre answer to your personal saddle height measurement; from the classic 109% of inside leg length from saddle top to pedal - with crank set to six o'clock, to the newer 88.3% of inside leg length for centre of the bottom bracket - to top of saddle, as favoured and practiced by three time Tour De France winner Greg Lemond. Whether you measure centre to top or pedal to top, why does it have to be so exact? With research showing that as little as five millimetres discrepancy has a major effect on power, and a potential source of injury and discomfort, so, getting the precise measurement dialled in is really important.
3. The numbers game. I’ve always measured my personal saddle height from centre of the bottom bracket axle, to the saddle top. Using this metric, I eventually settled on 72cm dead - as the saddle height which gave me best power and maximum comfort (when riding 175mm crank arms as I always do - I'm a mountain biker at heart). My inside leg measurement is 81.5cm. So, out of curiosity, I checked this matrix using the Greg Lemond 88.3% formulae, and by that calculation my ideal saddle height would be 71.9cm. So, my 'by feel' measurement was correct to within a millimetre. Cue mild smug face. Use whichever calculation method works for you, but don't stop tweaking the measurement if the result doesn't feel optimal when you're riding.
4. A friend indeed. It sounds daft, but when making the the calculation based on inside leg measurement, don't assume your chosen trouser length will do, trousers fit differently and the quoted measurements are never exact. Never try to take your inside leg measurement yourself, it'll always be wrong. Have a friend do it for you. Make sure you're in bare or socked feet, as we're looking for a high degree of accuracy to get you as near perfectly positioned as possible. Remember we're talking single millimetres making a difference.
5. Getting hip, without the hop. Away from the numbers, correct saddle height has outwardly visible signs. As well as maintaining low muscle stress, through the stroke cycle, you're also looking to maintain stable, horizontal hips when spinning in a seated position. Viewed from the rear, when pedalling seated, your hips shouldn't be rising or falling, at their outsde edges, by more than 2cm. This isn't a finite target for setting saddle height, but a reasonable guide for knowing when it isn't quite right. Wildly rocking hips, as over extended legs reach for the pedal in the bottom of the stroke, or hips disturbed by cramped, under extended hip joints both mean you should make saddle height adjustments. There will always be some hip movement, it's the nature of sitting on a fulcrum, but it should be minimal - a soft movement, and not be overly engaging or stressing your lower back, sides or frontal core. naturally seeing yourself from the rear is tough, so get a friend to check next time you ride.
6. Ankling. A sign that your saddle height is too great, is when you're having to reach for the pedal with the ball of your foot (the cleat area) through the low part of the pedal stroke, it looks from outside like you're slightly pointing your toes through the low part of the pedal stroke. This causes the leg to over extend and shift the hips downwards to wards the pedal. Likewise, a saddle that's too low, will cause the angle between your foot and shin to close to at, or near, its maximum. As a rule of thumb, for comfort and efficiency, feet should be, more or less, at ninety degrees with the shin through the entire stroke.
7. Naturally cocked. The general consensus on the level of leg extension, is that when your foot is on the pedal and the crank arm is in the six o'clock position the leg should be what is referred to as 'naturally cocked'. To feel what that looks and feels like, sit on the saddle and let your leg hang under its own weight. It will not naturally hang fully locked out (to its maximum length), but instead hold itself in a slightly cocked position. This is the ball park angle you should find the leg in, when the foot is on the pedal, with the crank arm in the six o'clock position.
8. Going slowly. Seatpost adjustments, either up or down, should be made one at a time and in single millimetres. It can be a slow process, riding the bike between each adjustment, noting the differences in power output either actual via a power meter, or by feel. Don't be blinded by the power meter however, bikes are mostly for riding for smiles, not winning races. Do not disregard your comfort as a vital factor. The fact is, if you're not comfortable seated and pedalling, regardless of what the science says, then you probably aren't going to improve your cycling experience.
9. Little things, big differences. Remember that the final measurement can be affected by many things; your health, the weather - temperature makes a difference in how flexible your muscles are, your clothing, your flexibility, the specifics of your saddle - curved shell models can have 1.5cm difference in height between nose/tail and middle, your stem reach and bar height, pedal height, shoe sole depth, even the thickness of the socks you choose to ride in. As you boil your personal measurement down to the final millimetre - and then get a bunch of miles ridden at that height - you'll come to sense any new differences in your saddle height as instinctively as changes in your health.
10. Make notes not notches. Making your mark. There's no point in knowing what measurement you need, then not using it. Write it down and commit it to memory. Even the pros know sooner or later their seat post will get removed or adjusted and the measurement will be (temporarily) lost. Some like to mark the correct height on the seatpost with a small wrap of electrical tape, or if you're detail obsessed, a small mark, or dot on the seat post with a permanent marker pen or a white china graph pencil. Fizik make a neat rubber memory marker for their seat posts. Don't be tempted to make a scratch, or scribe, a mark in the seat post, as an aide memoir, for that way disaster lies.
Bonus tip.... Be kind and pass it on. Once you've got your own saddle height measurement perfected, don't be afraid to help other riders achieve theirs. I see a lot of riders under, or over extended, legs cramped or straining, hips rocking, not achieving good power, efficiency or in many cases, basic cycling comfort. Most have set their saddle heights by guesswork or blind ingorance that it makes such a difference, so some friendly, constructive advice from you might be helpful.