Adjust A Bike’s Saddle Height


saddle height is the most basic adjustment on any classic bike. On a recumbent the measure is less critical as the rider can slide up and down the seat.

Step 1

Where? - Adjust A Bike’s Saddle Height


Each rider can decide their own best saddle height. Then remember it to save time setting up new bikes in future. A good starting point for inexperienced riders is that when sitting on the seat with hips level and a pedal rotated to be as far from the seat as possible that knee should be straight but not locked straight.

Step 2

Measure correct saddle height - Adjust A Bike’s Saddle Height

Measure correct saddle height

Measure saddle height from the centre of the crank axle to the top of the saddle. Use a tape measure before and after any adjustments that way you can go back if you don’t like the new position.

Step 3

Crank Length - Adjust A Bike’s Saddle Height

Crank Length

The standard length for bicycle cranks is 170mm from the centre of the pedal axle to the centre of the crank axle, but this may vary. Using different length cranks or even different shoes or pedals may require that you change your saddle height to stay comfortable.

Step 4

Unclamp - Adjust A Bike’s Saddle Height


The seat-pin – also known as the seat-post – telescopes into the top of the seat-tube. The top of the seat-tube is clamped around the seat-pin by a threaded bolt or a quick-release mechanism. The clamp may be part of the frame or a detachable ring that slides onto the seat-tube. Loosen the clamp to start adjusting the saddle height.

Step 5

Reposition - Adjust A Bike’s Saddle Height


Reposition the seat-pin and do up the clamp finger-tight. Check the saddle is pointing straight ahead, and at the right height.

Step 6

Reclamp - Adjust A Bike’s Saddle Height


When you think you have found the right saddle height, lock it in place.

Pro Tip

Make small adjustments and give the rider some time – a few days or a couple of weeks – to get used to the new position before going back or making further adjustments.

Step 7

Safety Limit - Adjust A Bike’s Saddle Height

Safety Limit

The seat-pin needs a minimum amount of overlap with the seat-tube. This is usually marked on the seat-pin with a set of vertical lines and the words ‘minimum insertion’. 2.5 times the diameter of the seat-post is a rule-of-thumb if the mark is missing.

Pro Tip

If you can’t get a comfortable position without exposing the safety limit replace the seat-pin with a longer one. There’s a wide variety of seat-pin sizes, their diameters vary in increments of 0.2 mm. Getting the right size is critical so the best practice is to take the one you’re replacing to the bike shop.

Pro Tip

An aluminium seat-pin can lock itself into a steel frame by a chemical process known as ‘bi-metallic corrosion’, ‘cold setting’. To avoid this remove the seat-pin once a year, wipe both surfaces then apply a coat of anti-seize grease to the inside of the seat-tube. If the bike is run without mudguards in wet and salty conditions – the salt can come up from the road, or from the rider’s sweat – the surfaces need to be checked and greased more frequently, maybe as often as once every three months.