The Abbey Bike Tools Saddle Height Bullet, available as part of the Fit Kit or separately, allows you to accurately locate your tape measure at the centre of the bottom bracket. Simply place it into the crank arm fixing bolt or the crank arm preload cap of Shimano caps, in conjunction with Abbey's own Crank Preload Tool.
Perfectly machined and anodised, it's available in both 8mm and 10mm sizes, with each featuring a slot for your tape measure end, with a small magnet inside to hold it there so that a finger touch will keep it in place, leaving you free to turn away and pay attention to the business end. The hold is gentle, so you'll never need to force the end in or worry about scratching the tool as you take it out.
The two different sizes and the option for Shimano crank compatibility mean you'll be able to use the bullets to achieve an accurate, consistent saddle height on your whole fleet of bikes, regardless of crank interface. Whether you're resetting after travel, adjusting for riding with winter shoes or worried your seat post is slipping, consistent, repeatable measurements, accurate to a millimetre or less, are now achievable.