Bike Axle Standards

For decades quick release skewers were the standard for attaching wheels to a road bike.

Bike axle standards.

But 142mm and 157mm soon superseded these standards with the extra 7mm allowing a stiffer interface with the frame. Yeah i know i m supposed to hate it because it s new and wtf bike industry but years ago i was one of small group who got to participate in a blind taste test of current axle standards and potential offerings and in the end i unknowingly chose boost which had no name at the time. In bicycle nomenclature qr refers to a skewer and ta refers to a thru axle. Know your thru axle from your super boost spacing.

Quick release thru axle. If it is a thru axle it would have a ta in the description such as 110ta. Front mtb thru axles currently use three standards. 15x100mm 15x110mm boost and 20x110mm the first number refers to the axle diameter while the second refers to the dropout width of the bike.

The bike industry is known for not creating or adhering to standards but it wasn t until i needed a rear axle i realized how bad it had gotten. As always there are some exceptions but we will focus on modern axle standards that are supported by pub wheels. Skewers are for the bbq. Our resident mechanic al explains axle standards.

At first 135mm was the most common rear axle spacing with 150mm used for dh. It looks as if the pace of change in disc bike axle standards will slow now with 12x100mm front and 12x142mm rear thru axles dominating. But this does build in constraints at both extremes of the. In this example 15mm is the diameter 100mm is the o l d 127mm is the overall length and 1 5mm is the thread pitch.

There s also a 20mm boost version out there which is also 20 x 110mm but has different brake spacing it s pretty limited at the moment so we. 15 x 100mm 127 length 1 5. Best mountain bike wheels. Hub axle standards don t worry brands like boyd enve alto and others are still improving the performance of the humble rim brake hub.