Mountain Bike Thru Axle Vs Quick Release

Thru axles thread through the wheel hub and circular dropout holes.

Mountain bike thru axle vs quick release.

My mountain bike uses a quick release rigid fork and i will be shopping for parts at a bike part swap in a couple weeks. Thru axles are also inserted through a hollow hub axle but they re bigger rear ones are 12mm in diameter and screw into closed dropouts. If you like to use the newest and most modern cycling equipment thru axles are a good choice. At first 135mm was the most common rear axle spacing.

This popularity is changing though as more bikes are coming standard with wider thru axle designs. Currently the most widely used axle on bicycles is the 9mm quick release or qr skewer. Early cyclocross bikes borrowed the 15mm front thru axle diameter but as disc brakes became more common on drop bar bikes they all standardized to 12mm. I imagine over the next 10 years most manufacturers will switch to thru axles even on lower end bikes.

The decision on the rear gets a bit murkier. While my current road disc bike has quick release front and back and they work just grand if i was getting a new disc bike road cross or mountain it would definitely be a thru axle front. The quick release standard for disc rears is to have the dropouts 135mm apart with 10mm diameter dropouts. You may recognize it from such activities as taking your front wheel off to put your bike in your car or locking the back wheel into a mag or fluid trainer.

Skewers use a camming mechanism to secure the wheel to u shaped fork dropouts. Thru axles work better to keep wheels attached to the bike. When mountain bikes first went to thru axles the standard was 12 142 which was the same effective width as the quick release hubs they replaced.