Even if you do no maintenance on your wheels at all, it’s important that you know how to take them off so that you can fix punctures and even more vital to be able to refit them securely. If you’re not confident, ask your bike shop or an experienced rider to go through the procedure with you.
The standard quick-release lever was designed for roadracing bicycles. It’s a great system, allowing you to lock your wheels in place without tools. But the original designers of the quick-release lever had no idea what we would be doing with bicycles now. Suspension for bicycles existed already, but was a feature of butchers’ and postmen’s bikes, and they seldom tended to use their machines for hurtling around off-road with 6 inches of suspension. The design has been modified along the way to make the fitting more secure – the ’lawyer tabs’ at the bottoms of your fork dropouts force you to undo your quick-release lever nut a few turns before you can release the wheel. This gives you a little more time to notice that something is wrong before your front wheel jumps out and plants you face first in the dirt. Similarly, the move away from horizontal rear dropouts, which allowed you to adjust the chain tension to avoid dropout, was necessary to make wheels more secure. Once common on mountain bikes, these are now seen only on singlespeed-specific frames.
On mountain bikes, many suspension forks and the back of some suspension frames now come with a quick release ’through-axle’. This system is considerably stiffer and more secure, and is designed to resist the heavy forces that disc brakes are capable of applying. The two most common systems are the RockShox Maxle and the Fox QR15. The Maxle system uses a 20mm through-axle on a 110mm wide front hub, while the QR15 system uses a 15mm axle on a 100mm wide front hub. Each type requires a matching fork and a dedicated hub to take the through-axle. Compatible hubs are available from Shimano and a range of other manufacturers. For Maxle rear ends, RockShox also make a 12mm rear Maxle. If you find that your skewers work loose, take your bike to your shop for a second opinion.
There is some disagreement about the best position for the lever. Traditionally, quick-release skewers were oriented so that the lever was on the left-hand side of the bicycle, and lay along one of the stays to prevent it getting caught. This is another legacy of road racing – the levers were always placed on the same side to save vital seconds after crashes – your mechanic could leap out of the team car and run with your wheel, already knowing which side your lever was on to reduce delay. Nestling the levers against the chainstay reduced the chances of your lever becoming entangled with someone else’s bike and accidentally releasing your wheel.
On mountain bikes, it’s important that the levers don’t point straight forward, because they could get caught on a branch as you ride past and flip open. It’s preferable to fit them on the opposite side to disc rotors, as this reduces the chances of getting burned when fixing punctures. But the shape of your forks will often dictate where the skewer can fit, especially if there are adjusting knobs or fitting bolts behind the dropout. The most important thing is to ensure that the levers are firmly fitted. A ziptie around the skewer as an extra line of defence does no harm – we like Shimano XT skewers for this, as they already have a handy hole in them that’s the perfect size.
Fitting quick-release levers securely
Step 1: Your skewer and locknut should have deep, sharp serrations to grip the frame. A spring sits on either end of the skewer, with the small end pointing inwards. To secure the skewer, fold out the handle until it points straight out from the frame. Hold the handle and tighten the locknut on the other end finger tight. Fold – don’t twist – the skewer handle, so that the ’closed’ label points outwards.
Step 2: The lever should resist being closed. If it closes easily, flip it open again, tighten the locknut, then fold the handle closed. If the handle won’t close fully, flip it open, loosen the locknut and fold closed. Once you’re satisfied, flip open the lever again and twist locknut and skewer the same amount, in the same direction, so that when you close the handle it lies beside the frame or fork.
Through Axles: Both the RockShox Maxle and Fox QR 15 systems work by threading the axle through the dropout and hub and screwing into the opposing dropout. The remaining slop is then taken up by firmly closing the quick-release lever. Each type will only work with dedicated fork and matching hub but the extra security and increased stiffness are well worthwhile.
Source : BIKE MAINTENANCE TIPS, TRICKS & TECHNIQUES
See also bike maintenance tips, tricks and techniques “Swapping hub sprockets”