Skip to main content

Straighten a bent brake rotor


1. If your brake is rubbing, first check that the calliper is aligned with the rotor. Loosen the calliper bolts just enough to allow you to move it from side to side. Spin the wheel, then adjust the position of the calliper by hand until it no longer rubs, or only rubs at one point of the rotor.

2. Rotor still rubbing at one point? It’ll need straightening. If it’s the back wheel that’s a

3. Spin the wheel and listen out for a rubbing sound. Stop the wheel at the point where the rotor contacts the pads. Look down through the calliper to see which pad the rotor is touching. If it’s the right pad you’ll need to bend the rotor left, and vice versa.

4. Note which part of the rotor is rubbing, then rotate the wheel until the bent section is free of the calliper. With a rotor truing tool, adjustable spanner or clean hands, pull the rotor a few millimetres in the opposite direction to the pad it was touching.


5. Rotate the bent section of rotor back into the calliper and look down through the pad slot again. If the rotor is still touching the same pad, repeat step 4, but this time bend it a little further than before.

6. If the rotor now touches the opposite pad, you’ve bent it too far. Repeat step 4, but this time bend the rotor more gently and in the opposite direction to before. Repeat until it’s central between the pads.

7. Spin the wheel again, listening out for any rubbing spots. If necessary, repeat steps 3 to 6. When the rotor is no longer rubbing, put the chain back on the cassette and you’re ready to ride!


ROTOR TRUING TOOL
Also known as a truing fork, this makes it easy to bend the disc back into shape. A (clean) adjustable spanner can be used instead. Sometimes it’s easier to straighten the rotor by hand, particularly if a large section is bent.

Popular posts from this blog

Merida Big Nine 100

Wit the bikes swapped over, we head out on the same loop again, this time on the 29in Big Nine 100. Whereas the Big Seven was snappy off the line, the 29er takes a couple more pedal strokes to get up to speed. That said, once it's up there, it's easy to keep the big wheels rolling, allowing us to cover ground with ease. The fire road is at times a little rough, and the bigger wheels roll over the imperfections so we barely notice them.

Chromag HiFi 35 (50mm) stem

This is a seriously solid stem. Chromag use 5mm Allen bolts throughout, which makes it that bit easier to fit because you don’t have to swap tools. Once torqued up to the recommended 6-8Nm, it clamps both steerer and bar solidly, with no appreciable flex. We couldn’t get it to twist on the steerer, either in our static test or when riding. It’s also available in a 35mm length and three other colours. At 204g the HiFi is the heaviest stem on test by some margin, despite being one of the more expensive offerings here. Price $112

CANYON NERVE AL 8.0

  S ince their entry into the UK market a few years ago, Canyon have made a name for themselves as purveyors of well-made bikes that exhibit often extraordinary value. The secret (or catch, depending on your point of view) is that the brand don’t have dealers – they ship bikes directly to your door.

Cannondale Trail SL 29 SS

The fat aluminium tubes are a constrast to the skinny items seen elsewhere in the test, but this rigid Cannondale uses them to create one of the most old-school - and lightest - rides here.

Trek Session Evolution

In this series we’re looking at the evolution of three bikes that enjoy enduring popularity with UK riders. Each fits into a different category – we’ve had a hardtail and a full-suspension trail bike, so for this final feature it’s the turn of the long-travel bike. And few ‘big bikes’ have undergone such a transformation as the Trek Session, which had a bit of a confused birth at a time of overlapping disciplines but has evolved into a sleek, lightweight race bike with multiple World Cup wins to its name.