Upgrade Centerlock 15/20mm rotor lock ring review

You may need an external spline locknut to fix a centerlock disc brake rotor to some wheels. Upgrade Bikes sells one

Cycling Weekly Verdict

The Upgrade Centerlock 15/20mm lock ring provides an inexpensive, trouble-free, universally fitting way to fix a disc brake rotor to your centerlock equipped wheelset.

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    Lets you fix a brake rotor to a wheel with a large diameter hub

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    Tightened with a standard bottom bracket tool

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You can’t fix disc brake rotors which use Shimano’s centerlock standard to all wheelsets using an internally splined locknut, because often the axle is too wide for a standard cassette locknut tool to fit. The Upgrade Centerlock 15/20mm lock ring is externally splined, to get around this problem.

Because of the proliferation of axle standards, many wheel manufacturers make its wheels with a wider diameter axle and sell or provide adapters to fit other axle standards.

>>> Best road bike wheelsets

So you usually find that you can adapt a disc brake rear wheel to 12x135mm thru-axles, 12x142mm thru-axles (which are becoming the de facto standard) or quick release axles. Usually, 12mm is narrow enough that you can use a cassette tool to tighten an internally splined locknut onto the centerlock rotor threads.


The Upgrade Centerlock lock ring can be tightened using a standard bottom bracket tool
(Image credit: chris catchpole)

The problem is usually with the front wheel, where road bikes can come with 15x100mm thru-axles, 12x100mm thru-axles (again, this is becoming the standard) or quick release axles. To fit a 15mm thru-axle, the wheel axle is usually too wide for a cassette tool to fit and let you tighten the lock ring.

>>> Disc brakes: everything you need to know

So you need a lock ring with external splines. Sometimes, you’ll get one with a wheelset, but if you don’t, you may need to source one yourself. They’re not that easy to find. Fortunately, Upgrade Bikes sells one as part of its extensive range of spares to fit its Kinesis branded wheels.

The Upgrade Centerlock lock ring can be tightened using a standard external bottom bracket cup tool. It will also work with narrower hubs, as they follow the same thread standards.

It’s a simple solution to the lack of compatibility between standards for thru-axles, although disc brake road bikes are increasingly standardising on 12x100mm front thru-axles and 12x142mm at the rear. Centerlock rotors are rapidly taking over from the 6-bolt standard too. Upgrade also sells adaptors to let you run 6-bolt rotors on centerlock wheels. Centerlock rotors aren’t compatible with 6-bolt wheelsets though.

Paul Norman
Paul Norman

Paul started writing for Cycling Weekly in 2015, covering cycling tech, new bikes and product testing. Since then, he’s reviewed hundreds of bikes and thousands of other pieces of cycling equipment for the magazine and the Cycling Weekly website.

He’s been cycling for a lot longer than that though and his travels by bike have taken him all around Europe and to California. He’s been riding gravel since before gravel bikes existed too, riding a cyclocross bike through the Chilterns and along the South Downs.