Disc brakes - center lock versus 6 bolt

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Since cross is coming and gravel is coming (have had multiple emails recently referencing "the fall gravel season") and fall is coming and all of that, and all of that means disc brakes more and more each year, it's time to go through the differences between center lock and 6 bolt disc brakes.

Slight smoke break here - congratulations for finding this page and thanks for reading. We'd like to offer you free US domestic shipping on any order over $100. Just use code "ilearnedsomething" at checkout. And now we return to our regular programming. 

Because we'd be dumb not to accommodate as much personal consumer preference as possible, almost all of our builds are available with either 6 bolt or center lock. There are certain hubs like Chris King where some axle types (12mm) are only available for center lock and some are only available with 6 bolt (15mm). In these cases, we show the limited options on the relevant product page to prevent confusion. We also do our Aivee MP2 based builds in center lock only, just to keep inventory manageable. 

A good place to start is this video that we did a while ago. Bear in mind that when we do videos, it's basically "have an idea, turn on the cameras and go" so these aren't quite as produced as a GCN video. Please excuse that. With that done, the biggest thing to point out is that both center lock and 6 bolt hubs and rotors will work with your brakes. Yes, if you have disc brakes, you can use either format. The hub's rotor interface is only an attachment method between the hub and the rotor. So long as that rotor is delivered to the place where your brakes expect and want and need it to be, which both formats do, the brakes themselves don't care at all whether your hubs and rotor are 6 bolt or center lock. If need be, you can shim your rotors using either commonly available 6 bolt rotor shims or our super genius, exclusive center lock rotor shims. These allow you to set your rotor alignment precisely so that swapping wheels happens without any adjustment needed and no rotor rub. 

If you have center lock hubs, you can use 6 bolt rotors. There are adapters that are cheap, readily available, and effective. Many people are reluctant to change from 6 bolt to center lock hubs because they have a bunch of 6 bolt rotors hanging around that they don't want to turn into junk. Adapters make that a non-issue.

Centerlock rotors are typically a few dollars more than most 6 bolt rotors. That is because center lock rotors need to be 2 piece (there's an aluminum center part for the hub attachment and then a steel part for the actual business end of the rotor). The better 6 bolt rotors are also 2 piece, so they are the same cost. Two piece rotors seem to stay true and resist warping a little better, plus the aluminum does a good job of dissipating brake heat. 

Centerlock rotors are generally easier and more error proof to install. One simple lock ring versus 6 small bolts to get cross threaded or stripped or lost or whatever else happens to these things. 

We carry the appropriate rotors for any disc type anyone reading this is likely to have or need in the store, which again helps make it easy. The only critical thing you need to know is rotor diameter, which is printed on your existing rotors if you have them, or will be in your brake and/or bike specs. For almost everyone reading this, you have either 140 or 160mm rotors. Some of you will have 180s on your mountain bikes. If you do downhill, you might have bigger rotors. 

So the center lock versus 6 bolt debate is actually pretty straightforward. All else being equal, my personal preference is center lock, but once they're on and tuned, you really don't notice too much one way or the other. 

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Re: White Industries using HB20 lockrings up front.

Looks like they are milling down the 12mm TA endcaps a bit more to be compatible with the internally notched lockrings. Some of the newer flat-mount disc race bikes have clearance issues with the bigger lockring.


Sean – Ask and you shall receive: https://novemberbicycles.com/collections/brake-pads-rotors/products/centerlock-hub-rotor-shim-pack-of-4

Dave Kirkpatrick

Thanks, Dave. I figured there must be a way. Had never found bike-branded or CL “disc spacers” when searching, though.

Sean Y

If you watch the video, I go through that in detail. When you use a front hub with an axle bigger than 12 mm, you need to use the externally splined lock ring. What Industries supplies this lock ring as standard with all their front hubs. it is not at all a problem or deficiency with the system, just one of those things that the “development” of new “standards” raises.

David Kirkpatrick

I have run into issues with some center-lock installations. 15mm thru-axle DT Swiss hubs don’t have room to put the internal wrench (Shimano/SRAM cassette tool) on the rotor lock nut supplied with Shimano rotors. I had to buy DT Swiss rotor lock nuts that have an external tooth and are tightened with a Shimano bottom-bracket wrench (or socket if you want to torque them to spec). Not a huge deal but something to consider if you’re working to a deadline. btw does anyone want to buy some Shimano rotor lock nuts?

David Bettridge

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