Which rotor lock rings?
 

I’m moving from rim brake to disc and realize that I know virtually nothing about disc tech. I splurged on Enve 4.5 wheels and plan to build up a Tarmac SL8 (if the frame sets ever become available in my size).

Which rotor lock rings should I buy? I know I need center lock, but internal or external? Does the stack matter? Are particular brands better than others or does it not really matter?

From the standpoint of simply holding the rotor onto the hub, there's little difference between centerlock lockrings*. However, some forks have very little clearance between the lockring and the fork blade. Many carbon road forks don't have enough clearancee for a lockring with external splines, and only internal splined lockrings with tapered edges will fit. This is the case with the Tarmac SL7 fork, and is likely the case with the Tarmac SL8 fork as well.

*The exception here is Campagnolo/Fulcrum wheels, which require proprietary Campagnolo/Fulcrum lockrings.

If you purchase Shimano rotors, they come with lock rings. If you buy Sram or Galfer or SwissStop rotors, you need to buy lock rings. Which ones you need to buy can also depend on your hub axle size.

But this is a good one as any and show fit any axle size. https://www.universalcycles.com/shop....php?id=109971

There are much cheaper ones out there on aliexpress and amazon. I have tried them too and they work just like the branded ones.

Go with this style just in case you end caps are tapered or on the larger size.
This is because the cassette lock ring type might not leave enough room for your cassette tool to get in there.

This, splines out the outside.
https://m.media-amazon.com/images/I/...1000_QL80_.jpg

Not these, spies on the inside.
https://m.media-amazon.com/images/I/...1000_QL80_.jpg

Counterpoint:

The points you mention may apply to lockrings on MTBs, but generally not for road bikes.

The new wheels are Enve 4.5, which have 12mm axles, so there should be no issue with space around the end caps (even with internally splined lockrings).

The new frame is a Specialized Tarmac SL7, and there is often little clearance between Specialized fork blades and rotor lockrings, so lockrings with external splines often won't fit.

The internal spline lockrings will be fine for all 12mm hubs and are required for some frames/forks due to limited clearance in other spots. If you're riding 15mm front hubs, use the external style lockring for both, the threads on both styles are the same.

Don't forget the tool to tighten/remove the ring.
I did, and had to wait another 4 days after the rotors showed up to find out I'd bought the wrong size.

For Shimano disc lockrings, the internal spline is a cassette lockring tool. The outer spline lockring's a BB tool.

No 'extra' tools that you probably don't already have needed.

For other manufacturers? You'd have to try em and see, but I'll bet they follow the Shimano standard

HTH

M

Somewhat correct, except wheels built with the nicer DT240 hubs that were all conical shaped like so:
https://mikesbikes.com/cdn/shop/file...g?v=1691182920
These are on my Enve G23, Enve CX Tubualrs, and Roval CLX50s which are installed on my Tarmac SL7.
Why might you ask? Due to the many end caps DT Swiss offers they support 12 and 15mm on the front which is where most of the clearance problems are for the lockings in question.

OP = check your hubs and see how much room you have before making a decision.

I've used internal spline centerlock rotor lockrings from a variety of makers (SRAM, Tektro, Specialized, Jagwire, Wolf Tooth), and all have used the same splines as Shimano cassette lockrings.

However, there is a caveat: A front hub rotor lockring is further inboard (further from the end of the axle) than a cassette lockring, so a splined tool for a rotor lockring has to have a deeper recess to fit over the longer axle extension. Many older cassette tools aren't deep enough for rotor lockrings. The Shimano cassette lockring tool I've used for years worked okay for rear rotor lockrings, but it wasn't deep enough for front rotor lockrings, so I had to get another one for the front lockring. (Fortunately many newer lockring tools are deep enough to work for both rotor lockrings and cassette lockrings.)

That's odd - I've got Roval Alpinist wheels, which use DT internals (including axles and end caps), and I've had no problem using internal spline lockrings. Also, I tried two brands of external spline lockrings, but in both cases the lockring rubbed against the inside of a Tarmac SL7 fork blade, so I had to get internal spline lockrings.

I have internal spline lockrings for Hope RS4 (road disc) hubs and I need to remove the end cap to loosen or tighten the lockring.

I dont know if there are other hubs like this.

Counter-counterpoint: :)

The i9 Torch hubs with 12mm axles on my gravel bike have fat endcaps that require the external version of the lockring. The internally splined version needs a cassette tool that won't fit over the fat endcaps.

So I went with the externally splined version from Wolftooth and bought a BB tool to install them.

Thanks guys. I’m happy that the cycling industry continues to innovate and I’m excited about moving to disc brakes and electronic shifting, but learning the fiddly little info about the seventeen kinds of lock rings (and all the rest of it) seems like a real pain at the moment.

ftfy ;)