Bicycle Mechanics - Don't Get CenterLock

How do you undo this (with thanks in advance)?

290229

Undo what?

With a 17mm open spanner.

- Joel

It appears to be a threaded axle, so the locknut should unscrew. See of the cone behind it is slotted for a thin wrench (cone wrench). If so, you canuse an open end on the locknut and the cone wrench behind it. There are plenty of tutorials on adjusting hub bearings, so this will be fairly straight forward.

If there aren't flats for a cone wrench, see if the left side has them. Or you can possibly wotk the right locknut against the left one, and disassemble from whichever side comes free first.

I'm so confused. Why is the title "Don't Get CenterLock"? You don't even have a rotor on there to remove.

I was presuming that the silver circle thingy needed to be unscrewed so that I could insert a rotor "underneath" and tighten up again. I've since learned that you simply place the rotor here then screw a lockring down on it. If I had been supplied the lockrings it would have all made sense. Thanks anyway all.

yup... Enlarging the picture provided by the OP, I can just make out what looks to be the tiniest corner of wrench flat at about the 4 - 5 o'clock position under the lock nut.

ouch. 26 spoke wheel with disk brakes? what could possibly go wrong with that? :(

How do you undo this (with thanks in advance)?

290229

If you don't mind Mark S, I'm inclined to use part of your photo in the following:

http://www.mrrabbit.net/docs/spokeheads/main.html

=8-)

If I had been supplied the lockrings it would have all made sense. Thanks anyway all.

The rotors (not the hubs) are supplied with lockrings, and you use a TL-LR15 to tighten it to 40 Nm, this is covered in the tech docs http://techdocs.shimano.com/media/techdocs/content/cycle/SI/Deore-XT/DiskBrakeSystem/BRM765/SI_8A30G_En_v1_m56577569830604906.pdf which you get a copy of, if you buy the rotor in retail packaging.

ouch. 26 spoke wheel with disk brakes? what could possibly go wrong with that? :(

looks like a 28 to me, probably from a factory MT-65 wheelset (the pictured hub looks like an SLX HB-m65x). The spokes are particularly thick, as I recall, and it will hold up just fine to disc brake use. Spoke count in isolation does not determine the strength of a wheel or its suitability for disc brake use.

- Joel

I'm so confused. Why is the title "Don't Get CenterLock"? You don't even have a rotor on there to remove.


Like everyone else I thought the OP wa trying to service the bearings! I have to get a bike with those fancy disc brakes one day.

I was presuming that the silver circle thingy needed to be unscrewed so that I could insert a rotor "underneath" and tighten up again. I've since learned that you simply place the rotor here then screw a lockring down on it. If I had been supplied the lockrings it would have all made sense. Thanks anyway all.

If you really insist - you can use the lockring from most cassettes and its the same tool used to tighten both of them. But yup - you'd probably be much happier with a brake rotor installed there first and the lockring does come as part of the kit. Optionally if you really really hate centerlocks - adapter rings are made to convert the system to a standard bolt pattern.

For me its a little late - I kinda like them!

More like
I don't get centerlock


cone adjustment, I'd just use the opposite side of the Hub and do the loosening,
re packing and re adjustment on that side.

Make the side , shown, you have a hard time dealing with ,
Tightened against each other, 2 wrenches, 1 a cone wrench,
so It won't come loose.

then put the axle back in, with the fresh grease, or what ever you had in mind.
and do the cone adjustment from the other side.

BTW- don't throw out a worn out disc. If you ever decide you need to remove the center-lock ring, mount the old disc to it and tighten the lockring Then mount some improvised U shaped piece of steel in a vise, slip the disc over it, and turn the wheel to the left to turn off the ring the same way you would to remove a freewheel.

Warning, if you've done some hard braking it'll take serious torque to get the ring off.

I have a center-lock to 6 bolt disc adapter on mine.. , lets you use any 6 bolt disc.

such as may be included with low cost cable disc brake, sets.

BTW- don't throw out a worn out disc. If you ever decide you need to remove the center-lock ring, mount the old disc to it and tighten the lockring Then mount some improvised U shaped piece of steel in a vise, slip the disc over it, and turn the wheel to the left to turn off the ring the same way you would to remove a freewheel.

Warning, if you've done some hard braking it'll take serious torque to get the ring off.

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The centrelock splines have been a machined part of the hubshell on every shimano or DT hub I've ever seen.

- Joel

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The centrelock splines have been a machined part of the hubshell on every shimano or DT hub I've ever seen.

- Joel

That might be true, and I don't know either way. But if you look at the OPs photo the centerlock spline appears to be a threaded ring added to what would otherwise be a standard threaded road shell flipped left/right.

The threading on the inside is for a lockring. The silver finish is because the CL mounts are machined after the anodising process (I guess).

For those recommending a cassette lockring, it must be at least a 12t lockring, not an 11t as this won't have the diameter to engage with the serrations on the rotor.

- Joel

The threading on the inside is for a lockring. The silver finish is because the CL mounts are machined after the anodising process (I guess).

For those recommending a cassette lockring, it must be at least a 12t lockring, not an 11t as this won't have the diameter to engage with the serrations on the rotor.

- Joel

Thanks for the heads up.

The threading on the inside is for a lockring. The silver finish is because the CL mounts are machined after the anodising process (I guess).

For those recommending a cassette lockring, it must be at least a 12t lockring, not an 11t as this won't have the diameter to engage with the serrations on the rotor.

- Joel

LOL Joel - that was me just being facetious to further confuse the issue! Those rings are included with the rotors and a complete description of the installation procedure is normally duplicated in documents included with hubs, rotors and brake assemblies. For some reason - most people just don't seem to want to read them.

For those recommending a cassette lockring, it must be at least a 12t lockring, not an 11t as this won't have the diameter to engage with the serrations on the rotor.
- Joel
I (and my LBS mechanic) discovered this searching for a lockring tool. Luckily I took the wheel and tried them, some fit and some don't.
I fit my tool in a bench vice and rotate the wheel, like a freewheel tool.

I think the centerlock system for brake rotors is great. It's taken me a while to finally come to this realization, but it makes great sense. One small benefit I particularly like is that you can install a brake rotor in a few seconds, avoiding the tedious process of tightening six separate bolts.

My Front hub on my Bike Friday uses a center-lock disc, it allows easy removal, on case of travel packing,
to pack the disc separate from the wheel so the disc stays flat.

.....tedious process of tightening six separate bolts.

6 hex cap screws is tedious?

6 hex cap screws is tedious?

If you work in a bike shop, particularly, it can be just because there are sometimes a lot of brake rotors to install. New mountain bikes, for example, come out of the box without the front disc brake attached, including the rotor. Give me a choice of a centerlock or a 6-bolt rotor to install, and I'll choose the centerlock every time. Like I said, one of the SMALL benefits of the centerlock system: quick, easy, installation of the rotor.

Yes, I agree that there's a big difference in tedium between 6 bolts, and 60.

Yes, I agree that there's a big difference in tedium between 6 bolts, and 60.

There's also a difference in tedium between one lockring and six bolts, or two lockrings and twelve bolts for a set of brakes on a bike. I'm not saying it's a huge deal, but centerlock really is a more user friendly system in terms of installation and removal.

Another thing I've noticed is that with Shimano hubs with the centerlock system, the hub weights are less than with the six-bolt mount.

Again, not that big a deal, but for some reason it took me a while to see that the centerlock system really does make good sense; seems to me that it's a better system than the six-bolt hub/rotor, and I didn't see it that way until fairly recently.

Another thing I've noticed is that with Shimano hubs with the centerlock system, the hub weights are less than with the six-bolt mount.

Thinking the difference there, is the non-centerlock hubs, like the HB-M756 are high flange, where as the centerlock ones, like the HB-M775 are low flange, the high flange 6 bolt hubs do weigh more, but also do look nicer than the lower flange ones (personal opinion there)

Another thing I've noticed is that with Shimano hubs with the centerlock system, the hub weights are less than with the six-bolt mount.


True, but the rotors must weigh more. Heck some (all?) of the rotors are just standard 6-bolt rotors with an adaptor riveted to them, I doubt that's any lighter than using a hub with the 6-bolt fitting machined into it.

I would think high flange would be better for high force hub (disk) braking (thinking hard core mountain biking here), as it would put less torque on the spoke ends.

I had XT high flange hubs (6 bolt) on some 29er wheels I built, and I agree, they're good looking hubs. But they're heavy. I sold them....I built a really nice set of mtb wheels about a year ago with very expensive, very lightweight American Classic 6-bolt hubs, and with the lighter rims I used, fewer spokes, and lighter hubs, saved about a pound of weight compared to the previous wheels. Those wheels have been great......... I decided I wanted another set of wheels without breaking the bank. I also wanted to use the same rims and spoke count as the wheels with the American Classic hubs, and centerlock Shimano hubs are IMO the best option, when all things are considered, for the budget minded. I had resisted centerlock for a long time for no good reason, and now I'm sold on them.