MTB Wheel Question

[wonduhboy]

Since my MTB become unridable a while back, I stopped following MTB equipment.

I'm looking to buy a new bike, so what's the difference between centre-lock and 6 bolt? (I'm talking about benefits, not the obvious design stuff)

 

also what does a through-axle refer to?

[AndreZA]

I don't think there are any structural or weight benifits. With centerlock you can still fit 6 bolt rotors with an adapter but not the other way around.

 

 

[wonduhboy]

so one is no better than the other?

[brussel]

IMHO stick with 6 bolt design...there are much more rotors available, that being said if yo udo get centerlock you can get an adapter to use 6 bolt rotors.

 

there is no advantage other than the rotors on centerlock are easy to take on and off using a cassette removal tool.

 

B

 

 

[AndreZA]

I think the centrelock is easier because it's just one nut that you use but the rotors are more expensive.

JB, where are you?

 

 

[bustthesickness]

6 bolt rotors are perfect.

 

Through axel [bolt through] hubs are used instead of the quick release hubs on some forks. It's got a 20mm diameter shaft that screws into the fork and locks the wheel in. The benefits are a much stiffer, stronger fork, faster response and super quick wheel removal. This 20mm standard will at some point be replaced by 12mm.

 

[Bos]

[ This 20mm standard will at some point be replaced by 12mm.

 

Where do you get that? Fox is making a 15mm bolt throughfork and Shimano and Mavic is making hubs for it.

 

12mm is the rear through axil

 

All other forks is still 20mm, Rock shox has what they call "maxil" which is quicker than a QR, as for the others Im not so sure kind of the same

 

You had the rest spot on.

Through axil forks used to be only fior DH use but It seems the AM market is going this way and you even get a throughaxil reba now!

[Johan Bornman]

I think the centrelock is easier because it's just one nut that you use but the rotors are more expensive.

JB' date=' where are you?

 

 

[/quote']

 

Hier's ek. What you guys said is true. Nothing to add....on second thoughts, isn't a centre lock disc more expensive? If it is, I'll go for 6-bolt. Structurally, there's no advantage to either.

 

 Edit: Oops, see you already mentioned it is more expensive.

Johan Bornman2009-01-14 09:06:33

[Johan Bornman]

cut cut cut cut

 

 The benefits are a much stiffer' date=' stronger fork, faster response and super quick wheel removal. This 20mm standard will at some point be replaced by 12mm.
[/quote']

 

Hey troll! You forgot to add "faster rolling, see-through, lighter, low-emission, zero carbon footprint and USB compatible."

 

And make the 12mm bit "augmented by 15mm options."

 

 

Do I really have to add a smiley? OK.

 

[Johan Bornman]

 

cut cut cut cut

 

there is no advantage other than the rotors on centerlock are easy to take on and off using a cassette removal tool.

B

 

Only some cassette tools work. Ironically, the Shimano tool doesn't work on some Shimano wheels. The front wheel's axle protrudes too far and the tool isn't long enough so can't get traction in the locknut. If you force it, you ruin the tool. The right tool has a large open hole on the back so that the axle can go through.

 

 

Johan Bornman2009-01-14 09:09:52

[Guest Big H]

The 20mm through axle (also 23mm, 12mm, and 15mm) came about to lessen abnormal flex on front forks. There have also been documented cases where the normal quick release skewer failed leaving the rider with a loose front wheel. Larger disks (180mm and 200mm) also creates extra flex and tension on the front fork. Some fork manufacturers have a "quick release" for the 20mm maxle and some hubs (Hope) can be changed form 20mm to normal quick release. Normally a 20mm hub is for 20mm forks only and cannot be used in quick release forks. Some fork manufacturers offer a replaceable lower stanchion to change from quick release to 20mm.

[Wernervdmerwe]

Thanks - the info has been quite helpful.

 

I presume the weight diff is very small on the through-axle? It seems it is more the AM and DH forks that ship with that option - might that change as well?

 

 

 

 

[Johan Bornman]

The 20mm through axle (also 23mm' date=' 12mm, and 15mm) came about to lessen abnormal flex on front forks. There have also been documented cases where the normal quick release skewer failed leaving the rider with a loose front wheel. Larger disks (180mm and 200mm) also creates extra flex and tension on the front fork. Some fork manufacturers have a "quick release" for the 20mm maxle and some hubs (Hope) can be changed form 20mm to normal quick release. Normally a 20mm hub is for 20mm forks only and cannot be used in quick release forks. Some fork manufacturers offer a replaceable lower stanchion to change from quick release to 20mm.[/quote']

 

Hey Hendrik, I just want to clarify some things in case we start another movement here with strange beliefs.

 

The abnormal flex you refer to is pretty normal and not as terrible as most people make it out to be. Yes, QRs can work themselves loose on disk brake wheels without retention tabs. This is as you say, documented. But, most of it is scaremongering and the fact that it has happened doesn't make it commonplace. It happens when you go for many, many rides on a non-retention fork with disc brakes and never remove and replace your wheel.

 

The cure for that was retention tabs. I know through axles are marketed as the cure for it but that's nonsense. It happens to prevent it but nowadays no forks are supplied without retention tabs, whether they need it or not.

 

http://www.yellowsaddle.co.za/QR%20Operation.html and

 

http://www.yellowsaddle.co.za/Lawyers%20Lips.html

 

I've also done some calculations on the forces on a drop-out during braking with a disc. I'll put that up on the website as well. Makes for interesting reading.

 

 

Although the large through-axle is a cure for some bearing problems, I am not entirely convinced about this hub flex story and here's why. If you flex a hub just a little bit, it puts a brake on the bearings. This is very easily demonstrated in a bicycle in a workstand. Try this experiment on someone else's bike: Bend the rear dropouts slightly so that they're not parallel anymore. Now half insert the wheel and spin it. It'll spin freely. As soon as you tighten the QR, the wheel comes to a halt. As you tighten the QR, the axle bends to accommodate the out of parallel dropouts and misaligns the bearings.

 

I've never come across this on a MTB - not even a sensation of it and I just cannot understand where the front wheel flex is supposed to come from. Perhaps Lefty is lurking and he can give us some insight.

 

I agree that the thicker axle is stiffer but I don't agree for the reason the industry is giving for this new development.

 

As you so rightly point out, the diameter of the new through-axle concept is still a standards quagmire and I hope they sort it out soon. Also, a through-axle without a QR is in my view, a pain.

 

Some bike anatomy tips:

 

1) A fork's stanchions are attached to the crown. They're thus the upper legs. The lowers are called sliders.

2) A bike has only one fork and that's the front one.

 

 

 

[Dirtbreath]

Johan, a lot of problems with QR's releasing are because of incorrect tension in the skewer. I believe the new system tends to eliminate the required "feel" to tighten the front wheel.

 

I have not had the pleasure of checking one of these set ups though.

 

[TheLegend]

 

The 20mm through axle (also 23mm' date=' 12mm, and 15mm) came about to lessen abnormal flex on front forks. There have also been documented cases where the normal quick release skewer failed leaving the rider with a loose front wheel. Larger disks (180mm and 200mm) also creates extra flex and tension on the front fork. Some fork manufacturers have a "quick release" for the 20mm maxle and some hubs (Hope) can be changed form 20mm to normal quick release. Normally a 20mm hub is for 20mm forks only and cannot be used in quick release forks. Some fork manufacturers offer a replaceable lower stanchion to change from quick release to 20mm.[/quote']

 

Hey Hendrik, I just want to clarify some things in case we start another movement here with strange beliefs.

 [...]

Some bike anatomy tips:

 

1) A fork's stanchions are attached to the crown. They're thus the upper legs. The lowers are called sliders.

2) A bike has only one fork and that's the front one.

 

 

 

 

I take bets about the possible replies via PM. Winner gets a date with the sexiest hubber (t.b.c.)

 

[linnega]

I must say the through axle concept was designed to fix minor issues (as far as I'm concerned).  The fact that disk brake wheels have no decent quick release system is the main issue for me - and this only exacerbates the problem with a sideways "not like quick releases are that quick to release anyway..." from magazines and marketers in favour of the new system.  I would love an MTB wheel that could be removed with a single flip instead of my twice daily flip, rotate 12 times and release effort.  As far as flex goes the only noticeable flex to me has been because of different forks, never because of the way I inserted the fork (and I can assure you sometimes insertion has been really bad to accomodate misaligned brakes by not too bright mechanics that serviced my forks and did me a "favour" by messing with the brake alignment).