Author Topic: Skewers: cam vs hex  (Read 5101 times)

Skewers: cam vs hex
« on: July 15, 2012, 11:06:17 pm »
Just looking at different QR skewers. I note that there are these new fangled hex key ones, which dispense with the lever and cam and you simply tighten up two nuts on the skewer. To begin with I though, hmm, might as well have solid axles then, but for hollow axles, is there any advantage over cam types? Firstly, does tightening the skewer with a small hex key provide more clamping force than a conventional QR (as the sales guff claims, for some of them), and how do you judge when they are tight enough?

Kim

  • Timelord
Re: Skewers: cam vs hex
« Reply #1 on: July 15, 2012, 11:28:45 pm »
I believe it does.  Certainly more than the naff external cam type, probably more than the internal cam type, too.

Some people may find the lower absolute force required to turn an Allen key compared to operating a QR to be a significant advantage.

And of course, they require a tool (possibly an obscure one, for security types) to remove the wheel.
Careful, Kim. Your sarcasm's showing...

Re: Skewers: cam vs hex
« Reply #2 on: July 16, 2012, 12:25:46 am »
I've got them on a handful of bikes for those two reasons.  On a couple of bikea, because it provides marginally better security than a QR skewer (but can be dealt with using fairly easily available tools).  On a single speed bike, because the QR skewer does have a tendency to move slightly, and I know the hex non-QR version can't easily loosen off.  I have less faith in relatively cheap QR skewers.
Actually, it is rocket science.
 

Re: Skewers: cam vs hex
« Reply #3 on: July 16, 2012, 12:29:52 am »
Nothing new about them, my Schmidt SON hub came with a hex key skewer 6 or 7 years ago. FWIW, the hex key skewer that came with my SON is a touch lighter than the titanium skewer that I bought to use on the SON. So, lighter weight, a little more security and (possibly) more clamping force.

PaulF

  • "World's Scariest Barman"
  • It's only impossible if you stop to think about it
Re: Skewers: cam vs hex
« Reply #4 on: July 16, 2012, 06:40:44 am »
I'm slowly switching over, partly because they may provide more force! Partly for the security benefit but also for less possibility of an accidental release.

frankly frankie

  • I kid you not
    • Fuchsiaphile
Re: Skewers: cam vs hex
« Reply #5 on: July 16, 2012, 07:59:37 am »
I have hex key skewers dating back over 25 years.

And there is such a thing as over-tightening, by the way - QRs should only be 'tight enough' not 'tight as possible'.
It's not dark yet but it's getting there.

Re: Skewers: cam vs hex
« Reply #6 on: July 16, 2012, 09:53:10 am »
Definitely seemed to provide better clamping force here.  I had a front wheel which was moving slightly in the dropout under disc brake squeal.  Hex skewer (which I happened to have already) cured it.

I didn't have to crank down hard on the hex either.  And because you have to spin a QR in the front anyway then iteratively find the right tension, it's not really any slower to use the hex.

Re: Skewers: cam vs hex
« Reply #7 on: July 16, 2012, 10:20:04 am »
Thanks for all the info. I see the Halo ones specifiy a torque of about 9 Nm which is a fair old tension.

Slight thread drift: my reason for looking at skewers was that I find it difficult to get my rear wheel out due to interference between the QR nut on the drive side and the derailleur. I was looking around for QRs that had a nut that was more conical to see if I could get round this.

tiermat

  • According to Jane, I'm a Unisex SpaceAdmin
Re: Skewers: cam vs hex
« Reply #8 on: July 16, 2012, 11:39:10 am »
Thanks for all the info. I see the Halo ones specifiy a torque of about 9 Nm which is a fair old tension.

A word of warning

DO NOT buy the Halo ones.

If you tighten them up to the recommended tension the grip washer compresses then you get a skewer that slips in the drop out.

They also do not have a cut out in the ends, so if you are using them on a steel framed bike (i.e one with thinner than is the norm now dropouts) they bottom out on the axle end first before gripping.

They are cheap (I paid ~£8 as set from Tredz) and when you use them you find out why.
I feel like Captain Kirk, on a brand new planet every day, a little like King Kong on top of the Empire State

Re: Skewers: cam vs hex
« Reply #9 on: July 16, 2012, 11:41:55 am »
In terms of ability to clamp, I'm happy with Shimano skewers. I think I might just stick to what I know and just pull the skewer out when I take out the back wheel.

PaulF

  • "World's Scariest Barman"
  • It's only impossible if you stop to think about it
Re: Skewers: cam vs hex
« Reply #10 on: July 16, 2012, 11:52:49 am »
Thanks for all the info. I see the Halo ones specifiy a torque of about 9 Nm which is a fair old tension.

A word of warning

DO NOT buy the Halo ones.

If you tighten them up to the recommended tension the grip washer compresses then you get a skewer that slips in the drop out.

They also do not have a cut out in the ends, so if you are using them on a steel framed bike (i.e one with thinner than is the norm now dropouts) they bottom out on the axle end first before gripping.

They are cheap (I paid ~£8 as set from Tredz) and when you use them you find out why.

B*gger I wish this thread was up yesterday as I ordered a set last night :(

Re: Skewers: cam vs hex
« Reply #11 on: July 16, 2012, 12:39:41 pm »
Definitely seemed to provide better clamping force here.  I had a front wheel which was moving slightly in the dropout under disc brake squeal.  Hex skewer (which I happened to have already) cured it.

I didn't have to crank down hard on the hex either.  And because you have to spin a QR in the front anyway then iteratively find the right tension, it's not really any slower to use the hex.

I've filed off the 'lawyers lips' on three bikes, but hesitate to do the same on the disc-braked mtb.

Re: Skewers: cam vs hex
« Reply #12 on: July 16, 2012, 12:42:42 pm »
I've filed off the 'lawyers lips' on three bikes, but hesitate to do the same on the disc-braked mtb.

Likewise. Given that I need to loosen off the skewer anyway, thus rendering it not-very-QR, this led me to consider the hex alternatives. I'm not convinced, so far, that they are a better job than a good Shimano internal cam QR.

Cudzoziemiec

  • Eating all the pies and drinking all the tea.
Re: Skewers: cam vs hex
« Reply #13 on: July 16, 2012, 01:01:29 pm »
I've not heard that they're tighter on the dropout than QRs, though that doesn't mean they aren't. I've got some 'hex' key skewers which are actually pentagonal - a security feature. Whether this is worthwhile for you depends on things like where you leave your bike.
Days become simply the spaces between dreams, spaces between the shifting floors of time...

Biggsy

  • A bodge too far
  • Twit @iceblinker
    • My stuff on eBay
Re: Skewers: cam vs hex
« Reply #14 on: July 16, 2012, 01:07:56 pm »
Just looking at different QR skewers. I note that there are these new fangled hex key ones, which dispense with the lever and cam and you simply tighten up two nuts on the skewer. To begin with I though, hmm, might as well have solid axles then, but for hollow axles, is there any advantage over cam types?

1. They provide a tad of security since not every scrote has an allen key.  A bit more still if you opt for pentagon rather than hex ones.
2. They are lighter in some cases.
3. More convenient fine tuning of clamping force.

Quote
Firstly, does tightening the skewer with a small hex key provide more clamping force than a conventional QR (as the sales guff claims, for some of them)

They can provide less, the same, or more clamping force, depending on the model, use, and lubrication.  Lube = greater ability to tighten.  You can easily get more force with Tranz X ones if you want, for example.  Remember that overly tight clamping can be bad for the bearings.  Tightening the skewer compresses the hub axle, which in turn affects pressure on the bearings, with all type of bearings.  Readjust the bearings in preparation for a change in clamping force, when possible.

Quote
and how do you judge when they are tight enough?

- With a conventional (cup and cone) bearings: when the play in the bearings just disappears.  Set QRs like this as well.
- With cartridge bearings: you just have to guess when it feels right.  QR levers aren't pre-set precisely either, as you adjust the nut to provide the desired force before first use, using your own judgement.

I use hex and pentagon skewers, including Tranz X (available under various other brand names too).  I'd only prefer QRs now if I was racing.
●●●  My eBay items  ●●●  Twitter  ●●●

Cudzoziemiec

  • Eating all the pies and drinking all the tea.
Re: Skewers: cam vs hex
« Reply #15 on: July 16, 2012, 01:36:34 pm »
1. They provide a tad of security since not every scrote has an allen key.  A bit more still if you opt for pentagon rather than hex ones.
And if a regular pentagon isn't secure enough for you, there are unique polygonal ones for £60 or more.
Days become simply the spaces between dreams, spaces between the shifting floors of time...