Author Topic: QR skewers coming undone (Read 5643 times)

Wobbly · « **on:** 13 April, 2011, 05:46:13 pm »

I'm having a problem with the QR skewers coming undone on my new (ok, it's four months old) bike . It's happened to both the front and rear wheels. I've never had this problem before with any of my bikes. However, this is the first bike I've had with disk brakes.

What causes them to come undone? I'm tightening them as much as I have on any other bikes but am I simply being too wimpish and not tightening them enough? Do you have to tighten QRs with disk brakes until you go purple in the face?

Any suggestions?

Ta

PhilO · « **Reply #1 on:** 13 April, 2011, 06:05:06 pm »

There is a school of thought which suggests that QRs come undone more often with disk brakes. In my opinion, this is utter tripe but it is undoubtably true that the QR is much more safety-critical when you have disks.

What type of QRs? IME, external cam designs are more prone to relaxing than decent internal cam ones. If the cam runs on a plastic bearing surface, bin them immediately. I've always stuck with bog-basic Shimano skewers (Deore or XT) on my MTBs, and have never had one come loose in the 13 years I've been an exclusive disk brake user.

Finally, don't over-tighten them. This can be just as dangerous as under-tightening and failure will occur suddenly if it happens.

Steve Kish · « **Reply #2 on:** 13 April, 2011, 06:27:14 pm »

I always have mine done up so that they're past the parallel to the forks/stays setting and have the levers always pointing downwards.

YahudaMoon · « **Reply #3 on:** 13 April, 2011, 06:41:25 pm »

Ive never heard of a skewer coming undone. Sounds like a total design flaw and dangerous.

You could always swap for some of a old bike you know are OK and see what happens

Four month old ! Straight back to where it came from for me for a explanation and refund/replacement/replacement part till its fixed..

I don't understand how a disc brake would make any difference, what type are the skewers ? I ve had people undoing mine when my bike has been locked up unattended by the way, is this a possibility ?

Biggsy · « **Reply #4 on:** 13 April, 2011, 06:52:50 pm »

One point of view:

Disk brake and Quick Release problem

marcusjb · « **Reply #5 on:** 13 April, 2011, 06:58:46 pm »

This is why the lawyer lips on forks came about as far as I am aware.

I've never had a Q/R loosen at all with calipers, cantis etc. - however, it does happen with discs. Our tandem has discs (203mm rotors with Avid BB7 and the Q/R does Certainly loosen a little over the course of a few days, though I do check them often (I am about 100times more careful with everything on the tandem as it's more than just me that'd get hurt if something broke).

Never noticed a problem with the rear.

The forks on my new Condor have the biggest lawyer lips you ever saw - you have to virtually unscrew the Q/R all the way to take the damned wheel out.

LittleWheelsandBig · « **Reply #6 on:** 13 April, 2011, 07:00:45 pm »

Lawyer lips were created because stupid riders were tightening QRs like wingnuts.

marcusjb · « **Reply #7 on:** 13 April, 2011, 07:01:30 pm »

Quote from: PhilO on 13 April, 2011, 06:05:06 pm

What type of QRs? IME, external cam designs are more prone to relaxing than decent internal cam ones. If the cam runs on a plastic bearing surface, bin them immediately. I've always stuck with bog-basic Shimano skewers (Deore or XT) on my MTBs, and have never had one come loose in the 13 years I've been an exclusive disk brake user.

I have also heard this about external cam designs (and guess what's on the tandem?). Should pony up for some decent internal cam ones really and see if that helps.

I just bought a set of wheels for the new bike, and the builder completely refuses to use external cams for anything because they are not at staying tight.

andygates · « **Reply #8 on:** 13 April, 2011, 07:07:14 pm »

Quote from: LittleWheelsandBig on 13 April, 2011, 07:00:45 pm

Lawyer lips were created because stupid riders were tightening QRs like wingnuts.

I worked in Halfords (Saturday boy) over the period when this was happening, and yes, they were that stupid, and they were furious, and we were not allowed to laugh at them.

Wobbly · « **Reply #9 on:** 13 April, 2011, 07:23:33 pm »

Quite a few replies while I was cooking dinner, so apologies for not replying to each of you.

"What type are they?" erm.. how do I tell an external cam from an internal one? Sorry if that's a really stupid question.

I was also told not to overtighten QRs, so that's why I'm asking here rather then simply tightening then up more and more.

I like the suggestion about trying QRs from my other bikes - I'll do that.

Yorkshireman · « **Reply #10 on:** 13 April, 2011, 07:34:21 pm »

Sound advice on QR squewers on the late Sheldon Brown's site
Bicycle Quick-release Skewers

LittleWheelsandBig · « **Reply #11 on:** 13 April, 2011, 07:36:05 pm »

It is difficult to overtighten a QR and resultant failure is incredibly rare IMHO. In the shop, I removed some QRs that needed a spanner looped over the lever before I could release them and there was almost never any damage. If you can release the lever by hand (and it isn't a stupid-light QR), it isn't too tight. The 'correct' range is quite wide, depending on vertical/ horizontal dropouts and pitiful Hon-derived designs.

henshaw11 · « **Reply #12 on:** 13 April, 2011, 08:14:39 pm »

There's been a fair bit of discussion on singletrackworld (and elsewhere) about this some years ago - one of the riders mentioned in that link
(in particular Diary )
was a forum regular and was left paralysed from the chest down)

Without (re)reading the link, ISTR two problem areas are qrs that release tension slightly once they've been pushed home, and ti skewers (stretchier than steel) - and that the best things to use were bog-standard, cheap n cheaper Shimano qrs.

Regardless of which bits you believe. it's good reason to be very careful about doing them up securely - and if they're still not working, bin 'em (tho' it sounds like they may just not be tight enough..)

Kim · « **Reply #13 on:** 13 April, 2011, 09:03:06 pm »

Alternatively, bung a set of allen key 'security' skewers on. Much easier to get those done up Bastard Tight, and as long as you ensure that any special key required is religiously kept in your on-the-bike toolkit, they're about the same effort as normal QRs when there are lawyer lips involved.

Wobbly · « **Reply #14 on:** 13 April, 2011, 09:19:22 pm »

Thank you for the continued advice - especially the Sheldon Brown link. Very sad to hear him described as the late Sheldon Brown.

And I now know the answer to why they are coming loose.

I've now learned that all QRs on my other bikes are internal cams. The QRs on this new bike are external cams. Consequently it seems I've simply not been applying enough force when closing them to take account of their inferior design compared to internal cam QRs.

I am now better educated - and safer.

Thanks all.

Sergeant Pluck · « **Reply #15 on:** 13 April, 2011, 09:23:59 pm »

Varies a bit between skewers, but in general I think you have it in the right area if the lever begins to tighten about half way through its 180 degree swing. Or in other words the point where the lever changes from free to needing force is about half way through the swing.

Tight but it shouldn't need to be a bugger to loosen.

Kevina9 · « **Reply #16 on:** 13 April, 2011, 09:49:12 pm »

Quote from: Biggsy on 13 April, 2011, 06:52:50 pm

One point of view:

Disk brake and Quick Release problem

Interesting article. Reading between the lines, it seems to imply major design fail on just about every disk-compatible fork out there - for wheel security with disk brakes, the caliper would be better placed on the front of the fork, so that braking produces a vertical force acting upwards on the axle, correct?

I know that the Cotic Roadrat fork mounts the front fork disk caliper on the front of the fork.

Anyone know of any other similar forks?

Chris N · « **Reply #17 on:** 13 April, 2011, 10:36:01 pm »

Not that I can think of.

Lots of MTB suspension forks now have forward facing dropouts that stop the wheel from being forced out of position when braking. Even more have some variety of bolt-through axle arrangement.

frankly frankie · « **Reply #18 on:** 13 April, 2011, 10:36:28 pm »

Quote from: henshaw11 on 13 April, 2011, 08:14:39 pm

ISTR two problem areas are qrs that release tension slightly once they've been pushed home, and ti skewers (stretchier than steel)

... but this is what qrs do - nothing wrong with that - it's the ones you can't push 'over the top' that you have to worry about.

henshaw11 · « **Reply #19 on:** 13 April, 2011, 11:45:12 pm »

Quote from: frankly frankie on 13 April, 2011, 10:36:28 pm

Quote from: henshaw11 on 13 April, 2011, 08:14:39 pm
ISTR two problem areas are qrs that release tension slightly once they've been pushed home, and ti skewers (stretchier than steel)

... but this is what qrs do - nothing wrong with that - it's the ones you can't push 'over the top' that you have to worry about.

That's part of the issue as I **recall**- I think you may find something along those lines in the links, bear in mind this was from about 7 or 8 years ago and a related stw link's dead where that bit might have come from. I suspect the feel at the qr probably isn't the best measure of what the cam inside's actually doing - the tension in the skewer is the relevent bit.

The main point was that some are worse than others for releasing tension - certainly some Richey(?) qrs I have on my P7 feel uniformly hard to close once they're past a certain point, which is before the 'over the top point'. I've had them come undone once, but a *very* long time ago and I've been more wary since. Tho' whether those are any better I dunno.

Fixedwheelnut · « **Reply #20 on:** 14 April, 2011, 01:27:26 am »

I have only had QR skewers loosen twice, both times it was a damaged thread in the nut part opposite the QR cam, throw it away and get a new one.

CommuteTooFar · « **Reply #21 on:** 15 April, 2011, 02:29:10 pm »

Another factor to consider when QRs slip is the fork. Pretty polished stainless steel dropouts are far harder and slippier than ordinary steel.

Author Topic: QR skewers coming undone (Read 5643 times)

Chris N