woodcraft

It could have been that the concave washer was not seated correctly when the QR was tightened,

& so came loose, and similar for the rear, or it just wasn't tight enough- that's common enough.

The theory of knob loosening, and vilifying Ti or Enve are all unwarranted, IMO. Not particularly defending external cam QRs,

but they work OK.

2manybikes

I could never get my Ti skewers to grab properly. I don't use them anymore.

mpath

Difficult to describe how tight they should be on a post, but quite frankly no tighter than with my other skewers. Mine are all Ti now (Enve, Zipp, Reynolds, and Mad Fibers), but it's more or less the same "tightness" when I used steel skewers. I know it's not so tight that I have to put a lot of effort untightening it.

dabac

For the same dimension and load, Ti stretches more than steel.
Even closing the levers with a vengeance isn't a guarantee against ride conditions stretching them a bit more.
And while disc brake bikes are more prone to skewers self-loosening, rim brake bikes aren't entirely immune.
There are regular ride forces pushing the axle up, then there are braking forces pushing the axle back.
And since axles aren't press-fit in the dropouts, these un-aligned forces provides the opportunity for the skewer to work itself loose, if the clamping force is ever less than the forces trying to nudge the axle around.

79pmooney

Yes. Titanium has one half the modulus of elasticity of steel, meaning that for the same stretch as steel, you need twice the cross section area. Since we are limited by the hole in the axle, we are stuck with the same diameters so materials with lower modulus of elasticity stretch that much more. (Aluminum skewers are even worse, by another 50%. They do exist!)

QR skewers can only take up so much slack. (To do more would require either a longer, uglier, heavier lever or require more hand strength.) All of the "slack" that is just the skewer stretching is direct loss of clamping power.

As mentioned above, internal cam QRs have more clamping power than external cams. Steel of all the common metals has by a bunch, the highest modulus of elasticity. Not using steel skewered internally cammed QRs is tossing out some to all of the safety factor. (My view - QRs are the poorest place on a bike to save weight.)

Ben

FlashBazbo

Maybe I did just receive a bad set. I will give the new set a try.

CliffordK

Buy a new set?

Try the ones you have once more, but get them really tight, and maybe mark the nuts if you wish.

FlashBazbo

No, ENVE is sending a new set, free of charge. They said to use the new ones exactly as I did the old ones and I shouldn't have any problems.

joejack951

Titanium skewers even with external cams work just fine in my experience (American Classic).

Anything beyond the stretch at the clamping force required to keep the wheel tight in the dropouts is for convenience. Using a pretty standard torque value for a grade 8.8 M5 fastener (skewers are 5mm diameter) and some maths, I get 0.26mm (.010") of stretch for a steel skewer at the rear (assuming 145mm total length). So for titanium you'd need ~0.52mm, or about .020" of stretch. That's not much.

Internal cam QRs have a lower input force for a given clamping power. That's it. There's no inherent clamping force advantage in their design. And so long as the titanium skewer stays below its yield stress, there's no reason why they shouldn't work either.

CliffordK

Internal cam QRs lack that nylon washer that adds to the elasticity.

Most of the external cam skewers have a separate nylon washer.

joejack951

Constrained plastic doesn't really compress much. It needs space to expand to do so and the better-designed external cam skewers don't give the plastic any room. Here's an image of the bushing from my titanium American Classic skewers:

External cam skewer bushing by joe jackson, on Flickr

Note that this bushing was on the side of my bike on which I fell after getting sideswiped by a passing a-hole driver. The aluminum portion of the bushing is slightly distorted from the road grabbing the quick release lever and ripping the wheel out of the dropouts in which it was so firmly clamped

FlashBazbo

I naively didn't realize this thread would devolve into a debate on skewer design. (How could I NOT have realized that?) But, since the thread has run its course (for now), I will feed the beast:

Have you noticed how much difference there is in the travel of skewers? Most external cam only travel about 1.2mm or 1.3mm with the full lever throw. That's not much. Internal cam QRs seem to offer between 1.8mm and 2.0mm.

So, if you're doing the standard, "tighten until the lever meets resistance at 45 degrees" rule of thumb, the internal cam skewers WILL be tighter than external cam once they are closed -- by design.

That's also, no doubt, why you feel more of an "over center" detent with internal cam designs. The ramp is a lot steeper so, when it peaks out, it's more noticeable.

popeye

It sounds like they may know there was a problem with some skewers.

Sy Reene

Indeed.. lawsuit prevention mistaken for awesome customer service.

rpenmanparker 

The point is that force in the handle is not transmitted to tension in the rod with an external cam skewer as well an with an internal cam one. You don't' have to worry about over tightening as much as not tightening enough. It takes a lot of force to get external cam skewers to hold.

FlashBazbo

I understood your point the first time. I just didn't buy it.

exmechanic89

That's pretty cool.

Cyclist0108

I was under the false impression that the newer external cam QR skewers were better, until I got set straight on this a few days ago. I just got some Dura Ace ones. Nice, heavy and robust. I've only ridden 25 miles on them so far, but nothing has moved.

https://www.bikeforums.net/bicycle-me...disc-fork.html

rowebr

+100. If the skewers work themselves loose, perhaps they are best used as paperweights, unless they are too light even for that.

Cyclist0108

In my case, it was Salsa skewers and an Enve CX disc fork, and the disc brake force was causing some slight slippage. I haven't put enough miles on the Dura Ace internal cam skewers yet to be certain the problem is solved, but so far they have been much more solid, and I invested a lot of effort since mid-2014 trying to get the Salsa skewers to behave. See that linked thread for details. In other words, I think his point has a considerable degree of merit.

FlashBazbo

Yeah, I wouldn't ride QR with disc brakes. The forces are very different (and much greater) than with rim brakes. I have some near-death experience there off road. At the very least, I would go with the DT Swiss RWS threaded skewers with disc brakes -- and ideally, I would go with thru axles.


The only functional difference between internal cam and external cam is the slope of the cam. And, it appears, almost all internal cams have a greater slope than almost all external cams. I'm not sure that's big enough difference to paint external cams as a design failure. Lots of people use them successfully.

Cyclist0108

Well, I guess I could email Enve customer service and see if they would upgrade me to a second-gen CX fork (which is now thru-axle), but somehow I don't think that will fly.

FlashBazbo

In all seriousness, I would give the DT Swiss RWS skewers a try. They thread in (like a thru axle) by hand, but they fit a QR axle/dropout. I used them on my gravel bike before going to a thru axle-equipped bike. You can get a lot more leverage on them than on a QR. (That's not a QR lever on the skewer -- it's the handle by which you tighten the skewer.) It's basically a thru axle for non-thru axle bikes.

Cyclist0108

Where were you last week?

I had no idea. In addition to everything else, it would restore a bit of red bling.

Considerably cheaper too. Maybe I will get them and put the others on my wife's bike.

bikeman68

So why not just contact manufacturer to see if they can take a good look at the cam mechanism to see if it was their design flaw? You realize these things need regular maintenance with oil or grease lubrication? And that the lever cam must be oriented correctly in the receiving (female piece) piston that fits over end of skewer rod? I would put these aside and either try to get company to look at them, or a good shop mechanic (I wish I could see them) to determine all this? AS FOR NOW, USE ANY QRs that clamp tight! YOu could have been hurt or killed from a front wheel falling out! So many light yet affordable steel/alloy QRs on market, just lube the levers and they clamp tight! Dont spend big gobs of money on pricey Ti QR skewers!