Yellowbeard

I've been searching for a while and haven't found any interesting past discussions on the mechanical differences between conventional quick release skewers and allen head bolt-ons. Does anyone have any knowledge to share, or the links to any previous threads in the archives that eluded me?

I'm curious about the relative clamping forces. For example: if you have a typical closed-head quick release with a ~2" lever will it generally clamp tighter or looser than a bolt-type skewer tightened with, say, the 5mm allen wrench on a multitool with a 2 1/2 to 3" handle?

I ride a single speed with stamped, semi-horizontal dropouts and hollow-axle wheels. So far I've been using an old Shimano skewer for the rear wheel with mostly satisfactory results. For theft prevention I just bought a basic set of allen skewers so that I could use a variation of the ball-bearing trick to secure the front wheel (appreciably trouble-free) and saddle, but I'm interested in the utility of swapping the rear QR for the allen-head skewer. I remember once reading something about bolt-ons having less clamping force, but I'm pretty sure that was just someone's speculation.

I guess it'll basically be a direct comparison of the mechanical advantage of a QR's cam to the pitch of the skewer's threads. Maybe I can measure the travel of the QR head myself vs. the thread pitch.

What's the communal knowledge on this?

DannoXYZ 

I think you're on the right idea here. Measure how much travel the QR head moves with the final tightening of the lever and compare that to an equivalent # of turns of an allen-key bolt-on. Be aware that there's a wide range of cam-profiles on QR levers. I had a set of Ringlé cam-twist QR skewers way back when. It kinda combined both, you give the QR lever a 1/3rd squeeze like normal, then twist it around 1/2 a turn for the final tightening.

Yellowbeard

Well, I never bothered to try and measure it, but today I opened up my multi-tool a little more to get some extra leverage after fixing a flat and this happened:



I was less interested than I was pissed off, since I ended up paying $10 for a new skewer just to get home when I had exactly the same skewer sitting in my basement. On top of that I was planning to respace my rear hub down about 12mm on each side to ease stress on the axle and I'll need to use a front skewer for it after that.

I doubt this means that allen-heads clamp more strongly than QRs, though, since it's most likely the torsional stress that caused it to break. I'm sure the tension alone was WELL within the limits of a Cro-Mo skewer. Lesson learned: no allen-skewers for horizontal dropouts.

operator

If you're going to use allen key skeweres, reuse the shimano steel nut on the other side. It will hold much better than the stock nuts that come on those.

And post #3 isn't surprising. They're notorious for not taking torque well.

Yellowbeard

I know, I was annoyed that they made the nuts out of aluminum.

I never actually planned to use the allen-head in the rear wheel, I just wanted one for the front and the seatpost to help deter theft. Then I could keep a QR on the rear and use a good lock on it.

ryker

Is the axle of that broken skewer alu or cro-mo?

I just bought a set of allen skewers with cro-mo axles but alu nuts. Subjectively the clamping force feels like an improvement over my old Shimano QR skewers. As long as they don't break...

operator

It's not.

andr0id

That's because it's resisting the turning motion more than than the improved clamping force.

You can use DuPont Krytox® grease which is very good at allowing bolts to tighten and not shear, but it is also expensive.

Nessism

A bunch of years back some MTB magazine did a skewer test where they looked at clamp load from various skewers on the market back then. The bolt on skewer was at the top in this test. Obviously, clamp load will depend on how much torque is applied; in the case of a bolt on skewer, the leverage of the allen wrench makes it easy to get high clamp load. Maybe that is why that skewer in the photo is broken, high clamp load overworked the metal in the skewer causing it to snap?

dperreno

That's surprising to me! I would not have expected a steel skewer to shear like that unless it had some prior damage, especially if the threads were lubed (which it appears that they were). I think that speaks to the quality (or lack thereof) of the skewer more than anything else. A well-made steel skewer should easily be able to handle the torque from a multi-tool. I would certainly return that one to the vendor (or preferably the manufacturer) - that's recall material.

Yellowbeard

The skewer brand was Axiom, it was lubricated and the threads were smooth enough that the broken part came out of the nut really easily. I'm not all that surprised that it broke, but I AM surprised at how easily I snapped it. The multi-tool is no more than three inches long, although I'd extended the screwdrivers out of the other side so that I could shift my hand another inch or so outward.
I haven't had it long enough for it to be worn, dunno if it there was a defect. I'm guessing that once thread friction mounts the torque is excessive for such a long and narrow bolt. Quill stem bolts see at least the same amount of torque, but they have a larger diameter.

DannoXYZ 

I would try to verify what material was used. I've seen steel skewers break like that plenty of times, but never a chromoly one.

silver_ghost

Good call.

I've observed that if you adjust hub bearings properly for use with a quick release (with hint of play, that will be "taken up" by compression of the axle by the QR clamp) and then install them with a bolt on allen skewer, the play in the hub remains, indicating that the allen bolt skewers aren't compressing the axle as much, so they musn't be clamping as tightly, right?

I've used regular cheapo allen skewers and expensive "anti theft" skewer sets and I've never been really happy with either. The cheap ones come with knurled, soft aluminum nuts that only deter theives without opposable thumbs and vice grips, and the expensive ones use short, propriatary keys that make it very difficult to apply proper torque.

Has anyone tried those Zefal skewers that Rivindell sells (https://www.rivbike.com/search/run?qu...oduct=18-304)?
If they work well, that might be a better solution. How is someone going to turn you bike upside down if it's locked up?

Yellowbeard

The hub adjustment actually worked for me with these skewers, at least while they stayed in three pieces.

And I never thought about that second thing; you could probably twist an aluminum nut loose pretty easily. What about switching the nut for one whose serrated surface is made of steel? Could it still be wrenched loose or would it have enough bite into the dropouts to resist that kind of attack? I might have enough spare parts to make an experiment out of it.

Oh, and I'm amused by the picture on the Zéfal package . If you look at the way that bike is locked, you could turn it perpendicular to the rack and slide it up over the bend until it was upside down.

silver_ghost

Ha. Good point.

One time just for kicks I took a pair of vise grips to the nut ends of the "anti theft" skewers on one of my bikes. I think it was actually faster to remove the wheels that way than using an allen key. It seems to me like a steel shimano nut would be harder to grab, but still doable. Havn't tried it though.

My Pinhead brand skewers have low profile ends that are far less susceptible to tools, but the special key is short and impractical.

tatfiend 

I just ordered a set of Pitlock skewers for my Rohloff QR Hub bike as added insurance. Hate to lose the Rohloff hub wheel or my Dynamo front wheel. I note that their special keys have a cross hole for a 5mm Allen wrench or 6mm rod to be inserted to provide a handle.

I was looking at the security skewers offered by OnGuard but was not impressed by either their finish quality or the likely torqueing capability of their installation/removal tool.

sean999

What, specifically, did you not like about the OnGuard locking skewers "finish quality"? A bit rough or uneven surface, or something more? Did you get the sense that someone could grab on end with some ViceGrips and turn to loosen? I've been told (by a shop that sells PitLock) that the OnGuard (= Kryptonite) skewers have ends (not shafts) made of aluminum. *That* seems unlikely, but I could imagine they're made with steel softer than high-grade stainless.

I'm about to install a new hand-built front wheel with a Shimano dynohub (3N80), and, having recently had a $40. (ie, *not* high-end) seat stolen, I'm determined to get decent protection for the new wheel. But PitLock is a pricier option. I live in San Francisco, CA.

Has anyone had a chance to examine, or use, the new Zefal locking skewers? I've got their new locking seatpost binder-bolt thing-y, and it seems to work, but I've only had it for a few days. One shop told me they stopped selling the Zefal skewers because several customers had problems with the gravity-sensing ball-bearing getting stuck in the un-locked position. That's hearsay, however.

-Sean