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I was looking into upgrading my current skewers to security skewers, e.g. Pitlock skewers (These are skewers which are designed so that its harder to remove a wheel without a specific key provided with the skewers).

An example is here:

enter image description here

(From Peter White Cycles)

My bike has horizontal dropouts, but front facing (i.e. not a track forkend, in contrast to this question).

The Pitlock FAQ states: "If you have horizontal dropouts on your bike's rear wheel (horizontal and open at the rear), we dissuade you from using the Pitlock system.

Usually (almost) all rear wheels are assembled in vertical dropouts (opening diagonally towards the bottom). Here the assembly with PITLOCK works without problems. "

They specifically highlight track-style forkends, but not horizontal dropouts which open in the front. So, can Pitlock skewers be used safely with horizontal dropouts? If so, why can they be used safely with horizontal dropouts which are front facing, but not track forkends?

An example of the dropout types is here (mine is similar to the second one from the left on the top row):

enter image description here

(From Sheldon Brown)

The Peter White page claims this is due to Pitlocks being unable to exert enough clamping force (similar to some aluminum QR skewers, since aluminum can't bite into the drop out enough), but Pitlocks are made from steel, so I'm still not sure why the track forkend was specifically highlighted by the manufacturer but horizontal dropouts were not.

  • I'm thinking that the problem is whether the force imparted by the chain under load will pull the wheel out of line. – andy256 May 23 '15 at 23:42
  • I am reading that as should not be used with any horizontal. – paparazzo May 24 '15 at 7:10
  • You can padlock your quick release to the chain stay, or switch no a non-skewer hub and buy a security nut. – Darth Egregious May 25 '15 at 2:51
  • andy256, Blam - That's what I think, but I'd like confirmation. user973810 - the latter is essentially the problem (if it is a dropout problem, since a leading manufacturer mentions a forkend specifically). – Batman May 25 '15 at 3:00
  • I think that in all the other mechanisms, with the exception of the track dropout, the hub will touch the frame, and the skewer just adds a second level of protection. In the track dropout, the skewer is an important part on maintaining the wheel installed and aligned on the frame. Imagine you rear brake where you stop the wheel and squid. In all dropout except the track one, the hub is forced against the metal in the dropout. With a correct installation, the wheel would hold even without a skewer. So I think you are safe on your bike. Have you tried to contact Pitlock's support. – super May 28 '15 at 6:24
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This may be too late (just joined StackExchange), but the reason that Pitlock does not recommend using their skewers in any horizontal type dropout is in the configuration of washers between the "cup" of the rotating end, and the Pit inside the "cup".

Please refer to the photograph below; all numbers begin from the left side of the image.

Pitlock Seat Binder

The toothed washer (3rd) grips the hex flats on the end cap (6th), which passes through both the cup (5th) and the nylon washer (4th). If the Pit (2nd) is torqued down too much, it can cause the toothed washer to deform to the point where it no longer grips the end cap. It can also dig too deeply through the nylon washer and eventually secure some purchase against the cup. This would allow a would-be thief to be able to grip the cup with some sort of pliers and potentially loosen the Pit.

To avoid this (and this is not common, but any locking skewer only works correctly if used correctly), Pitlock does not recommend any torque on their skewers above 10Nm. A wheel held at this torque in a horizontal or semi-horizontal dropout, under heavy load, has a much higher chance of slipping. They also recommend replacement of the toothed/nylon washers over time to avert this.

You can over-clamp a skewer to avoid this. If you still want security skewers, I would go with Delta locking skewers, and white-glue a ball bearing into the 5mm hex head opening. You can torque them down to your heart's desire, and still have a good measure of security.

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Please see my comment above. Reading the complete FAQ actually confirms my claims, as the track dropout is "horizontal AND opens at the rear", whereas your dropouts "open diagonally towards the bottom":

If you have horizontal dropouts on your bike's rear wheel (horizontal and open at the rear), we dissuade you from using the Pitlock system. Usually (almost) all rear wheels are assembled in vertical dropouts (opening diagonally towards the bottom). Here the assembly with PITLOCK works without problems.

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