QR skewers weaker than regular "nutty" axles?

[DougC]

I am considering a bicycle motor kit; one of the installation
requirements is that the rear axle use nuts, as the info says that QR's
won't hold on hard enough. ...But it also says that if you have a QR
wheel, you can use the QR wheel, /but/ you should get a regular skewer
with nuts that tighten with a wrench instead of a QR lever.
-----
Is a QR lever any stronger than a skewer with regular nuts on it? The
bike's online specs gives the F/R wheels as {26" Shimano Deore, M510,
AlexDA 16},,, Alexa is the rims, M510 is the spokes? What's the
strongest QR and regular-nut skewer that will fit into a Deore rear hub?
Is there a difference in thickness of MTB and road skewers (aside from
width)?
~~~~~~

 

[JeffWills]

DougC wrote:
> I am considering a bicycle motor kit; one of the installation
> requirements is that the rear axle use nuts, as the info says that QR's
> won't hold on hard enough. ...But it also says that if you have a QR
> wheel, you can use the QR wheel, /but/ you should get a regular skewer
> with nuts that tighten with a wrench instead of a QR lever.

I've never seen such an animal... there's something lost in the
translation, I guess.

> -----
> Is a QR lever any stronger than a skewer with regular nuts on it? The
> bike's online specs gives the F/R wheels as {26" Shimano Deore, M510,
> AlexDA 16},,, Alexa is the rims, M510 is the spokes?

Nope. "Alex DA 16" is the rim's manufacturer and model. "Shimano Deore
M510" is the hub's manufacturer, model, and model number.

What's the
> strongest QR and regular-nut skewer that will fit into a Deore rear hub?

Older Deore and Deore XT skewers had hefty, all-steel nuts, levers and
cams. They're about as strong as you'll find.

> Is there a difference in thickness of MTB and road skewers (aside from
> width)?
> ~~~~~~

No.

You could convert a QR hub to standard nuts pretty easily. All you
really need is an axle with the correct threading and a couple
corresponding nuts, like this:
http://harriscyclery.net/page.cfm?PageID=49&action=details&sku=HU6104
http://harriscyclery.net/page.cfm?PageID=49&action=details&sku=HU7105

Switching between a QR and a solid axle is quite easy.

Jeff

 

[[email protected]]

On Fri, 25 Aug 2006 22:15:26 -0500, DougC <[email protected]>
wrote:

>I am considering a bicycle motor kit; one of the installation
>requirements is that the rear axle use nuts, as the info says that QR's
>won't hold on hard enough. ...But it also says that if you have a QR
>wheel, you can use the QR wheel, /but/ you should get a regular skewer
>with nuts that tighten with a wrench instead of a QR lever.
> -----
>Is a QR lever any stronger than a skewer with regular nuts on it? The
>bike's online specs gives the F/R wheels as {26" Shimano Deore, M510,
>AlexDA 16},,, Alexa is the rims, M510 is the spokes? What's the
>strongest QR and regular-nut skewer that will fit into a Deore rear hub?
> Is there a difference in thickness of MTB and road skewers (aside from
>width)?
>~~~~~~

You seem to have two issues here.

The specification of your "bicycle motor kit" (itself an issue; why
anyone would think that a motor added to a cycle frame is a good idea
is perhaps just one more example of the gullibility of hoi polloi)
seems to require better than the normal clamping force afforded by
normal QR skewers. This is different from simple axle - or skewer -
strength.

The clamping force is generated by either the inclined threads of the
axle and the nuts, or by the cam action of the qr clamp.

In the former case, the clamping limit is determined by the strength
of the threads. With a hand spanner, you could tighten these enough
to strip them, but you would have to be particularly ham-fisted to do
so.

In the latter case, there are two limits - one is the force which can
reasonably be expected to be available to force the skewer clamp
closed, and another, presumably higher, which is that of the strength
of the threads (or possibly the skewer itself, should it be made of
something other than good quality steel).

These threads do not normally strip under the action of closing the
clamp, even when cut rather than rolled; but the limit is, of course,
much less than for threads cut (or rolled, as the case may be) on the
outside diameter of the axle. Were you to use a nut that bears on the
skewer threads it might well be that you would strip them.

For the greatest clamping strength, you will use nuts which fit on the
outside of the axle, have a set of serrations or indentations on the
bearing surface, and need a hand spanner. This is a much better
solution for most cycling situations; not the least of which is
bearing adjustment and life.

For the greatest pure axle strength, you will use a solid axle.

 

[jim beam]

DougC wrote:
> I am considering a bicycle motor kit; one of the installation
> requirements is that the rear axle use nuts, as the info says that QR's
> won't hold on hard enough.

that may well be true of some qr's, but not all. high quality closed
cam skewers are very hard to beat.

back when i was a kid and used to race, i used to bend low end solid
rear axles all the time, literally one every few days. then i
discovered campy qr's and all those problems disappeared.

> ...But it also says that if you have a QR
> wheel, you can use the QR wheel, /but/ you should get a regular skewer
> with nuts that tighten with a wrench instead of a QR lever.
> -----
> Is a QR lever any stronger than a skewer with regular nuts on it?

a qr axle at the high end is often better than a solid axle at the low
end - which most solid axles are. highest quality solid axles are from
track hubs, but they won't be long enough.

> The
> bike's online specs gives the F/R wheels as {26" Shimano Deore, M510,
> AlexDA 16},,, Alexa is the rims, M510 is the spokes? What's the
> strongest QR and regular-nut skewer that will fit into a Deore rear hub?

highest end steel is stuff like shimano ultegra or xt

> Is there a difference in thickness of MTB and road skewers (aside from
> width)?

no difference in thickness or stiffness. higher end equipment is higher
quality material and therefore stronger.

 

[DougC]

JeffWills wrote:
>
> I've never seen such an animal... there's something lost in the
> translation, I guess.
>
>
....I was imagining that a skewer was thinner than a regular axle. And if
that is true--then why would they say it's okay to use a skewer that
uses regular nuts, but not a QR.

> You could convert a QR hub to standard nuts pretty easily. All you
> really need is an axle with the correct threading and a couple
> corresponding nuts, like this: ....
> Switching between a QR and a solid axle is quite easy.
>
> Jeff
>
This is the actual webpage--the note about not using QR's is at the very
bottom.

http://www.bikeengines.com/measure.htm

....It also notes that 27" wheels/bikes aren't strong enough, which
surprised me. I was aware that they are considered obsolete among
high-performance companies, but I never heard that 27" setups were
significantly weaker than newer road wheels (-or just 27" rims, I guess?)
~