choddo

Hi

I don't understand how QR sizes are listed - they seem to be all over the place but I might just be ignorant of multiple standards or something,

I've got a 126mm OLD 7speed frame and I guess I can shorten a skewer that's too long as long as I still have threads (and ideally enough margin onto which I can screw a nut a bit tighter, to then back out to clean up the sawn off end?) but is there a correct length (however that gets specced) to try to get hold of for this width of dropouts?

Ta!

SJX426 

This might be useful when considering a replacement.
Bicycle Quick-Release Mechanisms (sheldonbrown.com)

• Skewer length depends on the distance between the outside faces of the dropouts, and the depth of the adjusting nut. It is easiest to measure the distance between the outer faces of the dropouts after removing the wheel. This distance must match the length of the skewer from the base of the cam body to the base of the adjusting nut. Some anti-theft replacement skewers have thin nuts and shorter skewers, but if you know the spacing between the outside faces of the dropouts, you will be able to specify the correct replacement regardless of the skewer design. Most front hubs have an overlocknut distance of 100mm. Rear overlocknut distance may be anything from 110mm for older bicycles with a single rear sprocket up through 160mm for tandems. 130mm is most common on newer road bicycles, and 135mm on mountain bikes. Dropout thickness, counting both sides, ranges from 8mm for stamped steel dropouts to 20mm for aluminum dropouts. A derailer adapter claw, trailer hitch or other accessory may add to the length.

choddo

Yeah thanks I’ve read that, the problem is I can’t measure the replacement. They all just say 140mm or 180mm or 192.5mm and I have no idea what specific points they are talking about.

maddog34

140mm is the "outside of dropouts" or "inside of both clamping faces" of a QR for that length axle...the distance for a steel frame at 130 O.L.D... the actual skewer length for those will be about 158 to 160mm. Nut lengths vary from 15 to 18mm, basically.

an old, old school Simplex here is about 155mm skewer length... it was in a road bike 126mm O.L.D. axle/hub....

all my dimensions are listed in the "QR Closed" configuration, and not done with any extreme precision.

the 180 and 192 dimensions sound like an "overall length" and are not very helpful, eh? kinda like sellers that list the shipping weight and package or box size, but neglect to list actual Part dimensions

SurferRosa

Yes, it must be 126mm + dropouts width + skewer nut length.

I measured a few of mine from the end of the threads to the base of the skewer. They are all 156-157mm. If they protrude very far, I use a hacksaw to cut them down with the nut threaded on to clean the threads of the cut.

soyabean

Just how far are they protruding for it to become a problem?

Skewer nuts aren't acorn nuts, the M5 skewers can poke thru them as required.

I use titanium bolt skewers as an anti-theft on all my bikes, and some of them protrude as much as 1cm and it doesn't bother me.

I won't cut them because all my bikes are always for sale and when they do, I take them back.

FBinNY 

Skewers are typically measured from under the cap to the end, aka the length of the rod itself.

The easiest approach is to measure and existing skewer and the corresponding hub OLD. Then add or subtract the difference between the baseline hub and the new one.

SoSmellyAir

Pardon my ignorance, but is it the case that a regular rear QR skewer for a 130 mm OLD frame would not have an additional 4 mm of thread length?

FBinNY 

Not necessarily. CPSC rules on pertrusions mean that makers cannot use a 130mm(OLD) skewer for a 126mm hub. So every skewer is specifically made for each hub width. There are no rule on thread length, with each maker allowing enough thread for the nut, along with a margin of error allowing for differences in dropout thickness.

So, that 130mm skewer might work with 126mm hub, if the dropouts are somewhat thick. Then again, it might not.

BTW if you only need a mm or two, you can use a drill or Dremel to create some thread relief inside the nut.

choddo

Yeah my front one on my main road bike protrudes by about 5mm because it has very thin dropouts on an aero fork and I just don’t like how it looks but try to ignore it. This might end up the same way (have ordered a pair) but it’s the amount of thread I’m more concerned about. Fingers crossed.

soyabean

If the OP is bothered by skewers that "protrudes by about 5mm", they should just get a new perfect bike instead of their "OLD 7speed frame".

It is not an industry problem for longer skewers to be unsafe. There is no problem and thus nothing to resolve.

choddo

The 5mm is on a different bike. Mine.

Not sure if you meant OLD as in measurement or age there, but the 7speed isn’t my bike, I’m sorting it out for my son’s girlfriend after she was a bit ripped off by a 2nd hand purchase. Not terrible but has needed quite a bit of work to get rideworthy.

I’m not trying to replace one that’s too long? I’m trying to find out which one fits to replace a shot rusty one, and if it works but protrudes 1cm I’ll trim it.

Bit of a strange aggressive wade-in.

veganbikes

I think it was an attempt at the old comedy. Hence the picture of Bike Snobs book (which is fantastic, thanks to whomever left it at the shop years ago). I think the CSPC is over concerned on safety to the point they don't understand bicycles so they have silly rules that don't make any sense on certain bicycle things but exist none the less.

FBinNY 

Way back when the CPSC originally drafted the rules, there was little debate about the necessity. During the boom of the late Sixties and early Seventies, people were slapping wheels and tubing together and calling them bicycles. Bikes were breaking and causing injuries and deaths in ways that people today couldn't imagine.

Things like headtubes coming off because they were butt joined without lugs or filets. Front wheels collapsing because spokes ended 5mm shy of the rim, riders getting slashed and gouged because of razor sharp edges all over.

I was involved as part of the industry, and the CPSC process was very different from how government regulates today. They identified the issues that were causing injuries, and listened to the industry about what was possible. In the end, they established very minimal and necessary standards, and left it to manufacturers to work out the details.

Generally the standards created minimal hardship for those already producing decent (not necessarily good) bikes, but forced the worst players to get serious about quality.

FWIW I was very resistant at the time, and felt that they should limit themselves to children's bikes. But as things were worked out, agreed that the process and final rules were sound. Except for the "secondary retention" rule for QRs which IMO causes more problem than it solves.

veganbikes

True it was a mess back then!

Kontact

Might be hard to find a modern skewer for a hub width abandoned 25 years ago. Cut it or find old used ones.

choddo

Reason I need to get this is I accidentally put an old (unused and mint) one on from some 6speed wheels my father-in-law lent me and I owe him it back

but yeah I have no problem cutting it as long as the threads reach.

This bike is only 12 years old I believe. All the reviews for it date from 2011 onwards. Must have been clearing some old inventory!