UKC

Can somebody explain these please? 

I had a look at some new bikes last week, all seemed to be sporting thru axles. I asked the salesman about removing the wheel, well you use an Allen key, different size for the front and the back!

There was a distinct whirring sound, was it Ernesto Campagnolo spinning in his grave? 

Through! 

I think you’re getting your Campagnolo and your Colnago mixed up)

Road or mountain ?

Either way it’s all about stiffness, my new disc equipped road bike is thru axle and the difference is noticeable between that and normal QR

In reply to 

Ah yes Tuillo Campagnolo. 

I am sure I have seen them referred to a thru axles, after all they are new and cool and not at all like the solid through axle bolt on hubs that were once used. 

I take it you are talking about road bikes?

MTBs have had through axles for years. One major advantage on an mtb is you don't have a lever to catch on rocks (as easily - most still have a lever of sorts).  Main thing though is lateral stiffness

Performance is good in my limited experience but mine on a Suntour fork is a bas***d to get out.....recently confirmed by the mechanic in my LBS!!

Fairly straightforward, really - it's just a beefier version of a quick release. The main advantage over 9mm QR being that it can't accidentally be pulled out of the drop-outs by the torque on disk brakes.

Some use a hex key, some have a built-in handle. Putting wheels back in is a bit more fiddly to line up, especially the rear wheel, and you need to make sure the threads are clean.

Downside is a lack of consistency in standards as there are different sizes, so swapping wheels might not be as easy as with 9mm QR. Not popular in the pro peloton for this reason, as it's slower and causes issues for the neutral service vehicles - not a problem for most people, though.

Some hubs now come with adapters so they fit both QR and various sizes of through axles.

By and large, unless you take the wheels off a lot (transport/punctures/etc), it's unlikely to cause you a problem compared to QR.

They increase stiffness. Started out as 20mm axles on downhill specific forks, where the long travel and big impacts can cause them to flex a lot leading to poor handling (though a little bit of flex is a good thing)*. They then migrated to longer travel trail forks. Then rockshox brought out 15mm and they gradually appeared in all mtb forks and on rear wheels (though some downhill specific rear hubs had 10mm thru axle style setups before this). Then crept into road bikes, I guess to help deal with having disc brakes on less beefy forks, where asymmetric braking forces could cause the fork to twist excessively. Probably overkill on rear wheels on hardtails/road bikes, but eventually quick release will disappear so at least there will be slightly fewer hub standards. There's also an element of the bike industry's relentless drive to redesign every possible standard to encourage people to 'upgrade' their now obsolete kit. The phrase 'if it ain't broke don't fix it' has no meaning here. 

* there have also been a few other odd sizes down the years, e.g. Foes 30mm and Maverick 24mm

Sorry this may be more info than you wanted. 

Mine, on my winter bike, have levers on and are the same size back and front width wide, but different lengths. 

My new 'qr' on my summer bike don't cam over. Dt swiss. Simpler and effective enough. Though, I didn't realise initially you could lift the lever part to rotate it to a neat position... 

Solving the problem that most people didn’t know that they had.

I rode with a fairly inexperienced cyclist the other day who's through axle had undone itself whilst cycling ! Presumably it hadn't been tightened fully but then thinking about it, im pretty sure MrsD couldn't tighten hers properly either, or release a properly tightened one.

Tullio Campagnolo was credited with coming up with the inspiration for the QR mechanism whilst trying to fix a flat on the Croce d'Aune, Italy. I guess that is what they're referring to.

I think in general through axles are better and easier to line up. It is either aligned correctly or not in at all with a through axle, not something you can say with a QR.

You're absolutely right. I've just done a training camp for a bunch of American friends and all the rental bikes were all top end BMC Teammachine SLR Disk equipped with SRAM E-Tap. 10k bikes!!!!

What an absolute pain in the f**cking arse these bikes were.

Imagine almost 90 years after Tullio Campagnolo invented the QR mechanism having to use an allen key to change a wheel????

(Regarding the E-Tap, Bauke sums it up perfectly here https://www.zurnal24.si/sport/nibalijev-novi-kolega-povedal-prevec-sponzorj... )

What the F is going wrong with current bicycle innovations?

Enty

The through axles on my MTB are excellent. Screwed in and out with an integrated lever that looks like a QR and that you can adjust in any orientation when not engaged. The stiffness improvement over the older forks (similar specs but quick release) is amazing. No idea why you cannot have a similar design for a race bike, where I would always go for TAs when combined with disc brakes.

I also cannot imagine that the weight saved by having a separate key is noticeable at all, especially when UCI has to specify a minimum weight anyway. It is even more pointless if you are not followed by a team car, when you would have to carry the keys in your tool kit.

The less said about the abomination that is electronic shifters the better!

CB

Because when you try to reinvent the wheel (for no other reason than that you can sell new wheels to people who already have perfectly good wheels) you end up adding stuff that wasn't needed.

Except that, as a number of posters have already pointed out, you don't have to use an allen key.  Plenty of thru-axles have built-in levers, even generic cheapo ones like these:

https://www.chainreactioncycles.com/s?q=brand-x+twist+lever+thru+axle&c...

One thing I would say is to steer well clear of the Rockshox (ie SRAM) Maxles.  They appear to be manufactured from cheese.  OK, I haven't tried the Ultimates (because they cost silly money) but the Lites are renowned for the built-in lever mashing the one slot that it is supposed to engage in.  And the hole for the hex key in the one Stealth Maxle that I had (that's the version that does need an allen key) rounded off completely the first time I tried to undo it.  OK, it might have been overtightened (not by me) but still.

Certainly for bikes equipped with disc front brakes, a thru-axle (with a lever) is IMO a vast improvement over a QR dropout with those horrible "lawyer tabs".  (And yes, I know you can mount the caliper on the front of the fork to avoid the torque tending to eject the axle from the dropout, but that's hardly ever done in the mass market.  And in any case, it doesn't address the stiffness issue which is also caused by using a single disc brake on the end of a two-legged fork.)

In reply to DubyaJamesDubya:

And it's not the wheel that was re-invented, it was the brake - which then precipitated a rethink of the wheel because the re-invented brake did actually turn out to cause issues.

I have heard people claim that having thru axle on the rear of a road bike helps make the rear triangle stiffer. So there may be some benefit there too.

Except on the 10 grand rental bikes we got from the BMC pro shop you did

Enty

I think you'll find you're mistaken. All axles by their nature go through. Thru is a term which defines a specific type of axle. 

As to the many posts questioning their value. In the bicycle business there are many, MANY innovations which are at best highly questionable at worst negative but make manufacture easier/cheaper (pressfit BBs?) or offer a solution to sell more bicycles. However in the case of the thru axle they provide an engineering benefit to an issue caused by something else. Disc brakes on a bicycle wide level brake better, have the ability to be lighter and and allow rim, frame and fork profiles to be designed in a way that they are more aero. One of the "downsides" is that a system that was designed 75/100/? years ago which overcame a problem at the time having to use multiple spanners to mount/remove a wheel is now been replaced by something better. Thru axles ARE a better engineering solution and do offer an engineering advantage. Having to carry a 6mm allen key isn't the end of the world for 95% of people 95%, this isn't an actual issue for most people. It takes fuck all time to unscrew a thru axle, if you're really upset at having to carry an allen key take 5-10 seconds longer to screw/unscrew then stick with quick releases but they're not the issue people make them out to be and are a superior system from an engineering perspective. 

As to the OP any bike that is sold with 2 different size allen key thru axles is just badly specified that however isn't a reason not to use this superior system. 

Not sure it's been specifically mentioned so far: For me the main advantage of a thru axle is that your disc brake pads are 100% precisely aligned with the disc rotor each and every time you remove and replace the wheel. With QR it was always a struggle to get it to the exact same place and you'd end up with a pad rubbing quite often.

My mtb doesn't need an allen key. The front has a camming lever a bit like in a QR axle, and the rear has a handle you literally just turn around until its finger tight.

Looks like I’ve been missing out on this marvellous invention.

So how much is it going to cost me to convert my MTB from qr to thru axles?

New frame, new fork, new wheels (or at least hubs). Probably not worth going for an parts upgrade of the original bike.

If you ever consider replacing your MTB I would not touch a QR bike with a barge pole anymore. It just does not compare.

CB

Guess I’ll be keeping my old bikes then.

It’s always been my lack of talent rather than poor equipment that’s held me back.

Another downside us that a correctly torqued up througjh axle is too tight for MrsD to undo.