Through axles, are they marketing hype?

[johnniecakes]

As I was riding this weekend on a bike with horizontal dropouts I got to thinking about through axle frame and forks. The more I considered through axles the more I could not see any real benefit. On the bike I was riding the wheel was clamped into a horizontal dropout. As I stood up and cranked with everything I had (admittedly not the strongest guy) the wheel did not budge. Merckx and Hinault both rode frames with these same type and were quite strong. On a modern quick release frame the dropouts are vertical meaning the axle is contained on 3 sides, the top, front and back. The possible direction the wheel could move is downward but the weight of the rider is exerting force in that direction. Now add to that the considerable clamping of a properly quick release skewer and I cannot see how a through axle is any more positive than a vertical dropout/quick release combination. If the wheel and skewer were moving in the dropout I would expect to see galling of the dropout, which I do not see on any of my bikes. Seems like marketing to me? Thoughts?

[David Tollefson]

Thru axles are in answer initially to suspension designs, especially forks, where the sliders in the fork can work independently (the bridge at the top isn't all that effective). The thin QR skewer doesn't provide a lot of stiffness. Motorcycles don't have that upper brace at all, but just use a large thru axle. Add in disc brakes, which tend to force the axle downward and back, and a standard dropout and QR starts to look a little wimpy. Overkill? Maybe. 100% marketing? Not quite.

[shortwaveradio]

The real benefit is the alignment of your disc brake rotor in the caliper. With thru axles, it's in the same spot, every time.

An additional benefit is the stiffness. I haven't noticed on a road bike in a sprint necessarily, but when railing a downhill turn on a MTB, I've found it marginally easier to hold a line.

[Gummee]

what they said and the QR and fork interface is gone so your disc-braked wheel won't lever itself out of the dropouts like some had a problem with a few years back.

Road bikes? They're meh. Mtn bikes with suspension? doGsend

M

[ptourkin]

No

[bshell]

15(?) years on disc brake mountain bike with vertical drops/skewers.

Zero wheel ejections.

Zero rotor alignment issues.

Zero times 'flex' affected handling compared to tire squirm or loose terrain.

[Gummee]

15(?) years on disc brake mountain bike with vertical drops/skewers.

Zero wheel ejections.

Zero rotor alignment issues.

Zero times 'flex' affected handling compared to tire squirm or loose terrain.

That's me too, but like I said: 'some.' There were evidently some problems with wheels levering themselves out of QR forks with discs.

'So much so' that they re-designed the dropout to make the openings front-facing. My take: people not using QRs right. ...but hey! perception is reality, right?

M

[Mikej]

Well your wheel will never fall off - that’s a plus for lawyers-

[unterhausen]

I don't generally have trouble with horizontal drops either. Except the two times my bike has come off the trainer. Replaced the open cam skewer with a closed cam skewer and fixed the problem.

I really like TA though. Don't see any reason not to get new bikes with them.

[CMiller]

I see thru axles as better in almost every way. Way cleaner, stiffer, more foolproof. How many times have you seen a quick release installed wrong? Once a day at least when I worked in a shop.

Not marketing hype, they are awesome.

[Cicli]

I see thru axles as better in almost every way. Way cleaner, stiffer, more foolproof. How many times have you seen a quick release installed wrong? Once a day at least when I worked in a shop.

Not marketing hype, they are awesome.

You expect me to believe some moron that figure out a QR has no issue with a TA?
Don’t get me wrong, I have seen people who could not figure out quick releases but don’t think thru axles solve that.

[dustyrider]

Depends on the length.:bike:

[CMiller]

Yes thru axle is one big bolt turned all the way in then safe, most people can figure out a bolt. People install quick releases and never close the lever, they know how to tighten it on just not close it. So yes, I believe a lot more people will figure it out.

[Jaybee]

Yes thru axle is one big bolt turned all the way in then safe, most people can figure out a bolt. People install quick releases and never close the lever, they know how to tighten it on just not close it. So yes, I believe a lot more people will figure it out.

I agree with this. The most common way to mis-install a QR is just to use it as a bolt, screw it in til tight. That's what you're supposed to do with a TA, so it is intuitive.

[spoonrobot]

The real benefit is the alignment of your disc brake rotor in the caliper. With thru axles, it's in the same spot, every time.


This was/is a marketing lie that was allowed to propagate due to thru-axles being limited to mostly bikes with hydraulic brakes - now that they're in much wider service people with mechanical brakes people are running into the same issues they were with respect to centering and QR.

Thru axles with mechanical brakes require the same diligence of marking the hub lock nuts and dropouts to ensure the rotor falls into the same relative position when removing and reinstalling the wheel.

Personally I only want thru-axles on my mountain bikes. They do nothing on my road and gravel bikes and actually may be worse since they stiffen up the connections that don't need it for non-technical riding.

[Bob Ross]

You expect me to believe some moron that figure out a QR has no issue with a TA?

LOL! ^^^This.

I like to think *I'm* not a moron and that I'm at least somewhat bike-savvy, but my wife recently brought the first TA-equipped bike into our fold and I gotta admit, for something that ought to be completely foolproof -- IT'S A FREAKIN' THREADED ROD, JUST SCREW IT IN! -- I'm surprised at what a...well, I don't want to say "nuisance", how about "obstacle to instant gratification" ...TA can be. Wouldn't surprise me at all to learn there are people riding around with incorrectly-installed TA.

btw, just based on intuition I would guess that one of the advantages [sic] of TA is attributable to the large diameter of the axle, regardless of how it's afixed at the dropouts. But what do I know?

[oldpotatoe]

I see thru axles as better in almost every way. Way cleaner, stiffer, more foolproof. How many times have you seen a quick release installed wrong? Once a day at least when I worked in a shop.

Not marketing hype, they are awesome.

Almost..I know 'we' aren't concerned about speed of wheel change and rotor alignment after a wheel change but...'almost'...
As the race continued, most racers quietly switched back to rim brakes. The yellow jersey contenders had used rim brakes from the beginning. Why?

The racers were concerned about flats. Through axles require extra time during wheel changes. Worse, the inevitable manufacturing tolerances change the alignment of the disc rotors on different wheels, even if the same model of hub is used. Unless the disc calipers are adjusted, the new wheel’s rotor will rub. (We realized this during our most recent tire tests, where we thought we could speed up the changes between different wheel sizes, but had to adjust the disc brake calipers after every run.)

BMC Racing found a work-around solution to the problem: When a rider flats, they don’t change wheels, but the entire bike. However, this also means they no longer can use neutral support. Most other teams weren’t willing to run that risk.

[BikeNY]

This was/is a marketing lie that was allowed to propagate due to thru-axles being limited to mostly bikes with hydraulic brakes - now that they're in much wider service people with mechanical brakes people are running into the same issues they were with respect to centering and QR.

Thru axles with mechanical brakes require the same diligence of marking the hub lock nuts and dropouts to ensure the rotor falls into the same relative position when removing and reinstalling the wheel.

Personally I only want thru-axles on my mountain bikes. They do nothing on my road and gravel bikes and actually may be worse since they stiffen up the connections that don't need it for non-technical riding.

Pretty much nobody marks their hub and fork to assure they are in the same position when reinstalled. I've been using thru axles on my mountain bikes and now my gravel bike for many years, and that's just not a thing. Slide the wheel in, stick the thru axle in and tighten, no alignment required. A thru axle stiffening up the bike cannot be a bad thing. It may not always be an improvement, but it's never worse.

Almost..I know 'we' aren't concerned about speed of wheel change and rotor alignment after a wheel change but...'almost'...

I guess for Tour racers that is a real issue. For the other 99.999% of cyclists, fast wheel changes from a support vehicle is not on the list of requirements. Yes, different hubs can be off a bit when using multiple wheels, but a couple of shims when first setting up and it's all good. Then again, that's a disc brake issue, nothing to do with thru axles. Also, I've found that hubs from the same manufacturer do not require any shims, at least that's what I've found with all of my DT hubs.

The only issue I have with thru axles is there a bunch of different 'standards', especially from the fork manufacturers, and they all work a bit different and are not interchangeable. Some just screw in, some screw in and then have a lever to tighten like a QR. It's also a pain to change the lever position on some of them. I have a Fox fork on one of my mountain bikes, and to change the lever position, i have to remove a tiny screw, rotate the insert to where I think it will work, put the tiny screw back in and then see if I guessed right. If not, repeat the whole process. Stupid! I'm a big fan of the DT thru axles, you just screw them all the way in, and then the lever can be positioned wherever you want.

[unterhausen]

funny thing is that some companies have combined the worst aspects of both systems. My salsa mtb has a TA where you have to undo a qr and flip the handle around to use as a wingnut. Tightening it is an iterative process, and it just seems stupid. I can almost see why Fox does this on forks, but not on the rear. Actually, I'm not really sure why Fox does it on forks. I guess it does make it so if you're an idiot, you are not going to be able to put the wheel on successfully. But that assumes an idiot is going to be able to figure that out.

[oldpotatoe]

Bike NY writes,

I guess for Tour racers that is a real issue.

BUT win on Sunday, sell on Monday is alive and well in 'bikes'..

[spoonrobot]

Pretty much nobody marks their hub and fork to assure they are in the same position when reinstalled. I've been using thru axles on my mountain bikes and now my gravel bike for many years, and that's just not a thing. Slide the wheel in, stick the thru axle in and tighten, no alignment required. A thru axle stiffening up the bike cannot be a bad thing. It may not always be an improvement, but it's never worse.


You have mechanical discs on your mountain bike and gravel bike?

Anyway, I know, I see several people a week through my shop that have "spontaneous brake rubbing."

Usually they start with "I think I warped my rotor on X descent" I listen and nod and then flip their bike upside down in the stand, put a little sharpie dot on the locknut and slowly rotate it around the dropout as I tighten and loosen the skewer. I find 3-4-5 spots where the rotor runs perfect so I mark those too. Then I put the wheel in the stand and check the rotor, almost always it's reasonably true and always within spec for thickness. So my pitch ends up being - you can get a new rotor for $25-$50 or you can make sure to align your wheel at these points when reinstalling. A lot of guys choose to do both so I repeat the exercise with the new rotor and then they really understand.

For road and gravel bikes a stiffer frame/fork is unnecessary, the benefits are always obscure and the negatives are hand-waved away. Stiffer fork requires less tire pressure for the same comfort level, it's easy to run into the point where lower tire pressure is prone to sidewall collapse but the comfort level is still not there as it would be on regular QR fork. It's also heavier and is pushing the theme that gravel bikes are "mountain bike lite" with overly stiff frame and forks that ride poorly except for the heaviest riders or roughest terrain. I prefer lighter built gravel bikes that ride like road bikes or even cross bikes from 3-4 years ago.

I am limiting my consideration of gravel bikes to around 47mm of tire width. That tire width and lower below, most riders do not have the fitness and skill to ride fast enough to benefit from a stiffer frame/fork connections. Something like the Open UP with 2.1 tires? I see the benefit there same as I do for mountain bikes.

[BikeNY]

You have mechanical discs on your mountain bike and gravel bike?

Anyway, I know, I see several people a week through my shop that have "spontaneous brake rubbing."

Usually they start with "I think I warped my rotor on X descent" I listen and nod and then flip their bike upside down in the stand, put a little sharpie dot on the locknut and slowly rotate it around the dropout as I tighten and loosen the skewer. I find 3-4-5 spots where the rotor runs perfect so I mark those too. Then I put the wheel in the stand and check the rotor, almost always it's reasonably true and always within spec for thickness. So my pitch ends up being - you can get a new rotor for $25-$50 or you can make sure to align your wheel at these points when reinstalling. A lot of guys choose to do both so I repeat the exercise with the new rotor and then they really understand.

For road and gravel bikes a stiffer frame/fork is unnecessary, the benefits are always obscure and the negatives are hand-waved away. Stiffer fork requires less tire pressure for the same comfort level, it's easy to run into the point where lower tire pressure is prone to sidewall collapse but the comfort level is still not there as it would be on regular QR fork. It's also heavier and is pushing the theme that gravel bikes are "mountain bike lite" with overly stiff frame and forks that ride poorly except for the heaviest riders or roughest terrain. I prefer lighter built gravel bikes that ride like road bikes or even cross bikes from 3-4 years ago.

I am limiting my consideration of gravel bikes to around 47mm of tire width. That tire width and lower below, most riders do not have the fitness and skill to ride fast enough to benefit from a stiffer frame/fork connections. Something like the Open UP with 2.1 tires? I see the benefit there same as I do for mountain bikes.

I have mechanical discs on one of my mountain bikes, and had mechanical discs on my gravel bikes up until a few weeks ago. Not sure why this would be any different between mechanical and hydraulic brakes though, clearances are about the same. I guess if the clearances are already really close because of other issues aligning the hub could help, but seems unnecessary if everything is setup properly.

As far as frame/fork stiffness, thru axles do not change vertical compliance of a frame or fork, or at least shouldn't. A disc fork clearly needs to be stiffer than a rim brake fork, but switching from a QR to a thru axle doesn't change the vertical compliance, it stiffens the fork under twisting and lateral forces, which is a good thing. Is that required on a gravel or cross bike? Maybe not, but it can tighten up the handling in rough conditions, so I'd say it's a good thing.

[Mark McM]

I can see how racers would be hesitant to convert from QR axles to thru axles, but for most people, in balance the thru axle is probably a better design. Had thru axles been introduced first, people would probably say that only racers should use QR axles, and that it was nonsense to for most others to switch to QRs. Any deficiencies of the thru axle are merely minor incoveniences.

The recent move to thru axles on road bikes has mostly be due to issues involving disc brakes. I still feel that that disc brakes on road bikes introduce more problems than they solve, and I hope that high quality (and mass produced) road bikes continue to be made with rim brakes. But I'd have no objection if even rim brake bikes moved to thru axles.

[MattTuck]

Is 100/142 the long term standard?

If I got a new bike, the only thing that would give me pause about thru-axle is that it seems somewhat hard to future proof the purchase.

[Gummee]

Well your wheel will never fall off - that’s a plus for lawyers-

That's a minus for lawyers. It's a plus for shops and manufacturers that don't get sued by people not using QRs right

M

[David Tollefson]

Is 100/142 the long term standard?

If I got a new bike, the only thing that would give me pause about thru-axle is that it seems somewhat hard to future proof the purchase.

It is, until the next "best thing" comes along.

Actually, this would be true for road disc, but already I see huge segments of the MTB market going to "boost".

[BikeNY]

Is 100/142 the long term standard?

If I got a new bike, the only thing that would give me pause about thru-axle is that it seems somewhat hard to future proof the purchase.

As mentioned, there is no 'standard'. For road/gravel, the most common setup right now is 142x12 rear and 100x12 front. Just a few years ago it was 100x15 front, but then somebody decided 12mm was better than 15mm for road bikes!

For mountain bikes, it's 148x12 and 110x15 right now.

[dustyrider]

Come on guys! We’re on to super boost now. :banana: and I didn’t even think about widths. 12mm, 15mm, 20mm...the sky is the limit!

[Bob Ross]

I still feel that that disc brakes on road bikes introduce more problems than they solve, and I hope that high quality (and mass produced) road bikes continue to be made with rim brakes.


We can hang.

:::beer:::

[shoota]

Totally agree with the marketing hype. I can't tell a difference in stiffness between any of my bikes with different axle types. I don't have a problem lining up my QR discs.. they don't fall out.. the TA axles on my other bike work just like QR do, so there's ease of use advantage there..