Bicycle Mechanics - Why Torx?

Why in the name of all that is sweet and holy, did they decide to use Torx over allen heads on rotor bolts? I have wondered this forever, and anyone who has ever owned a Chrysler can understand why Torx absolutely sucks. Any good reason for this?

Good question..

The torx is the evolution of the allen style. I prefer it, altho it is annoying to have two styles of almost the same wrench.

This is the third time I typed this. The backspace function, as it relates to a webpage is far more annoying than any silly bolt/nut/capscrew design.

its a consprisy with brake makers and torx bolt makers to take over the world

They will need to get in line, i think the cell phone guys have the jump.

I think Torx are fine as long as you have the proper tool for it. Otherwise, I curse like a sailor...and then some.

They are so horrible though... if you look at them cross-eyed, the head strips. The bits wear out after a few uses sometimes (one of my friends is a custom 4x4 fabricator and goes through extremely high grade Torx sets like nothing working on Jeeps). Actually my first exposure to Torx was in the 4x4 world, and if you ask any Jeep owner about Torx, guaranteed you get an eye roll and groan. Its a painful subject for most. I absolutely cannot see how Torx improves on any way from an allen key. The heads on the screws for most rotors are so shallow that you wind up slipping the bit a few times in the torquing process. Can you tell I HATE Torx? Thanks to Chrysler, I have 4 Torx bolts on my Mitsubishi, and hey, guess what? They are all stripped out! Once the bolt rusts, if it has a Torx head, its gone... the bit will just tear the head apart.

Rant over. For now.

you need the exact torx size bit, or your completely ****ed

Why in the name of all that is sweet and holy, did they decide to use Torx over allen heads on rotor bolts? I have wondered this forever, and anyone who has ever owned a Chrysler can understand why Torx absolutely sucks. Any good reason for this?

Thanks for speaking out. I always wonder the same thing since frist time I saw those but afraid to ask because there is some good reason that I don't know. I'm glad to know I wasn't the only one. Hex wrench works for me. I'll avoid torx as much as I can.

* TORX requires no insertion pressure for driving and no cam out forces are generated.
* TORX has axial power transmission areas, Tools don't slip. Reduces possibility of distorted screws.
* TORX has 6 large torque transmission surface areas that allow for higher sustained torque forces.

Raiyn, I have found the exact opposite of all 3 of those points to be true... I just don't get it.

They will need to get in line, i think the cell phone guys have the jump.
Hey Rev

Did you notice Jon Stewart was absolutely LOSING it?

Its not just Chrysler that is crazy about Torx; many cars are peppered with these fasteners these days. I have been told they are favored because they are suited to robotic assembly techniques. Can't see that being a big factor for bike, except for some low-end mass produced models.

Joe

Anyone who worked on military aircraft instruments back in the day would remember screws that had "hex spline" heads. These were basically a six sided spoked kind of pattern. They were commonly used on the little knobs that adjusted (whatever) on the gauges. The big problem with these was that the tools would strip with just a thought at times. Torx ended up as a kind of cross between hex spline (there were 4_spline and 5_spline, too) and what's commonly called an Allen hex head. The big advantage to Torx (over hex Allen) is that there is substantially more surface contact between the tool and the fastener (as Raiyn alluded to). It's the same as when you hear "the distance between Oregon and Mexico is 400 miles, but the California coastline is actually 2500 miles long". I'm just guessing at those numbers, but we've all hear those kind of stats and said "huh?".

If Torx fasteners are not overtorqued when installed, you should never have a problem with stripping the heads. Yet one more reason that most people should use a torque wrench. The two major causes of fasteners getting stuck are overtorquing and not lubricating the threads. You see it hammered home almost daily on this forum. You need to grease (or use anti-seize paste) just about every fastener and mating surface on a bike. If you don't, expect problems down the road.

Another thing that a lot of people seem to miss is that if you Loctite something and it gives you a difficult time coming out, take the time to heat it up for a couple of minutes with a hair dryer or heat gun. Alternatively, there are release agents available for threadlockers, but they are nasty chemicals and heat works just as well. This will save you a lot of stripped tools and fastener heads. For people that don't have a lot of experience with using Loctite, it's very important that you match the strength of the Loctite to the size of the fastener. If you put 270 on a 4/40 or 2mm screw, that is no good. If you did not understand that last sentence, then you need to either seek advice when using threadlockers or spend the time to learn what threadlockers match what fasteners and applications. It's ain't rocket science, but you have to take the time to learn the correct matches and applications for this stuff. If you get it wrong, plan on plenty of stripped fastener heads and tool bits (and the accompanying frustrations).

Sorry about the tangents, but alot of this stuff is related. Experience mechanics can often get away without the torque tools, but a good example of why you should use them is stated in Gerd Schraner's book. He states that after years of building wheels with no tensiometer, he was surprised at how inconsistent his own work was when later checked with a calibrated tool. Anyone who does not use torque tools, and starts to, will find out the same thing.

Its not just Chrysler that is crazy about Torx; many cars are peppered with these fasteners these days. I have been told they are favored because they are suited to robotic assembly techniques. Can't see that being a big factor for bike, except for some low-end mass produced models.

Joe

One thing that I will absolutely guarantee you about Chrysler, or any other big manufacturer, is that they are using torque-limited drivers to install these fasteners. All of this is motivated by TQC (total quality control) or some other form of statistical quality analysis, and, the ergonomics of repetitive motion for the assembler.

* TORX requires no insertion pressure for driving and no cam out forces are generated.
* TORX has axial power transmission areas, Tools don't slip. Reduces possibility of distorted screws.
* TORX has 6 large torque transmission surface areas that allow for higher sustained torque forces.



True, The torx is a metric only size, it is the evolution of the phillips tip and allen head.
I threw all my slotted screws away a long time ago.

TORX screws are available in standard sizes also, not just metric.

TORX screws are available in standard sizes also, not just metric.

I believe there is only one set of actual driver tools though, that's what I meant, not thread sizes.

* TORX requires no insertion pressure for driving and no cam out forces are generated.
* TORX has axial power transmission areas, Tools don't slip. Reduces possibility of distorted screws.
* TORX has 6 large torque transmission surface areas that allow for higher sustained torque forces.


On paper, it makes sense, but in the real world, they suck.

On paper, it makes sense, but in the real world, they suck.

If you guys have touble with Torx, I'd hate to see what you do with conventional phillips! Actually, a Flat Blade, Phillips, and Allen will all fit a Torx head.

I don't know what torx are, but I'm guessing theyre the star shaped bits, like the ones that hold my disc rotor in?

I don't know what torx are, but I'm guessing theyre the star shaped bits, like the ones that hold my disc rotor in?

exactly

you need the exact torx size bit, or your completely ****ed

This also holds true for allen head bolts!

If you guys have touble with Torx, I'd hate to see what you do with conventional phillips! Actually, a Flat Blade, Phillips, and Allen will all fit a Torx head.

If this is true, this would be the biggest advantage by far. I don't know much about Torx because I have never used it. It maybe worth looking into.

From the Newman Tools website:

Get The Wiha TORX Advantage.

TORX requires no insertion pressure for driving and no cam out forces are generated.
TORX has axial power transmission areas, Tools don't slip. Reduces possibility of distorted screws.
Wiha TORX has 6 large torque transmission surface areas that allow for higher sustained torque forces.
Wiha TORX has 15 degree efficient drive angle Tools and screws won't become distorted. better screw to tool contact.
Wiha TORX profile is precision machined for an exact fit and long tool life.
Smooth rounded edged reduces possibility of damage to parts or assemblies

I will say, i have never rounded out a torx bit or bolt. I have rounded several allen head, i like the deisgn. Plus its not like torx stuff is hard to find

I've used 'em all over the years as typewriters from IBM and Facit were full of Bristol spline fasteners. I always hated it when they mixed Bristol and hex setscrews in the same machine.

The biggest problem I see with Torx fasteners is using crappy tools. You must buy decent tools. This is especially true with the smaller sizes. At least buy a tool made by Allen or Eklund or Bondhus.

My pet peave is the difference between US and JIS Phillips heads. The angle is different and I see screws every day stripped out because someone used brute force with the wrong screwdriver.

Doc

JIS seems to be the same as US with higher tolerances and smaller radiuses in their corners.

EDIT: radii.

I know that we used to have them in the phones at verizon so that any customer could not get into the inside and mess with it without going out an buying a torx bit of the correct size. Rest of the phone is just regular philips head. Dont see torx on the new phones however.

All of which may be totally overkill for a fastener with spec's of maybe 6 to 6.5 Nm torque? I suspect its a sweetheart deal with Craftsman and Park who must make $6 to $10 on every sucker (like me) who decides to go disc.
I don't know where you got your discs but each of mine came with a T-25 wrench included in the package

I've used 'em all over the years as typewriters from IBM and Facit were full of Bristol spline fasteners. I always hated it when they mixed Bristol and hex setscrews in the same machine.

The biggest problem I see with Torx fasteners is using crappy tools. You must buy decent tools. This is especially true with the smaller sizes. At least buy a tool made by Allen or Eklund or Bondhus.

My pet peave is the difference between US and JIS Phillips heads. The angle is different and I see screws every day stripped out because someone used brute force with the wrong screwdriver.

Doc

Oh, yes, "Bristol" spline. Thank you, I could not remember that ;) I think the same people that made those typewriters must have been designing aircraft instruments. Yup, mixing the two type drove me nuts, too.

Yes, get good quality tools. In addition to the vendors you list, Wiha is very good - all made in Germany and lots of cool stuff for all types of fasteners. See: http://www.wihatools.com. If you buy torque wrenches and are looking for 1/4" and 3/8" drive hex Allen bits, Wiha is a good source.

And Phillips ....... Don't forget Reed&Prince (a pointier Phillips type fastener head) and PosiDrive (like Phillips, but with wider, better gripping splines). These fastener types are so abused. It's really sad.
I was responsible for supplying tools at work for almost fifteen years and it's just incredible at how many people will use a #1 Phillips screwdriver on a #2 screw. Your comments are right on.

I don't know where you got your discs but each of mine came with a T-25 wrench included in the package
Yea when i ran discs they came with that too. But those are the ones that came with avids. Sometimes on ebay i see them with the 3mm.

Yea when i ran discs they came with that too. But those are the ones that came with avids. Sometimes on ebay i see them with the 3mm.
My Hope rotors came with the 3mm like that. I had a choice between the TORX and the Allen bolts I went TORX even though the chrome allens would have been better bling :lol:

well personally i like the torx over allen, its easier since its just likt T25 T20 etc. And its much harder to round out. Though your right, the chrome attracts chicks :)

well personally i like the torx over allen, its easier since its just likt T25 T20 etc. And its much harder to round out. Though your right, the chrome attracts chicks :)
I've got what I need. :D
Besides the rotors themselves are a much bigger draw than the lowly hardware. (Although I do have the chrome bolts in my toolbox as spares)

you know though that reminds me once, my english teacher was talking about the appeal men to to have in high school and hes just saying. Does the girl want to go for the guy who has a top of the line sports car? Or the top of the line....pause........mountain bike. And I was not sure what to say, becuase you know ive spent more money on my mountain bike than a car.

Eh, being the consummate salesman that I am (when the need arises coff), I've never had a problem getting a date (I can be one smooth SOB). I didn't start back with the bikes until I had been dating my current girlfriend for about a year.

Well i find cycling sometimes got in the way with past relationships, but my current girlfriend has dealt with it for a year. Even a few times she went riding with me, but she has a car now so its one more excuse not to get one.

how did a discussion about torx bolts turn into this? Did i do that?

Stop your whining and go to a fastener store and replace all your torx bolts with high grade hex bolts. You'll be in Nirvana.

Personally I hate them too, but I am not heavy handed, and haven't really had many showstopping issues with them

how did a discussion about torx bolts turn into this? Did i do that?

Yes. You mentioned that you could attract chicks with just a couple of bolts. :rolleyes:

back on topic?




http://www.semblex.com/products/licensed/images/torx.gif

Many products are made with torx screws for additional safety, and security. Torx tools are less common and are used as a temper proof system. There is also a "Secure Torx" standard where their is a pin sticking out in the middle of the crew head, and a corresponding hole in the torx driver..
http://www.hudsonfasteners.com/sec/sec_images/sec_tx_bhpms.jpg

Mmm.... larger lobes...

Torx is great for high torque applications. But for pure ease of assembly, I like having a good ball hex so I have more flexibility in my angle of penetration.

The problem I have with Torx (never stripped one--yet) is when I am torquing a rotor to spec, I have to put a lot of pressure on the back of the torque wrench to keep the bit seated in the bolt. Its so shallow that if I am not holding it perfect level, and I mean perfectly, it will slip right out and eat a few of those amazing splines. You'll never be able to convince me they are a superior idea.

well thats true, some are pretty shallow. At least the ones on my disc brakes i had were, but the ones that held together my leaf blower sucker thing seemed to be a bit deeper. But i suppose for clearance issues you have to have a shallow head.

http://www.hudsonfasteners.com/sec/sec_images/sec_tx_bhpms.jpg

They have these "secure" torx screws holding together the walls for the toilets and stalls in the bathroom at school.

They have these "secure" torx screws holding together the walls for the toilets and stalls in the bathroom at school.

Guess why? To stop those "meddlesome kids" pulling them apart when they get bored.

and those meddlesom kids eventually smarten up and get torx stuff. They do the same at my school. I sat in a desk once and the whoile top fell off because some bored kid removed the nuts

If you guys have touble with Torx, I'd hate to see what you do with conventional phillips! Actually, a Flat Blade, Phillips, and Allen will all fit a Torx head.

I just looked at Tox bit. Philips bit won't fit in Torx screw head. Philips 4 points, Torx 6 points. Flat screw bit may work if the size fits. But Torx screw heads come in more various sizes where flat screw much fewer sizes. In emergency situation, if you have to try something, you can try the size that you happen to have, but I'm not counting on it, if I'm the one in that situation. Also Torx screw are made for havier(tighter, higher torque) use, where flat blade screws are made for much lighter use. Flat screw bit to use on Torx screw head maybe usefull no better than having a hammer in the emergency case.

and those meddlesom kids eventually smarten up and get torx stuff. They do the same at my school. I sat in a desk once and the whoile top fell off because some bored kid removed the nuts

LOL that happened last year in english. good times :lol: