# <RANT> Do bicycles really need Torx bolts?



## lew242 (Aug 7, 2008)

I'm been wrenching my own bicycles and motorcycles for a few years now, but I still fail to understand the reason for Torx bolts. If I bring an Allen Key set with me how do gain an advantage when bolts on places like my brake rotors and even chain guides have Torx bolts? Just means that I can't wrench half my own bike on the trail unless I bring yet more crap in my backpack. Even more infuriatingly these bolts are often semi permanently locitited with bolts made from cheap aluminum that can easily get stripped.

Is it just me or would chromium-steel Allen bolts be the best option for the industry?

If you are a mechanic or engineer who likes Torx bolts please tell me what I'm missing here!


----------



## dundundata (May 15, 2009)

I didn't even know rotor bolts were torx until I got new wheels/brakes. I think Centerlock is a better system.


----------



## GrampBredo (Dec 18, 2007)

I think it's harder to round out the torx heads then standard allen heads. That means they can make smaller, low profile (button head) bolts that are stronger than comparably-sized allen bolts. It would have to do with the greater amount of surface area on the curve of indents vs. the points of an allen bolt.

I'm not an engineer or anything, just a guess.

IMO the best option would be steel torx bolts. I don't mind carrying the extra tool- it's tiny and weighs next to nothing. Certainly much smaller than a wrench for the Centerlock lockring. 

I think centerlock is mechanically superior, but it could be harder/more expensive to produce, and it's not available on all hubs yet. For now, all my bikes use six-bolt.


----------



## reptilezs (Aug 20, 2007)

yes for aluminum fasteners on higher end components. 5mm hex on aluminum= stripped. the industry has somewhat standardized t25 for almost everything except t30 for chainring bolts


----------



## mitzikatzi (Sep 9, 2008)

> By design, Torx head screws resist cam-out better than Phillips head or slot head screws. Where Phillips heads were designed to cause the driver to cam out, to prevent over-tightening, Torx heads were designed to prevent cam-out. The reason for this was the development of better torque-limiting automatic screwdrivers for use in factories. Rather than rely on the tool slipping out of the screw head when a torque level is reached, thereby risking damage to the driver tip, screw head and workpiece, the driver design achieves a desired torque consistently. The manufacturer claims this can increase tool bit life by ten times or more.


from here


----------



## rkj__ (Feb 29, 2004)

mitzikatzi said:


> from here


A comparison to a Phillips head is not very meaningful here.


----------



## mitzikatzi (Sep 9, 2008)

rkj__ said:


> A comparison to a Phillips head is not very meaningful here.


I disagree. Did you read and understand the article?

It states that a Philips head is designed to "slip or twist out" to prevent over torquing with poorly calibrated tension/torque screw drivers. In factories this can result in wear on the "tool bit". With the invention of better torque screwdrivers a better bit can be used which will not slip and the better screw driver will still prevent over tightening. Hence saving money on tool bits.

So Torx bolt heads resist slipping. So it seems logical what others have said it allows softer or lighter metals be used for bolts with out fear of the head being damaged which would occur if a phillips head was used.

YMMV


----------



## rkj__ (Feb 29, 2004)

mitzikatzi said:


> I disagree.


Hex head cap screws also resist slipping much better than a Phillips head.

It is more relevant here to compare hex heads to torx heads. When is the last time you saw a Phillips head on a chainring bolt, disc rotor bolt, or any other fastener on a bicycle that requires any significant torque?


----------



## dkbikes4life (Nov 20, 2010)

I hate torx bolts. I would rather have everything allen head. I'm an auto tech and they use torx bolts for a lot of stuff and I hate them. They round out way easier than allen heads.


----------



## Drew Diller (Jan 4, 2010)

Just anecdotally here, and I'm not a car guy: I've noticed for small fasteners, Torx heads tend to round out less. I can round out a 4mm hex head way easier than an equivalent Torx.


----------



## lew242 (Aug 7, 2008)

Ah, I see so the industry thinks that if they use Torx bolts then they can get away with using lower quality aluminum. Sorry to say I had some round out on me already on rotor bolts. Cheap aluminum is cheap aluminum, the head will strip whatever. The same as dkbikes4life I'd just prefer Allen bolts preferably steel.


----------



## ALS650L (Apr 19, 2009)

dkbikes4life said:


> I hate torx bolts. I would rather have everything allen head. I'm an auto tech and they use torx bolts for a lot of stuff and I hate them. They round out way easier than allen heads.


I'm with you. Work on cars for a liviing. Small stuff torx is ok, bigger stuff it isn't. As soon as any rust or corrosion get's in there it's much worse. Also most companies torx drivers are poor quality. I've tried cheap brands, Craftsman and Mac, all of which you can pretty much break at will. The only drivers I've had any luck with are Snap On, which are the least expensive of course.


----------



## JonathanGennick (Sep 15, 2006)

I hate the proliferation of bolt sizes and types of drive on a bike. There's only a need for maybe three different bolt sizes in the main. Yet I'm with the OP--I need to carry maybe ten different drivers just to be sure I have the right one for whatever I need on the trail.

Torx is just the latest manifestation of the problem. Just when I have a good collection of hex wrenches and such, along comes Torx to throw a monkey-wrench into the scenario. Frustrating!

I also dislike that shifter clamp bolts tend to be 5mm, whereas brake-lever bolts tend to be 4mm. WTF? Just use one size for everything on the bar so that I don't have to keep swapping wrenches. Sheesh!

IMHO, everything should come down to three bolt sizes: 5mm, 4mm, and 2.5mm hex bolts, or some equivalent in Torx. I include derailleur adjustment screws in that. The industry should standardize on three sizes and a consistent driver-interface and be done with it.


----------



## bad mechanic (Jun 21, 2006)

GrampBredo said:


> I think it's harder to round out the torx heads then standard allen heads. That means they can make smaller, low profile (button head) bolts that are stronger than comparably-sized allen bolts. It would have to do with the greater amount of surface area on the curve of indents vs. the points of an allen bolt.


^ This. Much smaller chance of stripping the bolt head with torx. Considering how meat fisted and ignorant a lot of users are, I understand the decision.


----------



## JonathanGennick (Sep 15, 2006)

bad mechanic said:


> ^ This. Much smaller chance of stripping the bolt head with torx. Considering how meat fisted and ignorant a lot of users are, I understand the decision.


Is it about the end users, or more about the people in the factories putting these things together? I'd bet the latter.

Torx would be ok if we went with torx across the board. I don't care much whether we have three torx sizes or three hex sizes. Although I do like that with hex bolts, that I can buy wrenches that let me work from a slight angle.


----------



## dundundata (May 15, 2009)

Never had a problem with allens, even the really small ones. Just make sure it's secure before turning. I'm guessing the people who are stripping allens will find a way to destroy torx as well.


----------



## JonathanGennick (Sep 15, 2006)

dundundata said:


> Never had a problem with allens, even the really small ones.


I have slipped a few times, when tired or distracted. I don't recall ever totally rounding out a bolt, but I've begun the process more than once. I hate to admit that, but it is true. I am not perfect, and do screw up now and then.



> I'm guessing the people who are stripping allens will find a way to destroy torx as well.


I'm way ahead of you. Last fall I pulled apart a crankset using some hex wrenches only to realize when I was done that the bolts were Torx. Oops! I guess I was a) lucky to get it apart, and b) lucky I didn't do any really serious damage.

I also find it's easy to grab the wrong size torx key. I make a point now of going up the line to find the largest key that will fit, because once or twice I've grabbed a size smaller and used the wrong size wrench without realizing it.

I'm not a complete klutz, but mistakes happen. It's interesting that I simply make a different set of mistakes with torx than with hex.


----------



## dundundata (May 15, 2009)

JonathanGennick said:


> I hate to admit that, but it is true. I am not perfect, and do screw up now and then.


Well nobody said it was easy being perfect, I work hard at it.


----------



## customfab (Jun 8, 2008)

Torx fasteners are playing into consumer demand for lighter parts. One way to make lighter parts is to use lighter hardware. IMHO if you are going to make a fastener out of anything other than steel it should be torx. That said a cheap fastener is cheap regardless of material. I also agree that a ham fisted consumer will F it up regardless of what driver is needed. Why should we play to the lowest common denominator?

The only thing we really need is for multi tools to have a T-30 and T-25 on them and your good to go. There are a few smaller torx fasteners on some things but your not going to need to bleed your Magura brakes trail side for instance. 

I for one embrace torx but I completely understand your desire for common sizes.


----------



## Mr.Magura (Aug 11, 2010)

Well, it's really quite simple.
Just replace the Torx with allen bolts, problem solved. 
That's how I got around that little hurdle.

A stock of stainless allen bolts in M4, M5, and M6, is not gonna break the bank.


Magura


----------



## Blaster1200 (Feb 20, 2004)

By the way, if you replace the torx bolts with the same sized button-head bolts for a hex wrench, they use a 3 mm hex. Let us know how well that works out for you.

You may be able to get away with standard head bolts in the rear with some frames, but they won't clear most forks.

And seriously, what bicycle specific multi-tool doesn't come with a T25 these days?


----------



## Mr.Magura (Aug 11, 2010)

Blaster1200 said:


> By the way, if you replace the torx bolts with the same sized button-head bolts for a hex wrench, they use a 3 mm hex. Let us know how well that works out for you.


At least on my bike, there is no bolt that small, but yours may differ.

Magura


----------



## Blaster1200 (Feb 20, 2004)

Mr.Magura said:


> At least on my bike, there is no bolt that small, but yours may differ.
> 
> Magura


You're not using disc brakes? Go find some button head (low profile) bolts for disc brake rotors, and you'll see what I mean.


----------



## rkj__ (Feb 29, 2004)

Blaster1200 said:


> You're not using disc brakes? Go find some button head (low profile) bolts for disc brake rotors, and you'll see what I mean.


FWIW I have seen some disc rotors bolted down using 3mm hex pattern bolts. I don't recall what brakes they were.


----------



## dundundata (May 15, 2009)

rear derailleur pin bolt, now that thing is tiny


----------



## Mr.Magura (Aug 11, 2010)

Blaster1200 said:


> You're not using disc brakes? Go find some button head (low profile) bolts for disc brake rotors, and you'll see what I mean.


My disc brake rotor bolts are a 4mm hex.

Magura


----------



## Mr.Magura (Aug 11, 2010)

dundundata said:


> rear derailleur pin bolt, now that thing is tiny


That's true, and come to think of it, the reach adjustment bolt on my Hope M4's is a 2mm hex, but neither are an issue.

Magura


----------



## Blaster1200 (Feb 20, 2004)

Mr.Magura said:


> My disc brake rotor bolts are a 4mm hex.
> 
> Magura


Those are brand specific and only used by some of the off brands. You won't find those from the larger brake companies like Shimano, Hayes, Avid, etc. The problem with those is that since they're very shallow, they're quite prone to stripping - at least moreso than the common torx bolts. However, if you go to a hardware store, you won't find button head bolts with a 4 mm hex.


----------



## Mr.Magura (Aug 11, 2010)

Blaster1200 said:


> Those are brand specific and only used by some of the off brands. You won't find those from the larger brake companies like Shimano, Hayes, Avid, etc. The problem with those is that since they're very shallow, they're quite prone to stripping - at least moreso than the common torx bolts. However, if you go to a hardware store, you won't find button head bolts with a 4 mm hex.


That's true. It takes a bit of looking around to find those, but they do exist.

They are though only prone to stripping, if not tightened with the right torque. 
As others have pointed out earlier, it is a matter of skill level. Some will strip whatever, and what they can't strip, they will break instead. 
Others use a torque wrench for their critical matters like rotor bolts and bolts in the stem.

Magura


----------



## Ecogeek (Aug 30, 2009)

Lots of things on bikes seem designed to make home wrenching difficult. The more expensive the tool you need, the less likely you can do it yourself.
But, let's not go there.
Your complaint is not the best I've heard, as any cheapo bit-set should have a full compliment of torx bits. If not, eBay. Read up on the torx spec on wikipedia to find what side you need. You should have a digital caliper to measure with. #1 tool.
Get caliper, measure, read, buy what you need.
Torx is not such a bad idea on larger bolts. On smaller bolts, the tolerances between tools and bolts mean it REALLY sucks. But even then, when done right, it can be the best way. Otherwise you need bigger bolt-heads to get enough purchase and that's inefficient. Could almost argue that torx should have been the standard in the first place, that way we would have no complaints. Obviously there are a lot of reasons why it wasn't the first bolt head invented. You try and make a T5 bolt on an anvil using just a hammer, tongs and maybe a punch - which you also have to make yourself. 

Remember that until about 130yrs ago, humans were literally just shaved monkeys. Now we're shaved monkeys that think we're smart as it only took a few tens of thousands of us a decade to put a shaved monkey on the moon once upon a time, and also make some really really big bangs. 
The evolution of fasteners has not really been amazing. At least we have coms to share the monkey-knowledge now.
The bolt is so low tech. Maybe some things can't be beat? I think the rivet is finally being superceded in a fair few applications.
That didn't take long! Lol.
Standardised range of camming + locking QR piv 'skewers'/'axles' (like maxle) might be nice. But they'd cost loads more, break more unless you made them bigger, require all sorts of design considerations. Only really help a few users that mess with pivs a lot. And they are the ones that can best handle the inadequacies of the ancient and worshipful monkey-bolt.


----------



## acer66 (Oct 13, 2010)

I would like to have to Torx screws all over my bike


----------



## Blaster1200 (Feb 20, 2004)

Ecogeek said:


> Lots of things on bikes seem designed to make home wrenching difficult. The more expensive the tool you need, the less likely you can do it yourself.
> But, let's not go there.
> Your complaint is not the best I've heard, as any cheapo bit-set should have a full compliment of torx bits. If not, eBay. Read up on the torx spec on wikipedia to find what side you need. You should have a digital caliper to measure with. #1 tool.
> Get caliper, measure, read, buy what you need.
> ...


What's your point?


----------



## m85476585 (Jun 7, 2007)

customfab said:


> The only thing we really need is for multi tools to have a T-30 and T-25 on them and your good to go. There are a few smaller torx fasteners on some things but your not going to need to bleed your Magura brakes trail side for instance.
> 
> I for one embrace torx but I completely understand your desire for common sizes.


My multi tool has T-25, and I don't have any T-30 fasteners on any of my bikes. I think my Avid bleed screws are T-10, but I hope I never have to do anything with those on the trail.
http://www.topeak.com/products/Tools/Mini9


----------



## nov0798 (Nov 27, 2005)

How often are you taking the rotor bolts off and on, or for that matter how often are you loosening and tightneing these items? I ride almost every day, keep my bike maintained, yet have never had an issue with any of the fasteners breaking, stripping, etc.


----------



## Trower (Apr 27, 2009)

There are alot of reasons to use Torx. They will torque down more without stripping than pretty much any other design. They also allow the bolt to ride closer to flush with the object without sacrificing strength of the bolt itself. The reason alot of Torx fail is A. Worn tools. B. Improper implementation of tools. C. And the Torx bolt being made of lesser quality metals, because the design of the Torx drive allows them to "cheep" out. 

I work in a CNC shop and alot of the tooling bolts are Torx for a reason, they don't stick out and they apply more torque. I mean you don't want it coming undone at 10k rpm:no:


----------



## nov0798 (Nov 27, 2005)

How does the shape of the drive mechanism(hex, torx, etc) of the head of a bolt apply more torque than another? 10 ft/lbs of torque is 10 ft/lbs of torque regardless of the shape of the head of the bolt. The amount of force applied is the same.

Again, are folks breaking or stripping these? I dont get it? If the proper torque, and tools are used you should never have a problem.


----------



## Trower (Apr 27, 2009)

nov0798 said:


> How does the shape of the drive mechanism(hex, torx, etc) of the head of a bolt apply more torque than another? 10 ft/lbs of torque is 10 ft/lbs of torque regardless of the shape of the head of the bolt. The amount of force applied is the same.
> 
> Again, are folks breaking or stripping these? I dont get it? If the proper torque, and tools are used you should never have a problem.


The Torx pattern has more surface area so more torque can be applied with less stress to the bolt. You have to seat the tool well, and if you don't you'll start to wear the bolt and then its all over, you can ruin the part and tool very easily if your not cautious. Also again Torx can often be made of crap metals which are easier to strip/damage.


----------



## gearwhine (Aug 20, 2009)

Actually...I have tried replacing the rotor torx bolts with hex a while...and realized that the T25 torx bolts for rotors (from avid and magura at least) are specially machined with a shoulder to help center the rotor. Basic bolts do not have this shoulder and are noticeably more loose before torquing them down. I ditched that idea and stuck with torx.

The non shouldered hex bolts conveniently became perfect water bottle boss bolts though.


----------



## Jvan_wert (Apr 8, 2007)

*In a pinch...*

Heck of a rant. Somthing I learned working on newer Chevy's, an allen wrench will work on a torx bolt in a pinch. Be warned there is a real good chance you'll strip that sucker if you are not really careful. Just a little something good to know when stuck on the side of the trail.


----------



## One Pivot (Nov 20, 2009)

Cheap torx tools are a bit better than cheap hex. Cheap hex tools fit just enough that you'll round out the fastener. Cheap torx either work fine, or they physically dont fit. 

I used to really not like torx for the same reason.. seemed unnecessary. Seemed like more crap I had to buy. Then again, whats the difference between a T25 vs 6mm hex, and a 6mm vs 7mm hex? Really nothing, they both mean I need to grab another tool. 

Theres nothing worse than working on something that uses 52 different headed fasteners, hex, torx, or any other standard. Chevy did a real poor job on this for a while, just made working on them a nightmare! On a bike, theres usually only a few metric hexes you need, and a T25. Its reasonable.


----------



## Cunha (Feb 23, 2011)

Small allens are the easiest things to strip of all time, torx is a lot better. 

I don't know about big stuff but if they are of equal quality it makes sense that larger torx is still much stronger than allens.


----------



## SnowMongoose (Feb 18, 2007)

It's really that hard to carry a single torx wrench?
Most multitools include one, I'm failing to see the difficulty.

Bonus points: I can't recall *ever* needing a torx wrench on the trail.


----------



## Blaster1200 (Feb 20, 2004)

SnowMongoose said:


> Bonus points: I can't recall *ever* needing a torx wrench on the trail.


I have, back in about 1999. I don't know how or why, but all of the rotor bolts holding one of the rotors were loose on my buddy's bike. They were Hayes brakes, but what was confusing is that Hayes bolts have threadlock on them. I'm guessing that my buddy simply never fully tightened them, and it went unnoticed until that ride. Fortunately, even some multi-tools even had Torx wrenches on them back then, and he was good to go within minutes.

The only other scenerio I could see for legitimately needing one on the trail may be for spoke replacement. Some epic rides I actually do carry spare spokes, but I've never needed them. And yes, I also have a cool little JA Stein cassette tool. This is usually to help out guys with crappy Mavic hubs at or near the point of complete lockup. http://www.jastein.com/Html/Tools_for_Wheels.htm


----------

