Hex vs Torx / standard vs security
 

I have a Surly LHT equipped as a trekking bike. It came with hex socket bolts. My rack came with Torx button cap bolts. I want a single standard type of fasteners.

I could get a couple of hex and replace the Torx. Or buy a bunch of Torx and replace the hex. And while at it, I could purchase the "security" variant of either type.

My inclination at this point would be to go with standard hex socket bolts all the way (I assume that a socket screw is easier to remove if stripped; that a hex bit is easier to find if you have lost your tools away from home, etc.). On the other hand, Torx is said to be less likely to strip and requiring less material to achieve the same strength as an hex, hence the button cap design. I also happen to have excellent security Torx bits, so...

What would you do?

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Update -- I went for regular socket cap hex all-the-way
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For what it is worth -- I ended up replacing the few Torx bolts supplied with the racks with socket cap hex fasteners. Paradoxically, I had made up my mind in favour of replacing hex fasteners with Torx, because the latter is supposedly superior. It is while taking stock of the screw inventory that I changed my mind. The main reason being that while Torx is theoretically a better interface (more positive grip, less likely to strip), it assumes that the driver is properly positioned and that (significant) downward pressure keeps the bit firmly in place. It became obvious that in practice Torx would be finicky in harder to reach locations (e.g. rear dropouts). For instance, it is not possible to use a Torx bit to hold a screw horizontally, something that is easy with hex sockets.

Even though button (rounded) caps might give a better appearance, a socket cap provides much more material to work with if the head were to become stripped (either the Dremel trick, or the ViseGrip trick).

I saw no compelling reason to bother with security variants of either type because it would have meant having to always carry a-typical bits. Murphy being who he is, someday, someplace a screw would have become loose, without it's exotic bit in my tool bag, because it's been lost in the dust, on in a puddle, somewhere far from the convenient-exotic-bit-store

I’ve also taken this opportunity to replace a few M5 that were using the smaller 3mm drive.

Hex bolts are pretty standard. It's easy to find in appropriate bolts to fit your rack, and there's a good chance those will also fit other things on the bike, so sparing is easy.

Specialty shops (e.g. Fastenal) will probably have all the Torx bolts you can wish for.

I don't know about security. It's easy to find multi-tools with hex wrenches. You can also walk into a good hardware store and walk out with a pile of Torx drivers. I think Sears has a Christmas pack of Torx drivers. How much security does that offer?

It's a simple case of do you want more convenience or a little more security with the "security torx" fasteners. As you mentioned hex sockets are easier to find, cheaper and much easier to find tools for and you can share your tools with other riders stranded on the road. As for torx, they will definitely provide a little more security and you can often use a torx wrench on some socket head screws in an emergency. Some thieves may carry "security torx" wrenches but most don't so it may be just the one occasion where you have to leave your bike in a questionable area and some dirtbag can't remove your parts. Most bike thieves are morons that own a few stolen tools which don't include a broad selection of specialty tools.

Security bolts require a hollow wrench to fit over the pin .. they're hard to find.
which is why they are more secure and a PITA for being where you do regular maintainence.

Torx Drywall screws are great (building supplies ) for power tools ..

This. I'm not a bike thief but I don't own a single security-torx bit. I suspect most people don't either, unless they specifically had to remove them from a product they owned.

An average idiot thief is unlikely to have these tools, giving you an advantage. If a professional bike thief comes across your bike and they want it, it will be Gone in 60 Seconds. No matter what kind of bolts you use.

I used to have a set of Torx security bits for a task I had to do at my previous employers. It wasn't that difficult to get them, about $20 if I recall. But I agree, it wouldn't be something that most casual thieves would think of bringing along. However if someone saw a coveted expensive bike with some nice parts they want, they wouldn't hesitate to go to a hardware store and get them.

I once worked at a big corporation, and they had us install these special snake eye security screws in the PCs because someone was stealing RAM from PCs (back when it was $400 a module). This slowed down the thefts but didn't stop them, we found out another common tool could be used to remove them.

Torx is for high-torque applications which only applies to bicycles in specific areas like brake rotors.

The only other place I've seen it make sense is aluminum fasteners like FSA chainring bolts; the extra surface area of the tool/fastener engagement helps to prevent stripping.

I'd stick with hex...

I agree that security TORX® fasteners will give some measure of theft deterrence. Nothing will stop a truly determined thief, but make it difficult or time-consuming enough and they will seek out easier pickings. These guys http://tamper-pruf-screws.com/ have a large assortment of fasteners and tools. If you want to take deterrence (and cost) to another level there are specialized theft-deterrent fastener systems like Pitlock https://www.pitlock.de/en

These folks offer small quantities of security screws (hex and Torx) in common sizes used on bikes. Here's a posted Torx up under my Persons leather saddle.

http://bikeforums.net/attachment.php...hmentid=485952

When I mentioned this before, I was assured the Emir of Qatar had dispatched a ninja team in a white van full of tools specifically to stalk, case and ultimately steal my hi-ten framed commuter bike. Whatever.

Not a bad idea for an expensive or broken in saddle! But then the post pinch bolt should be changed too.

The 1st problem with Torx generally is that it the shaping tolerances for both bit and fastener head need to be extremely tight.

The 2nd problem with Torx is economies of scale. Most bits and fasteners are made en masse to low machining standards, simply to improve the company bottom line and F the consumer, and consequently are not at all up to spec re: tolerances...which leads to...

Problem #3 ...premature wear of fasteners or bits or both.


If you use Torx...you have to use good quality fasteners and bits. It is a safe bet that your bit set in your $10USD Wally World toolcase that includes Torx is precisely the kind of thing I'm talking about. And in the FSA scenario you mention, I'd be skeptical of the FSA fasteners being up to spec either given FSA being a lower tier company typically used to save $$ by Bike Labels.

I am not that concerned with theft deterrence. I am looking for fasteners long-term performance and standardization.

Torx appears to be a superior alternative as long as one uses high quality bits (I use Wera). However, hex is the dominant standard and it is not clear that I could replace brakes' and shifters' hex with proper Torx, although I haven't really looked into it, yet. Still, it now looks like I'll change cage/rack/fender fasteners with Torx after all. And consider replacing component screws as well, if not components altogether (ZIPP stems and seatposts come with Torx)

One thing I think I have learned -- stainless steel fasteners and (cheap) alloy components (my stem to be specific) must be handled with extreme care. It took maybe 4-5 handlebars removal (travel related) to damage the stem clamp threads. Looks like you have to thread as if you were trying to break a safe...

I think you are over-thinking it.

I have those FSA fasteners on my bike and I use civilian-grade wrenches on them, and the world is still turning...

I always use an anti-seize like Tef-Gel, or at least a light application of grease to help avoid galling (to which stainless is prone) and electrolytic corrosion. A torque wrench is helpful for the heavy-handed among us. The aerospace business uses Helicoil inserts preemptively in aluminum parts with threaded holes to avoid thread damage from stainless fasteners.

It's not just to prevent damage from SS; steel to is stronger and less likely to strip.

Shimano does this on its Dura Ace clamp-on FDs...

Kershaw, makers of decent to great knives of all sorts will tell you the same exact thing. Many of their folding blades have Torx screws, and as they lifetime warranty their wares they warn people against cheap Torx bits as they have gotten tired of customers having issues due to their using cheap "tools" to do rudimentary home service.

You don't need to go and by a military-grade NIST certified driver set....Husky makes some good Torx hand drivers.

Understandable; those tiny fasteners need tiny bits so cheapos are not the way to go...

You're not going to round out a six point allen unless you're using the wrong size key; you won't strip it unless you cross thread it or over torque.

Security torx bolts and wrenches are ubiquitous...that argument is currently in about 1000 threads here.

Yes and no... I would agree with you if the bike is well maintained. But a couple of weeks ago the local coop mechanic told me about someone who couldn't figure what to do because fasteners has seized in the fork. The story doesn't say whether heads were stripped (I assume that they were), but googling on the topic of bike fasteners brings all sorts of stories, often involving aluminium, titanium or "cheese":)

Anyway -- I have concluded that hex was a better option. Have edited the OP to explain the rationale.

Thanks for opinions an information