[Sandwich]

ohhhh....i thought he was saying it was his rotor....but I see it says "a rotor"....

hard to tell what he meant, I assumed he was defending the three bolts and saying that running them makes it easier to swap when that happens...

 

[Kanye West]

I REALLY hope that people in this thread are joking about using Ti bolts with red loctite...or at least have the decency not to use that combo on a nice hub.

 

[jonKranked]

i think the e-spec is close to reaching critical mass...,

 

[IH8Rice]

I REALLY hope that people in this thread are joking about using Ti bolts with red loctite...or at least have the decency not to use that combo on a nice hub.

my guy at Tekbolt recommends only Blue Loctite on Ti bolts

 

[bdamschen]

i think the e-spec is close to reaching critical mass...,

Oh man, DON'T get this forum started on critical mass. The last thing I want to argue about is how many rotor bolts I should run to properly hold up traffic in an intersection.

 

[wood booger]

me neither...

here is a pic of a Formula rotor that completely wrapped under heat - snapped this pic after a shuttle un up in Ashland this summer:

Yeah, I forgot about the newer Formula rotors that are not joined near the mount points. I have already seen one completely destroyed (taking some of the caliper with it) due to running 3 bolts. Don't do it!!!

 

[DirtyMike]

Yeah in theory, except in practice they don't need that much torque, and torx heads suck in general thanks to a notoriously shallow head depth (especially on the button head screws used for rotors).

I have been running 3x Ti per rotor (red loctite, never had a loose bolt) for the last 4 years with no dramas. The only issue you run into is getting them back out again without wrecking the torx heads because the loctite is brutal, thankfully I've used the same hubs about that long as well.

I'd recommend loctite for people having them come loose, because in my experience, 3-4 bolts per rotor won't fail (given that they stay there), while an arbitrary number of tight bolts between 0 and 6 thanks to loosening would be quite dangerous.

Yeah I havent seen them fail, Ive seen the rotors warp up though. I wouldnt use red loctite on anything I want to come apart again though.

There are other loctites with more than adequeate<sp> holding power for this application.

I put everything on with a torque wrench, I am anal like that. I see what your syaing with the shallowness of a button head bolt, and fully agree with someone using a better quality bolt in the first place. Ti though? are you really saving much? Yeah its rotating, but its also center mass on the wheel so you really are not going to see a difference..... If ti for the fact the wont round off as easy... I will go with that, makes sense....

Good parts, and good tools go along ways, I always hear of people bitching they strip out the torx that comes with their brakes.... yeah well its a ****ty tool.


Overall, what reason other than being trendy would anyone not use all six bolts? I cant think of any reason other than that. A rotor is designed to use a six bolt mounting interface, you should use six bolts... if your lighter on the brakes you may not see the repricussion of not, but as they get hot it can allow for easier warping of the rotor....

 

[4130biker]

I actually have a friend, a lifer in the industry, who runs Torx for pretty much all of his bolts on his bike. Claims it was actually really cheap and easy to switch them all over, and never rounds out a bolt head.

How often do any of us round bolt heads on bikes?
Why not just switch the rotor bolts to socket head if you want the same throughout?
I'm not psyched on this new torx trend- just more uncommon wrenches to carry around.

Does anyone else miss uts (standard) bolts? I have a redneck with 1/4" socket heads and they are the most positive, perfect fitting allen bolts I've ever used.
Same with my profile cranks...

 

[Acadian]

Why so hard on the brakes? Lay off them a bit and you wont have this problem

actually that's not my bike pretty boy.

that's Wild Bill's bike (who runs Ashland Mountain Adventures), tell you what - he's twice your age and probably twice as fast as you.

After a long run on a hot summer day, we got to the bottom and he did a nose wheelie. after he jumped back on his bike, his front wheel didn't want to spin. this was the reason.

Oh and for the record I dont know how many bolts I run.

for some reason, I'm not surprised...

 

[DirtyMike]

How often do any of us round bolt heads on bikes?
Why not just switch the rotor bolts to socket head if you want the same throughout?
I'm not psyched on this new torx trend- just more uncommon wrenches to carry around.

Does anyone else miss uts (standard) bolts? I have a redneck with 1/4" socket heads and they are the most positive, perfect fitting allen bolts I've ever used.
Same with my profile cranks...

Because alot of hex head bolts wont clear the fork when used on a rotor, depending on the rotor/brake/fork combination

 

[4130biker]

Because alot of hex head bolts wont clear the fork when used on a rotor, depending on the rotor/brake/fork combination

You're right, most wouldn't work- I'm sure they exist, no?

But- in this case where it must be so shallow, I bet the torx is better. I was just arguing for no good reason that I'd rather have socket head than torx on everything, thats all.

 

[infamous24]

Let those who want to run less than 6 bolts do so. Something known as Darwin's Law will probably come in to play.

 

[Udi]

I REALLY hope that people in this thread are joking about using Ti bolts with red loctite...or at least have the decency not to use that combo on a nice hub.

If you use good tools and aren't a hack it's really not an issue hey...

Given sometimes that's not me, I found you can grab the head of the bolt in a vice and rotate the wheel around it.

There are other loctites with more than adequeate<sp> holding power for this application.

I agree, 222/242/blue is more than adequate here, but as I pointed out, I think (well at least for non-warptastic rotors) that less bolts might work just fine... but regardless of how many bolts you run, if they come loose it can be pretty dangerous.

Not suggesting that anyone else do it, but for me it means I don't ever have to check my rotor bolts unless I need to remove them. And when it comes to that, the solution is to use a good torx driver with ratchet fitting instead of one of those silly avid allen keys.

As for weight etc, I don't care that much, it's just from days when I did... and if it ain't broke...

 

[infamous24]

If you use good tools and aren't a hack it's really not an issue hey...

I don't think it's an issue of good tools. Red loctite needs heat to be removed. Combine that with the fact that titanium has a tendency to gall and those bolts could be stuck for good.

 

[Udi]

Yeah, except you're speaking in theory, and I'm speaking from experience.

Look - I didn't ask anyone else to do it. Just pointed out that it's how I've done things and it's been fine for 4 years. Replace red with blue and what I said still stands.

As for galling, I would say that running any loctite product on the threads will reduce that possibility greatly - and on the one occasion that I did remove those bolts, they were absolutely fine.

 

[Kanye West]

I don't think it's an issue of good tools. Red loctite needs heat to be removed. Combine that with the fact that titanium has a tendency to gall and those bolts could be stuck for good.

Exactly. I've seen LOTS of those with the heads just sheared off with the threads permanently stuck inside the hub. They don't work so hot with bolt extractors either because the Ti is so gummy.

 

[DirtyMike]

I don't think it's an issue of good tools. Red loctite needs heat to be removed. Combine that with the fact that titanium has a tendency to gall and those bolts could be stuck for good.

There is more than one red loctite you know.

In fact there are over 500 types of loctite......... Many MANY applications and uses.

UDI and I agree.... Good tools make all the difference. a quality tool used will help with the galling, and taking your time will help out more.



UDI.... I didnt quote you on the last, mainly cause I think we are agreeing on what we are thinking. FOr guys that are not hammertime on the brakes itll be ok, and from what you have had on your posts over time, I think we all know you keep up with your gear. I think we also agree that for the most part, its a fad that the mass's it really doesnt matter

 

[Udi]

Of course it's a fad / wank / whatever you want to call it. It's part of the fun for some people, and I'm happy to admit I'm one.

I just think it's funny that people want to call out darwin awards and wheelchairs for an issue that has no affect on the performance of a DH bike (or safety in my case, if something was going to fail, it would have by now), yet people are more than happy to run XT / gravity light cranks and single ply tyres.

I guess if it works for you, that's fine. This is what works for me.
And judging by acadian's pic, if you have rotors that aren't joined between the bolt holes, then you probably want to run 6 bolts too. I have the old gen formula rotors that are joined and they have been fine.

 

[Kanye West]

I will agree that the last gen Formula rotors are pretty burly. I run those with my Saints and never have any serious warping or rotor singing.

3 bolts installed securely and properly will beat 6 bolts installed half-assed, but neither of those will beat the available 6 bolts installed properly, and for all of a red Irish cvnt hair of weight savings is just asinine unless you're trying to top 10 a WC.

 

[pillete]

I have been running 3 bolts on all my DH bikes for over 7 years, and never had an issue.
I run only 3 bolts just because I got tired of hitting my rotors and bending them all the time. With 3 bolts the rotors have a little more room to flex sideways, and not bend. However it does require to check them more often, and I also replace them twice every season, just to be on the safe side.
Does anybody else do it because of this reason, or is it only me?

 

[Kanye West]

That's the first I've ever heard of someone doing that for the purpose of LESS rotor warping. Interesting idea though. I'd be really interested to see some data to substantiate that one way or another.

 

[yuroshek]

actually that's not my bike pretty boy.

that's Wild Bill's bike (who runs Ashland Mountain Adventures), tell you what - he's twice your age and probably twice as fast as you.

After a long run on a hot summer day, we got to the bottom and he did a nose wheelie. after he jumped back on his bike, his front wheel didn't want to spin. this was the reason.



for some reason, I'm not surprised...

Hey relax I know your not a squid, I was just trying to have fun. Why so defensive? And the reason why I dont know how many rotor bolts I have on my DH bike is because I havent touched it since the end of october, and quite frankly does it matter how many rotor bolts people run? I dont care that much If I have 3, 4 or 6 rotor bolts, theres bigger stuff to worry about then that.

 

[Sandwich]

yeah really, like how much yaw ya got and whether you got enough shimz and whether your suspension has the correct ratio of patentz to travel, and whether trek or DW or bradflyn has the rights to market over/under specific TP.

 

[SthFRider]

yeah really, like how much yaw ya got and whether you got enough shimz and whether your suspension has the correct ratio of patentz to travel, and whether trek or DW or bradflyn has the rights to market over/under specific TP.

agreed. hahahaha

 

[infamous24]

There is more than one red loctite you know.

In fact there are over 500 types of loctite......... Many MANY applications and uses.

UDI and I agree.... Good tools make all the difference. a quality tool used will help with the galling, and taking your time will help out more.



UDI.... I didnt quote you on the last, mainly cause I think we are agreeing on what we are thinking. FOr guys that are not hammertime on the brakes itll be ok, and from what you have had on your posts over time, I think we all know you keep up with your gear. I think we also agree that for the most part, its a fad that the mass's it really doesnt matter

Yeah there are something like four types of red loctite. All of them are "permanent" and require heat to remove.

The argument about single ply tires and gravity light cranks doesn't make sense. Rotors are designed to run with 6 bolts for a reason. Unless you know the factor of safety on the rotor, you're just taking an unnecessary risk imo.

 

[Udi]

Get off your high horse mate.

They don't "require" heat to remove, it just makes it easier. I've used the product (262) many times for stubborn bolts that come loose even with blue loctite (lower shock pin in sunday for example). They come undone with just an allen key.

I clearly stated that I wasn't asking anyone else to try it - and that it had worked for me for many years. In that respect I disagree with you that it's a risk, because my experience has shown that it works just fine.

Your argument of "designed for a reason" goes against most of the discussion that happens on these forums. Suspension dampers are also designed and tuned the way they are for a reason, very lightly valved compression and heavier rebound most likely for safety and liability reasons. Yet world cup configurations are valved much more firmly.

Plenty of frames in the 2008-2009 era were designed with 65-66 headtube angles, yet many people jumped on the slacker reducer cups. The frames were not "designed" to run these, they would very likely place more stress on the headtube (not a pleasant failure), yet in practice this mod has worked just fine for myself and many others.

Manufacturers are just trying to save themselves from getting sued, doesn't mean that you can't take something they have come up with, and mod/change it within the limits of safety.

I more than happily admitted it was a wank to be saving weight in the region being discussed, but that's not to say it's not possible, and that's not to say it doesn't work just fine.

 

[infamous24]

It's your choice to run them. I have an opinion as do you. Go ahead and run them that way, it's your choice.

Your argument against "designed for a reason" is irrelevant. Tuning suspension dampers and altering head angles is a little bit different than running rotors with half the bolts in them. Tuning suspension does not effect its strength. And if you have any knowledge of basic engineering principles, altering the head angle by a couple degrees places only places a little additional stress on the headtube. The length of the moment arm would increase by maybe 2 inches.

You also mention modifying things "within the limit of safety." Do you know what the factor of safety on the rotor bolts is? If not, then how do you know its "within the limit of safety"? And don't forget that just because it hasn't failed yet doesn't mean it can't.

I know you are pretty skilled at working on bikes (seen some of the other threads/mods you've done), but this one just doesn't make sense.

 

[IH8Rice]

I clearly stated that I wasn't asking anyone else to try it - and that it had worked for me for many years. In that respect I disagree with you that it's a risk, because my experience has shown that it works just fine.

thats a pretty bad argument.

 

[Udi]

Show me one case of rotor bolt failure from shear alone. Given five pages of discussion, and no doubt a myriad of grades and qualities of titanium and steel used in bolts, I still haven't read about a single case of bolt shear in use.

I can show you plenty of broken headtubes. Food for thought.

 

[IH8Rice]

im not saying its anymore dangerous. i ran 4 bolts on my front hub for years w/ no problems since thats how the hub was designed.

im saying your argument that just because it hasnt happened to you, doesnt make it a fact.

 

[yuroshek]

damn!! only on RM will the correct number of rotor bolts piss people off so much. touchy subjuct? yes.

 

[DirtyMike]

Yeah there are something like four types of red loctite. All of them are "permanent" and require heat to remove.

The argument about single ply tires and gravity light cranks doesn't make sense. Rotors are designed to run with 6 bolts for a reason. Unless you know the factor of safety on the rotor, you're just taking an unnecessary risk imo.

First.... only one of the red loctites will actually "require" heat to remove. If you need heat for the other three.... your using too much.

I didnt argue about the gravity light cranks or single ply tires.... but that is a relevant point, some people the lighter, not as tough stuff works well with there riding style and terrain, personally, I destroy GL cranks, and 2 ply or single ply for me.... depends on what tire, and were I am riding. Noone can argue that tire selection is more about terrain than anything else.


Oh and to repeat myself.... I use six bolts. I look at it like this... maybe three will be fine, but six are available, and I will take the extra clamping force. I will also only use a steel or Ptoper Ti bolt for my brakes.





On the note of your arguement that changng the headtube angle is a minimal effect on the bike.... try again, a degree or two can increase the stress on the frame immensly. No I dont have numbers to back it up, BUT its a parabolic curve, the further you go, the more change per degree... IE... going from a 70 degree HTA to a 68 HTA... wont be adding near as much stress as going from a 65 to a 64...... No enineering needed there, thats just simple udnerstanding of how a lever works.

Show me one case of rotor bolt failure from shear alone. Given five pages of discussion, and no doubt a myriad of grades and qualities of titanium and steel used in bolts, I still haven't read about a single case of bolt shear in use.

I can show you plenty of broken headtubes. Food for thought.

Only time I have seen a sheered rotor bolt..... One of the local pros was running the wrong allow bolt, and was only running three..... Personally I file that under the wrong application over only having three bolts.... I dont belive that the alloy bolts in question would have held up even if he had all six

 

[infamous24]

Show me one case of rotor bolt failure from shear alone. Given five pages of discussion, and no doubt a myriad of grades and qualities of titanium and steel used in bolts, I still haven't read about a single case of bolt shear in use.

I can show you plenty of broken headtubes. Food for thought.

Maybe the reason you don't see it happen is that most people find it reasonable and sensible to run all 6 bolts. Food for thought.

I'm sure you could show me plenty of broken head tubes. Could you also tell me definitively how it broke? What if it was from running too long a fork on the bike, or a headset pressed in improperly damaged it?

And you honestly thinking five pages of discussion in one thread, on one forum is all inclusive? Give me a break. You haven't read about it here because maybe 30 people have chimed in on this thread. I'll go out on a limb here and say that more than 30 people ride downhill.

You know what I did see in these 5 pages though? A rotor failure from running less than 6 bolts.

 

[freeridefool]

actually that's not my bike pretty boy.

that's Wild Bill's bike (who runs Ashland Mountain Adventures), tell you what - he's twice your age and probably twice as fast as you.

After a long run on a hot summer day, we got to the bottom and he did a nose wheelie. after he jumped back on his bike, his front wheel didn't want to spin. this was the reason.

I know Bill and he isnt all that fast. And nothing on Mt. A or anywhere in ashland is long enough or steep enough to warrant getting your brakes that hot. But Bill is a great guy.

You can really tell its the off season when we have a 5 page thread about rotor bolts. I want the world cup back.

 

[DirtyMike]

Oh yeah.... I want my knee back, my sternum back, both my wrists, and my calf muscle..... but much like the WC's I have to wait too!!!

 

[Udi]

I have an opinion as do you.

And that's all they are. Until you perform an analysis that suggests that 3 bolts are inadequate (which would indeed be more valuable than my opinion, or yours), an analysis beyond simply saying "the manufacturer did it for a reason", then I don't really think you have the right to suggest people will end up in wheelchairs. Of course I don't want to be held responsible for that, which is why I didn't suggest anyone try it either. But plenty of people have and I'm yet to hear of a failure.

And if you have any knowledge of basic engineering principles, altering the head angle by a couple degrees places only places a little additional stress on the headtube. The length of the moment arm would increase by maybe 2 inches.

Headtubes seem perfectly happy to crack and fail with ZERO additional stress on them, so you suggesting it is safer to run slacker cups than less rotor bolts is absurd. All these changes are risks whether you like it or not, riding DH isn't exactly lawn bowls in the first place.

You also mention modifying things "within the limit of safety." Do you know what the factor of safety on the rotor bolts is? If not, then how do you know its "within the limit of safety"? And don't forget that just because it hasn't failed yet doesn't mean it can't.

Again as above, how do you know what isn't "within the limit of safety"? What is the fatigue life of bolts when running 6, 4, or 3? Sure 6 is better than 3, but for example if 6 bolts take 20 years to fail and 3 bolts take 10, who cares?

There are plenty of people running bolts without loctite, and plenty of cases of bolts loosening. Is that safe? I suggested loctite because I have seen this "method" of failure many times compared to bolt shear which I have never seen. But you want to pick a fight about that as well - red vs blue, big deal.

You know what I did see in these 5 pages though? A rotor failure from running less than 6 bolts.

Jumping aboard your ship, how do you know it's not the rotor design that caused failure? It's the first rotor I've seen that is not joined between the bolt holes, I think common sense would point to using all 6 bolts in that case. Even then, who's to say the rotor wouldn't have failed anyway?

im not saying its anymore dangerous. i ran 4 bolts on my front hub for years w/ no problems since thats how the hub was designed.
im saying your argument that just because it hasnt happened to you, doesnt make it a fact.

I didn't claim it as fact, I just suggested that my experience was sufficient for me to consider it safe. Just like you apparently consider 4 bolts safe.

 

[infamous24]

First.... only one of the red loctites will actually "require" heat to remove. If you need heat for the other three.... your using too much.

I didnt argue about the gravity light cranks or single ply tires.... but that is a relevant point, some people the lighter, not as tough stuff works well with there riding style and terrain, personally, I destroy GL cranks, and 2 ply or single ply for me.... depends on what tire, and were I am riding. Noone can argue that tire selection is more about terrain than anything else.


Oh and to repeat myself.... I use six bolts. I look at it like this... maybe three will be fine, but six are available, and I will take the extra clamping force. I will also only use a steel or Ptoper Ti bolt for my brakes.





On the note of your arguement that changng the headtube angle is a minimal effect on the bike.... try again, a degree or two can increase the stress on the frame immensly. No I dont have numbers to back it up, BUT its a parabolic curve, the further you go, the more change per degree... IE... going from a 70 degree HTA to a 68 HTA... wont be adding near as much stress as going from a 65 to a 64...... No enineering needed there, thats just simple udnerstanding of how a lever works.


Only time I have seen a sheered rotor bolt..... One of the local pros was running the wrong allow bolt, and was only running three..... Personally I file that under the wrong application over only having three bolts.... I dont belive that the alloy bolts in question would have held up even if he had all six

I have some quick numbers for you. So let's use a 2009 Boxxer, which has an axle to crown length of 568mm. For a 65 degree HA, the length of the moment arm (lever) is 240.0mm (568cos65). For a 64 degree HA, the length of the moment arm would be 249.0mm. Lets say a 1000 pound upward force was generated at the axle. The resulting change in torque is 2 percent. This is simplified, but it proves my point.

 

[infamous24]

This thread is getting out of hand; we're just arguing about opinions here and no one is going to win. Let's just move on.

 

[Udi]

Agreed.

 

[DirtyMike]

I have some quick numbers for you. So let's use a 2009 Boxxer, which has an axle to crown length of 568mm. For a 65 degree HA, the length of the moment arm (lever) is 240.0mm (568cos65). For a 64 degree HA, the length of the moment arm would be 249.0mm. Lets say a 1000 pound upward force was generated at the axle. The resulting change in torque is 2 percent. This is simplified, but it proves my point.

My point was that its not a steady 2 percent increase in torque on the HT per degree of change in HTA. the further slack you go, the more per degree your going to get.



I do belive that it was decided along time ago in this thread though, that six works better, and that is obvious to engineers and non engineers..... Fact is though, that some people less works fine and is well within the limits of safety.