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As per title, I want to just get on and do it or is it wise to wait and buy the TR?
It depends on how hamfisted you are.
I have never used one to attach rotors and never had any rotor or hub failure.
I never use one for rotors. From memory the recommended torque for 6 bolt rotors is 2-3nm? That's tighten it up hand tight in my estimation.
Don't forget the blue threadlock.
I never bother. I might put a bit of loctite on if the blue dry stuff that's generally on them has disappeared. Firm nip as they aren't massive threads and you're good to go.
Never used a torque wrench, never used threadlock (aside what was already on the bolts new)
Yep, screw them in and nip them up, use blue threadlock and you should be fine (excepting any of the previously mentioned hamfistedness!).
Considering quite a few XC racers only use 3 of the 6 bolts I don't think you have to worry as much about them not being tight enough as much as going all Hulk with them and stripping the hub threads.!! 😉
Tighten them till they strip then back them off one.
2 dakdaks.
They aren't critical until you have a problem. But then they're also not much good for repairing threads so maybe you never need one?
Never been an issue.
I have a torque wrench. I’ve never used it for rotor bolts.
Just tighten until your elbow clicks.
I have a torque wrench. I’ve never used it for rotor bolts.
Likewise.
From memory the recommended torque for 6 bolt rotors is 2-3nm?
based on the size of the bolt I'd expect it to be more than that.
However, critical bit is threadlock - I've lost a few when they've not had it or not been tight enough
However, critical bit is threadlock – I’ve lost a few when they’ve not had it or not been tight enough
Should have used a torque wrench 😁
I use a multitool for stuff like this, pretty much impossible to overtighten and ruin the threads.
based on the size of the bolt I’d expect it to be more than that.
Yes, I was surprised by it too, but I recently read some Shimano rotor instructions (gripping read, highly recommended etc) and it is indeed 2-3Nm. That’s not even fully ‘hand tight’. Threadlock is important IMO.
I have a torque wrench, but don’t use it for rotor bolts.
I use a multitool for stuff like this, pretty much impossible to overtighten and ruin the threads.
Possibly, but it’s also a lot easier to inadvertently fold the tool and ruin a bolt. I use a torx-headed screwdriver.
2 dakdaks
Same, always use the impact gun for fitting and removal. It's just less tedious
It will need to be a really good wrench to be accurate that low. There's a fair amount of thread, I just go hand tight and use loctite.
Just set your T25 to mildly FT and ride
See the little torx key you get with some brakes (Avid and Clarks). As tight as you can get them with that.
Think we've had discs for 17 years (multiple bikes, multiple people) and never had a rotor bolt loosen (and never used fresh loctite if refitting bolts). But we aren't heavy or brake draggers so might be different experience for others.
If you are using a standard hex key set then it's pretty difficult to over-do the torque. That's why the keys generally get shorter as they get narrower. Similarly with a "standard"ish Torx key.
5.5nm on my centreline discs I think. I always use a torque wrench as I have one so why not. It’s not a lot though. I also tighten them in a diagonal sequence to minimise risk of warpage. I’m sure neither of these thins are essential but they don’t hurt either..!
I use a T25/allen key, use the long shaft end on the bolt, and make it finger-tight using the short shaft for reduced leverage.
I have never used one and I’ve never died. Not that I know of anyway. Perhaps I have abs this is an afterlife. Makes you think...
I have never used one to attach rotors and never had any rotor or hub failure.
This.
quite a few XC racers only use 3 of the 6 bolts
Only because they’ve stripped the other three, didn’t use a torque wrench😀
I got a torque wrench after my hope pro 4 hubs got cracks at the edge of some of the bolt holes. I must've over-tightened them but I don't think I did it a silly amount. I didn't get an expensive adjustable torque wrench, just a couple of pre-set ones for 5Nm & 6Nm, they cover most bolts on the bike.
thanks for the advice
More important is to tighten them evenly. I do every other bolt , then the remaining 3 in the same alternating order. This ensures all bolts are taking their share of the load and none will work loose.
I start off by hand (as in fingers) to make sure its threaded properly then switch to the drill set at very low torque on the clutch (2/10 on my makita) (if I'm at home)... then I pop round with a small hand wrench (TX or hex depending on bolts) or multitool and just nip them up. Sometimes if they are new with blue loktite the drill clutch won't go then I just use the hand tool... (rather than risk higher torque)
I have a torque wrench and use it often... just not on rotor bolts.
More important is to tighten them evenly. I do every other bolt , then the remaining 3 in the same alternating order. This ensures all bolts are taking their share of the load and none will work loose.
Not sure how important that is... but its the way I've always done it.. come to think of it I usually leave the first bolt slightly loose then 3rd/5th all to pre-nip.. then do opposites as I nip up
Interesting that Shimano recommend quite a low torque setting, however iirc the bolts come with threadlock and they also have those washers to stop them backing out.
quite a few XC racers only use 3 of the 6 bolts
I think I can safely say I will never be at the stage where the weight of 6 rotor bolts is going to make any difference.
Good tip I heard for the first time today though (after 15+ years of MTB). Rotor bolts and cleat bolts have the same tread pattern. So use a cleat bolt instead of one rotor bolt and then if you ever lose a cleat bolt mid spin (it happens) you have a replacement to hand.
I use a torque wrench because I have one and they are critical components. I never used to use one, never had them come loose. Obviously, use some commonsense about the size of the bolt and how tight to do them up.
I use a torque wrench to do a final check on rotor bolts. I got into the habit of checking all the bolts on my bike with a torque wrench after maintenance.
I'm a bit prone to rushing jobs so I find I'd leave the odd bolt a bit slack or whatever. Just the act of slowing down and systematically checking through the bolts really helps me do a good job consistently.
I don't think you need one for rotor bolts, the most likely errors resulting in death are under tightening or uneven tightening. You should be able to avoid those easy enough if you take care. As above, the torque is quite low on rotor bolts. A T25 screwdriver is a good idea to avoid over tightening.
Only tighten to FT rather than RFT.
I think I can safely say I will never be at the stage where the weight of 6 rotor bolts is going to make any difference.
It's about how long it takes to change a bent rotor
Good tip I heard for the first time today though (after 15+ years of MTB). Rotor bolts and cleat bolts have the same tread pattern. So use a cleat bolt instead of one rotor bolt and then if you ever lose a cleat bolt mid spin (it happens) you have a replacement to hand.
Yes someone did that for Mrs Kilo when she lost a cleat bolt on a race in Canada. The bolts are also the same size as bottle cage bosses so if your frame has random bosses you are not using you can stick a spare clear bolt in one
Good tip I heard for the first time today though (after 15+ years of MTB). Rotor bolts and cleat bolts have the same tread pattern. So use a cleat bolt instead of one rotor bolt and then if you ever lose a cleat bolt mid spin (it happens) you have a replacement to hand.
My touring bike has a couple of cleat bolts in the rack eyelets. Prob never need them but it's just an M5 bolt and cleat bolts are a specific shape as well as low profile for things like rotors.
From memory the recommended torque for 6 bolt rotors is 2-3nm?
Been tightening mine to hand tight all these years which is approx 6 Nm.
T25 magnusson chunky screwdriver gives the right torque for me, I check with a 5nm torque key but can always undo with the magnusson.
Just tighten until your elbow clicks.
This.
I use a multitool for stuff like this, pretty much impossible to overtighten and ruin the threads.
That's what you'd expect. I managed to break a seat clamp with my multi-tool! I now have and use a torque wrench for all my low setting bolts.
Rotor bolts - threadlock and a torque wrench.
Lets take a looksky are the path of the rotor bolts. Small circle and they all pass very close to the suspension fork leg(or carbon or whatever)
One rotor bolt wobbles, rattles out, and lets examine that then. Apparently industry uses this stuff called threadlock, but it does nothing whatsoever and they use it because it comes in a few different colours. Really ?, of course not. The invented the stuff because under vibration nuts,bolts and screws can vibrate out causing catastrophic damage to life and limb and the parts themselves.
So I think we can all agree that vibration causes bolts to loosen.
But we dont get such a thing on mountain bikes ?. You guys might ride smooth as silk but i bump and bash my way around.
So all in agreement vibration happens on mtbs, and vibration happens to fixings, causing them from hundreds of years of study to come loose and even fall out completely.
I've just measured the distance between the top of the dome headed torx bolt on the pro2 front wheel and the RS revelation fork and its about.... 5.5mm.
Length of a rotor bolt...I take it you see where this is going....about 13mm.
Vibrates out by half and it's a fond adieu to the left fork leg. Damage would be one hell of a scar. Whats a fork these days ? anything up to a grand.
Cost of threadlock ? £3
When you use a torque wrench at 5nm or whatever exactly it is, you can feel in your wrist that its actually not that tight, not in comparison with the torque and strength you can apply only with your wrist, but tight enough to hold it, and the threadlock keeps it there.
For anyone use to older steel stems, its in no way as tight as that.
A torque wrench is a nice addition to any tool kit, and doesnt have to cost the earth to do an adequate job. It is easy to get it as tight as it needs to be without a torque but its the threadlock that holds it in place.
I think a basic wrench is about £30 and a small tube of threadlock non permanent is a about 3 quid, call it a fiver. Total outlay-£35.prob $50US.
Cost of new fork leg ?, or entire fork.
Personally I feel its an important tool. Much of what we have is alloy, and while strong seems prone to cracking if overtightened, rendering it useless, or dangerous.
What speed is it you chaps do bouncing down hills ?, for something possibly horrendous to suddenly happen to the front wheel/fork.
Doesn't bear thinking about eh kids 😕 For 3 quid.
No devils advocate this time. You dont threadlock them in place you're an 4r5e.
Fair assessment ?.
most rechargeable drill/drivers have a torque setting for the screwdriver bit. Just stick a hex bit in the end and set torque appropriately (you may need to experiment with the first bolt). Then bang em all in in seconds, and all to the same torque! Easy peasy
Not at all critical :p
No devils advocate this time. You dont threadlock them in place you’re an 4r5e. Fair assessment ?.
"You're not wrong, Walter."
It was a bit aggressive but I agree completely re: threadlock. Not so much about the Torque wrench, though.
I'm gonna use that tip re: cleat bolts. A spare cleat bolt is one of the few remaining bits I haven't got sleekly secreted in/on my bike yet (Living the one-up EDC/strap life). Great tip!
[strong]dyna-ti[/strong] wrote:
I was trying to be humerus
More power to your elbow, I say.
OOPS. I never coulb sbell.