i was torquing up my new IMA triple clamps the other day. there was no documentation at all with them when they arrived so i looked at the Ducati manual and it states something like 24Nm. i set my torque wrench to 20 to be on the safe side as it is a cheaper wrench. i didn't get near the click before i didn't like the way it was feeling. anyone that's stripped a thread will know that soft feeling a bolt can get just before it happens. so i stopped, re checked the manual and sure enough it is what i read the first time.
my brother came home and saw what i was doing and he agreed what i had read and that these triples should handle factory specs. he grabbed the wrench and decided to feel it and proceeded to torque it further. i voiced i wasn't feeling good about that and he undone the bolt in question and sure enough out comes some swarf. but it was quite a large piece, larger than i would expect from stripping a bolt of that size. probably an m8/m10 bolt from memory.
i did notice bits of swarf around the clamp opening too. heres to hoping it was left over from when they triples were bored to a larger diameter!!
i asked IMA about what torque settings they recommend and they replied 7Nm bottom and 5Nm top!! these numbers seem very low to me. i told them i have gone further and the reply was "I don't believe you could have any damage on threads, but it would be the forks doesn't works well....Threads and screws are able to bear greater efforts."
what are your thoughts,
can 24Nm clamping force do damage to forks? bear in mind i haven't ridden the bike yet.
would 18-20Nm on a m10 bolt likely strip a billet alloy triple? i will get the torch out and have a look when i get home but i doubt i can see much as it is quite inset. ill also play with the bolt a little and see if there is any excessive play in it now..
Cheers Clint
http://www.cncexpo.com/MetricBoltTorque.aspx (http://www.cncexpo.com/MetricBoltTorque.aspx)
You are right at the limit for an 8mm 8.8 hard bolt. If it is 8mm 10.9 hard, not even close. Having said that, most torque wrenches are notoriously inaccurate at low settings. The cheaper they are, the worse it gets. I would not think you could damage the forks at that setting though.
Clint, I have an IMA Model 2 and torqued the bolts to 24Nm. I got that figure from Patrick at IMA and it seems to be be working fine. I do the 1-2-1-2 and 1-2-3-1-2-3 sequence when tightening.
Quote from: 64duc on May 24, 2011, 04:59:36 AM
http://www.cncexpo.com/MetricBoltTorque.aspx (http://www.cncexpo.com/MetricBoltTorque.aspx)
You are right at the limit for an 8mm 8.8 hard bolt. If it is 8mm 10.9 hard, not even close. Having said that, most torque wrenches are notoriously inaccurate at low settings. The cheaper they are, the worse it gets. I would not think you could damage the forks at that setting though.
even further from the max considering they are cap screws.. but i would have thought the limit of the material the bolt is threading to would be more the limiting factor. thanks for the link mate
i undid and re torqued them to the 7 and 5 that patrick told me and they seemed fine. tho it does seem a very low figure torque setting.
Quote from: battlecry on May 24, 2011, 06:10:21 AM
Clint, I have an IMA Model 2 and torqued the bolts to 24Nm. I got that figure from Patrick at IMA and it seems to be be working fine. I do the 1-2-1-2 and 1-2-3-1-2-3 sequence when tightening.
strange that we get such different torque settings from the same guy!?!?
Yes! Ducati specced different torques for the upper (24Nm) and the lower (20), plus the middle column (23) and the handlebar (20). I emailed them all to Patrick and he emailed back to do them all at 24Nm. Which is probably based on the strenght of the materials and a need to stretch the fastener.
That was in Feb of this year. Maybe they know more now??
May I suggest that you use some threadlocker compound and paintstripe those bolts if you want to run them at 5-7Nm?
the bolts came lubed so i dont imagine they want thread locker on them. heres the earlier response.
"Hello Clint,
bolt recommended torque is 5,5 Nm for your upper Mod.4 and 7 Nm for your
lower Mod.2 with grease (I've already put grease).
I don't know torque for stem ferrules, you should ask to manufacturer of
bike.
It's all right for the rest?
I wait for pictures, thank you
Patrick"
ill send him another email to just confirm..
is there anyone that has speedymoto or some other brand billet triples that can give their specified torque rating for?
the torque rating is for the bolt not for the triple.
What kind of bolt are you using? (material, size?)
for bolts of that nature (as in the area it is used for) i almost always do it by hand with thread locker. You get a feel for how tight something should be. Torque values that low require a very high quality torque wrench and a torque wrench that is only designed for those low values (which in US are sometimes measured in inch-pounds instead). Otherwise use your hand and muscle memory + threadlocker.
http://www.imasrl.com/index.php?option=com_content&view=article&id=7&Itemid=7&lang=en (http://www.imasrl.com/index.php?option=com_content&view=article&id=7&Itemid=7&lang=en)
this lists the 5.5Nm and 7Nm for the relevant triples.. and with grease only
did they supply the bolts?
I should have to mention that if you use a bolt that is stronger than the material its being threaded to, yes the bolt can take more force, but the material itself cannot. Such as steel bolt on aluminum. the stock bolt is aluminum. but the stock bolt might not be the same size.
however, the recommended torque is usually well below that of failure anyway...
you can defintely hurt the forks if you over tighten them, but i dont think 24nm is enough.
the stock triple bolts dont appear to be aluminium... id be very surprised if they are!
the IMA triples have steel cap screws going into billet alloy of unknown grade. im 100% sure the bolt could pull the thread out of the triple trees if i tried.
im happy to follow the websites and Patricks recommendation of 5.5 and 7Nm with no threadlock. ill keep an eye on them tho.