I find tightening my crank you dont get a feel about it . It just stops dead if you know what i mean . My torque tool doesent go high enough it's never loosened though.
Ah lake garden hired a non ebike there once dumped at top with van and down hill all the way through tunnel at the end brilliant
Hmm, trying to work out where you would do a dropoff with a tunnel at the end. there are loads of tunnels, Tremalzo then from Pregasina through the tunnel instead of the trail perhaps? It was the Tremalzo trail well before Pregasina where I lost the bolt.
Tremalso rings a bell Tunnels and road in James Bond movie
i had to tighten mine and a was surprised how tight 30nm was when it was on the stand, ideally you need to have 3 arms, two to hold the torque wrench and one to hold the none drive side crank. I’ve only had the bike out once since I torqued it back up, 20 miles ish, and it’s not budged.
Bugger. What poor shop maintenance caused that?
With grease on the threads there is much more force applied to the threads at the same torque setting! I'd try to clean it all out by twisting a small piece of rag soaked in petrol (wear gloves) through the threaded holes. Clean the bolts too. Keep using little bits of clean rag till they don't show grease any more. Same with the bolts. Then loctite when all dry.
Isn't that the whole point of greasing threads? The grease helps you reach the proper torque. Dry threads have too much friction and can trip the torque wrench before the proper torque at the bolt head has been reached. Loctite performs the same function as grease in that it helps reach the proper torque. Until it sets of course. My rule of thumb is to loctite the bolts that should have it, and grease all the others.
For sure. There's a bit of a theme going on here though with crank arms coming loose. The same thing is happening over in the shimano forum. I agree with you - I either lube or use loctite; with these I'd use loctite. I'm also going to clean the ends of the crank shaft and crank arms and use some contact adhesive. I used to do that with square taper cranks - I could always get them off, but they never came loose. You can actually over tighten using grease at the same torque setting! I did with teflon tape on a car sump - I kept breaking the fibre washers with minimal effort. Now I just snug them. I imagine you could actually strip a thread esp in aluminium.
I torqued mine up good, but after reading this thread I'm going to check them again sooner rather than later. If I find them loose I'll do the same, Clean them off and apply loctite instead of grease.
Must be something wrong somewhere, never had issues like that can't see why e bike should be any different from an ordinary bike. Heard of problems on ordinary bikes as well with that , never had a problem and I pedal strike as much as anyone if doing technical stuff. Never heard of torque values before ebikes came on go . I'm not really mechanical but mtb since 86 hopefully I've picked up something along the way.
For sure, that's the theory. Use grease and a greater force is applied to the threads. Don't use grease and less force is applied to the threads. Both these examples would show the same torque setting on your tool. As I found with the teflon tape though, you can easily apply too much force, despite what the torque wrench is telling you. Threads, especially in aluminium, have limits too.
If you use grease, you're actually applying a lot more torque to the threads. I often wondered about this - where are the torque values measured? Lubricated or not lubricated?
the torque value relates to the thread pitch, bolt size, and bolt material. The engineering specification is tabled and primarilly sets a figure where the greatest friction is achieved between male and female thread faces whilst staying within the shear limits for that bolt size and material. Lubricating a fixing ensures the friction along its complete length does not lead to a false ( usually under) torque being applied. When the correct torque is applied the grease is displaced in the mating faces of the male and female thread but remains in place above those faces providing some protection against corrosion etc.
