Installing cranks

get a torque wrench or borrow one, tighten to correct torque, forget about it.

not necessarily. The left crank arm falling off is a nice indication of a problem. Id bet on you having to get new crank arm/s or possible a new BB. The problem occurs when you dont tighten it up in the first place and it has play, which with all the stresses on it wears out the threading or the bb.

but dont ov ertighten as you can damage the bb. it probably best to get a torque wrench and do it properly. I personally just tighten it up nice and hard but not to the point where i am forcing serious strength into it.

Just get new cranks and BB if the ones you have aren't mega expensive.

Something like that is more trouble than it's worth.

not necessarily. The left crank arm falling off is a nice indication of a problem. Id bet on you having to get new crank arm/s or possible a new BB. The problem occurs when you dont tighten it up in the first place and it has play, which with all the stresses on it wears out the threading or the bb.

my advice was more for when installing cranks initially. his are probably fwucked.

my advice was more for when installing cranks initially. his are probably fwucked.

yeah, you're right. good advice on the tool, i'll get hold of one and fit the replacements properly next time. there were not expensive components though i'm not strapped for cash so is expensive for me to buy twice :( one lives and learns....

if you need a torque wrench i have one that does 20Nm-80Nm that you can borrow.

Loctite or some other thread sealer is a good idea, too. Or you can use the bolts that have a nylon "friction patch" running down the shank of the bolt.

You cant really beat having a torque wrench of course, but if you install them 'pretty tight'. Then tighten out the slack when the crank arm works its way up the BB spindle due to the force from the bolt (this made occur two or three times). You should be sorted.

Sounds like you installed them correctly but did'nt take out the slack that developed, before the cranks had a chance to wear, due to the play availible.

Another crank installing question. I bought a new bb ive installed it and when putting the cranks onto i cannot get them onto the bb spindle all the way so my chain line is slightly off, any ideas of how to get them to sit further up the bb spindle?

sounds like you bought the wrong BB mate

Its exactly the same size as my old one 68mm shell 122.5mm width square taper etc. just the cranks need to go on maybe 5mm more.

my cranks are shimano and jis taper i assume,the bb is rpm (fsa) anyone know wether that will be jis or iso?

FSA will be JIS also.

Strange...

are you using a torque wrench

yeh i did a little search and found that fsa was jis, and yeah im using a torque wrench. I was thinking of using a g clamp to try and push them on further???