Shimano Hollowtech II Cranks - Stopper Plate

rothers_bikeo

What is the purpose of the stopper plate fitted to the left hand crank arm on Shimano Hollowtech II cranks ? i.e. as shown here:

http://techdocs.shimano.com/media/techdocs/content/cycle/SI/Ultegra/SI_1LJ0A/SI-1LJ0A-002-ENG_v1_m56577569830750016.pdf

gaspode

It locks into the groove on the axle as shown in the little picture at the bottom - I believe it ensures that the crank is positioned correctly on the crank.....

rothers_bikeo

mmmmm... I thought that as well but the crank arms have one wide tooth which fits into a wide groove in the axle so you can't put it on the wrong way even without the stopper plate.

Slow Downcp

I don't use Shimano so may be barking up the wrong tree, but doesn't it stop you overtightening the 5mm bolt?

ugo.santalucia

It serves the purpose of gently pushing the crank arm in the correct position on the axle. It's made of plastic, which suggests you only gently tighten it, before doing the crank bolts well tight. In an emergency, you can whack the crank arm in place without using it, as technically it is superfluous

gaspode

rothers_bikeo wrote:

mmmmm... I thought that as well but the crank arms have one wide tooth which fits into a wide groove in the axle so you can't put it on the wrong way even without the stopper plate.

sorry, when I said correct position, I meant that it makes sure that the crank is far enough onto the axle before you tighten the bolts (without the plate being engaged correctly in the groove, it would be possible for the crank to be too far away from the centre of the axle when the bolts are tightened - this could be fairly catastrophic as the crank could potentially fall off....)

keef66

That's what I thought. The little metal pin won't drop into it's slot if the crank isn't on far enough, and if the pin isn't in then you can't get both pinch bolts through it.

Highburton

I guess it's there to help prevent the pedal sliding off the crank. If it is then it's totally useless. I am now on my third replacement during which time |I have covered less than 100 miles. (I'm 70 and don't ride far) The only real solution is to "Locktite" the pedal on and pray that you won't need to get it off in a hurry.

crankycrank

That part is to prevent the left crank arm from coming off the spindle if the clamping bolts should come loose. Loosen up the bolts and try to pull off the crank arm and you'll see that it won't come off with the plate in place.

cooldad

Highburton wrote:

I guess it's there to help prevent the pedal sliding off the crank. If it is then it's totally useless. I am now on my third replacement during which time |I have covered less than 100 miles. (I'm 70 and don't ride far) The only real solution is to "Locktite" the pedal on and pray that you won't need to get it off in a hurry.

You resurrected a six year old thread to write total bollocks? Well done on both counts.

cooldad

crankycrank wrote:

That part is to prevent the left crank arm from coming off the spindle if the clamping bolts should come loose. Loosen up the bolts and try to pull off the crank arm and you'll see that it won't come off with the plate in place.

And I think the OP has lost interest by now.

svetty

cooldad wrote:

Highburton wrote:

I guess it's there to help prevent the pedal sliding off the crank. If it is then it's totally useless. I am now on my third replacement during which time |I have covered less than 100 miles. (I'm 70 and don't ride far) The only real solution is to "Locktite" the pedal on and pray that you won't need to get it off in a hurry.

You resurrected a six year old thread to write total ****? Well done on both counts.

And you've just bumped the thread to the top of the list.........errm...... :oops: