Any issues with shimano 8000 motors throwing cranks !

[Dan63]

It's worth noting that the plastic bolt is not the primary method of retention here. It is the pinch bolts which clamp the crank down onto the spline that does all the work. If they're tightened correctly they should not come loose and the plastic(or alloy) bolt should not even come into play.

I recently swapped cranks, i have tensioned the pinch bolts to 13nm and checked/re-tensioned after a short ride and then again after each ride until i was no longer getting any any movement from the bolt before the tension wrench clicked off.

Various factors will cause the pinch bolts to lose some tension after the cranks are installed, the components will settle in after some riding and the bolts may "stretch" a little as well. I think it is important to check the bolts and tighten a several times to ensure they stay nice and snug.

 

[Gary]

Try reading the whole thread Dan

 

[urastus]

I've got 1300km up and no issues. I did remove the right crank to fit a new chain ring. All the youtube videos show greasing the end of the axle before putting the crank on - I don't understand why - I wonder if they know why? I cleaned everything with iso. I always use loktite and I did use the tension wrench - so should be good. Thanks for the heads up - I might do some preventative maintenance on the left crank

There is a theory for greasing the threads of some bolts - they do up tighter at the same tension.

 

[MrBrownstone]

In over 2900 miles my right crank arm came off once about 1000 miles ago ruining the threaded plastic cap. Got a new cap, greased everything up, tightened everything up super snug and haven’t had the problem again. Now I check the snugness of everything from time to time.

 

[HORSPWR]

Try reading the whole thread Dan

Pretty sure his comment is thread related as opposed to yours, if you need alloy caps to hold them on then you're doing something wrong just like Dan stated!

 

[Gary]

Pretty sure his comment is thread related as opposed to yours

Yeah, and from your input here I'm pretty sure you have very little actual experience of the issue we're talking about nevermind understanding of why it happens.
Re-read my earlier comments on page one describing why it happens and why Alloy caps help.,

if you need alloy caps to hold them on then you're doing something wrong just like Dan stated!

Then why a year ago on this very thread did you ask my advice on which alloy caps to buy and then buy a set yourself?

 

[HORSPWR]

Yeah, and from your input here I'm pretty sure you have very little actual experience of the issue we're talking about nevermind understanding of why it happens.
Re-read my earlier comments on page one describing why it happens and why Alloy caps help.,


Then why a year ago on this very thread did you ask my advice on which alloy caps to buy and then buy a set yourself?

I only ever wanted them for bling factor, to this day they have never been fitted and I've swapped out 3 sets of cranks!
Why have they never been fitted...because with my mechanical engineering degree I decide to compare them to the original plastic Shimano ones and found that the aluminium ones have a shoulder on them that is larger than the genuine plastic ones have. When the crank arm uses the pinch bolts to clamp the crank arm to the shaft I could see that the crank arm would try and tighten to the aluminium shoulder before it allows clamping to the shaft.

I know heaps have fitted these aluminium caps and if you use enough Loctite you can get anything to stay put but I'd rather have my cranks correctly clamped the shaft and not clamped to the Loctited aluminium cap.

 

[Gary]

because with my mechanical engineering degree

I don't care if you have a gold star from MacDonnalds mate.
The arms clamping that tiny soft Aluminium lip you've described actually stops the cap bolts from rotating loose and doesn't affect the Aluminium crank arms connection to the harder steel axle spline. Seems odd someone with your engineering excellence wouldn't have thought of this. But even odder that you'd put your trust in weak Miranda crank arms over Shimanos or purchase cheap chinese components for "bling factor"
You still don't seem to have read and understood the reason I gave for the cranks actually ejecting so please stop trying to WIN an internet arguement about a solution to an issue you have no actual experience of.
.

 

[HORSPWR]

I don't care if you have a gold star from MacDonnalds mate.
The arms clamping that tiny soft Aluminium lip you've described actually stops the cap bolts from rotating loose and doesn't affect the Aluminium crank arms connection to the harder steel axle spline. Seems odd someone with your engineering excellence wouldn't have thought of this. But even odder that you'd put your trust in weak Miranda crank arms over Shimanos or purchase cheap chinese components for "bling factor"
You still don't seem to have read and understood the reason I gave for the cranks actually ejecting so please stop trying to WIN an internet arguement about a solution to an issue you have no actual experience of.
.

Who cares if the aluminium caps come off, you’re such a tool. The caps aren’t even needed on an ebike, you can take them out and throw them away!

Now your a metallurgist too, you’ve done lab tests on Miranda cranks and Shimano ones excellent work.

So you’re knocking cheap Chinese components for bling factor but you’re installing them to keep your cranks on?

I’m not going to argue with this idiot anymore you’ll only try and drag me down to your level!

Plus I don’t eat Maccas but I bet it’s a daily essential for you.

 

[Gary]

I’m not going to argue with this idiot anymore you’ll only try and drag me down to your level!

No one asked you to argue. But don't worry, desperately sniping away missing the mark with your pointless inexperienced input and resorting to insults when you're proven wrong puts you firmly below idiot level already in my eyes.
Enjoy the rest of your weekend .

 

[HORSPWR]

No one asked you to argue. But don't worry, desperately sniping away missing the mark with your pointless inexperienced input and resorting to insults when you're proven wrong puts you firmly below idiot level already in my eyes.
Enjoy the rest of your weekend .

Proven wrong?
Even you know that those caps are purely for preload on a standard bike crank and don't even serve any purpose on an ebike except to fill in the blank space!

 

[Gary]

Still desperately trying to win a tiny slice of an argument no one is even having?

It's quite sad.

 

[HORSPWR]

Still desperately trying to win a tiny slice of an argument no one is even having?

It's quite sad.

Not trying to win an argument, I just can't believe the shit that comes out of your mouth sometimes, that's all!

 

[Spiff]

Still desperately trying to win a tiny slice of an argument no one is even having? It's quite sad.

Not trying to win an argument, I just can't believe the shit that comes out of your mouth sometimes, that's all!

Come on guys (both), grow up!! Do not waste our time having to read your...whatever.

I know I am risking both of you joining forces to attack me, but what the f., I like to live dangerously.

 

[urastus]

I still haven't done preventative maintenance on mine. I'm going to clean the splines on crank and crank arms. Then I'm going to put a drizzle of contact cement (quick grip) around the spline on the crank and put them together. Loctite on the the bolts and torque them normally. Quick grip is pretty safe - can always get things undone. I used to do this with square taper cranks - they never came loose. It also prevents wear and movement.

 

[Lordhanson]

So luckily stumbled upon this thread. My Shimano e8000 throwing cranks. Last time on Friday as I was 13 miles from home. ?

Anyways I've ordered the alu bolts and some thread glue and hopefully can get this problem fixed. I have a quick question... Are there any recommendations for replacing the Miranda cranks? Some alternative?

 

[MrBrownstone]

1400 miles since I threw a crank. Replaced stock stripped cap with another plastic cap and no issues since.

 

[Lordhanson]

Ok new crank bolts for the trick. Really happy. Thanks for the post guys

 

[iXi]

Where are people getting there caps from. Checking ebay they are all from the UK. Would rather an aussie seller. My right has started to come off. Also anyone know what specifications the pinch bolts are. There seems to be a 1000 different types.

Struggling to get the right torque due to chainring in the way. Think I may have nearly threaded one of the pinch bolts

 

[urastus]

Where are people getting there caps from. Checking ebay they are all from the UK. Would rather an aussie seller. My right has started to come off. Also anyone know what specifications the pinch bolts are. There seems to be a 1000 different types.

Struggling to get the right torque due to chainring in the way. Think I may have nearly threaded one of the pinch bolts

This might help.

 

[urastus]

This might help.

it looks like the code is Y1GS00030 - I did a quick search because I think I need one too. It looks like it is easier to order through LBS - I'm guessing any merida dealer will even have them in stock.

 

[iXi]

it looks like the code is Y1GS00030 - I did a quick search because I think I need one too. It looks like it is easier to order through LBS - I'm guessing any merida dealer will even have them in stock.

Yeah googling came up with a few suppliers but all overseas or out of stock. Same with the ALU caps, not keen on waiting 45+ days. Might just have to bite the bullet and see what the LBS says

 

[Gary]

Are there any recommendations for replacing the Miranda cranks? Some alternative?

Yes. Shimano

 

[R120]

A lot of us got Miranda cranks a few years back as at the time they where the only option on the market if you wanted cranks under 170mm. However Shimano now do shorter cranks, and I think there are more options from other brands too.

I have the Mirandas as they are not great quality, and will be going back to Shimano for sure when they bite the dust.

 

[iXi]

Mine are 165mm shimano, I've had 19mths of flawless operations until two days ago and now it's thrown the right one twice. Unsure what's happened.

 

[iXi]

So I got alu cap and it sits proud, anyone else get this? It says tighten to 1.5nm but if I did that it would sit a fair distance out, so I've tightened it down a bit more. What's the worse case scenario here?

 

[Gary]

Which cap did you buy?
And what crank do you have?
and did you undo the crank pinchbolts to fit the cap?

The cheap chinese Alu caps are very slightly oversized so when you torque down the pinchbolts the crank grips the cap. But don't worry about it as this actually helps secure them even more

If for some reason you need caps sized exactly to the same dimensions as the plastic shimano caps Shimano SAINT caps are Alu and Burgtec also make slightly higher quality Alu caps. (I haven't used the burgtecs personally)

 

[iXi]

I bought a TITO Titaniium Crank Cover M20. It's about 0.5mm bigger.

I have shimano cranks. I did take the pinch bolts out before tightening down.

I've attach a pic of how far out they are. Took it for a quick 12k ride yesterday and so far so good. Just looks odd.

 

[Gary]

Yeah. That doesn't look right at all.

 

[iXi]

I can tighten it down more so it sits more flush, not perfect but better than that but I'm worried what will happen if I over tighten it. Any chance it can destroy the thread inside the spline?