I don't have cracks in my SLX cranks. Has anyone contacted Shimano to ask their opinion?
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Cracks in Cranks!
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Posted 2 years ago #
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Just checked my Hone, 2yrs old maybe, double with bash.
Definite cracks on one side - same as pictures above, not sure about the other side, its a bit too scuffed to be sure.
Has anyone heard of any actual failures?
Posted 2 years ago # -
I can't believe the amount of posters on here with cracks, it seems that 90% of the people who have read this thread then gone and checked have found cracks!
Posted 2 years ago # -
Has anyone heard of any actual failures?
I'm very interseted in this too.
I've just asked that same question on my sdh post (link on previous post) about slx cranks cracking.
I'm guessing no one has had any fail yet.Posted 2 years ago # -
Photos of the XT770, non drive side. Much smaller than the others, but exactly the same, same chevron lead in, then single crack. you may not see it on these flickr images, but there OK on my big pics.
the 760 is too fine to photo, but pretty sure it will show with dye-pen inspection.Posted 2 years ago # -
Whats the best course of action for us now then..?
Posted 2 years ago # -
Either get in touch with who you bought in from or try and forget about it and hope they don't break I suppose.
Posted 2 years ago # -
I thought they were hollow forged - which then raises another question - where is the forging split line.
Ive been thinking about this a bit more and i reckon i know what there cracks are. The cranks are made from an extruded tube and i reckon the poster above has got it right, its just the join where the inside surfaces of the tube are squished together, leading to a weaker join in the middle of the crank compared to the solid parent material at the edges. Im (now ive thought about it) pretty sure those cracks wont extend any further than the pictures we have here.
EDIT: The crack cant easilly extend past the end of the join made in the hollow forge process, it would take a significant impact/force to force the crack to extend into the edges of the crack, prob about the same size force that would snap a normal crank! Of course if the crack entend from the end of the crank arm upto the pedal threads then if your pedal works loose it could have the leverage to peel the front part of the crank arm off (though theyd have been screwed anyway as a loose pedal would ruin the threads)
Those with cracks in XT cranks, can you take your pedal off and see if the crack can be seen in the threads?
Posted 2 years ago # -
Good thinking stato.
Posted 2 years ago # -
Thanks for that Stato - makes perfect sense.
Posted 2 years ago # -
I still think youd be within your rights to ask for a replacement if your cranks look as bad as the first pic in this thread tho. No matter what the manufac process is you shouldnt be forced into a situation where you worry about wether a crack is going to get worse and possibly injure you, not matter how unlikely it is.
Posted 2 years ago # -
Hi everyone, Albert from Madison here.
Understandably some of you are concerned about what might appear to be cracks at the tips of your crankarms just below the pedal inserts.
This was brought to Shimano's attention some time ago and upon further investigation they were identified as forging marks (Stato's hit the nail on the head with his explaination). This is why so many of you will have discovered them upon further investigation.
Rest assured these marks do not in any way affect the performance or durability of the cranks/chainsets and to date no cranks have been returned to us with actual cracks at the end of the crank arm.
Thanks
Albert
(Madison)Posted 2 years ago # -
Oh Gwad... - going to check my XT / XTR cranks very carefully over the weekend...
Posted 2 years ago # -
So, Shimano cranks don't have an inherent design flaw, and it hasn't been discovered on this very website?
Posted 2 years ago # -
how is it a design flaw? surely they are functionally fine then, just show a mark where the tube has been forged together?
Posted 2 years ago # -
I dunno, I can't say I'm too bothered if they're not going to break. I probably would have never thought about it if I hadn't read this thread.
Posted 2 years ago # -
Well thats that cleared up, though I'd have thought it odd to leave the join visible in that manner. Certainly had me baffled as to the stresses that might be causing a crack there!
Has anyone else (Alb?) found their shaft flaking off where it sits in the top hats? Mine is and I'm concerned about it. While its only a surface coating, thats a fairly tight tolerance fit and any gaps will a) let gack down the shaft and b) could cause the shaft to spin in the tophat, wrecking it (if the bearings dont remain perfect).
Posted 2 years ago # -
No-one else had this?
Posted 2 years ago # -
I won't be buying the slx double chainset I had in mind. Maddison - it's a cop out, it's not a quality product, and whats going to happen over time, these cranks haven't exactly been around for long.
Posted 2 years ago # -
Ck, i have that on some oldish lx ht2's so much so that with direct contact bb like hope, there is play within the axle/bearing interface, fine with a shimano bb though, but still clearly visable as a worn groove on the axle..
Posted 2 years ago # -
but, how else would you expect them to make a hollow alluminium crank?
Extrude, then squish together, but you see the mark
Extrude, squish together, wrap in crabon to cover all manufacturing marks? Adding cost and weight?
I reckon Shimano make the best performing cranksets, at a very good price, on the market at the moment.
A small mark (not crack) at the end of the arm due to a manufacturing process is fine by me.
Posted 2 years ago # -
yeah I'm really not bothered about the crack - don't like the sound of the axle wear thing though.
Posted 2 years ago # -
If the crack isn't visible when new and unused then it is a deterioration. I had a look at riding buddies slx after reading this thread, and it was more of a jagged seperation or de-lamination (if you don't want to call it a crack) than a mark!
Posted 2 years ago # -
I check my saint cranks but they're a little battered so no joy there
Posted 2 years ago # -
If the crack isn't visible when new and unused then it is a deterioration
SLX - XT and XTR in the shop all new and unused still in box - all bar XTR showing hte marks ....
my XTs do not .... imho its not an issue.
Posted 2 years ago # -
Old and battered Saints Mk.1 here - no "cracks".
All it means is that in a couple of years' time I'll be changing them to Middleburn, simple.Posted 2 years ago # -
Coffeeking
Has anyone else found their shaft flaking off
*snigger*
Posted 2 years ago # -
BoardingBob - I should bloody hope not!
Back to the subject in matter - you pays your money you make your choice etc etc.
It ain't good what ever way you dress it up IMO.
Posted 2 years ago # -
have anyones failed yet ? how longs the system been out ? 5 years ? show me a failure caused by these pseudo cracks and i might worry
worry machine at work - some people just want to create problems.
Posted 2 years ago # -
checked my mk1 saints and they have the cracks. you can just about make them out on one side.
the other side they are hidden by the gouges and chips missing where I keep smashing into rocks.
not too concerned....
Posted 2 years ago # -
(1) Strong, (2) light, (3) cheap..
Posted 2 years ago # -
Has anyone else (Alb?) found their shaft flaking off where it sits in the top hats? Mine is and I'm concerned about it. While its only a surface coating, thats a fairly tight tolerance fit and any gaps will a) let gack down the shaft and b) could cause the shaft to spin in the tophat, wrecking it (if the bearings dont remain perfect).
Yeah I had this problem a while back. My shaft was flaking really badly. Everytime I went to the loo, great big flakes would come off. I think it was because I got gack down my shaft in the first place that caused the problem. Next time I will make sure I wear a tophat before putting my shaft into any other tight fits.
Posted 2 years ago # -
Albert from Madison - are the cranks cold forged? if they are then the inside surfaces of the extrusion may not be bonding properly on the cranks in the photos. As the ends are worked on (pedal thread and shaping of end) after this process any marks/evidence of this would only become visable when the cranks are put into use, appearing as cracks due to movement between the front and back of the crank.
Be interesting to see if anyone with first gen hollowtech (octalink style bb) has found any cracks.
Posted 2 years ago # -
No cracks on my aged Octalink XTs.
Posted 2 years ago # -
Has anyone else (Alb?) found their shaft flaking off where it sits in the top hats?
I have marks on my Hone ones (triples) where they fit the BB but it all seems fine to me though it would be the reason that i replace them (or the one i use with the wife). i also have the marks at the end of th ecranks but am not to worried about it as i can't see how it would lead to any kind of failier of the cranks.Posted 2 years ago #
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