sth

I took my LX Hollowtech cranks off the bike yesterday and removed the external bearings for an inspection and cleaning. I was surprised to see the amount of wear on the non drive side of the axle shaft at the point where it contacts the plastic bearing cover. The shaft was lightly pitted and some of the plating had worn away. This assembly is only about 18-20 months old and the bearings have already been replaced. When I tapped the crank back into the bearing, a fair amount of the plating shaved off as it went into the snug fit. Most disappointed. Is this the normal life I can expect or is something wrong here?

mtnbiker4791

1 are your bearings still running smooth
2 are you greasing the spindle before you put it through the bearings or are you running it dry.

vasracer

I had the same experience with my Saint cranks on a downhill which I barely used. The solution i came up with, when i replaced the crank for same model, was to junk the Shimano bottom bracket bearing and purchase a set or Race Face external cups. Since then I have not had any problems and have not seen any of the pitting or fading on the axle like on the previous crankset.

sth

1) Yep, the bearings are smooth and feel good. Like I mentioned, I have already replaced them, too soon in my opinion.

2) I do put a film of grease on the shaft prior to inserting it but since the fit is very snug, not much grease is going to get past the first bearing.

I was thinking I would change this crankset to an ISIS drive when it is time to replace but looking at what's out there, I think that will be nearly impossible. Very few old style bb cranks left out there. I guess I will try a RaceFace or something when the time comes.

Thanks for the input.

edzo

shimano hollowtech bb wear out faster than they should imho


the old un-72 internal cartridge hunk o junks used to last ---forever---

wroomwroomoops

Just to clarify: by hollowtech, do you mean a hollow Octalink spindle, or do you mean the crankarms which are hollow inside (and hence the Hollowtech trademark)? I have a set of square-taper Hollowtech cranks. They are lighter than you'd expect if they had been made of bulk alloy.
Then there are octalink hollowtech cranks, and then there's Hollowtech II, which is yet again a different beast, with the hollow spindle connected to the driveside crank. I am guessing that the latter is the one the OP is talking about?


I am a huge advocate for square taper, as some of you might know. There's absolutely nothing wrong with square taper.

well biked

In the first sentence of the OP, the term "external bearings" is used, so it's Hollowtech II (outboard bearings).

sth

What I have is the latest style of crankset (they gotta keep changin' so we keep buyin') with individual, external bearings. I think I agree with "edzo", these parts are wearing way too quickly. The old style, one piece bearing kept on turning, for years, with not a stitch of maintenance. I have to say though that I am not a real fan of the the square taper. They are fine when all is good 'n tight but if the crank wiggles loose a few km's from home you can kiss the cranks goodbye. I like the idea of splined spindles to crank arms so I think I am going to hunt around for a quality ISIS crankset and then buy one or two extra ISIS bearings cuz I dont think they are long for the world. Everyone is going external.

wroomwroomoops

The same would happen with splined interfaces as well: if, for some reason, the crank loosens off the spindle, pedaling will destroy it.

sth

I gotta disagree with you a bit. Given that the square taper is tapered, if the crank arm loosens then the arm tends to back off the spindle, it wobbles about a bit and then you have a square hole made round and your crank is shot. With the isis or octalink, I feel you get a more positive connection between the two parts and if the bolt loosens you aren't going to chew up the arm as easily, though I wouldn't say it absolutely won't happen. All the different crank set ups have pluses and minuses. I think the weak link with the old style is the single bolt that holds each arm on. I actually quite like the idea of the new external bearings and the crank design, just not the way the inner plastic cover is only contacting the crank spindle via friction. To me that just causes all the wear I have prematurely.

wroomwroomoops

I don't mind disagreeing, but the thing is, just last month there was a guy, right here, showing pictures of his octalink crankset destroyed for exactly the reason our discussion started: the crankarm loosened, he kept on pedaling...
That's just an example, but very fresh, of this issue. If you install your cranks correctly, they'll work well. If you don't, you might screw them. This statement is as true for ST as it is for the splined ones.

erader

1000s and 1000s of miles and i've never that happen with a square taper and i prefer the un-72 to a phil wood or any of the others .

ed rader

blamp28

This is true regardless of the system. Additionally, this is the reason we carry multi tools. In the very rare occurrence, you simply stop and snug up the fastener until you can get home and torque it properly.

wroomwroomoops

Absolutely - cycling anywhere further than the local grocery shop without a multitool, pump and patches, you're asking for trouble. I say this even though I tighten my cranks real good (I apparently don't do that for the pedals, though, as I had several occurances of pedals coming loose in some circumstances. Why am I lazy with pedals??) and have puncture-resistant tyres. I ghost-cycled (pushed the bike from the seat) home for 12 Km once - thanks, that was enough experience for a lifetime. Never again.