[RideMonkey]

I got some of the new XT hollowtech cranks this spring. They were way light and inexpensive, so I should have known it was too good to be true.

They made a "knocking" sound after a few rides. No amount of tightening would fix the problem. I took the cranks off and reinstalled them and everything was ok..... for two rides. Now the knock again.

Whats up Shimano?

 

[hobbi]

i know what u mean, i'm runnin LX cranks, and it is constantly makin this noise, i've tried tightening it, it temporarily fixes it but it's screwed again

 

[Sand Dune King]

I have heard of that happening only two other times with a spline-drive system, but both were also with Shimano hollowtech units, and both fairly new. I strongly recommend returning the one you have. If possible, get a different brand. I think the Shimanos still need to be debugged. Strangely enough, I've never heard of this happening with their splined Dura Ace components!

Personally, I have a RaceFace Next crank and RaceFace Steel BB on both of my MTBs and have never had any problems with them, and since I weigh 247 lbs, if anything was to break, or even make noises, it should theoretically happen more in my case.

I also know a few people with TruVativ components, all of which seem to be doing well; that is, no complaints so far, and these all fall well within the XT price range.

 

[muddywolf]

I work in a shop thats put out alot of splined systems and havent heard a complaint yet. I ride the XTs myself and have never heard anything.
the only thing I've ever seen go wrong is the spindle snapped off on one bike.
maybe the problem is in your bottom brackets???
I'd definatley try and return em
good luck

 

[Sand Dune King]

Just out of curiousity, a couple of questions for those of you who HAVE had problems with the splined hollowtech cranks: What BB are you using with it? Have you analyzed your chainline??? A bad chainline will cause excessive lateral forces in the chainrings and transmit these forces unevenly to the BB bearings, which may groan and click under the strain.

 

[Ravenrider]

AAAAAGHHH!!!! these things drive me to drink!.....I'm running XTR BB with coda spline cranks I have also reied the XT craks............CREAK! CREAK!...SNAP!..CREAK!.. ....the creaking and snapping are unbelievable. I have used torque bars to crank them down to no avail. I've tried greasing EVERYTHING,,,then Not greasing everythin i've plumbers taped the bb cranked the chain ring bolts down..but to no avail.....I really miss my heavier but problem free race fave bb and crank set...

 

[RideMonkey]

I am using the XT BB. Maybe it is the chainline, but there is no way to adjust it. And when this "creaking" is really bad, I can actually feel a slight "shift" in the cranks through both arms, its as if the entire spindle is moving. But the bottom bracket is tight so I'm at a loss.........

 

[ridemonkey2]

The cranks need to be TIG welded to the BB and then heat treated while on the bike. Do NOT try this with a thremalplastic frame as the heat treating prosess will make a big mess.

 

[RideMonkey]

lol good one RM2

 

[KrusteeButt]

ummmm....okay, this is probably pretty basic to you guys, but you'll have to bear with me...
What does "splined" mean?
I'd like to upgrade both of my bikes and figure I need to really learn about all this crap before I start making decisions and possibly throw money away.

 

[TwoWheelinTim]

when the shaft and mating hole have small gear like teeth that mesh with each other. When machined properly this can make for a very nice coupling. If not, then you can have all sorts of problems. In automotive use you'll find splines in your clutch, transmission, engine, and many other places you'll find spinning or rotating parts. If you don't have a splined BB chances are it's a tapered square spindle.

 

[greasemonkey]

crank shifting on spindle = damaged splines due to improper installation, or using the wrong bottom bracket. XT and LX splined cranks can only be used with the ES-70 bottom bracket. using them with ANY other bottom bracket will not work. that's all there is to it. chainline has nothing to do with this issue in any way at all. the off-axis loads from a 5mm difference in chainline are miniscule compared to the off-axis (and completely anticipated) loads of a leg pushing on a pedal.

every problem i've seen with splined cranks has been either mismatched cranks and BB (usually destroys the cranks beyond repair) or mashed splines from someone cranking the bolt tight when the cranks and spindle weren't aligned right (also not repairable). doing it wrong one time is all it takes. take out the self-extracting bolt before mounting the arms, so you can *see* the splines engage properly before you tighten the bolt. if it's just creaky and problematic, the damage might be very slight. try taking them back and exchanging if they appear undamaged (2-year warranty against defects), but otherwise all you can do is load the splines with anti-seize compound and keep them tight, and hope for the best. if your arms are shifting around, you're probably out of luck entirely. double check that you have the proper BB - and if it's not, get the right one and pray you haven't already destroyed your cranks. that's not covered by the warranty.

 

[RideMonkey]

Yeah probably true. Can't imagine how the splines could have been misaligned..........

Seems that the cranks damage pretty easy!

 

[greasemonkey]

they damage easily if the self-extracting bolts are installed before you put the cranks on, because the bolts start threading into the spindle before the splines start to engage.

then it's hard to tell the difference between "splines engaged" and "feels engaged because the spindle splines are butting tightly against the wrong part of the crank"

 

[RadRacer84]

All that I have to say is that the XT spline system is terrible. I have and splined bb and the thing won't work. I have gone through 2 sets of cranks and I know they are lined up right cause there is no damage on the splines at all. I think that shimano just made a poor product. It is nothing like the xtr spline system that obviously works. I think i am just going to go back to square taper cause it is easy you don't lose that much weight (5grams) and the spline doesn't seem anymore stiff than the square.

 

[RadRacer84]

To those who will read this I hope this gets to you casue i kow this will help. I had the same prob with a few bikes that came into the shop that I used to work at. Tthe first thing you need to do is make sure that there is enough grease on the spindle. I mean grease the crap out of it. Put as much as you can on there. This should stop the noise. Also make sure that the chain ring bolts are torqued to the proper amount this plays a roll. Also make sure that the bb is torqued as well as the cranks. These all play factors. When you take the cranks off make surer that they are aliegned properly when you go to put them back on because if they are not you jsut ruined a set of cranks. If they are not aliegned properly the bb will ruin the splines on the crank and the crank is now usless. The XTR and Dura-ACE splines are completly different from the XT splines so don't try to put cranks on that aren't matched properly. XT cranks only work with the ES70 bb from shimano. I hope this helps some of you
pease RadRacer84

 

[bscarola]

My XT's went bad on me after a few weeks... when the creaking get's real loud I take them off and re-install. After that they're ok for a few rides. I've found that cranking the hell out of the bolts helps. How are people doing with the ISIS stuff? Seems like they did a little more R&D for it.

 

[Merwin5_10]

shimano has experienced some machining problems with both the xt and the xtr spline units. The problem actually has nothing to do with your splines or your BB's. It's the big chainring that's slipping. Assuming you've already checked for the obvious loose BB and crank arms, use this trick to fix the prob. Even a new unit may have the same problem. It's a machining problem at the factory.

Remove your chainrings from your drive side crank. You see that the small grooved ring holding everything on can not be tightened enough to full press the chainrings onto the crank. That's the problem. Use a small (1.5 mil by 5 mil) peice of tin and place it on the inside edge of the crank. Tap the crank arm onto the chainrings (chainrings facing down, crank braced level to big ring) until everything is snug. Tightening the retaining ring will seat everything level. It's best to have a certified tech inspect everything to ensure you've got everything level and on tight. No more squeak. I performed this fix on my XTR cranksets and haven't heard a peep since. For the record, splined systems are NOT CRAP. They just require more attention than press-fitted systems.

 

[greasemonkey]

splined XT cranks have a permanently mounted spider, which is held in place by a pressed flaring of the crankarm material instead of a lockring. if that's the source of the creaking on a splined XT crank, it is absolutley unfixable. only the non-splined XT cranks from the last couple years had the removable spider.

IMHO, i think the pressed-on spider is a bad move. it could very well be a source for creaks, and I've seen similarly manufactured low-end shimano cranks/spiders loosen or separate after a few years' use. hopefully the Deore thru XT units will hold up better. it's too early to tell.

i'm still convinced it's mostly an installation issue as far as creaking and loosening are concerned. i've yet to see a chronic creaking or loosening problem that didn't involve either damaged splines in the crankarm, mismatched components, or a simple lack of lube. not a single one. this goes for shimano cranks of both spline varieties, as well as third-party cranks (like ricthey, coda, specialized, etc.) that use shimano spline patterns.

 

[Merwin5_10]

true dat. Good call, I forgot the XT's were different in that respect. BTW, I totally agree with the comments on the creaking. The VAST majority of the time, the problem will be a maintanence issue. If all else fails, take it back your shop and go through the drivetrain point by point with your tech. Don't forget, he works for you.

 

[novice]

ISIS is the way to go, just remember it's ShimaNO.

A nice set fo Truvativ cranks can be had for about the same price as the XT's. And the splines on the crank/BB start at the edge of the spindle. This way you don't run into the problem of mashing the splines together. My $0.02

 

[RideMonkey]

My drivetrain was creaking and grinding like crazy. So I got a new XT casette (8 speed) and an 8 speed SRAM chain. I put them on and the drivetrain hardly worked at all. Their was a mysterious grinding noise and the cahin was skipping all over the place. I took it to a local shop and they couldnt figure it out either.

I have been wanting to get rid of my 180mm cranks anyway. So I dug an old set of Sugino Impels and a square taper BB out of my parts box and put those on. The result:

1. No more creaking
2. These cheapie Sugino cranks look way better than the XT's
3. I'm a lot happier.

Good riddance XT splined cranks!