[Razor]

My friend and I were installing a new crank/bb (hollowtech xt) on my bike yesterday and we ended up crushing the plastic insert that fits between the bb cups.

It seems incredibly weak/cheap (plastic) for a new xt bb. Has anyone had similiar experiences or problems with this part? I like the crank, but I'm not sure about the bb now.

 

[POG]

You have to install the spacers appropriately...

My friend and I were installing a new crank/bb (hollowtech xt) on my bike yesterday and we ended up crushing the plastic insert that fits between the bb cups.

It seems incredibly weak/cheap (plastic) for a new xt bb. Has anyone had similiar experiences or problems with this part? I like the crank, but I'm not sure about the bb now.

to avoid crushing the plastic sleeve. With a 68mm shell you have to use all three spacers. I think the sleeve is really only intended to be a dust barrier - it may also provide some reinforcement to the cups to keep the threads from creaking.

 

[Razor]

We initially used two spacers and then noticed that the chain line was a bit off. We then removed the extra spacer, replaced the drive side cup and tightened the cup down. But, stuid me, the cup wouldn't tighten down all the way. I never losened the left cup, allowing me to push the right one in all the way, thereby crushing the sleeve. I wouldn't have noticed it until the crank wouldn't rotate freely. It was binding up on the sleeve inside.

 

[fred3]

So it's not so much that the crushed piece was designed as too weak as you were not paying attention to what you were doing and due to faulty installation on your part the item was crushed? Sorry it happened, but it's a typical now a days for people to put the blame everywhere buy where it belongs. It would be my guess(and yours, by the small admission of guilt after you say the piece might be too weak) that if you'd installed it correctly after putting in another spacer that it would have been fine. Going way out on a limb I'd say there's likely a torque value and since you don't mention using a torque wrench I'd say you might have another questionable building practice.

Since the hollowtechs are used successfully by thousands of bikers I'd say it was your installation process that is at fault, not the parts.

 

[Speedub.Nate]

So it's not so much that the crushed piece was designed as too weak as you were not paying attention to what you were doing and due to faulty installation on your part the item was crushed? Sorry it happened, but it's a typical now a days for people to put the blame everywhere buy where it belongs. It would be my guess(and yours, by the small admission of guilt after you say the piece might be too weak) that if you'd installed it correctly after putting in another spacer that it would have been fine. Going way out on a limb I'd say there's likely a torque value and since you don't mention using a torque wrench I'd say you might have another questionable building practice.

Since the hollowtechs are used successfully by thousands of bikers I'd say it was your installation process that is at fault, not the parts.

Two problems I have with this new crankset are (a) the chainline is fixed at 50mm and (b) even though Shimano lists torque values for the installation, no adapters exist with which to measure torque (Park, which makes a version of the tools, has no plans for a "crows foot" type of attachment).

I have to agree w/ Fred here, the instructions are extremely clear as to how many spacers are required on each side for all the various BB/front derailleur combinations. Shimano could be more obvious about the non-adjustable chainline in the installation sheet, but they do make mention that the chainline of this crankset is 50mm (no range of adjustment given).

 

[Razor]

So it's not so much that the crushed piece was designed as too weak as you were not paying attention to what you were doing and due to faulty installation on your part the item was crushed? Sorry it happened, but it's a typical now a days for people to put the blame everywhere buy where it belongs. It would be my guess(and yours, by the small admission of guilt after you say the piece might be too weak) that if you'd installed it correctly after putting in another spacer that it would have been fine. Going way out on a limb I'd say there's likely a torque value and since you don't mention using a torque wrench I'd say you might have another questionable building practice.

Since the hollowtechs are used successfully by thousands of bikers I'd say it was your installation process that is at fault, not the parts.

WOW fred. You sure like being confrontational dont't you?? I've noticed that in some of your other posts. Were you abused as a child?? I'm sorry if you were, but you should learn to take a breath before you hammer your keyboard.

Regarding your post......yes, I admit I screwed up. I was just wondering if anyone else had experienced the same incident.

And, I know that the hollowtechs are "used successfully by THOUSANDS of bikers." I've actually heard a lot of good feedback from people using them. I just couldn't believe that the sleeve damaged so easily with VERY LITTLE TORQUE.

Thanks fred!

 

[D.F.L.]

Another thing...

The 3 plastic spacers that ride behind the outboard bearing cups...well, they work better on aluminum BB shells than they do on steel. A normal steel BB shell is smaller in diameter than those 3 spacers, and it's pretty easy to deform those. If you overtighten, the plastic spacer will try to ride up and over the BB shell. Not as much of an issue as with a thicker aluminum BB shell, though.

I think the chainline on those cranks is pretty horrible, and made a steel spacer to help improve it. It's still crappy.

Anyway, use a torque wrench and follow those instructions.

 

[fred3]

You call it confrontational. I call a spade a spade. If someone has been stupid and tries(initially anyway) to pass the cause on to someone else then they deserve to be corrected so that someone else doesn't get blamed without due cause. You mamby pamby types have really screwed things up by not taking responsibility for your actions. The results: 1) whiney multimillion dollar sports stars 2) millions going to people through court actions for lack of common sense on their part 3) increased costs for everything(insurance, medical, food, cars, etc, etc, etc.). You want to whine and be pampered? Forget it! Grow up and take responsibility for any stupid mistakes you make. You don't want confrontation? Think before you act. It truly isn't rocket science or brain surgery. I reserve my feelings for those who strive to survive and take it upon themselves to do what is correct, not what just makes "themselves" feel better.

 

[Razor]

You call it confrontational. I call a spade a spade. If someone has been stupid and tries(initially anyway) to pass the cause on to someone else then they deserve to be corrected so that someone else doesn't get blamed without due cause. You mamby pamby types have really screwed things up by not taking responsibility for your actions. The results: 1) whiney multimillion dollar sports stars 2) millions going to people through court actions for lack of common sense on their part 3) increased costs for everything(insurance, medical, food, cars, etc, etc, etc.). You want to whine and be pampered? Forget it! Grow up and take responsibility for any stupid mistakes you make. You don't want confrontation? Think before you act. It truly isn't rocket science or brain surgery. I reserve my feelings for those who strive to survive and take it upon themselves to do what is correct, not what just makes "themselves" feel better.

All I got to say is,

Your mental!

Believe me, my feelings weren't hurt. Read my posts. Don't go into some wild extrapolation of your intrepretation of what I was trying to convey.

But ya know what fred, sometimes I do enjoy, "whining" and sometimes when I do "whine," I get pampered and I never want to "grow up."

It's great having people like you fred. Thanks for your concern friend!

Oh, fred, I thought "before I acted" this time. Thanks for pointing that out.

BREATH fred!

 

[POG]

Did everyone receive instructions with the 2003 XTR...

crankset? I paid full retail for mine soon after they were released and received no instructions whatsoever. I was able to find them on the internet, but I think it is ridiculous that Shimano couldn't stick an instruction sheet in, especially since the information about the spacers is critical to avoid damaging the sleeve.

 

[Schtoojp]

Nate. I'll say it just once more just for you.

The chainline is NOT fixed.

I'm running about a 47.5mm chainline right now and I am very comfortable about doing it after we got a hold of the Big S guru around here.

He said go for it.

After all, he's part of reason why the cranks exist, I figure if he says it's ok, then it must be. But it's also NOT the official party line...

Based on the official policies of those who shall not be named, I say to heck with them. They wanna pull funny stuff, they can go right ahead. I'm not going to be sucked into it.

 

[Speedub.Nate]

Nate. I'll say it just once more just for you.

The chainline is NOT fixed.

This is the first I've heard of it, from you or anyone else. Is it more complicated than shifting the spacers over to the non-drive side?

Edit: I should add that I came really, really close to buying that crankset for one of my bikes, but my frugality got the better of me and I went with another not-so-cool-but-does-the-job-admirably LX setup.

I had a tough time getting past the chainline issue, where a 50mm chainline is off by just enough to be noticable on my Speedhub setup, and I'm really bugged by the torque wrench thing.

In the end, through various coupons, pricematching and ebay, the LX will end up setting me back a cool $30 (maybe evel less) for the crank arms and bottom bracket, but man... I sure like the look of that XT.

 

[D.F.L.]

The overall Q-factor is limited by the amount of spline on the BB shaft. They don't give you much to play with. I measured everything to see how much narrower I could go, and it wasn't much. I apologize for not recalling all of the numbers. I ended up machining a steel spacer that was narrower than 2 of the plastic spacers, and installed that on the non-drive side, running only one stock spacer on the drive. The crankset is asymmetrical, this way.

(I run a 68mm BB shell. But, if all shermano's cranks go to this system, a 73mm shell would be a better choice. (I predict that sh!tty performance will open yet another door for the Troovatives and FS-ayes of the world))

If I recall correctly, moving any more spacers to the drive side is pretty scary because you end up with very little cup insertion over there.

To really improve chainline, while maintaining symmetry, you'd have to remove spline from the crankarm, or add it to the spindle. I seriously thought about the former.

Would love to hear the 'insider's' cure, though...

 

[Schtoojp]

I've said it a few times now, but no-one really listens to me unless they want to argue with me.

It's as simple as shifting the spacers over, that's it. Make sure you have the right number of spacers to prevent the little incident we have here on this thread is all. Also means you don't over extend an older FD like the 50mm chainline does. Found my LX was waaaay over, and shifting really suffered for it. The newer spec FD's sutied for this have trouble running with an old-school crank. Gotta love that 'total degradation' huh?

I changed the chainline because I found I was getting knee problems. My seat height is critical (as is everyone's!) and with that massively offset crank setup, I would get a 'niggle' in one knee, adjust the seat post, switch the ouchy knee or change the pain from front to back.

Centred the crank, returning the chainline to original (or as close as possible) and the knee problems vanished.

Best solution would be to get the equivalent RF BB and use that. Sure it's a few extra bucks on top of the crank, but the chainline is fully adjustable and the BB is also fully compatible with the XT/XTR cranks.

Then again, you and the Rohloff don't use front deraillers, and don't get much problem with grindy noises from crank flex. I think you chose right there.

And that crank flex I tried to eliminate, I still get it with these cranks. No where near as much with the LX, but it's still there.

 

[Razor]

Thanks for the advice given recently. The adjustment of the spacers really helps. Again, I know that I screwed up in the installation and I probably should have taken some measurements before starting. You live and learn.