JeffOYB

I have a bike with what I think is some generation of HollowTech. It might be 10 yrs old. The spindle is attached to the driveside arm so it slides thru the shell. The left arm clamps onto it. And...? The spindle can slide back'n'forth doing its own thing, it seems. When I tap it w wood mallet it just shifts back or forth. That doesn't seem right. But I don't see any part of its design that would limit lateral placement. ???

cyccommute 

That bearing preload bolt in the picture should limit the side to side movement. It looks like it is threaded out from the crank. It shouldn’t be. They do work loose occasionally. If the bolt won’t screw in any further, you may need a spacer under the bearing cup to move it outboard.

JeffOYB

I wondered about that but doesnt it just affect placement of the arm on the spindle? The spindle itself is sliding back and forth. ?

Eggman84

You may be missing the plastic spacers that go between the outboard bearings and crankarms (quite often 1 or 2 spacers on each side). Look at the backside of the crankarm for the Shimano part Number (e.g., FC-____) then do a search on the internet for the assembly instructions. Then you can see if your missing something.

tFUnK

What do you mean the spindle itself is sliding? Assuming that you mean the spindle is sliding in the bottom bracket? That sounds like a preload issue or it could be you're missing some spacers. Are you using a MTB crank in a road frame?

dedhed

Picture shows "Ultegra"

Trevtassie

All the answers are above mine, check the preload, check for missing spacers. The axle slides because that's how you install it. Once installed properly it doesn't slide...

dedhed

https://media.canyon.com/download/ma...50_6703_EN.pdf

https://si.shimano.com/pdfs/ev/EV-FC-6600-2365E.pdf

JeffOYB

I watched the video. I didn't know the cap pushes the arm on further. I dont have a cap wrench. I'm cranking down using scissors held in pliers. It seems to tighten with a fair bit of force and not go any further. i don't think i'm missing out by not using the right wrench. scissors are common DIY trick for these from what i'm reading. The bolt stops tightening with a 1/4" gap b/w arm and shell on left side. 1/3" on drive-side. More like 3/4" space b/w arms and chainstays. In the video the arm goes pretty snug to the shell.

because of that exposed spindle it can be slid either way if i whack it w wooden block. it doesn't easily slide but still it seems odd to me.

...wouldn't spacers cause friction? if bumped one way or another. i didn't see in any in the video. i kinda dont see spacers as being what we want to somehow keep it all in place -- in terms of physics.

headasunder

belting it with a mallet or the palm of your hand is standard practice as above odds on you haven't set the preload correctly

tFUnK

Good catch 😅

To the OP, make sure the non drive arm bolts are loosened all the way before using the crank bolt to tighten the arm all the way onto the spindle. I'm not sure about Shimano but I've seen other cranks with washers or wavy washers to take up slack between the crank arms and the BB.

dedhed

look in the diagrams for your model. Depending on model you may or may not have spacers.Also when in the right place on the spindle the stopper plate pin drops into a groove.

https://media.canyon.com/download/ma...50_6703_EN.pdf

Iride01 

Many probably mistake the stopper plate for just a spacer or such.

JeffOYB

Yeah that stopper is interesting. But, rats, that's not the issue I'm finding! The problem is the spindle slides in the BB shell!!! There's nothing to limit that ... except for spacers, I guess, which aren't in some models. ? And spacers seem a sketchy way -- if you come up against one to stop sliding then that's friction, right?

Davet

There are NO spacers on that model Shimano double crankset.

the cap on the end of the crank is to set preload on the crank. Loosen the two bolts on the crankarm, turn the end cap until it’s snug but not tight, then evenly tighten the crankarm bolts. The end cap will look like it’s not all the way in, there is an inner shoulder that meets inside the crank.

Iride01 

How much lateral movement does it have? A little is not a big deal. You might just have a narrower BB shell than others. If this is a hollowtech crank, then it doesn't tell you anything about your bb's condition as the crank axle floats in the bb.

JeffOYB

Yeah. My concern isn't about crank arms. It's the spindle floating in the shell! I suppose I should've got a shorter spindle but I think this is the one that came on the bike which was top of line Dura Ace carbon Giant... Oh well! I did change it from the DA cranks to Ultegra to get shorter arms. Maybe the DA cranks took a longer spindle. Always fun to have to change 2 things when you're changing 1... : (

Iride01 

Hollowtech spindles/axles are all the same length. That's why when you buy the BB's you have to know the width of the bb shell. The bb for them to a certain extent, control how much side to side play there is.

tomtomtom123

I think you're missing the point of the preload that everyone is talking about. You haven't explained what you have done to try removing the slack. Have you actually tried to disassemble the crank and pull everything out? You might then start to understand how it's supposed to be assembled. And if you do remove the crank then you can also inspect the bearings to see if there is some problem with it. Also the standard overall width of the Shimano road bb on 68mm shell from dust cap to dust cap is around 91mn if you want to measure it. When you reassemble, you're supposed to set the preload while the clamping bolts are loose. The preload is supposed to be around 2 Nm, just enough to remove slack. Then you tighten the clamping bolts. Make sure you use the right torque and alternate between the 2 bolts while tightening. The instructions will say how much torque. Also read the instructions about the pin thing.

Iride01 

I think we are missing the op's point. He doesn't have a loose crank arm. He is just seeing side to side play. IE. he can push the left side toward the BB and the right side moves away from the BB and vise versa.

The picture clearly shows the stopper plate in proper postion, so unless that got buggered up, then the crank arm is on correctly.

edit.... well looking at the pic again, now I can't be certain the stopper plate is correct. It might have gotten buggered up if the crank arm has been on and off a timer or two.

dedhed

if this is bothering you
Measure the distance of "slop" and get the required amount of BB spacers to remove the slop.
Remove the cups and install 1/2 the slop distance in spacers under the cups and reinstall the cups.
Put the whole shebang back together.

https://wheelsmfg.com/products/botto...p-spacers.html

JeffOYB

Nope, spacers mean friction. I'm not a believer.

The plastic stopper plate doesn't affect the relation of spindle to shell -- i don't think.

I could take it apart and measure -- I'm guessing I have a spindle that's too long for the shell. I guess. A very standard bike, one of the most common.

I don't really care -- I just haven't seen this kind of slop in an engineered situation before.

Smitty2k1

On both of my bikes with a Hollowtech bottom bracket the non drive side has to have a spacer in order to not have side-to-side movement. Sometimes these spacers are installed between the bottom bracket and the frame and sometimes they are installed between the bottom bracket and the crank arm.

If there was a spacer installed between the bottom bracket and the crank arm, and then you replaced the crank but didn't replace the spacer too, you're going to have the side-to-side play that you discuss.

It sure sounds like you need a spacer, or we need to see some more photos with measurements taken with a set of calipers...

dedhed

Is it possible you are using HT II BB mountain cups rather than road cups? Mountain cups are 1mm narrower than road.
One measurement is worth a thousand expert opinions - Grace Hopper

tFUnK

🤦 Spacers may be the acceptable solution in this case but it's hard to tell since you've not provided enough information. Basically it sounds like you may not have installed the crank correctly, or if you did, you may have the wrong BB, or if that's not the case, you're missing a spacer.