hodie21

I've installed plenty of BB30 cranksets. This is the first one from SRAM that has the BB30 I/A spindle with spacers etc...

Pictures show that I have the large spacer on driveside. After I torque the crankset to recommended lbs and turn the small adjuster ring in to the non-drive bearing the small metal spacer between the crank and non-drive bearing rattles constantly.

Anyone dealt with one of these? What's the fix?

If you follow SRAM's terrible instructions. They tell you to not but the big drive side spacer in for Force. This is completely wrong.
If it matters it's on a Cannondale Supersix EVO frameset.

hodie21

Nobody?

primov8

You can add 1-2 (1mm) spacers on the NDS. Either in between the preload adjuster ring and spacer or right after the NDS bearing seals.

Campag4life

Have you adjusted the preload to max width position on the adjustable ring shown? If you have and there is still lateral play when pushing and pulling on the crank spider, then you need more spacers as primo stated. To determine proper amount, rotate the adjustable ring to its thinnest position which creates the largest gap. Then fill that gap with spacers..or within 1mm or so. Then adjust the preload of the adjustable ring. BB30 spacers are available generically in all different sizes and if you can't wait, your local bike shop probably has some.

Elvo

Did you put in the wavy washer?

d_cushman

I have a quick and dirty fix for this. First, for those not understanding, this is different than the standard PF30 install from SRAM. The "I/A" the poster listed is important. This is the type with the preload adjuster, so there is no use of a wavy washer, etc. At any rate, I had the exact same problem. The black plastic spacer (pictured in the poster's second photo. between the gray preload adjuster and the silver crank arm) rattles - and boy is it annoying! I don't understand in what cicumstance this WOULDN'T happen, so I don't get SRAM's idea with this. By definition, the preload adjuster is meant to screw out, which creates space around that black spacer, and it rattles back and forth. But then again, that's SRAM for you...

At any rate, the solution: my crank (CX1) came with extra spacers, but I tried them in various spots and it just made the crank tight (i.e. not spin freely). So finally all I did is put it back to normal where the spacer rattles, then put a rubber band in the gap. It doesn't rattle anymore. Took 15 seconds and zero dollars.

If anyone knows what SRAM actually expects, let us know. I have a hunch they don't have a solution.

Campag4life

Just lose the mechanical preload adjuster. Use a std. 30mm BB30 wave washer and space the crank with generic spacers if you can't get it quiet. I personally wouldn't stick a rubber band in there...it likely wouldn't last and will compress/distort over time changing reducing preload.

d_cushman

The rubber band, which I admit is not ideal, is behind the preload adjuster, so it has no bearing on the mechanical effect of the device. Again, see the second photo from the original poster, and read my detailed description. And the preload adjuster can't simply be removed and replaced by a wave washer. It doesn't work that way. Will the band deteriorate and fall off at some point? I'm sure it will. Am I going to mind spending another 15 seconds and zero dollars to replace it? Nope.

tlman46

Hi - I am today installing a Force 22 PF30 crank, and am experiencing exactly the same issues as described. There appears to be a lot of confusion about setup, and conflicting opinions being expressed. I installed the crankset eactly as described in the instructions, no 15mm spacer. The inner chain ring rubbed on the chainstay. I thought about violating the instructions (that say don't use the spacer) and stuck it in -- it seemed to me that the splines no longer matched up well, and the chainrings were now out too far. So off with the big spacer, on with a couple of metal spacers - result, nice fit, inner chainring now 2-3mm from the chainstay. To finish up, I turned the preload adjusted until it was hand snug, and found exactly what the OP pictured in the second picture - a 5+mm gap between the preload adjuster and the crank, with the original metal spacer as shown free to rattle about. I can see no hint in the Sram instructions about this, and the design does not seem to make sense. SO - like d_cushman, I thought of using a rubber band or similar soft filler, but that seems like a kludge. So why not remove the spacer entirely (assuming the preload adjuster can be threaded off and removed then reinstalled, I have not tried it)? It serves no purpose. But I came looking for the experience/wisdom of others. Am I missing something??

Campag4life

People trying to build with this crank are not improvising as any decent shop mechanic would. This is not difficult.
1. Apply amount of spacers on the drive side (chain ring side) such that there is inner chainring clearance to the chainstay. Its obvious by your experience and the experience of the other poster that this amount of spacing on the drive side is less than 15mm because the crank will not assemble with 15mm. So create the chainline you want with spacing less than 15mm and you are good on that side.

2. Turn the preload adjuster all the way in so its the skinniest.

3. Without any spacers on the non drive side assemble the crank

4. Measure the amount of exposed spindle you have with a simple ruler, a metric ruler or metric calipers.

5. Amount of clearance in no. 4 is the amount of spacers you need on the non drive side...or 1-2mm under this value.

6. Install the proper amount of non drive side spacers per no. 5 and torque the crank arm to spec.

7. The 1-2mm clearance you have created is the adjustment you have to make in your preload adjuster. Turn this until there is just a hint of preload finger tight and then secure the locking collar.

That's all there is. No, Sram's instructions don't account for every permutation of frame or tolerance out there. Spacing is simple if done methodically.
A rubber band is a bad kluge. BB30 generic spacers are available in all kinds of widths to tune correct spacing on both sides of the BB.

Note: if you can't get it to build i.e. there isn't enough spindle length with proper clearance of the chain ring on the drive side, then remove the preload locking ring. Build the crank without it and measure what spacers you need in replacement (less than the lockring width) Use a wavewasher in replacement of the lockring.

Hope that helps.

tlman46

Campag4life, thanks very much for the very clear perspective. I used to do a lot of bike wrenching, but less over the past decade, and this was my first non-BSA BB frame. One last question, if you have the patience - what is the point of adding the NDS spacers as per your steps 4-5-6? It's unclear to me that these spacers would have any mechanical function, since there is a 1-2mm clearance - is it just a matter of esthetics? Thanks again!

Campag4life

The key tlman is to first establish your chainline on the drive side. There is an optimal position for the both chainrings such that that can run best cross chained. Most manufactures post a spec for this and you can look it up for Sram for their 11s. But if you don't want to be that precise, then simply space the inner chainring away from the chainstay as you say but a bit less than 15mm....which you have done.
Then the other side of the BB will be what it will be. Take all spacers off on the non drive side, turn the preload locking ring all the way narrow and measure the amount of bare spindle. Then simply go to the tool box and choose just a bit less spacer width to fill this entire gap. Then use the preload ring to take up the rest of the lash in the spindle to create a hint of preload. All there is to it really.

I don't quite understand your question. There is no aesthetic purpose for a 1-2mm clearance. The objective once the crank is properly installed is no clearance....line-to-line with a hint of axial compression referred to as preload...what the ring provides with adjustment. If you have a question about any gap or clearance, mark up one of the pictures above and post what you mean...or take a quick pic of your crank and draw an arrow to the gap you are speaking of.
If you still have a gap on the non drive side when the preload spacer is adjusted at full size width...then you need more spacer width with the preload ring turned down thinner.

Other than that, what I wrote is all there is.

Campag4life

OP,
If want to be more precise since your Sram Force 22 doesn't fit to the drive side without spacing and you are adding your own spacing on the drive side...something less than 15mm so the crank will assemble, you can follow the picture below to determine your chainline.

I couldn't find Sram's roadbike chain line spec but chain line for road bikes universally is 43.5mm. The picture describes how this is measured...measurement is the lateral distance .half way between the two front chainrings (triple is shown) and the middle of the cassette. This basically says that each chain ring is closest to having the best chain line across the cassette in back. Now if you want you can bias your chain line for a particular chain line you prefer to ride...or even a particular chainring...positioning it closer to the cassette centerline if clearance to the chainstay in front permits, but this will be a compromise to the other chain ring in terms of ability to cross chain.

d_cushman

tlman46 I never thought of your simple idea of removing the spacer between the crank arm and the preload adjuster - good idea! If you try it, take note that the preload adjuster does not unscrew off the spindle, but rather just slides off. (The threads and the adjuster are just one unit, in other words, and slide off like spacer.)

Campag4life - the rest of us must not be explaining our problem properly. You helped with chainline, but this post is about the rattle due to the preload adjuster. Let's see if this makes sense: regardless of number/size of spacers on non-drive side, as soon as you screw in the preload adjuster that opens a gap between it and spacers next to the crank arm. These spacers then rattle between the preload adjuster and the crank arm. Since the whole point of the preload adjuster is to be screwed in, there will be a gap opened up in all scenarios. So the spacer(s) will always rattle as SRAM designed it.

So again, for all others with this problem, we so far have two solutions: fill in the gap with something like a rubber band (zero effort, zero dollars, zero time, zero issues), or remove the spacer between the preload and the crankarm (not yet tested).

Campag4life

In bold. Then tlman was right. If you adjust the preload ring to increase preload...if this creates a gap between the ring and the spacer(s), then the only purpose of the spacer is aesthetics. Remove the spacer and no more rattle. The preload ring isn't going to rattle by itself because it is under the tension of preload. The spacer is just freewheeling on the spindle and bouncing between the crank arm and the preload ring. You put a rubber band in there to quiet it. There are a lot of ways you can keep that spacer from rattling. Notably you can create an interference between the ID of the spacer and the OD of the spindle so that the spacer is a semi fit or snug fit. You could even put a narrow band of tape around the spindle and then press the spacer over it. I presume Sram put the spacer in there because it looks better than not having one there. It isn't a very elegant design if the spacer does nothing and sounds like it doesn't because when you tighten the lock ring it tightens away from the spacer creating a gap.
I would have to be convinced that the preload lockring can not be removed all together from the crank and run a wave washer + suitable spacer stack in its place to create preload. If you say the preload ring can't be removed, I will have to believe you without personally playing with a Force 22 crank. Previous Force cranks were all wave washer designs.

PS: another option to quiet the spacer between the crank arm is to distort it...whether the spacer is plastic or metal. Basically you crush the spacer lightly to create a slight eccentric or egg shape ID. Then elastically deform it closer to concentric and press it on the spindle. This should keep it from rattling without a rubber band which acts as a damper.
A last option is something more robust than a rubber band. It is an O-ring. Most hardware stores sell different size O-rings. Simple find one that has suitable thickness with ID slightly less than 30mm. O-rings can stretch a fair amount so even if you found something 1 inch/25.4mm in diameter, it should work fine.

d_cushman

I agree with both of you, I think it is just for aesthetics. SRAM deosn't exactly have the best engineers in the game (just ask Andy Schleck, or anyone who's ridden their disc brakes), so I guess we shouldn't be surprised they created a rattle in exchange for making something look OK. And yes, you can remove the preload adjuster - I've done it (but didn't think of removing the spacer at the time).

DaveQB

In talking with others, there seems to be two different types of Sram Preload Adjusters. One that has the thread part of the spindle, doesn't come with a spacer and it spins clockwise to tighten and another that has a plastic sleeve with the thread, comes with a spacer and it spins counter-clockwise to tighten. I have the latter and you can slide the whole thing off the spindle. I did that in an attempt to change the spacer that you speak of rattling. Then I figured out how it works and ended up putting it back on.

This video I made may help you remove that elastic band hack.


HTH

d_cushman

Thanks Dave. I'm missing your point, I'm afraid...in your video when you tighten the adjuster it pushes itself against the spacer and the crankarm. While that does remove the rattle, it serves no purpose. The point of the preload adjuster is to press against the BB, thereby "adjusting the load" on it - hence the name. And just as your video showed, when the adjuster is pressed against the BB, it allows the spacer to rattle...and there's the problem!

DaveQB

It does serve the purpose. As the video tries to explain and show (I know, bad lighting but did my best) the sleeve under the adjuster is pushed out from under it and into the BB, hence wedging itself between the crankarm or spacer to the outside and the Bearing Shield or spacer to the inside. The Preload Adjuster device widens itself when your screw it forward, or counter-clockwise when facing the side of the bike.


Have another look at my video with that in mind and look for the sleeve to slide out from under and into the Bearing Shield. It's faint, but can be seen.

I came to this conclusion when I found two different Sram documents about their cranks both stating different directions to turn the Preload Adjuster. I think I mentioned the difference in my previous post.

rpenmanparker 

What keeps the preload adjuster from sliding left and right? How does it apply preload if it can just be slid off and there is no stop on its left? Doesn't the preload (lateral force) push it against the plastic spacer just as it pushes it against the BB? Can you push it snug against the plastic spacer before tightening it against the BB? If the preload is correct, it should push the adjuster tight against both the plastic spacer and the BB and keep the spacer from moving around. That would solve the problem. What am I missing?

ehdeeboi

I have the same set up so I'm subscribing to this thread. I have a feeling the info here would be beneficial when I put everything back together after I service my crank/bb set.

DaveQB

When you turn it, the unit (Preload Adjuster and it's threaded sleeve underneath) become wider, gradually, wedging itself in between the crankarm spacer and Bearing Shield on the BB.

It only slides off if you take the crank out and slide it down the spindle. Nothing to stop it then.

Correct. Once turned until it is firm. It is locked in place like you state.

Yes exactly. That's how it works. If you don't push it snug against the outer spacer, it should end up sliding along the spindle until it hits it anyway.

You are correct. Missing nothing.
Knowing HOW your Preload Adjuster works is the key. There are a few types (I think the IA is a different variation) and so you need to know which you have and how it works logically.

rpenmanparker 

So it seems that folks having noise from movement of the plastic spacer just aren't applying enough preload to immobilize the spacer. Or maybe reaching the end of adjustsbikity of the preload adjuster and mistaking the end of threads for conact with the bearing cover. That would leave the spacer loose to move around. Another spacer may be needed to snug everything up.

d_cushman

Thanks, that makes sense now! Here's the fix to my problem, in case others were thinking of it backwards like me: the part of the preload adjuster that you turn with your fingers does NOT push against bottom bracket to provide preload. That part pushes against the spacer. The plastic threads underneath are what get pushed against the bottom bracket.

It also finally explains why the arrow says to turn the adjuster such that it backs against the spacer...I thought that was in error or something, because force should be pushed against the BB! But I see now that when done, the threaded section underneath gets pushed the opposite direction, against the BB! (Kinda like an old square taper BB crank arm is removed by screwing the tool IN, and the arm gets pushed OUT.)

DaveQB

I am glad I explained it well enough. I have found it hard to explain this mechanism (hence the video). I agree Sram's documentation could be a lot better identifying what part you have and so which document you should be reading, rather than reading them all and trying to workout which applies, which is what I did.

Now go and remove that hack fix, the elastic band