rmwesley

Hopefully someone could give me some advice... I have a creaky bottom bracket and would like to replace it.

The bike is a 2021 Cube Agree C:62 SLT. The specs are here but they don't explicitly detail the bottom bracket.

The crankset is SRAM Force DUB Carbon 48x35T, 170mm (FC-FRC-D1) and the specs are here.

The SRAM specs indicate the bottom bracket compatibility is "All SRAM Road DUB BBs, DUB 83-A BBs Only, GXP/PF GXP 68mm".

Could anyone help me translate this from gobbledygook into plain English please, since I would like to expand my choice from a like-for-like SRAM replacement to other brand options.

Thanks in advance.

himespau 

Are you sure it's the BB and not the pedals (or pedal threads), or bars or post? Lots of things sound like they're a BB creak but are coming from other issues.

rmwesley

99.99% sure by a process of elimination. Definitely something the BB area which creaks in unison with pedal stroke. Pedals have been removed, threads cleaned, re-greased and reinstalled.

Iride01 

I didn't see in the bikes specs where they said what type BB shell is on the bike. Threaded or non-threaded?

The most confusing part of BB standards is just that at the start, few realize that a BB has to match both the BB shell and the spindle of the cranks. Once you understand those and learn to look for that, then it becomes easier.

Most cranks have both threaded and non-threaded BB's that will work with them and are also made by the crank mfr. However not all will have BB's to fit any size BB shell.

Not sure if this is any help to you at this point.....

https://www.sram.com/globalassets/do...bility-map.pdf


That said, noises from the BB usually aren't. I suspect many that claim changing the BB solved their noise really was something incidental and was unknowingly corrected during the change.

Have you checked the chain ring bolts? They make creaks when loose.

rmwesley

Many thanks for the reply. Easy bit... yes, the chainring bolts are torqued.
The info from the Cube website and the SRAM website is all I have to go on, hence the ask to see if anyone can decipher the "All SRAM Road DUB BBs, DUB 83-A BBs Only, GXP/PF GXP 68mm" info.
I'd seen the link you sent, which makes me think I need a 83mm frame shell width, pressfit BB & narrows it down to either a PF30 or BB30.
Just wondered if anyone could categorically say which one based on the limited info available.
I've emailed Cube direct also, but haven't heard anything back.
I guess I could just take it apart and measure it but was being lazy
Thanks again.

smashndash

Historically, Cube has used BB86 bottom brackets:

https://www.cube.eu/en/2022/bikes/ro...magreyncarbon/

That's unlikely to have changed, but you can email Cube to be sure.

You almost certainly have a DUB Road crank. If you have a BB86 frame and get a BB86 DUB bottom bracket, it will fit.

the GXP "gobbledy-gook" is referring to the GXP version of the crank, which was only manufactured for Trek because they used BB90. You can ignore this.

The "DUB 83-A" seems to refer to a special Ai DUB crankset made for cannondale and their proprietary bottom bracket standard. Again, this is something you can ignore.

source: https://www.sram.com/globalassets/do...bility-map.pdf

veganbikes

So beyond just doing a few things at the bottom bracket and crank area what else have you done to assure you that it is in fact the bottom bracket? Are your quick release skewers properly tightened, bolts are all properly torqued, seatpost is the correct size and either greased or pasted and torqued correctly, saddle is also torqued properly...check it all first before going straight at the B.B.

Once you have checked all of that I would reach out to Cube and confirm or head down to your local shop that you bought it from and ask them. They are likely to know or can help out.

pdlamb

My father-in-law was a bench chemist for years, and he occasionally was known to snark, "Sometimes 15 minutes in the lab will save you two weeks at the chalkboard!"

Relevance? Substitute "at the LBS with the mechanic" for "in the lab" and "checking web resources" for "at the chalkboard."

rmwesley

Many thanks, this has helped loads. Hopefully Cube will reply at some point to confirm

rmwesley

Generally all bolts on the bike are greased & tightened to the specified torque, but I have gone round and double checked every bolt.
The creak occurs in sync with pedal strokes & stops when I stop pedaling. It occurs in or out of the saddle when pedaling.
Therefore, I've narrowed it down to the drivetrain & the BB is the last thing (I think) which it could be.
Thanks for all your suggestions though

dedhed

Don't you have the bike to look at/measure? Maybe take pictures and post?

rmwesley

Yes, I was just being lazy & hoping someone else either had the same bike or already knew what the BB was
Once I've knocked the cups out of the frame I'll probably not press the same ones back in, so wanted to be fairly sure I'd have some replacement options available in stock.

KerryIrons

Unless the bearings are feeling rough or binding, you can most likely fix the noise by greasing things. It is often a metal to metal interface movement that causes the noise, and so grease fixes it. That may well involve removing the BB and reinstallation with greased surfaces.

veganbikes

A lot of folks don't do that, they assume bottom bracket always without checking everything else and it can easily turn out to be something different.

davidad

Bottom bracket type is determined by the crankset. The manufacturer will tell what BB you need.

davidad

This explains the bike industry. pardo.net/bike/pic/mobi/b.bottom-bracket-standards.html Be sure to look at the cartoon at the bottom.

JoeTBM 

Linky no worky

Hondo6

Seems to work only as a nonsecure HTTP connection. To access it, omit the "s" from the "https://" part of the URL.

davidad

somebody delete this for me
pardo.net/bike/pic/mobi/b.bottom-bracket-standards.html

Camilo

I won't question the assessment you've made that it's a BB creak and not something else. You seem aware that it could be a multitude of things mimicking the BB creak and have made a educated decision.

Assuming you identify the BB as a press-fit and the type it is, I might suggest replacing it with a "screw together" BB if you can. We have two press fit BBs in the family, both PF30. I have one assembled with a Praxis (for a PF30-Shimano Hollowtech crank) and the other a Wheels Manufacturing (for a PF30-Sram DUB crank). I can't remember why one is Praxis and the other WM, could be availability in general or specific availability on the day I wanted to order, or could be that I just wanted to see the differences so went with WM after having done the Praxis earlier. They follow the same general principle, but are somewhat different in design. I believe there's other options too, but not sure.

Both of these are, iMHO, really good alternatives to simple press fit installations. Check them out and see if they make one for your application.

JoeTBM 

You should be able to edit your own posts, look at your post and there should be an "edit" button at the bottom of it.

JoeTBM 

Here is the working link https://pardo.net/bike/pic/mobi/b.bot...standards.html

Hondo6

That link does not work with all browsers. The site in question (pardo.net) appears to use an outdated version of the TLS protocol allowing secure connections (e.g., HTTPS, which uses encrypted connections). Some browsers - later versions of Firefox, for example - do not support TLS prior to 1.2 because earlier versions have known security issues.

However, most browsers also support or can be set to allow non-secure connections (HTTP, which does not encrypt connections) as well as secure connections (HTTPS). Removing the "s" from the "https" part of the link will allow one to view the page in that case by using a nonsecure (unencrypted) HTTP connection.

JoeTBM 

Boy that is weird, I edited it to exclude the "s" and even tried it after I posted it and it was fine...... now it is changed...... spoooky

rmwesley

Like the idea of this, thanks very much for the info.