I chose PF30 for my new frame because it helps make the bike 'future proof' by giving more options. I can still run adaptors for a standard 24mm spindle. I can run a BB30 crankset and save a bit of weight.

But this is for a road bike, not a mountain bike.

I've tried the Praxis conversion bottom bracket. For awhile I thought I found a solution to my creaking issues. It was noise free bliss, but after a couple weeks the dreaded creak started coming back. I think the Mosaic builder is maybe on to something when claiming that using a thread on engagement type of BB or BB adapter might help alleviate creaking, but I honestly don't think it is a legitimate solution for these creaking issues people have with BB30 and PF30.

Please note: I have used the Praxis Conversion BB which is advertised as being better than what Praxis calls "Band Aid" type of adapters like the Rotor BB adapter. I bought the Praxis purely because I believed their marketing thinking the Praxis Conversion BB would stop my BB creaking. It didn't work for me. I was once a high level mechanic and i know what i'm doing. Needless to say, I am a little biased against Praxis. I have not tried the Rotor BB adaptor, but at this point am skeptical that it is going to do any better at fixing this creaking problem.

Hi All

thank you for all the answers - you WW's really got me thinking.

As I mentioned in my first post I actually do not need the BB30/PF30 right now. It is/was only for the possibility to run BB30 cranks in the future to come.

There is so much going on in the bike industry........

When I was writing the first post I was leaning towards the new Chris King PF30/24 BB or Praxis Works Conversion PF30/24 BB.

But you have got me thinking because:

1. Maybe the Praxis Works Conversion kit is not enough to prevent creaking (see Winky's answer)

2. The frame manufacture I am going to use is using the PF30/68 standard.

If the BB is the PF30/68 road standard used on a mtb frame (just like the Moots MootoX RSL), can the Praxis Works Converther then be used? As I see it, then it has to be the road version that has to be used. In that case the overall lenght of the BB will be 5 mm to narrow. Will the bearings the be in contact with the bearing contact surface on the 24 mm crank axle (XTR FC-M980) in that case? There has to be a 2,5 mm spacer between the outside of the bearings of the Praxis Works Converter and the crankarms.

Maybe I am leaning towards the old school BSA-68 BB (73 mm is not an option) and a Chris King BB. I all ready have the King BB injector tool.

@ Winky: when you used the Praxis Works Conversion kit, did you then use ti prep anti seize compound between the BB and the converter?

Ciao

ebsilon

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Speed of Lite

I admit. I did not use any Ti prep anti-seize paste in the BB shell. I tried grease only, Teflon tape only, and grease + teflon tape. Gave up after that. I just don't believe in using any thread locking or pseudo-thread locking paste in a bottom bracket. My feelings are that if you have to resort to that then something else isn't right.

I want to clarify my experiences about the Praxis converter BB. I didn't have a good experience with the BB, but that doesn't mean I don't think it's a well-made product. In fact, I think it is very well made. And it is, at least, worth a try if you've tried everything else to get your creaky BB to be quiet. I, personally, don't think it does anything significant to get rid of the creaky BB noise.

My theory on these creaky BB30 and PF30 Bottom brackets is that the frame's BB shell has to be super duper round and within really, really high tolerances of being perfectly round so that creaks don't occur. I might have an incorrect theory on this, but I think that the BB shell of more metal frames (steel, alu, ti) are more susceptible to creaks than that of carbon. When a frame is welded or brazed there is considerable heat that goes into the BB shell. That heat warps and makes the BB shell not-so-round. Maybe to the eye the shell looks round, but it really isn't. On BSA cartridge bottom brackets, the shell is screwed into the shell. There is a continuous tight fit, and roundness tolerances don't need to be as high. However, on BB30 and PF30 frames, the bottom bracket isn't screwed into the BB shell. It is pressed in. So, any out-of-round BB shell is going to have a higher chance of creaking.

PS - I also have a Moots. When I read one of the earlier replies about someone with a creaky BB Moots annoying people on group rides, I swear that person was talking about me. . LOL! And don't get me wrong on this. I love my Moots. It rides great! I just wish I went against the current trend for BB30 and PF30 BB shells.

Hi Winky,

now that you mention that your frame is a Moots, then it tells me that it has a PF30/68 BB.

What type of Praxis Works Converter did you purchase to make the installation of the non PF30 crank?

Road 68mm or mountain 73 mm?

I presume that we are talking about eg a Shimano crank, right??

In that case the Moots PF30 BB shell and the Praxis Converter combination is to narrow (Praxis Converter - Road 68 mm). Did you then use spacers between the outside of the bearings of the Praxis Works Converter and the crankarms then??

Ciao

ebsilon

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Speed of Lite

Sorry. I wasn't clear. I have the Praxis on a different bike, but I do have a press-fit BB on my Moots cyclocross bike, which I like to take on the road sometimes just to annoy my friends with my creaky BB.

[quote="winky"]I admit. I did not use any Ti prep anti-seize paste in the BB shell. I tried grease only, Teflon tape only, and grease + teflon tape. Gave up after that. I just don't believe in using any thread locking or pseudo-thread locking paste in a bottom bracket. My feelings are that if you have to resort to that then something else isn't right.


I have a trek or gary f. Superfly, if im correct it has. Bb95 shell ( i wish they would stop inventing new b.b. !) it has two braring that pretty much fall into place, quite a loose fit. I kinda bought the bike in a impulse, i was looking for a29r and got a realy nice deal. One of my friends back home deals a lot with these bikes and when i told him what i bought he said it wold be an absolute nighmare, it would brake at the seatpost end of things and it would creak. He also told me that in the shop he works they glue the bb bearings with a mild strenght bearing retsining compound, otherwise the bearings crak than move than oblong the shell.

First ride the bike was sillent, second ride the bike was so noisy that i was convinced that the bottombracket shell could fall out any minute.
After finishing my ride i ripped the bb appart inspected it, degreased it and used a bearing retainer while putting everything back together. That was the last noise it made, when time comes to replace the bearings i will have to heat them up with a hair dryer, now im not sure how much a c.f. Frame can tke but im sure a ti fame would have no issieus with that.

I agree with you that frames in that categorie should be perfectly reamed and machined and one would think that there should not be any creaking after that but if a 10$ bottle can cure i would certainly give it a go, it worked for me (;

ebsilon: If it were me I think I'd opt for the 68mm BSA and the Chris King BB. You can still fit a lot of 30mm cranks in there (like I said I've managed to install a Hollowgram SL2 in mine), and you know it'll be bomb proof. If you do want to go PF30/68mm, I'd suggest you get in touch with Praxis and ask them if there's a way to use their BB on your frame with Shimano cranks. I think your reasoning is correct, that the bearing surfaces on the crank will be in the wrong place relative to the bearings, but they'd know for sure. Personally I'd keep clear of the PF30/band-aid adaptor setup, so if the Praxis BB didn't work that'd definitely make my mind up.

Edit: I called Praxis since it was easy being in the USA... the conversion BB won't work on a mountain bike with 68mm shell width for the reasons you surmised Ebsilon. So you either need to convince your framebuilder to do a 73mm shell, take your chances with band-aid adaptors (bad idea I think), or stick with the BSA system.

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Enjoying my Funk

Hi dwaharvey

Thank you so much for your help - I really appreciate it

I think I will go for the BSA 68 then.

Ciao

/ebsilon

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Speed of Lite