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d_douglas
09-16-2019, 10:27 PM
I am in process of acquiring a cheap new-to-me frame and it has a PF30 BB shell. What BB do I get? I have a gossamer BB30 crankset that I could use or a square taper Sugino - either are great (though I guess I am leaning towards the sugino)

Is there a PF30 to threaded bb out there that is secure and maintenance free for a 200lber?

The seller had a thread-together Praxis that sounded good - would anyone agree? Others?

This bike will be cheeeeeeppp, so I want the cheapest possible solution that will still ensure a modicum of performance :)

dave thompson
09-16-2019, 10:38 PM
I’ll strongly agree with the Praxis recommendation. I’ve got a Spectrum with a PF30 BB using the Praxis BB. Absolutely quiet and seemingly bulletproof under my 14.29 stone butt. (That’s 200lbs in new money)

zmalwo
09-16-2019, 10:47 PM
I think anything threaded in the middle will give you a good result.

dbnm
09-16-2019, 10:48 PM
I am using a Kogel on my Moots Vamoots RSL with Dura Ace 9000 cranks. No issues whatsoever.
And I weigh 71 kg.

d_douglas
09-17-2019, 12:21 AM
Thanks ! Given my luddite tendencies, I would prefer to use the square taper Sugino crankset.

Is there a Praxis BB that converts PF30 to threaded BSA?

dave thompson
09-17-2019, 05:35 AM
Thanks ! Given my luddite tendencies, I would prefer to use the square taper Sugino crankset.

Is there a Praxis BB that converts PF30 to threaded BSA?

Contact Praxis directly. They’re good folks. https://praxiscycles.com/

VTR1000SP2
09-17-2019, 06:57 AM
Thanks ! Given my luddite tendencies, I would prefer to use the square taper Sugino crankset.

Is there a Praxis BB that converts PF30 to threaded BSA?

My Izalco Max frameset came with a PF30 insert that converted the frame to threaded BSA. I never used it and can send it to you if you cover the shipping.

https://images.coloradocyclist.com/product/800/s/sraixnpz.jpg

d_douglas
09-17-2019, 11:54 AM
Thanks! Now my next dumb question: what length BB does a Sugino triple set up as a 36x24t. And literally, you just grease up the threads and slide it into this adaptor?

Do I need to put Loctite on this plastic sleeve?

TEMPLE
09-17-2019, 02:43 PM
I am in process of acquiring a cheap new-to-me frame and it has a PF30 BB shell. What BB do I get? I have a gossamer BB30 crankset that I could use or a square taper Sugino - either are great (though I guess I am leaning towards the sugino)

Is there a PF30 to threaded bb out there that is secure and maintenance free for a 200lber?

The seller had a thread-together Praxis that sounded good - would anyone agree? Others?

This bike will be cheeeeeeppp, so I want the cheapest possible solution that will still ensure a modicum of performance :)

I got a cheap FSA PF30-to-threaded converter from MEC. Haven't installed it yet, but can't imagine why it wouldn't work. I have had a few Praxis PF30 BBs, including one on my main mountain bike. They are OK, but the durability doesn't seem great. I'll use the FSA converter on my mountain bike after I wear out my last PF30 BB.

kiwisimon
09-17-2019, 03:20 PM
why not use the most modern standard that you can get at whatever your budget is? Seems like a lot of effort to stay locked in the 20th century.

berserk87
09-17-2019, 05:42 PM
why not use the most modern standard that you can get at whatever your budget is? Seems like a lot of effort to stay locked in the 20th century.

Because the "most modern standard" that you reference is the press fit bottom bracket - something that did not evolve out of the need for solving a problem. It did nothing to make anything better for the consumer, but it did make the manufacturing process cheaper and easier for frame makers.

There was some argument about weight savings on the press fit stuff, but it was mostly marketing pablum to make the change more palatable to the end user.

I'm not sure about the need to add an adaptor necessarily, to convert press fit to threaded. I'm not sure what that accomplishes, but I am ignorant on the topic of press-fit to threaded converters. It would seem that it has to do with the application of the OP's crank of choice.

The short answer for your question (in my opinion) is "because the modern standard blows".

kiwisimon
09-17-2019, 06:09 PM
I was thinking more of the BB30 cranks he has. Slip in a threaded PF30 bracket and use the BB30 cranks. He solves the potential noise problem and has modern standards. I have only used PF30 once and experienced no major problems but perhaps I was lucky.

berserk87
09-17-2019, 06:53 PM
I was thinking more of the BB30 cranks he has. Slip in a threaded PF30 bracket and use the BB30 cranks. He solves the potential noise problem and has modern standards. I have only used PF30 once and experienced no major problems but perhaps I was lucky.

Got it. The additional explanation helped.

The issues that I've seen with the PF30 system are:

1. Mystery creaking and gremlins that seem chronic

2. The fact that a bearing press is needed in order to do an installation

3. The fact that a punch is needed to remove them (well, recommended anyway)

The threaded BB's go install and remove with the same tool, and seem to require a lesser degree of precision.

My advocacy of threaded systems may be irrelevant because he's talking about using an adaptor - the adaptor could have the same issues with creaking and such, no?

dddd
09-18-2019, 10:47 AM
I see potential issues with a composite adapter.

Since a cartridge bb installs with cup force pushing in to secure the cartridge, the adapter in turn must resist this "clamping" force by being heavily tightened into the smooth bb shell. This tightening tension in the adapter appears to be resisted by thin composite flanges, which leads me to suspect that the tension may not be adequate to keep a threaded cartridge installation tight over time. Not only will the flanges yield initially, but the clamping force on the bb cartridge itself will forever be trying to pull the two halves of the adapter apart, so would seem to encourage loosening (with resultant severe creaking) over time.

As much as I dislike the excessive and fixed chainline of today's modern-style cranksets, I might prefer here to use the pressfit bb, since I have had no troubles with these on quite a few of my own installations.

Most of the pressfit bb's I've purchased were SRAM, inexpensive and seemingly creak-free.