utoner34

I have this bike: https://www.specialized.com/us/en/di...e-dsw/p/119017

I need to replace worn bottom bracket so I am wondering about changing to shimano which should be cheaper to replace in the future.

Can you tell me which parts would I need to make it compatible with shimano cranks?

redlude97

That frame uses a praxis conversion BB to convert from BB30. If your goal is to use an adapter to be able to use cheap shimano threaded BBs, there isn't one(except an expensive press in sleeve). If you want to use shimano cranks, then you can purchase the praxis shimano conversion BB(still as expensive as the replacement) or other brand such as enduro/wheels mfg etc

caloso

I have a Praxis on my Tarmac so I can use my Quarq. It is excellent: super smooth, low drag, no squeaks or creaks. Very happy with it.

utoner34

what does it mean That frame uses a praxis conversion BB to convert from BB30?

sorry for being a noob

Cant I put for example this?

https://www.bike24.com/1.php?content...5D=0;orderby=2

https://www.bike24.com/1.php?menu=10...product=125054

redlude97

This is the BB on your frame https://praxiscycles.com/product/m30-conv-bb30-pf30/
You cannot just put that shimano crankset on your frame with the current BB or a shimano BB, you would need one of these:
https://praxiscycles.com/product/shimano-conversion-bb/

As you can see, the cost is the same, so you should just stick with the praxis crankset

utoner34

...

utoner34

Any what is this for? https://www.bike24.com/1.php?content...menu=1000,2,81

Kontact 

That's for an English threaded frame's BB.


I can't find any information on the Alba 2D's specs, but you can probably use a FSA BB30 or PF30. It just depends what size spindle the 2D has and which version of "OSBB" Specialized has blessed your frame with, as they are inconsistent.

If you want to go to a Shimano crank, you can get a cheap bb30/PF30 bearing set and combine it with an adapter from Wheels Manufacturing. But you'll still need 30mm bearings - you just won't need Praxis ones.


Is it possible you can rebuild or replace just the bearings on your Praxis instead of replacing the whole unit? Again, no information for whatever you have in there.

utoner34

hm...

I know I have praxis m30 bsa 68mm, 30mm spindle

Kontact 

The link to your bike you posted says it has an OSBB frame, not an English threaded BSA. OSBB is a 42 or 46mm diameter smooth hole, BSA is a 1.37" (35mm) threaded hole. You can't have both.

utoner34

Is this the same as this frame has?

https://www.specialized.com/us/en/me...mp-e5/p/128909

e_guevara

I'm guessing that that Praxis Alba has a 30 mm spindle since the bottom bracket is a Praxis BB30.

You can use a shim/reducer on the BB30 bearings so you can use Shimano cranks

https://glorycycles.com/fsa-pf30-or-b...e-adapter-set/

Kontact 

No. This bike description says the frame has "threaded BB", which means 1.370 English/BSA. The first bike you posted has OSBB.

utoner34

Can you add shimano bb and crankset to this frame?

Kontact 

As mentioned earlier by several of us, you can put a Shimano crank on either frame. The second one would allow you to use a Shimano brand threaded BB.

fietsbob

Not owning one .. I looked it up https://praxiscycles.com/bottom-brac...ttom-brackets/
there's several..

if its a threaded in external bearing , no problems but do you have the tools
to swap the bearing assemblies ..

for both ?, if different , if you have to buy a tool to remove the Praxis,
and another to install the Shimano

then having the dealer do that, can save money
vs buying a set of tools used just once..

caloso

Now that I've re-read the OP and understand what the actual question is:

I don't think this makes a lot of economic sense. Your bike currently has a Praxis BB30 bottom bracket and a Praxis crankset. (Both excellent quality) The BB is worn out. You could replace it for $75, which is a little spendy for a BB, but again it's excellent quality and it's a simple solution. Change the BB, move on with your life.

Or, buy a new crankset, an adaptor (because Shimano spindles are 24mm, not 30, they require an adapter to be used in a BB30 frame), and you'll still have to buy a new BB30 bottom bracket.

Kontact 

But he likely doesn't need to buy another $75 BB when other 30mm BB choices are available for a lot less.

caloso

He will when he is driven mad by the creaking of the adapter sleeve.

carlos danger

there are threaded alu cylinders that you press into all pressfit BB from for example FSA. There is a permanent loctite that they come with. If you have a metal frame I would have also drilled a 5mm hole in the bb shell and bolted it down to prevent rotation.


FSA BB30 Threaded Adapter (B3119) | Chain Reaction Cycles

Kontact 

There is no adapter sleeve with a 30mm BB and a 30mm crank.

caloso

Shimano cranks use 24mm spindles. That's the problem and why the OP's proposed solution makes so little sense.

Kontact 

The OP doesn't know all the different standards, and I don't think it is unreasonable to think that Shimano must make a BB that will fit in his frame - but they don't. If they did, then the OP's plan would be sensible - buy a new crank to use cheaper, high quality Shimano BBs.

But the OP is asking about this because the replacement Praxis BB for his bike is rather obnoxiously expensive, Which is why we are also discussing how to replace his BB with a cheaper non-Praxis model that would work with his Praxis crank.


The stumbling block is that Praxis doesn't have any 2D information on its website, and Specialized has called a variety of different 30mm press fit standards "OSBB" interchangeably when they are not. "OSBB" may refer to PF30, BB30 and even a version that is only 61mm wide. So until someone can say definitely which "OSBB" his frame has, it is hard to to make a recommendation for an alternative to the Praxis BB. I'm just pretty certain they exist.

TimothyH

Praxis makes a BB30 bottom bracket for 24 mm Shimano. This is what the OP already has but in a 30 mm version. It is a direct replacement for what's already on his bike.
https://praxiscycles.com/product/shimano-conversion-bb/

An Enduro Torqtite BB30/24mm bottom bracket will work as well. I own one of these. It is a gorgeous piece of equipment but not for those looking for a budget build.
https://www.endurobearingsonline.com...eel-bearings-1

Creaking will never be an issue with either of these. They take a couple of minutes to install and could not be simpler.


-Tim-

Kontact 

But if you read the OP, you'd understand that the point of changing was the high cost of Praxis BBs. So a $75 or $199 replacement really isn't much of a solution. I think the OP wants to be able to buy a $20 BB, like Shimano sells, instead of $75 every time for a consumable BB.