BB advice please

rogercoleman

I have a FSA SL-K LIGHT Carbon crankset BB30 with 30mm spindle that I need to fit into a threaded frame.
Can I use ANY BB30 bottom bracket or do I need to look at a specific type.

The frame currently is fitted with a FSA CRANKSET MEGAEXO 19MM SPINDLE. Thread is 1.37x24

any help gratefully recvd,

many thanks from 'easily confused'

rog

not sure what Im not making clear. the frame currently has a Megaexo crankset with a 19mm spindle. I want to remove it and fit a crankset with a 30mm spindle. surely I can just unscrew the existing bb and screw in a new one, only difference being the crankset spindle diameter.
So, what BB do I need

OK Guys, I see what you mean. the LENGTH of the 30mm spindle is too short to fit. I need a crankset with a longer spindle. Just so happens I have one, just not so light as the SL-K

Im going to close this item and raise a new one

BikerGroveish

.....

imposter2.0

I'm not completely clear on what it is you are asking, but it's not possible to fit a BB30 chainset into a frame with a 68mm threaded BB - if that was your question.

BikerGroveish

I think I get what the OP is getting at. In order to fit a BB30 crankset to a threaded frame you’ll need an adaptor. The threaded BBS are 35 mm spindles and the BB30 is 30mm. The adaptors are available from
Wheels manufacturing.

https://www.sigmasports.com/item/Wheels ... lsrc=aw.ds

Or from the manufacturer

https://wheelsmfg.com/threaded-to-30mm- ... black.html

Ben6899

Rotor are your friends.

http://www.chainreactioncycles.com/mobi ... prod130466

I'm pretty sure this is compatible with not only Rotor cranks.

Vino'sGhost

Like imposter says, it is not possible.

Grover the product you identified there is a replacement for the nylon or plastics cups that are pressed into a pressfit 30 frame which hold the bearings (the 30mm bearings)

The Wheels product shown there is pressed in from one side and then the other side is screwed on the thread on the BB itself. There is no thread in the frame itself. The idea is that because the BB screws together it removes some of the tolerance/ creak related issues by providing a more stable and properly aligned BB. There is a similar product to replace BB30 and other products which provide outboard 24mm and 22mm bearings for using shimano and sram cranksets without the need for delrin adapters.

The second product effectrivley puts the BB30 bearing outside of the frame . The cranks wont fit if they are standard diameter, though it may be possible to get a longer replacement spindle. This will then drastically alter the Q factor (distance between feet) and also play havoc with any chainline designed for standard cranks. (Maybe ok with single speed)

Thus speaks the voice of bitter experience.

Vino'sGhost

Ben6899 wrote:

Rotor are your friends.

http://www.chainreactioncycles.com/mobi ... prod130466

I'm pretty sure this is compatible with not only Rotor cranks.

Im not sure it is.

But id genuinely be really happy to be proved wrong

rogercoleman

Ben6899 wrote:

Rotor are your friends.

http://www.chainreactioncycles.com/mobi ... prod130466

I'm pretty sure this is compatible with not only Rotor cranks.

yes Im looking at those, 30mm spindle diameter, just needed some confirmation.

confused when people say it cant be done, not sure its that complicated, unless Im missing something blindly obvious, surely I unscrew the existing bb and screw these in.

Ben6899

I have a Rotor 3D crankset (30mm) in my Italia RC, which has a BSA bottom bracket shell.

I don't want to mislead the OP, so someone please shout up if there's a subtle difference between Rotor 30mm cranks and BB30.

jgsi

I didnt think there was a 'solution' for standard BB30 cranks like FSAs.
(Ive got 2 sitting in my shed)
Rotor may be 30mm but like Praxis (which I am currently using) the actual crank may be longer so their adapters only work with their cranksets.
Now, you might be able to swap the crank spindle, but it is getting even more expensive and with no guarantee it will work when you also take into consideration frame clearances etc.

imposter2.0

Ben6899 wrote:

I have a Rotor 3D crankset (30mm) in my Italia RC, which has a BSA bottom bracket shell.

I don't want to mislead the OP, so someone please shout up if there's a subtle difference between Rotor 30mm cranks and BB30.

There's more than a subtle difference. As mentioned above, Rotor 3D works with a Rotor external BB, so the crank spindle is inevitably longer than a BB30 spindle. BB30 is designed for 68mm shell width with internal bearings, so will simply not fit in a standard BSA 68mm threaded shell.

imposter2.0

BikerGroveish wrote:

I think I get what the OP is getting at. In order to fit a BB30 crankset to a threaded frame you’ll need an adaptor.

Again, you don't seem to understand the topic. There is no such adaptor. Just to be absolutely clear - it is not possible to fit a BB30 chainset to a frame with a standard 68mm BB shell.

Ben6899

Imposter wrote:

Ben6899 wrote:

I have a Rotor 3D crankset (30mm) in my Italia RC, which has a BSA bottom bracket shell.

I don't want to mislead the OP, so someone please shout up if there's a subtle difference between Rotor 30mm cranks and BB30.

There's more than a subtle difference. As mentioned above, Rotor 3D works with a Rotor external BB, so the crank spindle is inevitably longer than a BB30 spindle. BB30 is designed for 68mm shell width with internal bearings, so will simply not fit in a standard BSA 68mm threaded shell.

Of course. Makes sense.

BikerGroveish

Imposter wrote:

BikerGroveish wrote:

I think I get what the OP is getting at. In order to fit a BB30 crankset to a threaded frame you’ll need an adaptor.

Again, you don't seem to understand the topic. There is no such adaptor. Just to be absolutely clear - it is not possible to fit a BB30 chainset to a frame with a standard 68mm BB shell.

You’re wrong see my link. All you need to do is have an adaptor that fits in a BSA threaded frame and reduces spindle diameter from 35 to 30 mm. Which is what those wheels manufacturing adaptors do.

imposter2.0

BikerGroveish wrote:

You’re wrong see my link. All you need to do is have an adaptor that fits in a BSA threaded frame and reduces spindle diameter from 35 to 30 mm. Which is what those wheels manufacturing adaptors do.

You posted two links. The first link is a converter for press fit BB shells (ie larger dia than BSA) and the second link is not compatible with standard BB30 chainsets. It even says that in the description. Apart from that, you were spot on.. :roll:

One more time - a standard BB30 chainset spindle is designed to fit into a 68mm shell with INTERNAL bearings, so any adapter that offers external bearings will not be possible. As far as I'm aware, there is no such adaptor, and as far as I'm aware, it is not technically feasible to make one, for the reasons given earlier.

If you don't know what you're talking about, it's best not to post.

Vino'sGhost

At OP

It is not possible for your cranks I’m afraid . Or at least not unless you want to replace the axle, have bandy legs and gears that rub.

BikerGroveish

Ah yes to be fair the spindle length on your cranks is too short. That’ll teach me not to read it properly.

jgsi

Vino'sGhost wrote:

At OP

It is not possible for your cranks I’m afraid . Or at least not unless you want to replace the axle, have bandy legs and gears that rub.

and thats why I have 2 sets in the shed and cannot give them away.

Vino'sGhost

JGSI wrote:

Vino'sGhost wrote:

At OP

It is not possible for your cranks I’m afraid . Or at least not unless you want to replace the axle, have bandy legs and gears that rub.

and thats why I have 2 sets in the shed and cannot give them away.

Exactly.

BikerGroveish

So in summary You can fit an adaptor that screws into a threaded frame that reduces the 35 mm diameter hole to a B.B. 30 30 mm diameter hole. But the spindle length has to be 104 mm.

Vino'sGhost

BikerGroveish wrote:

So in summary You can fit an adaptor that screws into a threaded frame that reduces the 35 mm diameter hole to a B.B. 30 30 mm diameter hole. But the spindle length has to be 104 mm.

Look mate you were talking bo llocks and giving duff info to the op. Ive looked at your other drivel on the ride London thread, that paints a picture too

BikerGroveish

Vino'sGhost wrote:

BikerGroveish wrote:

So in summary You can fit an adaptor that screws into a threaded frame that reduces the 35 mm diameter hole to a B.B. 30 30 mm diameter hole. But the spindle length has to be 104 mm.

Look mate you were talking bo llocks and giving duff info to the op. Ive looked at your other drivel on the ride London thread, that paints a picture too

First off I’m not your mate ( thank god ). “Drivel” whatever.

Vino'sGhost

BikerGroveish wrote:

Vino'sGhost wrote:

BikerGroveish wrote:

So in summary You can fit an adaptor that screws into a threaded frame that reduces the 35 mm diameter hole to a B.B. 30 30 mm diameter hole. But the spindle length has to be 104 mm.

Look mate you were talking bo llocks and giving duff info to the op. Ive looked at your other drivel on the ride London thread, that paints a picture too

First off I’m not your mate ( thank god ). “Drivel” whatever.

I was using mate in the appropriately condescending way. Mate.