Bottom Bracket query

[Jordptp]

1st post! Hi all, have ridden a 2010 Trek Alpha 1.5 since new but finally during lockdown decided to chop it in and build a new bike for me. Components (costsbelow for those interested. Big question I have though is around the bottom bracket, the frame has arrived with bearings set in place although every video I’ve seen has the crank empty to start with. One spins on drive side and one doesn’t. Question to the far better informed out there, a) what are they? b) do I need to remove/change them c) I have an RS500 BB coming for it that is allegedly compatible? Is this true! Thanks again!

spec;
Specialized Carbon Tarmac Sport SL2 £150
Ribble Sportiv Forks (£97)
Shimano 105 GS (£130)
Shimano 105 Crank (£65)
Look Pedals (£30)
Toseek Carbon Bars (£40)
Wheels (not yet purchased! Need recommendations under the £250 mark)
Rubber (as above)

 

[rogerzilla]

I believe it has either a BB30 or PF30 shell so an RS500 BB (designed for the usual 1 3/8" ISO shell) won't work unless you slerve it down with an adaptor. The FSA adaptor is about £20 but you need a headset press and it's not for the faint-hearted. Cock it up and it could be stuck halfway in for life.

 

[Milkfloat]

That is a BB30. If you really want to use your Shimano groupset, then you will need to remove the bearings, circlips etc and fit this https://www.spacycles.co.uk/m2b0s110p4035/FSA-BB30-Threaded-Adapter This is a one way street, as you permanently mount the adapter using Loctite 609. You would then screw in the RS500 BB and change that when needed. If you don't want to go the permanent route, then replace the BB30 bearings with fresh ones (as low as £6 a pair) and then use a BB30 crank.

 

[smokeysmoo]

That is a BB30. If you really want to use your Shimano groupset, then you will need to remove the bearings, circlips etc and fit this https://www.spacycles.co.uk/m2b0s110p4035/FSA-BB30-Threaded-Adapter This is a one way street, as you permanently mount the adapter using Loctite 609. You would then screw in the RS500 BB and change that when needed. If you don't want to go the permanent route, then replace the BB30 bearings with fresh ones (as low as £6 a pair) and then use a BB30 crank.

I converted my BB30 to HTII several years ago due to the very well documented creaky squeky issues associated with BB30, (early ones anyway). I used the FSA adapter Milkfloat linked to above, and it's been brilliant, I'd recommend it to anyone

 

[Jordptp]

Thanks @Milkfloat really useful. Does anyone know if BB30 works with 105 GS? Rather go down the BB30 route than the permanent risk of fixing the adapter. Cheers! And if anyone is feeling super helpful I’ve written another thread on headset as my forks have arrived and I’m having issues. I’ll happily PayPal a coffee fee for any help, particularly anything that stops me having to buy other forks or frames!

 

[faster]

That is a BB30. If you really want to use your Shimano groupset, then you will need to remove the bearings, circlips etc and fit this https://www.spacycles.co.uk/m2b0s110p4035/FSA-BB30-Threaded-Adapter This is a one way street, as you permanently mount the adapter using Loctite 609. You would then screw in the RS500 BB and change that when needed. If you don't want to go the permanent route, then replace the BB30 bearings with fresh ones (as low as £6 a pair) and then use a BB30 crank.

There are other easy, cheap and reversible ways of using your shimano crankset (but not the RS500 BB). Just google something like BB30 to HT2 conversion. There are quite a few options.

This is presuming your shimano crank is HT2 (hollow 24mm axle) rather than an old square taper one.

 

[cyberknight]

https://www.sjscycles.co.uk/bottom-...bottom-bracket-to-shimano-adaptor-road-68-mm/

 

[Milkfloat]

Thanks @Milkfloat really useful. Does anyone know if BB30 works with 105 GS? Rather go down the BB30 route than the permanent risk of fixing the adapter. Cheers! And if anyone is feeling super helpful I’ve written another thread on headset as my forks have arrived and I’m having issues. I’ll happily PayPal a coffee fee for any help, particularly anything that stops me having to buy other forks or frames!

BB30 is a different size, so you either need a BB30 crank set or a converter. There are other non permanent converters but they retain a basic press fit BB30 style bearing and from what I have seen run the risk of creaking like mad. If it were me I would swap to a BB30 crank.

 

[Tenacious Sloth]

I’ve been using one of these on my CAADX for the last couple of years with no issues. It is removable if you later want to revert to BB30. You don’t need a press to install either, it just screws together.

You can find it cheaper if you shop around. I paid about £25.

https://www.sigmasports.com/item/Rotor/BB30-to-24mm-Converter-Bottom-Bracket-Steel-68mm/10S6