Bb30 vs gxp

[fresherjohn]

Hi all, long term lurker coming out from the shadows for help
I'm in the process of ordering a Chinese miracle bikes cx ta frame but stumped on what bb to order.
I've always used gxp in the past, have the tools and haven't had issues, but I'm struggling to find some new gxp cranks for the build, meanwhile I have loads of bb30 offers.
Internet suggestions are bb30 isn't a good idea for cx as it's too har on the bearings unless you spend mega money on the bb. From experience what do you guys think?

Once it's ordered I'll do a full post on the build and weight. Aiming for around 8kg with robust bits and without breaking the bank
Ty in advanced

[Birdman]

When you say GXP, do you mean a threaded BB (BSA) in the frame where you can install GXP threaded cups?

For reliability and easy of maintenance go with BSA.

If you care a lot about weight more than anything else, go with BB30 or PF30.

[fresherjohn]

Yeah sorry I mean BSA.
I'm just trying to figure out if the bad press around bb30 bottom brackets unreliability is reality

[bikerjulio]

GXP is an excellent, simple system IMO.

I have read criticism of bearing life in CX use, so it may be worth looking for the best sealed bearings you can find. On the positive side, bearings are cheap and very quick to replace.

I don't understand why you are struggling to find cranks when everything SRAM/TruVativ makes comes in a GXP version.

Alternatively there are many other non-GXP choices from Shimano and Campy (who make CX specific cranks and bearings).

[Calnago]

Try it. The bad press is real. Proper install is critical and often requires use of retaining compounds to get it solid and eliminate creaks. Then there's the issue of getting perfect alignment between the two bearings. It's doable of course but far more trouble than it's worth. Whereas a monkey could install a BSA system with a little grease and be trouble free for a very long time.

[fresherjohn]

Calnago - thanks that's what I wanted to hear, I've plenty of experience monkeying BSA bbs.
Bikerjulio - loads new but I'm on a budget so looking 2nd hand and due to the reasons mentioned everyone wants sram gxp cranks

[Marin]

+1 on BSA. SRAM and Shimano cranks are all available with 24mm axles, and a few more. All my bikes are BSA, and I just had a custom frame built and opted for a BSA shell while I could have had any standard I wanted for the same price.

Get an older Force or Red carbon crank, while not ultra light, these are at a great price/performance level. They will work fine with 11 speed - I have 2 10 speed and one 11sp cranks, all on 11 speed drivetrains.

[bikerjulio]

Calnago - thanks that's what I wanted to hear, I've plenty of experience monkeying BSA bbs.
Bikerjulio - loads new but I'm on a budget so looking 2nd hand and due to the reasons mentioned everyone wants sram gxp cranks

I'm seeing a selection of used GXP cranks on eBay sub $100. Also brand new Shimano CX50 can be had for $75 at Ribble.

[Birdman]

My Cannondale Trigger Carbon 2 with BB30 gets plenty of abuse, PLENTY. No BB creak at all. Not even after a few hits that loosen the drive side crank arm from the axle. Still, no creak

My other bikes, BB90, BB86, BB30, no creak either. However, haven't abuse them like I did to my Trigger.

I demoed a Superfly (BB95) few years ago at a Trek demo event, it was creaking loudly. Almost felt like it can be felt through the pedal. Maybe the guy rode it before me abused it? Who knows.