Rear sway bar options for eg hatch

[NelsonLSY]

I have been considering either getting a ultra racing 18mm or white line adjustable 20mm due to price factor.

I have searched across the whole forum but opinion varies.

What is actually the biggest diameter I can go for without putting a subframe brace on?
What are the differences between the genuine and the reps?they look like they are made of the same material

[liberx]

I've run the 20mm Whiteline adjustable (on stiffest setting). It comes with with mounting brackets and a bracing bar that reduce the forces on the mounting points, not as effectively as an ASR brace, however I never had any issues with it, which included std springs and some track days (a combination that would put more strain on the sub-frame).

This bar gave the car really good balance on the road rubber - it was quite adjustable between under and oversteer based on throttle and steering inputs, particularly in combination with Type-R springs that replaced the std springs.

I have no experience with the Ultra racing, while 18mm would be a nice upgrade, I'd suggest some form of bracing still.

[DreadAngel]

I have been considering either getting a ultra racing 18mm or white line adjustable 20mm due to price factor.

I have searched across the whole forum but opinion varies.

What is actually the biggest diameter I can go for without putting a subframe brace on?
What are the differences between the genuine and the reps?they look like they are made of the same material

If you're referring genuine as factory, these are aftermarket not reps as they're different diameter to stock.

Either one is fine, I went for UR with my Jazz and its good, having seen the Whiteline kit too I don't see THAT much difference so it's up to you. Adjustable on the whiteline RSB is a nice feature but honestly how much adjustment are you going to do? Unless you're trying to dial in your car for a specific track, like liberx you'll just have it on stiffest setting and leave it at that.

[MIKO_OL]

As above, majority of people won't be dialing or changing the settings if not ever. You said that price was a factor in the rsb it really depends on what you want to do with your car how is it you want to setup do you plan to track it or is it a daily ? etc. Few things to consider when gettting an rsb. 18-20mm is okay for the street. If you plan on going track and depending on what power your running could differentiate. There is also no need to put a subframe brace on. You can actually acquire reinforcement kits which is just an alloy piece to replace it which i have a pair if your keen. Beaks RIO subframe kit. But make sure you get a set with bolts and brackets or else they are useles !