Right from the get-go, we’ve raved about Beta’s 2023 RR390 – a machine that got a bunch of subtle but significant mods to engine, suspension, bodywork and mapping for 2023 (in addition to already copping a heap of upgrade attention in 2020, 2021 and 2022), and remains the Italian brand’s biggest selling four-stroke model in the Australian market.

When you ride the thing, you’ll instantly know why it’s so popular. As we outlined in this recent article about the RR390’s standout character traits, its 385.6cc powerplant is an absolute peach. With noticeably more torque than a 350, but nowhere near the gyro effect of a 450, it boasts the side-to-side agility of a smaller-capacity machine. In tight terrain, its torquey and responsive power works a treat. But the thing still pulls hard at higher revs when you’re holding the taps wide open on fast grasstrack. In other words, it’s a great allrounder – arguably even more so that the 350cc machines offered by several other brands.

Like many of the bikes coming out of Europe these days, Beta’s RR390 is a hardnose, lightweight, minimalist, race-ready enduro weapon. But that doesn’t mean it can’t be improved or customised to suit the sort of riding you do. And as we’ve been taking our 390 into a fair bit of extreme terrain of late, we decided to throw some extra protective parts on it (in spite of the fact that protective parts add weight), along with a few other judicious additions of practical parts and red Beta bling.

Here’s a snapshot of what we fitted and why, along with a parts table that itemises what it all costs, consumables included…

THE PARTS WE FITTED

AXP XTREME SKIDPLATE ($230)

The 390’s standard plastic skidplate is pretty bloody good, but to bolster and extend the underside protection for the bike’s engine cases, frame rails and shock linkage, we fitted this renowned AXP Xtreme unit. At 1400g, it does add almost a kilo to the bike, but we felt that was a small price to pay for the added insurance it provides. It is a bit fiddly to fit and needs to be removed for oil changes (which can serve as a bit of a maintenance disincentive). Also, be aware that the pressure it applies to the lower shock mount alters the rear shock’s static sag measurement slightly.

AXP XTREME RADIATOR GUARDS ($200)

Again, these AXP Radiator Guards add an extra kilo of weight, but they amplify the protection for your radiators (which cost $363 per side to replace!) significantly from both crush and fold-back damage – thanks to the way they’re neatly braced back to the bike’s frame itself. The downside is that they reduce the already more-restrictive-than-average steering lock and, with the front grill fitted, reduce airflow through the radiators.

THERMO FAN KIT ($280)

Without a thermo fan, the RR390 has proved incredibly resilient to boiling its radiator fluid, even in the most extreme conditions. But because the AXP radiator guards we fitted reduce airflow (a by-product of the protective grills that replace the OEM plastic louvres), we figured it’d be prudent to instal a thermo fan at the same time. If you fit the thermo fan directly (that is, without radiator guards fitted), it does take a bit of dicking around to instal – including dropping your radiator fluid and pop-riveting the fan into place via a couple of supplied brackets. But if you’ve already fitted the AXP Xtreme Radiator Guards to your bike, the good news is that the Beta thermo fan simply bolts straight onto the rear of LHS guard itself.

LIQUID INTELLIGENCE SUPER WATERLESS COOLANT ($65/Litre)

Glycol-based coolants raise water’s boiling point to 115º, but Liquid Intelligence MX 115 – a fully synthetic waterless coolant – gives you boil-over protection up to 190º! Aside from boosting performance by helping your engine run cooler, it gives you the confidence of knowing that your coolant won’t boil, no matter how snotty the terrain. Just note that it’s important to properly drain and flush your cooling system of all water before filling with Liquid Intelligence. But even if you do have to mix the LI with some water, your coolant’s boiling point will still be around 115ºC.

BILLET ALLOY REAR DISC GUARD ($200)

If you tend to ride a fair bit of technical terrain and/or deep ruts, then you’ve probably bent a rear brake disc or three. Fitting a shark fin-style disc guard is a cost-effective way to minimise the risk of a rock damaging your rear disc (which costs $195 to replace). This Billet Alloy Rear Disc Guard (a Beta Genuine Accessory from Propower) is beautifully made, super-strong, and comes with its own billet calliper carrier.

CLUTCH SLAVE CYLINDER GUARD (RED BILLET) ($150)

If your chain has ever thrown a rock through your engine cases or clutch slave cylinder (and called a premature end to an expensive day’s riding), then you’ll understand that $150 is cheap insurance. This red billet ‘case saver’ bolts quickly and easily in place in front of the countershaft sprocket. It comes with two supplied (longer) mounting bolts with neatly recessed 5mm Allen heads. This red alloy guard also offers better protection for the electrical wiring that runs up in front of the clutch slave cylinder (the Neutral sensor and stator pick-up).

BETA HAND GUARDS (RED) ($80)

Hand guards don’t come as standard equipment on Beta’s RR models. At first glance, the ones that came fitted to our project bike (a $80 Beta genuine accessory) seemed like flimsy, brush guard-style units. But we soon discovered that, because they’re designed to spin on their plastic mounting bracket in a crash, they’ve actually surprisingly resistant to busting.

AS3 BRAKE & CLUTCH BAR CLAMPS (RED) ($39.95)

With the Teflon lining only inside the AS3’s half-perches, we weren’t sure they’d allow the entire perches to spin on the bars in the event of a crash – but they do. Also, the 5mm Allen Key bolts (which replace the 8mm hex-heads) are recessed for a much neater look up on the bars. When you consider the cost of busted levers and/or damaged master cylinders, $40 is insurance money well spent in our view.

BETA RACING SWINGARM DECAL KIT ($30)

We dig the look of the black coating on sections of the swingarm. But if you ride a lot of rocky or extreme terrain, that black gets scuffed up pretty quickly – which is why we’re planning to fit a set of clip-on plastic swingarm protectors down the track. Meantime, this Swingarm Decal Kit adds a factory look to the bike, along with a little added protection.

BETA RACING FORK GUARD DECAL SET (RED) ($30)

The standard fork leg protectors are pretty bland, so why not fit some Factory-look decals?!

BETA RACING UPPER FORK DECAL WRAP SET ($35)

Aside from complementing the fork guard decals, these super-thick upper-fork decal wraps also offer protection against those unsightly stone chips.

AIRBOX WASH COVER ($60)

No, 60 clams isn’t cheap for a small lump of plastic with a sealing surface. But again, we reckon it’s a worthwhile investment because it prevents water from getting into the inlet tract when pressure-washing the bike. It also forces you to inspect and remove your air filter before cleaning the bike.

UNIFILTER FOAM AIR FILTERS ($42)

There’s nothing wrong with the Twin Air foam filters that come standard in the RR390, but we like to run Aussie-made UniFilter foam filters for two reasons. One, they come in two-options: a single-stage ‘02 Rush’ version for performance and a dual-stage ‘ProComp2’ for added protection in dusty conditions or on long rides (and which can be separated to clean and re-oil). And two, because we reckon UniFilter’s mineral-based foam filter oil (Filter Fix) is the best product on the market.

LIQUI MOLY OIL & BIKE CARE PRODS

Call us superstitious, but we’ve always been disinclined to change the brand of oil our project bikes have been run-in with. Thankfully, the boys from Lowry Australia (who distribute Beta Motorcycles in Australia) flowed us some Liqui Moly 4T Synth 10W-50 engine and transmission oil (both compartments use the same oil) and a few bike care products from Liqui Moly.

Stay tuned for our upcoming video edit that goes onto greater detail about the fitment and benefits of these parts on our RR390 project bike. Meantime, here an itemised table of what the parts we fitted cost (including a few consumables we’ve used)…