Road Tested: Öhlins fork springs and oil for the Bonneville

It’s common to see custom bikes with swanky high-end shocks propping up their tails. Swapping out the rear suspension on a twin-shock bike is quick and easy, and can have a big impact on both handling and style. But if you upgrade your rear suspension without upgrading your front suspension, you’re doing it wrong.

There are myriad ways to beef up your bike’s front end, from full fork swaps to cartridge kits. But there’s a simpler way to eke the maximum performance out of your forks—like a simple Öhlins spring swap and oil change.

The front forks on my air-cooled Triumph Bonneville are basic 41 mm right-side-up units with zero adjustability. According to the internet, their springs have a rate of around 7 N/mm, and their oil has a viscosity of between 5 W and 10 W. That might be fine for an 80-kilo [176-pound] test rider, but it’s woefully inadequate for a giant man-bear like me.

Rather than go down the rabbit hole of a full front-end overhaul, Öhlins sent me a set of springs and a couple of bottles of oil to see if they would make a significant difference. Since I was about to send my forks off for a service and fresh seals anyway, it was a timely upgrade that made sense. But how much better can a set of budget OEM forks perform with a simple spring and oil swap?

The short answer is ‘a lot.’ It’s simple math; the Öhlins springs, which are listed for €162,38 via Öhlins Europe and $159.00 via Öhlins USA, have a linear spring rate of 9 N/mm. The oil has a viscosity of 20 W, and both are quality products—so you’d expect at least some improvement in feel. What I didn’t expect though, was just how big that improvement was.

Right away, I noticed a tangible increase in stiffness and a decrease in static sag. And not only does the bike better suit my height and weight now, but it also handles a whole lot better. Before, the front end would feel unsure of itself in corners, with a vague feel that starkly contrasted my Bonneville’s top-shelf rear suspension—now, it not only turns in with more confidence, but it holds its line better too.

Sure, it’s not as revolutionary a change as fitting a set of fully adjustable performance forks to the bike, but it’s also not as expensive or time-consuming. A full front-end swap often involves a whole lot of work that you may not have budgeted for, like making sure your yokes, brake caliper mounts, fender mounts, wheel spacers, and axle all play nice with your new forks (or fabricating new parts).

This upgrade, by contrast, is no more complex than a regular fork service. So if you have the time and money to go the whole hog, don’t let me stand in your way. But if your choices are neglecting your forks or making a simple change like this, do this.

With thanks to Öhlins Racing | Images by Wes Reyneke

Sidecar Subject: Öhlins Racing Founded: Established in 1976 by Kent Öhlin in Sweden. Initial focus: Began as a workshop developing high-performance suspension for motocross bikes. Motorsports success: Achieved multiple championships in motocross, Formula One, and various motorsport events. Expansion: Expanded product line to include products for road motorcycles, cars, and mountain bikes. Brembo Acquires Öhlins Racing Announcement: Öhlins’ parent company, Tenneco, has announced its agreement to sell Öhlins Racing to the global braking system manufacturer Brembo. CEO Statements: Tom Wittenschlaeger, CEO of Öhlins Racing, expressed enthusiasm about the partnership with Brembo, highlighting the potential for new growth opportunities and the ability to drive innovation for customers and employees. Brembo Executive Chairman Matteo Tiraboschi praised Öhlins as a strong addition to their portfolio, noting its reputation in motorsports and the automotive market. Future potential: The acquisition is a step towards providing integrated intelligent solutions. Regulatory Approval: The deal is expected to close in early 2025, pending regulatory approvals.