John McGuinness pancakes his...
John McGuinness pancakes his suspension en route to another lap record around the Isle of Man.
With its nice lines and great motor, the Suzuki Gladius is quite a good bike. It's got all the right moves, save for feeble suspension that's so soft it not only wallows in the corners but bottoms over freeway expansions. The stock suspenders and rear shock are such a letdown they overshadow the rest of the stellar package.
But the Gladius isn't alone; in fact, most modern motorcycles can use a little help in the suspension department as well. We chose the Gladius because it epitomizes this two-wheeled epidemic.
"Unless you're talking about an expensive sportbike with top-drawer parts, most bikes can use a few suspension upgrades-especially the bargain bikes like the Gladius," Erick Hilton of Race Tech suspension said.
When it comes to improving your suspension there are two methods; the expensive route of replacing the forks and shock with aftermarket units and the more economical path of upgrading the internals of your stock pieces like we did on the forks of the Gladius.
"No matter the type of riding you're doing, whether it's strictly street, all track or a mix of both, your stock suspension can be tailored to your riding style," Hilton said. He also went on to explain that sportbikes tend to start with better equipment and oftentimes just need the internal pieces like the springs and valves upgraded. But on bargain bikes, especially ones with cheap rear shocks, sometimes a switch to a better unit is necessary since the stock hardware is too diminutive for spirited riding.
Here's a quick brush-up on how the various suspension components function before we show you how they affected our Gladius test mule.
Damper Rod Compression St...
Damper Rod Compression Stroke
Damper-rod forks (DRF) are most-commonly found in traditional fork layouts, with the larger lower legs and skinny upper ones. DRF are also commonplace on older bikes and lower-cost examples like the Gladius, because they are cheaper to manufacturer.
In essence, DRF regulate the speed of fork travel by moving a damper rod with a piston through the damping oil as the fork compresses. The drag created by the oil passing through the holes in the piston creates a rudimentary damping effect.
Since DRF only have one mechanism to deal with both low-speed damping like brake dive, and high-speed damping like hitting an expansion joint on the freeway, it can be difficult to excel at both.
Conversely, if the holes on the damping rod are made big enough to cope with high-speed bumps, they lose their low-speed compression capabilities and tend to bottom under low-speed compression situations like braking. On the flip side, if the holes are too small they work well for low-speed compression but can't flow oil fast enough for high-speed compression.
In essence, there's no perfect set of DRF from the factory, but they can be vastly improved with aftermarket pieces from Race Tech.
Cartridge Fork Compression...
Cartridge Fork Compression Stroke
The second set of common forks are called cartridge style and they can come as a standard style orientation or as an upside-down unit that has the thicker, outer legs at the top and the smaller, inner legs near the bottom. This setup offers far more rigidity than conventional forks.
Cartridge style forks regulate fork speed by using a damping piston with bendable shims stacked up against the face of the piston (like a roll of quarters inside a toilet-paper tube). When the oil flows through the damping piston at slow speed, the shims deflect (bend) and let the oil flow around the edges for good low-speed compression. Yet when a high-speed bump is encountered, the shims deflect even more to achieve great high-speed compression properties. Cartridge-style forks give you soft low-speed damping with great high-speed action because they have linear damping rates.
The feeble rear shock on the...
The feeble rear shock on the Gladius is better suited to a mountain bike than a sport cycle!
Unless you're riding a bike from the old days, your shock likely uses a combination of oil and nitrogen to dampen the bumps. When dampers repetitively move they create heat; when the two combine, the oil begins to foam, which hinders the shock's ability to dampen the bumps. The nitrogen helps prevent the damper oil from foaming by regulating the oil pressure inside the shock.
When stepping up to a remote reservoir shock it not only increases the amount of oil used in the shock, but it also allows the manufacturer to run a separate bladder for the nitrogen inside the reservoir. The increased oil capacity and larger remote nitrogen bladder work together for better cooling properties and increased stabilization of the oil pressure.