Mods For the Bonneville

Nowhere in the world of motorcycles does perfection exist.  Even a bike as good off the showroom floor as Triumph's Bonneville has areas that need to be addressed.

One area that is in glaring need of attention is the suspension.  The choice to go with simple off-the-shelf components from Japanese suspension manufacturer Kayaba was great from an economical standpoint.  The simplicity of the suspension helps keeps the costs down and makes the bike more attractive to buyers.  The downside of that is the suspension is cheap.  Bouncy and pogo stick-like are two ways to describe the stock Bonneville suspension.  Awful is another.

A bike like the Ducati Sport 1000 has beautifully machined upside-down front forks and remote-reservoir rear shocks that perform really well.  The Ducati is also a good $4,000 to $5,000 more than the Triumph.

Hope is not lost, however.

The aftermarket for the Triumph Bonneville is quite extensive.  There are literally tons of suspension options from well-known companies like Ohlins, Progressive Suspension, Hagon, Ikon and so forth.  The options are nearly endless.

After almost three years of riding on stock suspension, the time came for me to finally trade my pogo stick suspension for some quality components.  Really, this is an area I've wanted to tackle for a long time.  The Bonneville is a great bike but between the hardwood stock seat and the bouncy suspension, rider comfort leaves a lot to be desired.

Santa has already helped me address rider comfort by bringing me a Thruxton gel seat for Christmas this year.  Now it's time to make the bike comfortable on Pennsylvania's notoriously bad roads and to make it handle Pennsylvania's wonderful curves a little better.

At the front of the bike, the stock fork springs are going to be replaced with a fork spring kit from Progressive Suspension.  The kit for the Bonneville fits a variety of bikes and comes with two new springs, a 10-inch piece of PVC pipe to adjust preload and a nice sticker.

Progressive springs have the advantage of a variable spring rate.  The springs that come stock in the Bonneville's front fork are constant-rate springs.  They have a set amount of resistance and while that can be good when the road is level, finding those glass-smooth roads is tough.  What ends up happening is the front end begins to bounce because the spring is either too stiff or too soft.

With a progressive spring, the spacing between the coils of the spring is varied - the coils are closely-wound at one end and spread farther apart at the other.  The closely-wound coils allow a soft initial spring rate for quick shock absorption with spaced-apart coils allow a stiffer rate for more resisted shock absorbtion.  You get the comfort of a soft spring rate and the resistance of a stiff spring rate in one unit.    

Bringing up the rear of the bike are new shocks from long-time British company Hagon.  Hagon makes a wide range of shocks from replacements for your vintage bike to high-tech replacements for your superbike.  Somewhere in the middle is the Hagon 2810.  They feature a black-painted steel body with chrome-plated steel springs.  They also have a three-position preload adjuster.  The real reason I went with them (other than cost) is the 10-way dampening adjustment.  This way I can dial the back end of the bike to match the front of the bike.

Plus, putting British shocks on a British just seems right.

Once the suspension is dialed in, my Bonneville is going to be a nice little back road burner.  But the components have to be installed first...