Vintage Ride, Modern Shocks

You can dramatically improve the handling of your vintage ride with some comprehensive upgrades, including modern shocks.

| September/October 2013

Want your classic to handle like the latest from Ducati or Honda? That might be putting the bar a little too high, but you can dramatically improve the handling of your vintage ride, particularly if it’s from the Seventies and Eighties, with some comprehensive upgrades.

Compared to modern bikes, vintage motorcycles typically have pretty unsophisticated suspensions. During the 1970s, engine power — and by default top-end speed — developed at an accelerated rate, yet suspension improvements were slow in coming.

My 1983 Laverda RGS1000 is a prime example of this. With something like 75 rear-wheel horsepower on tap the Laverda isn’t exactly a powerhouse by modern standards. But it’s not exactly slow, capable of 125mph-plus speeds and quarter-mile sprints in the mid 12-second range. Unfortunately, the Laverda’s chassis isn’t quite up to its powertrain. Soft springs and poor damping allied with high friction forks leave the front end with a bad tendency to pogo, especially on small, repetitive bumps. The rear has the same buckboard characteristics, courtesy of a pair of vintage Konis, replacements for the original and notoriously poor-performing air-charged piggyback Marzocchis.

The heart of the problem

I can deal with less than ideal suspension on a bike I only ride a few miles every now and then, but I like to take the Laverda on all-day 500-mile jaunts, and the poor suspension was starting to blunt my enjoyment. Looking for a solution, I put the issue to Matt Wiley, the vintage go-to guy at suspension specialists Race Tech. A fixture at vintage-ride race events around the country, where he helps racers sort their suspension woes, Matt has earned a justifiable reputation for knowing how to make old suspensions perform well.

The problem, according to Matt, is simply one of technology. The Laverda has 38mm Marzocchi damping rod-style forks typical of the 1970s and 1980s. Damping rod forks are limited in performance and ride quality due to their simple orifice-type damping, where a series of holes control oil flow for damping. And despite the fact that road bumps — and riders — come in all shapes and sizes, the orifices are fixed in size and number, resulting in wide variations in fork compression speed. This is single-stage damping, with one damping rate for all situations. But for proper performance and comfort you need dual-stage, high and low speed damping — and adjustability is a nice plus.

Further, where modern fork legs are hard-anodized to reduce friction between the fork tube and the slider, the Laverda’s sliders are just machined aluminum alloy, typical of the era. And without a bushing carrying the load the sliders work directly against the tubes, shedding aluminum into the fork oil as they move up and down the hard chrome fork tubes. That wear shows up as dirty, gray/black fork oil, contaminated with aluminum oxide worn from the sliders. It becomes something of a feedback loop, with wear accelerated by the increase of aluminum oxide in the oil, further contaminating the oil.

7/10/2014 12:06:00 PM

I enjoyed your article a great deal, 18 months ago I purchased custom springs from RaceTech for my 1995 Honda VFR 750F - This totally transformed the bike for me. I am rather chubby at 6'2 and 320 lbs, and with the original springs, the bottoming and shaking in sweeping corners limited me to 90 mph or so, allowing Harleys to run away from me. The custom springs fit me perfectly, no shaking, no bottoming, and 25 to 30 mph higher speeds on the same piece of road. It was largely the expected costs of upgrading the suspension on a 1985 Goldwing that deterred me from purchasing it last month. thanks for your great magazine.

9/26/2013 6:07:31 PM

thnx guys, most awesome restoration how to ive read in a long time. its simply amazing what can be accomplished technology-wise in keeping those beautiful vintage motorcycles up to snuff. truly a painstaking endeavor and well thought out presentation. 110% effort, renewed confidence, maximum performance a simple twist of the wrist. respectfully, gaero

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