Gregory Bender

Fork spring and damper information

Moto Guzzi V7 Sport, 750 S, 750 S3, 850 T, 850 T3, 850 T3 California, V1000 I-Convert, V1000 G5, 1000 SP, Le Mans, Le Mans II, Le Mans CX 100, Le Mans III, Le Mans 1000, 1000 SP III, 1000 S, California II, California III, California 1100, California Jackal, California EV, California EV Touring, California Aluminium, California Titanium, California Special, California Special Sport, California Stone-Metal, California Stone-Touring, California Classic, California Touring, and California Vintage models

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I extracted this information from Robert Sharp (LeRoy) off of the old Yahoo! MGconvert news group (which has now moved to Groups.io). In LeRoy's own words:

The two-piece G5 springs are a good value proposition, but you can't just slap them in with the original (silver colored) dampers from the T-3, Convert, etc. They have their own specific (gold colored) dampers. If you go with the G5 springs, you should get the dampers that are specific to them.

As an FYI, the G5 springs have a bit more load-carrying capacity and the two springs are wound at different rates. Compared to the single-rate springs the Convert came with, the G5 setup gives a bit more progressive suspension; softer initial response and firmer springing at the end of travel.

I don't believe that the G5 dampers offer any damping advantage over the those that come with the Convert. They are just a slightly different length.

More from LeRoy:

I have on the bench one each of the silver damper with single-piece spring and gold damper with two-piece springs. Here are the salient comparisons:

  1. The gold and silver damper bodies are essentially the same length. The differences are not noteworthy.
  2. The difference in length of the dampers noted by MG Cycle is entirely accounted for by a longer piston rod on the gold damper
  3. As best I can tell from the slightly knackered gold and silver dampers I have, they appear to have the same or similar stroke. I'd also wager that their damping characteristics in jounce and rebound are similar, if not the same.
  4. The free length of a (used) single-piece spring is 16 716 inch (421 mm)
  5. The free length of a (used) two-piece spring with the essential plastic piece in between them is 17 116 inch (433 mm)
  6. The overall assembled length of a gold damper with springs is approximately 26 12 inch (675 mm) from the top of the damper to the circlip at the bottom of the spring seat
  7. The overall assembled length of a silver damper with single-piece spring measures 26 132 inch (661 mm)

Given that both of these damper/spring combinations fit into the same fork tubes, with the same caps and other fittings, it seems that the gold damper/two-piece spring setup is compressed/pre-loaded a bit more on installation.