As I explained in my December MPH article, the standard Vincent damper permits the Series C Girdraulic fork to extend excessively and thereby increases the risk of a wobble escalating into a tankslapper. The theoretical full extension (i.e. extension from the null position by half of the bump travel) of the Girdraulic fork occurs when the damper length is 9.812"; any further extension of the fork is unnecessary. The extended length of the Vincent damper is 10.188"; this additional 0.376" of travel does nothing to improve the bump absorbing properties of the fork (nor the roadholding) but allows the fork to extend into the zone where the wheel moves backwards alarmingly. The only justification for this excessive extension is that it permits the springboxes to be fitted without the need for spring compressors.
As I suggested in the article, the extension of the standard Vincent damper can be limited by placing a spacer on the damper rod between the piston and the seal holder. This should be of height 0.376" to achieve the recommended full bump/ full extension ratio of 2/1.
The Monroe damper extends to 10.066" so does provide a marginal improvement over the standard Vincent damper but the Koni extends to 10.5" and is therefore totally unsuitable for fitting to the Girdraulic fork. I understand that the AVO damper has the same travel and full extension dimensions as the standard Vincent damper and that the IKON is dimensionally identical to to Koni. I do not have data for the Thornton damper.
Although it can never provide the sophisticated damping characteristics of a modern gas filled damper, when the Vincent damper has been fitted with all the Paul Ennis mods (see Into the Millenium page 71), it can provide effective damping.
