Date: Sun, 12 Jul 1998 21:44:12 -0700
From: Ben English
Tom Davenport wrote:
> For that special occasion it is possible to put the Hagons on the
> Norton.... I took a pair of Fox's _off_ my (still not running
or titled)
> FT500 and put them _on_ the P11, to the immense delight of my sitter.
> The spring preload, on most stiff, is not enough and needs a spacer.
> Otherwise, it's a good interchange; the bikes aren't dissimilar in
> weight.
The Progressive Suspension application chart shows EXACTLY the same shocks & springs for Commando and FT500. Springs are listed as two options- standard and heavy duty.
Both Commando and FT500 angle the damper units forward at the top, while the P11 mounts them in the traditional mode closer to vertical. The FT500 lower mounts are also a bit forward of the axle.
The forward mount and angle ("laydown") were inventions of the late 70s when dirt riders attempted to get more travel out of the old twin shock layout by mounting the shocks so that less leverage was exerted on them. They got more travel and less spring & damping effect. FT500 springs _should_ be too stiff for the P11.
Preload is a different issue than stiffness. It affects ride height- and just where in the range of movement allowed by the suspension you start from.
Ben English
1972 Norton Commando Combat Roadster #201695
1982 Honda FT500 Ascot / 1972 Olmo 10 speed
Amtrak National Timetable / Pocket full of bus tokens / Good shoes
Albany, New York, USA