California rear suspension travel?

[MotoKuzzi]

I'm curious as to what effect a pair of longer travel rear shocks would have on the handling of my California. The centre eye length of my standard rear shocks is 340mm with about 15mm of pre- load applied. I'm looking at the idea that a set with more travel would help smooth the ride on our increasingly rough roads. If I went to say a 350mm set what effect would it have on handling etc? Would the change to the working angle of the drive shaft universal be too much? Any advice appreciated.

[Paul in NZ]

Try better quality shocks.

The rear drive is a solid heavy old lump so the rear ends always going to be a bit clunky...

[Kickaha]

Without appropriate valving and springing they could well turn out to be worse than what you currently have

[Robert Taylor]

Try better quality shocks.

The rear drive is a solid heavy old lump so the rear ends always going to be a bit clunky...

That is correct, its not only about the length of travel its also about the quality of travel.
Cheap shocks have little to no low speed compression damping to keep them riding high in their stroke and very crudely rely on heavy springs with lots of preload to compensate. But that then means that when you ride over very abrupt bumps ( served up with some regularity in our shaky isles ) there is too much spring force and you get a nasty ride.
Ohlins no longer produce twin shocks for Guzzis so the last few sets we have custom built, one set very recently for an old Le Mans and the guy is blown away with the improvement after suffering Konis for years.
A slight length and stroke increase can be effected and the main improvement with that is an improvement in geometry, steering response and balance. The limit of course is the angularity on the drive uj.
The Ohlins shocks will have a properly arranged low speed compression curve that will handle much of the duty of ride height control and allow significantly lighter springs than the ''jackhammers'' and cheap gap fillers that are peddled. That allied with very generous piston port size delivers an improvement in bump compliance that is night and day. Note also that the bore size of Ohlins twin shocks is 36mm, significantly more than oem and cheap stuff.
As an example of how effective a properly arranged compression damping curve is we recently built a set of shocks for a Triumph Rocket 3. The standard shocks are just awful, they are single acting and have heavily preloaded 5.2 newton springs. With the Ohlins dampers we have made the spring rates are now 3.8 newtons, the bike has much better ride height control and bump compliance.
Shaft driven bikes rise under acceleration so having effective and sophisticated rebound ( extension ) control is also a big bonus, allied with a little extra travel.
We can build in single tube for $1199.90 gst incl per pair or piggyback reservoir for $1599.90 gst incl per pair. Thats a little more than the ''jackhammer'' offerings but the level of performance is way better and it will be the very best money that you can spend on that bike.

[MotoKuzzi]

.... Cheap shocks have little to no low speed compression damping to keep them riding high in their stroke and very crudely rely on heavy springs with lots of preload to compensate. But that then means that when you ride over very abrupt bumps ( served up with some regularity in our shaky isles ) there is too much spring force and you get a nasty ride.
.....

Very interesting analysis, never looked at it in that way before. If I decide to keep the bike long term it sounds like a good next step.

[Robert Taylor]

Very interesting analysis, never looked at it in that way before. If I decide to keep the bike long term it sounds like a good next step.

Just pulled the spring off a new Thunderbird twin shock today. Same deal, only single acting and absolutely no low speed compression damping. Heavy spring rate with around 30mm of preload. Velocity squared rebound damping. This is common and there are at least 3 reasons why, low cost, low cost and low cost.

[MotoKuzzi]

Just pulled the spring off a new Thunderbird twin shock today. ....... Heavy spring rate with around 30mm of preload......

Sounds familiar, chances are I will be keeping the bike a while, so I had better start saving to give it a Xmas present or at the very least a new yrs gift.