How much does geometry affect ride

[kurth83]

Long story short, after going through many bikes, and being forced by my aging back to pick ones that have very cushy rides, I now have a few points of comparison and the following make me curious:

- dual shocks on the back of a cruiser = harsh ride no matter what shocks you put on it.
- my F700GS rides smoother than a Triumph tiger 800 XR, which rides smoother than my CB500X, which has a decent ride on its own.

The last point is the interesting part to me, all three are adv bikes, use simular types of suspension (dual front forks, single shock on the rear), the CB500X has a noticably shorter wheelbase than the other two, mostly a shorter swingarm, which seems to put the rider more over the rear wheel rather than in the pivot center between the two wheels.

So how much of the ride difference on the three adv bikes is attributable to shocks and how much to geometry, or is geometry even an issue? My gut tells me the longer wheelbase and the single rear shock (all other things being equal) is potentially softer than a shorter wheelbase bike, or dual rear shocks for which I now have PTSD - never again.

If true, what do you give up with a 6-8" longer wheelbase - everything is a tradeoff right? - is it some kind of agility? And why does the Tiger ride differently than the BMW, could a suspension change on it give it the cushier ride the BMW has (I think the Tiger 800 is a nice bike other than the ride).

I've read some of the other posts here and it seems you can tune a suspension to what you like to a point, but it seemed to me you have to at least start with a bike with a design that will let you get there.

Wanting to learn just a little bit more.

 

[motomania2007]

Suspension plushness is mostly determined by:
Suspension set up
Sitting position

For example, I can't ride any bike that has me sitting straight up or leaning back or with my feet anywhere but mostly under me so I can push down with my feet to support some of my weight.

I have to lean forward, at least a little, or every bump acts as a jackhammer up my spine.

 

[Butch]

Totally

 

[stangmx13]

if you were to optimize the suspension for a given geometry, I don't think most riders could tell a difference in ride quality or plushness btw two bikes with very difference geometry. it matters, but having the wrong spring in there or a shitty damping curve matters a lot more. and thats the thing, u gotta optimize the suspension. bikes with stock suspension are not optimized at all. so the original comparison doesn't really answer the question.

also, shock configuration doesn't really fall under "geometry". even so, there are still a few sport bikes bikes that have direct mount rear shocks and I doubt ppl complain too much about the ride. the cruiser had a harsh ride probably because the dual shocks were pieces of shit w/ poor damping and the wrong spring rates.

 

[Reli]

My gut tells me the longer wheelbase and the single rear shock (all other things being equal) is potentially softer than a shorter wheelbase bike, or dual rear shocks for which I now have PTSD - never again.

I don't think the number of shocks matters as much as their location, the linkage design, and whether the spring rate has been chosen correctly for you.

As for wheelbase, yes it affects the ride. For example if you install a substantially different sized sprocket/chain set.….your axle position will change....I've definitely noticed the difference in ride. But that's just one bike. You can't take 2 different bikes and say one will ride softer than another just because its wheelbase is longer.