S vs SS Suspension

[bmwonder]

I'm just about to fit my shorter 365mm torque arm on my standard S. But I still uncertain what this is going to do to the spring rate? If I keep the standard spring am I not changing the spring rate? I guess that I will be getting about 4-6mm extra at the shock end of the swing arm? Anyone know? I don't think that it will have any effect on the shock (we'll see?), but should I load up the pre-load a bit to take into account the slightly longer spring travel?

Thanks all!

[adamski49]

Shock rate is unaffected, it just pulls the rear bevel drive closer straightening the UJ angle, shortening the wheel base slightly and jacking the back up about 25mm IIRC.

The shock remains at the same length and the swingarm the same angle from the frame.

HTH

Adam

[bikemad99]

I'm just about to fit my shorter 365mm torque arm on my standard S. But I still uncertain what this is going to do to the spring rate? If I keep the standard spring am I not changing the spring rate? I guess that I will be getting about 4-6mm extra at the shock end of the swing arm? Anyone know? I don't think that it will have any effect on the shock (we'll see?), but should I load up the pre-load a bit to take into account the slightly longer spring travel?

Thanks all!

Could you please let me know what effect it has had on the side & centre stands, if you have one fitted. Do they still work, or do you need a longer one.
thanks.

[BMWR1150RS]

Hi All
I must have learnt something. The side stand needs a bit welding on it as does the centre stand or it just hangs in the breeze

Alan

[BMWR1150RS]

Hi All
I must have learnt something. The side stand needs a bit welding on it as does the centre stand or it just hangs in the breeze

Alan

[winger]

What you need is a side stand of an SS or Boxercup.

bmwonder,I like to think i've some idea about shocks and suspension!! but bloody hell you've lost me!!! what are you on about???,it'll alter the steering,leave the shock alone it'll have no affect on that what so ever.

Chris

[gus]

I,ve jacked mine up at the rear loads.(ohlins/adjustable paralever).I still use(did) the standard sisestandard,the bike just leans over further.Not too much that it would be unstable or owt like that.
gus

[bmwonder]

Most springs have a rising rate, right? That is that they get stiffer the more you compresss them. Therefore, lengthening the spring to with the shorter arm would have the same effect as reducing the pre-load wouldn't it? The spring might feel slightly softer.

I know nothing about suspension by the way. I was just thinking about it logically. I may be missing something completely obvious here? I don't think that it would make as much of a difference as the effect on the wheelbase and the steering. I just wondered if any of you guys who have the stock shock and the shorter arm felt any need to stiffen the pre-load? Anyway I shall try it myself when my part arrives and I'll report back.

[adamski49]

I think the BM is linear rate, not rising. To get a rising rate you need all that fancy linkage you get under most jap bikes. As I said above the shock isn't affected by the change in para arm.... or as Chris said "what are you on about???"

Adam

[bmwonder]

I think the BM is linear rate, not rising.

oh right. I'll shut up then!

[winger]

Bliiiiiiiiiiimey i've read your posting half a dozen times Bm and i'm gobsmacked,as Adam has already pointed out for riseing rate you need a linkage it's the relationship between the swingarm and the frame,the shocks got bugger all to do with it,it's a completely separate issue.

Looks like your going to be on a steep lerning curve,but's the only way to learn,best bench mark for what kind of height you want at the back put the bike on a genuine BM padock stand the back wheel needs to be touching the ground.

Chris