Suspendies for lightweights

Mucho searching appears to have revealed that most suspension threads are geared toward the big boned amongst us so forgive the Yet Another Suspension Thread (sidetrack, nerds amongst you will recognize YAST from someplace else - googling is cheating!)

Ok, I haven't actually weighed myself in years, but I'm probably about 9 stone give or take (more likely take) a couple of pies. The upside to this is I'm pretty much ideal weight for the allegedly soft SV springs and dampers, so the standard response of thicker oil and heavier springs doesn't immediately strike me as the solution. Rider sag is set to 25mm on top of static sag (or was it 30, can't remember) and ended up with preload front and rear just a click softer than default. (I know softer isn't the correct term, it just seems the easiest to visualise).

So, the problem. I'm crap at describing this, but mid corner the front seems light and the back feels wallowy. The front in particular seems really unsettled by the very slightest of bumps mid corner. It doesn't feel like it's skipping, just light and the very slightest hint of head shaking (note, not tank slappering, just slight head shaking). No signs of oil loss from forks, no play in head bearings, and it had a service a month ago. Tyres are the stock D220s, not the best tyres I've used but definitely not the worse, and they have plenty of life left in them and pressures are fine.
If anything it feels like there's too much rebound damping but given the SV's reputation I doubt that's the case. Stiffer springs may still be the solution

Without identifying the problem I'm loathe to start tinkering, a new shock and front end may well fix it but it's the why that's bugging me I just know that I've ridden much better. Was thinking about tipping more weight toward the front - dropping the forks is only real solution here as shorter dogbones to jack the rear would result in my not being able to reach the ground - but fear that sharpening up the geometry might just exacerbate the slight head shaking into something alltogether more vicious.

So, any other flyweights out there with sorted suspendies - how and what?

[johnnyrod]

I'm not much more than you. Here's the griff:

The front springs are too soft for anyone, as is the rebound damping. Get the right (linear) springs for your weight (check with the manufacturers like Ohlins etc. but there is also info here somewhere about it). Set the static sag a bit less - 25-30mm with rider, in total. Go up at to 15W or 20W oil, the vagueness at the front end is down to the crap rebound damping. If you want anything better then you want a GSXR front end or go for Racetech emulators.

At the back, unless you want to shell out majorly for a new shock then you'd better get used to it. The stock spring weight is good up to 15 stone (so is fine at 9-10) but it sounds like the preload is set too soft - click it up one or two.

You can try dropping the yokes if you measure things carefully and are worried about getting your toes down. Otherwise I found that the new BT014 sped up the turning in a lot over the old BT010, must be a different profile.

In short it is the very basic ‘damper rod’ type damping system an SV is fitted with. Hitting a big bump is when ‘high speed’ compression damping is taking part, the SV forks in standard trim is very poor at this. Your only solution is to change the damping mechanism for something a bit less agricultural, be it emulators or actual cartridge internals.

[johnnyrod]

True though the springs are such utter crap that you can goa long way just by changing them and setting the sag right.

[northwind]

Nothing at all wrong with the springs for your weight. Stock is .70kg/mm, which is pretty much bang on what 9 stone calls for. Your oil is probably overdue a refresh, 10W oil is probably about right, 20W is just way to heavy (though that's brand specific) If it's on D220s, is it a curvy? If so, then the parts are just old, and not very good. Springs aren't ever an upgrade, just a correction.

I can't honestly remember where the standard shock will come in for you, it's ages since i've worked with one.

Thanks for the tips folks, it's a K5 pointy btw (Red - it makes a difference!). Messed around with the preloads again tonight (hell, it's the only toy to play with), for the record upped the front one notch (to 3 - the default) and the rear up two (to 5 - one over default on the S, two over default on the nekkid). It's hard to objectively report, my initial reaction is "bit better" but that may just be placebo coupled with "bit different". One thing that has affected is that I can now only just tiptoe both feet at the same time (curse my stumpy pegs) so it may have tipped the weight toward the front a little.

I'll be honest, my brain finds it really tricky to identify exactly what's going on, but it does feel like more a damping problem than spring rate. At this point it gets even fuzzier, but I *think* it's more a prob with rebound than compression and I *think* the rear is more to blame than the front. It's almost as if the rear is planted and the bike pivots around that rather than the front leading.

Ultimately I guess I'm just doing unfair comparisons, expecting it to turn like an NC30 or a Lav 750 and without major transplant surgery it just ain't going to happen. It's not *that* bad by any stretch, it's just not the best.

If the forks are stock then it IS the fork damping that will be at least partially to blame, probably majorly to blame in any handling ‘issues’, the stock shocks aren’t that great, but yours is a fairly low mileage bike and as you are a whippet, its not like it has had a hard life to this point … and again quite well matched … Anyway, the damping in the forks IS poor ... you don't need to analyse it, just fix it!!

The springs are about the right weight for you so ~£100 thrown at emulators and new oil is the way to go. If you are ‘flush’ then go the whole hog and get some replacement cartridge internals which is the top solution!!

After you have done this then re-assess, my money is on you being happy as a piggy in … . . . .. . .

Originally Posted by Blue_SV650S

After you have done this then re-assess, my money is on you being happy as a piggy in … . . . .. . .

After I changed to Hagon progressives and new 15w oil I was as happy as that. After I got new road pilot 2's I was even happier - maybe as two pigs in it even.

[yorkie_chris]

I'm about 11 stone and considering doing something with the forks;

Progressive or linear springs? 10 or 15w oil? So many decisions!

[northwind]

I used to be your weight I did Ohlins springs (.80s apparently, linear) which were spot on, and 15W oil, which wasn't. If I'd kept it I'd have done 12.5W, 15W felt ace but it was a bit too firm really, and in deep winter it was much too firm.