110 miles on MT09SP

[Red Herring]

Personally I'd just let some air out of the tyres. I know I'm beginning to sound like a broken record but running 36/42 or even 33/39 solo is just bonkers. Bike and tyre manufactures are always going to play "safe" and running a tyre at to low a pressure is potentially dangerous, so they will recommend pressures that will put up with whatever you are going to do to the bike, for example loading it up with the Missus and a weeks camping gear and riding all day down the motorway at 100mph+......... If you are going to be riding solo at sensible speeds you could easily go down to 34 or 36 in the rear tyre and 32 in the front without any risk whatsoever and you will notice a significant improvement in the ride quality.

If it helps any I ride my VFR at 34/38 and that's going bonkers across France with all my camping gear on the back..... but I run Dunlop's and they have slightly stiffer sidewalls.

[Seeker]

Originally Posted by Bibio

its 90% rebound 10% compression. harsh ride quality is due to the rebound being too slow (hard).

useful info, thanks.

Originally Posted by Bibio

if the springs are not for your weight then you MUST change the springs or put up with it as is. yes that includes new bikes that you have just spent mega bucks on.

I think this is the problem. As I understand it with upside down forks you measure from the axle holder upwards and look for 70% of max travel. This would be 96mm on the MT, fully kitted I'm getting 90mm.
After an hours ride over bumpy roads only half of the fork travel has been used.

Originally Posted by Red Herring

Personally I'd just let some air out of the tyres.

yes, I'm trying that on the next ride but per above comment I think it's the springs that's the issue.

[Adam Ef]

Originally Posted by Bibio

its 90% rebound 10% compression. harsh ride quality is due to the rebound being too slow (hard).

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This is something I need to play with more. I always set compression by feel, but rebound just for the bike and then leave it. I think I need to dial in rebound more (or less) and get to know how that affects the ride.

[Red Herring]

There are lots of guides out there as to how to set up suspension. This one is in my humble view one of the better ones and well worth a read. It is all about finding a setting that suits you so apart from the dynamic sag advice don't look at numbers, just understand what the various knobs and screws do and then find your own sweet spot.

https://www.cycleworld.com/sport-rid...n-setup-guide/

[Seeker]

I always take my SV to a local independent company for MOTs and tyre replacement - I completely forgot that he has a dyno and specialises in Power Commander tuning and suspension set up. I called him told him the issue, told him my weight and he laughed and told me point blank that I need softer springs (but he will check sag before any work).

[Bibio]

front sag is easy, put a cable tie on the stanchion and slide it to the dust seal put the bike upright off any stands then bounce the front end a few times let it settle then slide the cable tie upto the dust seal again. without disturbing the cable tie pull the front end up to it limit of travel then measure the difference between the cable tie and dust seal this is your static sag and you should set this between 20-30mm. then put the fully kitted up rider on and then take rider back off and measure the distance between the dust seal and the cable tie, the difference is measurement should be about 15-25mm if it falls under or over that range then you need new springs. once you have established that the spring rate is correct you then go for a ride. the cable tie will determine if you need to alter the sag you are looking at using as much front travel as you can without going into the oil lock and a bit for reserve so around 15mm from full travel.

rear sag is harder as you need two people to do it. first you need to set static sag (bike upright without rider) at around 15-20mm for road use. you then put the fully kitted up rider on the bike and measure again and the number should decrease by around 10-20mm. if it goes too much under or over this tells you if you need to change the spring. YOU ONLY SET STATIC SAG AND LEAVE IT THERE, DO NOT SET/COMPENSATE FOR RIDER SAG. the only time you would change for rider sag is if you have a pillion and then you need two settings.


i'll do compression and rebound later.

[Red Herring]

Bibio, would you like to have a go at explaining the relevance of sag without the rider? The sag with the rider is what matters as that is the mass the suspension has to deal with.

[Bibio]

the suspension needs to sit at a level for valving to work properly. if you set rider sag only and the spring rates are not correct you will get whats called topping out when the rider gets off the bike or bottoming out if the rider is too heavy. this matters when you hit the crest of a hump the suspension tops out as there is no negative sag (bike sag). you can also have the opposite when too heavy a rider for the spring rate and you get bottoming out in dips.


if you set bike (static) sag only and have the correct spring rate for the rider then the bike will not top out easily unless the bike is in mid air or bottom out easily also the valving works properly due to having negative sag.


bike sag is the most important setting along with rebound.


lets say we put a rider that is 16st on a bike with springs designed for 10st if you set the correct overall sag of say 30mm for the rear and the rider gets off the bike will top out so the spring rate is not taking the weight of the bike. this in turn causes topping out during riding. now if we put the correct spring rate on then the bike will have say 10mm of bike sag (negative sag) and 20mm of rider sag, when the rider gets off the bike it will not top out.

rider sag measurment is to determine if you need to change the spring rate and nothing more.
can you understand now?

[Bibio]

i'll move onto rebound when everyone can understand sag settings. until then there is no point. if you dont understand what i have said above then ask specific questions about and i'll try to explain a bit more.



or one could just get on the bike and ride it like most people do.

[Craig380]

Originally Posted by Bibio

or one could just get on the bike and ride it like most people do.

Amen to that. Personally, I think I'm happier for having virtually zero adjustability on a bike's suspension.