Suspension, tire pressures, what worked well for me

[pilot]

I read a million threads to sort out some good suspension and tire pressure options before track day with my "new" 01 SV. Here was the end result:

Two top point SV650 WERA racers I spoke with recommended against installing a GSXR front end and they recommended using emulators with a proper spring and oil weight for the rider. I bought a set of Thermosman modified forks with emulators and adjusters from a WERA racer. They had .90 springs which are good for my weight and had been configured with 30W oil in one fork and 20W oil in the other.


The WERA racers I spoke with were using Penske shocks and they did not recommend the Ohlin shock because it is more limited in its adjustability. One of the WERA racer sponsors said that if budgetary reasons mandatated an alternative, the Showa ZX6 shock would be an excellent upgrade from the OEM shock. I weant with a Showa shock from a 2006 ZX6. It even looks nice--not that any of us would buy something for that reason. http://i3.ebayimg.com/07/i/000/92/c4/8dad_2.JPG

A friend helped me setup the suspension for proper sag, etc.

Tire pressure opinions are about as numerous as opinions on which oil is best. Because I was not running racing tires, I opted to begin with 29R 31F and monitor the tire pressures for the recommended 4-5# increase when the tires were warm immediately after coming off the track. After numerous tests of measuring pressure coming off the track, 30R 31F (cold tires) gave me the desired 4-5# pressure rise.

How did the first track day go? The track was Grattan, many turns, very technical and rough surfaces in parts--a place that will reveal suspension and tire weaknesses quickly. Everything worked beautifully.

Are there better setups? No doubt, but for $300.00 (148 GBP), this setup is a lot of "bang for the buck" or "bang for the pound" ;-)

[northwind]

Yep, the US guys will almost universally recommend Penske over Ohlins, it's just a better part. Penskes can be fiddly to set up, I'm told- certainly the triple is, it's got so much adjustability that it'd be beyond most people to get a good setup. But they're more durable (longer service cycles) and the default setup suits more riders than with the Ohlins.

Coincidentally, me and Scooby Drew are messing about with 636 shocks in, amazing as it may seem, a 636... Putting hte newer SHowa into his older 636. Very similiar in dimensions, spring rate etc, but without the drwaback of being, frankly, rubbish and misspecced. The old 636 shock is a reasonable choice for the SV, actually works better than it does in the kwak, but not great... I've never tried this new one in an SV but it should work very well.

(hmm, he's left it in my garage, maybe I'll sneak it into mine while he's not looking and try it out ;))

[Blue_SV650S]

Yep, the US guys will almost universally recommend Penske over Ohlins, it's just a better part.

:eek:

Dude, you are 'living life on the edge' saying that aren't you?!?!?! :D

Pilot, I am not sure I like the idea of setting each fork at a different weight?? If you are after 1/2 way between the two, why not just mix the oils and set them the same? :scratch:

[21QUEST]

:eek:

Dude, you are 'living life on the edge' saying that aren't you?!?!?! :D

Pilot, I am not sure I like the idea of setting each fork at a different weight?? If you are after 1/2 way between the two, why not just mix the oils and set them the same? :scratch:

Using different weight in each leg does matter as the suspension will work as a unit.

You can even use different rated springs in each leg to arrive at a rate that is not readily available off the shelf.


Ben

[northwind]

Dude, you are 'living life on the edge' saying that aren't you?!?!?! :D


No, living life on the edge would be "The only people I've ever seen recommend Ohlins are Ohlins dealers" :) But to be fair, the Ohlins parts are dead easy to work with, spares are more available, it's easier to find people who can work with them, resale value's better, and they're MUCH blingier, over here at least. Better isn't neccesarily best ;)

[pilot]

I can not conceptualize the differant fork oil weight thing. But, there are many threads that indicate this is commonplace with top racers and that big suspension names like Traxxion apparently do so. Rebound damping on my forks seems to be very good with the mixed weight oils.

[pencil shavings]

I can not conceptualize the differant fork oil weight thing. But, there are many threads that indicate this is commonplace with top racers and that big suspension names like Traxxion apparently do so. Rebound damping on my forks seems to be very good with the mixed weight oils.

sounds like a bush-ism to me! :D

[zunkus]

But do your have to clamp the lower legs together on right way up forks to do the different fork oil weight thing? If not wouldn's the bike behave strange? There would only be the wheel stud to keep things even. I'm guessing if there'd be one leg resisting a lot and the other little (thinking a bit dramatically here) the wheel stud would try to bend. A fork brace would keep things nice and even in this case.

[Blue_SV650S]

I am sure you could ‘brace out’ the torsion effects, but that is extra weight and well – why?? When you can just mix it up and set both legs the same on the damping??!?! :D If you are forcing the unit to act as one, then surely there is no benefit of doing them different?

I’d like to see the clear rationale behind doing it as there must be one?!!? :)

Also do you really think ‘top racers’ would have anything so crude? … depends what you mean by ‘top racers’ I suppose …

Ben, this example is using the same springs in both legs ... just diff damping ...

[chazzyb]

Using different weight in each leg does matter as the suspension will work as a unit.

You can even use different rated springs in each leg to arrive at a rate that is not readily available off the shelf.


I have read of some forks which have all the damping, and possibly springs too, in one leg only! Saves weight, I'd guess.

[Biker Biggles]

I recall some 90s Ducatis had rebound damping in one leg and compression in the other.Sounds like a good idea,but no one does it now do they?

[pilot]

The idea of using 20W oil in one fork and 30W oil in the other is apparently utilized by TRAXXION, see: http://forums.13x.com/showthread.php?t=114675&highlight=20w+30w+oil+forks

[Blue_SV650S]

The idea of using 20W oil in one fork and 30W oil in the other is apparently utilized by TRAXXION, see: http://forums.13x.com/showthread.php?t=114675&highlight=20w+30w+oil+forks

I can see the logic of using diff springs in each leg (and hence diff oils/damping), but with the same springs, the only logic that you don’t have to make a ‘home brew’ of the oil … bearing in mind the torsion issues you might get, that can’t be the only reason/reason enough surely? :confused:

[northwind]

If it was me, I'd mix the oil. But that's not to say it's a bad idea to do the 2 leg thing. The bike does have a fork brace, it's called the axle ;)

[philipMac]

I recall some 90s Ducatis had rebound damping in one leg and compression in the other.Sounds like a good idea,but no one does it now do they?

I didn't know that Ducati were doing that, but mountain manufacturers have been up to that trick for a long time now with their forks, particularly on the higher end bikes.
Its more or less the standard way of doing it for some fork guys I think, so I would bet that some trials bikes would run that set up today.

[Robw#70]

I didn't know that Ducati were doing that, but mountain manufacturers have been up to that trick for a long time now with their forks, particularly on the higher end bikes.
Its more or less the standard way of doing it for some fork guys I think, so I would bet that some trials bikes would run that set up today.

The new Triumph Speed Triple has comp and rebound in each leg...............And they're absolutely cr*p

Aprillia RS125's have been like this for years too.

One thing to bear in mind is the ambient temperature in the US is higher hence the heavier weight oil's, they do up to 50wt!! but anything over a 25 in our damp cold isle is not needed

[21QUEST]

Myself, I'd prefer same viscosity in each leg........just because (if nothing else)my brain would prefer symmetry. I know I'll probably keep thinking about it :rolleyes:

It's quicker to play around with changing the viscosity if need be, is one reason that I've read mentioned somewhere ie only needing to change oil in one leg to arrive at new Viscosity.

I think some Ohlins replacement catridge where set up with compression in one leg and rebound in the other ......IIRC early GSXR600 SRAD.

Also think think the first Kawasaki Z1000 also had an some sort of oddish(is that a word?) setup....compression in one leg and rebound in the other or springs in one leg and damping in the other. One of the above anyways I believe.

It could indeed actually be so they could isolate/control the compression damping/rebound damping of the SV damping Rod forks a bit better.
On the other hand, it may just be a Tuner making "snake oil" like moves on folks..... haha



Ben

[pilot]

I wrote TRAXXION directly about using differant fork weight oil in each fork. Their senior technician indicated:

"This does not affect the forks and it simplifies the tuning - if you want
to change the damping just leave the 20W fork alone and change the oil in
the right (30W) fork only. Use Maxima fork oil 10W-30W depending on conditions (temperature) and desired amount of rebound damping. 110-120mm oil level."

There you have it, directly from a company that many would say is one of the top suspension firms in the world.

[Blue_SV650S]

I wrote TRAXXION directly about using differant fork weight oil in each fork. Their senior technician indicated:

"This does not affect the forks and it simplifies the tuning - if you want
to change the damping just leave the 20W fork alone and change the oil in
the right (30W) fork only. Use Maxima fork oil 10W-30W depending on conditions (temperature) and desired amount of rebound damping. 110-120mm oil level."

There you have it, directly from a company that many would say is one of the top suspension firms in the world.

Aha, yep that makes logical sense ... you then only have to take one fork apart to change the damping rather than both ... quite sensible actually!! :)

[northwind]

Of course, if you have the same oil in both you can still change just one ;)

[Blue_SV650S]

Of course, if you have the same oil in both you can still change just one ;)

Er ... yeah ... one of the 'settings' will always be the same in both surely?? But you can also go more or less in one leg too ...