Spring rate Q's

Yes you can use different springs in each fork. Fairly common I believe.

 

You can always go within 1 spring rate difference in each side to make up a needed change. I wouldn't put all my faith in a spring chart, especially if you're talking about 1 spring rate. You need to do a sag measurement. If you're within 1 spring rate, I'd ride it and see where I'm at in the travel. Make not of your pre-load need and determine the need for a spring change from there.

 

One thing I've learned about the Racetech spring rate chart is that it's garbage. Don't believe it. Use it as a VERY rough baseline if you know absolutely nothing about springs and where to start, but I've seen that thing be off by as much as 2 spring sizes. On my previous bike that chart recommended .95-.975 if I remember well, which is BS because I had 1.0 and I was bottoming out the springs in hard braking zones. I listened to expert tuners who have experience with the bike I had and ended up getting 1.05 which was damn near perfect (still a bit towards the soft side).

 

26 without??? Without gear? For track riding, you only want numbers with full gear.
Figure out where your forks bottom out. Put a small zip tie on a fork leg and the shock. See how much travel you are using.

 

He said with him + gear. The "without" part means without him on the bike...in other words, static sag. You really think the gear compresses the forks by a whole 8 mm? lol

 

I would definitely trust the Ohlins USA guys way more than the Racetech online calculator. Brad from Ohlins knows his shit, and he's got tons of experience setting up bikes for pro racers.

 

I don't put much faith in those charts. There are lots of things that go into suspension setup (spring rate decisions), but contrary to popular belief, bodyweight is not one of them. How much you weigh is irrelevant. What matters is how the bike works on track, how much fork travel you are using, how much braking stability you have, how the bike carves into corners, etc.

A buddy of mine weights 135lbs soaking wet and uses 1.05-1.10 at most tracks (which by the calculator, are supposed to be for somebody that weighs 200-225lbs).

To be honest, we haven't checked the sag on any of my race bikes in like 7 years. We are worried about how the bike acts on track, not how much suspension I use when I sit on it in the pits. If you have no clue where you are with spring rates, then sure you can check the sag and that will give you a VERY generic baseline starting point. But that is not an end-all to the discussion/setup. It is just a base starting point to get you on the track.

In other words, I don't put any faith in any of those graphs or calculations that supposedly tell you what spring rates you need. How do those graphs know your pace, or what tracks you ride, or how you like your bike setup, or how much fork dive you prefer, or how much of a demon you are on the brakes, so on and so forth?

But to answer that question, yes you can mix springs. My R6 has a 1.10 and 1.05 in the forks right now.

 

Hey! I never claimed to be good at math. Thats why I asked. Seemed like he may be wearing the whole cow, and not the leathers?

 

I disagree. Body weight absolutely makes a difference and should be considered for suspension setup. Realistically it's actually the combined weight of the rider and bike, but most times it's assumed that the weight of the bike hasn't changed much. Your example of your friend is not that uncommon, many people like to run a stiff front end and if you look at their sag, it's way lower than what the perceived idea of a "good baseline", but that's fine because like you said, it's not the ONLY thing. However, it doesn't work the other way around. My fat ass was bottoming out the forks in every hard braking zone until I went up in spring rate stiffness. There was absolutely nothing else I could've done aside from not really braking. I was using .95 springs and I should've been at 1.05 - 1.10. Bottoming out is downright dangerous and you won't be getting any faster on those suspensions...ever. I agree that there is no magical equation or chart for which you can just look at your weight and it just tells you exactly what spring rates you should use, but expert suspension tuners know that you have to be in the ballpark at least, and after that it's all tuning based on rider preference/style, rider skill, track layout, track conditions, etc.

 

While disagreeing, you actually agreed with that I said.

In the middle of my post, I made this comment:
If you have no clue where you are with spring rates, then sure you can check the sag and that will give you a VERY generic baseline starting point. But that is not an end-all to the discussion/setup. It is just a base starting point to get you on the track.

Bodyweight can be used as an initial starting point if you have no idea what springs you should use. But that is where bodyweight stops becoming a factor.

What I don't like is when people say "you weigh ___ so you should be using ___ springs". When this conversation has come up on other forums, I have even had people respond with "well, maybe if your buddy used springs designed for his bodyweight, his bike would handle better". Perhaps I should have pointed out that my buddy has been racing motorcycles since he was 2 and at the time when I made that point, he was a Factory racer in World Supersport.

Like I said, if somebody is just getting into riding and has no idea what springs they should use, by all means...get some for your bodyweight. But aside from that scenario, bodyweight is irrelevant. What matters is where you keep the suspension in its stroke, how the bike handles and acts on track etc...not how much you weigh.

 

True. I only just disagreed with the "irrelevant" part. Because a guy that weighs 250 lbs definitely can't use .90 springs for example. You'd bottom out as soon as you reach for the brake.

So is your buddy PJ Jacobson? ...can't think of many americans riding in WSS right now.

 

When I originally made that comment (and the guy responded with stuff like "well maybe if your buddy would use the correct springs..."), I was referring to DiSalvo. He was riding for the Triumph Factory team in WSS at the time.