Sonic Spring weight...

[crzydood17]

Ok, so its time to get my bike ready for next riding season and that means sonic springs! emulators coming soon.

So now I need to figure out what to get...

I am going for .9 .95 or 1.

I am 6'2

320 LBS

and I have a GSX750F rear shock.

I want to keep it on the soft side and honestly, I have gotten to the point I don't bottom out the stock suspension but that's just because I hate using my front brake lol.

[burning1]

I'd recommend calling the fine folks at Sonic Springs for the correct spring for your weight. I suspect 1.0 might still be a little soft for you.

I'd advise you to get into the habit of using the front brake on the GS500. The front brake of a motorcycle provides the majority of our stopping power. When I'm braking aggressively, I don't use the rear brake at all - the front brake provides all of my stopping power, and the engine provides just enough drag at the rear wheel to keep the bike stable.

I make heaviest use of the rear brake while riding 2-up in the rain. In those conditions, the rear brake might provide 45% of my stopping power.

[crzydood17]

Bleh, I <3 my rear brake. its there for a reason, So I can go sideways

I use them both, just I like the feel of a solid rear brake with engine braking.

The front gets used less because in a super hard deceleration I just chatter along and would hate to ruin my fork seals.

I want this to not be too hard for the next person that owns my baby, the "calculator" says 1.1 so I figured 1 would be okay and .95 would be the sweet spot for a little softer than perfect. 

[Twisted]

Your post describes your riding as aggressive street riding? Why do you want a soft suspension then? I would be listening to burning1's advice as he races the GS so would know more than most what he is talking about.

[spcassell2125]

Ok, so its time to get my bike ready for next riding season and that means sonic springs! emulators coming soon.

So now I need to figure out what to get...

I am going for .9 .95 or 1.

I am 6'2

320 LBS

and I have a GSX750F rear shock.

I want to keep it on the soft side and honestly, I have gotten to the point I don't bottom out the stock suspension but that's just because I hate using my front brake lol.

I am 5'8" and 250 pounds and I got 1.0 granted I race with mine also but from what i hers especially for someone your size I would go with 1.0

[crzydood17]

1 it is I guess

[burning1]

Your front end chatters because the spring rates and damping are all off. I understand why you wouldn't feel comfortable with the front brake in that situation, and agree that even with a corrected front end, you'll probably need to use the rear brake a little harder than normal.

My recommendation would be to tune the suspension correctly, and work to improve your confidence with the front brake.

Keep in mind that a .1 mm/kg change is huge on the front end, and that RaceTech usually recommends springs on the soft end of things. Racetech recommended a .85kg/mm spring for my bike, and I'm finding that with my braking style, a .9 or .95 would work better.

[gsatterw]

MSF: 70% front, 30% rear

[burning1]

Ratios really depend on a lot of factors, and an experienced rider knows how to adjust their brake bias not only for conditions, but based on feedback from the bike.

70/30 forward bias is fine for a cruiser. On a modern sport bike 90/10. Under gentle braking, bias towards the rear more. Aggressive braking should bias much more to the front. With a passenger, add a little more rear. In the rain, bias towards the rear slipping before the front.

Lots of factors to consider. IMO, the best braking systems are semi-integrated ABS systems. The front brake lever applies a little bit of rear brake, but lets off if the rear starts to slip. The rear brake lever only applies rear brakes, allowing the rider to control the bike in mud or other traction compromised situations.

Braking is a very complex topic, and probably the most difficult thing to get right at the track. Braking sets corner speed, which determines a huge number of factors going into a turn.

[gsatterw]

When conditions are good and it's only me doing slow speed city riding, sometimes I only use my front brake, very little rear.

Get your front suspension squared away and start using your front brake. When you run into a sticky situation, you're gonna want all the braking power you can get your hand (and foot) on without locking a wheel.

[crzydood17]

I know you do racing... but I just can't agree with you on the rear brake, I love my rear brake, I know its bad but I use it to slow down mid corner and always apply it durring normal braking, I cant stand not using it at all. My buddy got a SV650 with a bad rear brake and the first time I rode it (test ride none the less when he was buying it) I almost crashed just because I was expecting more braking than I could give it with just the front.

[gsatterw]

I know you do racing... but I just can't agree with you on the rear brake, I love my rear brake, I know its bad but I use it to slow down mid corner and always apply it durring normal braking, I cant stand not using it at all. My buddy got a SV650 with a bad rear brake and the first time I rode it (test ride none the less when he was buying it) I almost crashed just because I was expecting more braking than I could give it with just the front.

...and thats why you want to be comfortable with the front brake. People tend to maintain the front brake better than the rear brake. Not being able to use the front brake is very dangerous.

[crzydood17]

I can use it, But my rear brake is maintained very well, and soon to be upgraded to sintered pads. I would honestly like a lot more power in my front brakes, thus a lot of thinking of upgrading to dual disks.

[burning1]

I know you do racing... but I just can't agree with you on the rear brake, I love my rear brake, I know its bad but I use it to slow down mid corner and always apply it durring normal braking, I cant stand not using it at all. My buddy got a SV650 with a bad rear brake and the first time I rode it (test ride none the less when he was buying it) I almost crashed just because I was expecting more braking than I could give it with just the front.

I'm not by any means saying you should stop using the rear brake! I'm just saying that once you fix the front springs you'll see braking improvements by using the front as well.

Listen, what I'm about to say isn't meant as a judgement or a dig at all. This is something everyone here needs to understand and consider: at 320lbs, your riding technique and experience will be different than mine. You have to use the rear brake more than I would - your limits of braking are different than mine. There is more weight on your wrists and front suspension. There is also more traction at the rear tire. Combine all that with an abysmally soft forks, your reluctance to use the front is totally understandable.

With an upgraded front suspension, you'll be able to use both brakes better. You won't have the chatter caused by the front end bottoming out. The bike won't dive as much either, which means less forward weight transfer. When you change the springs, I'd also suggest replacing the oil, possibly with 20wt fork oil.

When you do fix the front end, I recommend working to apply the front brake better - it will reduce braking distance and make you a safer, better rider. If you get a chance, try doing some safe practice stops. Slowly increase braking force, and try to find out what results in the shortest controlled stop. You might be surprised by what you find.

Something that might surprise a few people: The front forks on the GS500 are sprung for a 40-60lb rider. Glad to see you're addressing them. Most people ride on the stock springs with no idea what they are missing.

FWIW: I would never advocate using only the front on the street. On the track, I tend to ignore the rear because the attention I spend on it costs more than the benefits gain me. On the street, I absolutely use the rear - in some situations I use the rear as much as I use the front.

[gsatterw]

hey...I thought the stock springs were designed for an 80 lb rider lol

[rharding91]

When I ride I typically dont even use my rear brake, just downshift and front brake. I used them both together when I first started riding because the book said to use them together but after getting more comfortable on the bike I stopped using the rear almost 100% except when my girlfriend is on the back cause then I feel we always fall forward so much. I weigh 130, would I see any difference from upgrading the forks? I am very satisfied with the braking power I currently have but have never ridden a larger bike so wouldnt know what its like the only other bike I have rode is my honda50 and i actually removed both the brakes on that and just downshift to brake haha.

[gsatterw]

even at 130, I'd go for the progressive rate springs, no preload, and 10w or 15w oil in them, you will notice a marked difference in handling, comfort, and braking

[rharding91]

So that would just be replacing the springs in my forks then not replacing the whole fork? Never done anything involving my forks before

[adidasguy]

It would be a good idea to put in fresh oil. Many of us go 15w rather than stock 10w for a firmer ride.
If the seals are OK, then you don't have to replace them. If they are old, it is a good idea to replace the seals just to be sure they are not going to leak in the near future.
Remove the forks (it is real easy to do).
Take off the caps and remove the old springs & spacers.
Let them drain, pumping a few times to help get the old oil out.
Follow directions on your new springs to put in new oil then cut the spacers to the proper length, put caps back on then put the forks back on.
If your forks had fresh oil, you COULD get by with replacing springs & spacers on the bike. If more than a couple years old, put in new oil.

[burning1]

So that would just be replacing the springs in my forks then not replacing the whole fork? Never done anything involving my forks before

My racing was done on upgraded stock forks. I had springs, emulators, oil, and a brace on there. All told, it was about $500 worth of parts (including the brake upgrades,) but the performance was excellent.