Hi guys, and girls too,
I have been doing a lot of lookin around on the site for information on suspension. It sounds like a good and economical fix for the rear is a Katana 750 shock. Does it matter what year bike the shock came from? Will a 600 Katana shock work? The next question is for the front end. It seems most people would put in Sonic springs over Progressive springs. What's the difference? If I get the sonic springs what weight spring would I get? The bike is my daughter's, she weighs in at a whopping 115 lbs. Your help and expertise is appreciated.
The Katana shock is going to be a very bad choice for your daughter - it's very stiff, and really only appropriate for riders twice her weight. Even the R6 shock will be a little bit on the stiff side for her, but it's a more worthwhile change. Stock may be fine for her.
I strongly recommend sonic springs over progressive springs. Dual wound springs have some really wonky behavior, and are hard to tune. Hard to say how stiff to go for her weight, but I'd guess .75 would be a decent starting point. Email the guys at sonic, perhaps?
I would recommend the R6 shock because it doesn't raise the rear end any and has more adjust ability. Check out racetech's web page. They have a spring weight calculator, you put in you bike and weight and it gives you a recommended front spring rate. They also offer a spring for the R6 shock that is 1/2 way between the GS500 stock spring rate and the R6 stock spring rate which she may need.
Quote from: burning1 on January 17, 2012, 10:30:18 PM
I strongly recommend sonic springs over progressive springs. Dual wound springs have some really wonky behavior, and are hard to tune. Hard to say how stiff to go for her weight, but I'd guess .75 would be a decent starting point. Email the guys at sonic, perhaps?
I wish I had known more about all of this 2 years ago, I might have gone sonic (I put in progressives). I'm happy with my ride and its far better than stock, given the type of riding I do I cant say I've noticed anything "bad" but then again I don't exactly know what "bad" feels like :icon_confused: All I know is stock was mushy, bottomed out alot and braking was affected and now I have NONE of that.
http://www.sonicsprings.com/catalog/straight_vs_prog_tech_article.php
I don't know if I would make any changes to the suspension at 115lbs. I think I read somewhere that the GS comes tuned from the factory for a 145lbs rider. :dunno_black:
Yes atleast 150 lb before suspension needs upgrade.
You may just have a bad stock shock, which you would replace with a good stock shock ... should cost you next to nothing over shipping, there is so many that have joined the trash with the swaps we have done.
Cool.
Buddha.
Quote from: The Buddha on January 18, 2012, 07:54:23 AM
Yes atleast 150 lb before suspension needs upgrade.
You may just have a bad stock shock, which you would replace with a good stock shock ... should cost you next to nothing over shipping, there is so many that have joined the trash with the swaps we have done.
Cool.
Buddha.
yup. If you do determine the above I'm happy to offer you mine for free (just cover the shipping) if you want it. I put in an R6 shock and my stock shock (off my 09) is just sitting here now. It has ~12k on it and is in excellent condition otherwise. Just throwin that out there if you wanted it since I'll never use it again.
I'm similar weight (between 120 and 125) and I can tell you that the stock front springs are unacceptable. I got progressives in a few years ago. The difference is interesting. Under normal riding they feel similar to the stockers, but going over bumps and under heavy braking they are much less prone to bottoming. If you want to maintain the current ride quality while adding resistance to extreme dive and bottoming progressives may be a good choice.
I have not found the rear shock to be unsuitable for street use.
If you are planning on strafing canyons and tracking the bike my advice is probably worthless. I mostly commute and tour.
Quote from: redhawkdancing on January 18, 2012, 07:41:25 AMI think I read somewhere that the GS comes tuned from the factory for a 145lbs rider. :dunno_black:
Close, but not quite. The stock springs are tuned for a rider who is 45 lbs, not 145 lbs!!
At 165-170, I find the rear is just fine. Remember it can be adjusted stiffer or softer. Comes in middle setting.
Sonic has a calculator for springs. I use 0.85's. Really makes a difference. probably 0.75 or 0.80 for 115 lbs.
The newer shocks have better springs than the older ones. Some light weight riders and OK with the newer springs. Still good to upgrade them.
Progressive .vs. Regular: I have progressive on one bike. As of now, O do not remember which one. That means for ordinary street riding, it doesn't seem to make any difference. If I was riding lots of rough roads, maybe. Racing: let the racers chime in there. as I see it, progressives will be a little softer at first for small bumps then stiffen up more for big bumps. I guess only of going over curbs a lot would I find a difference. "Progressive Springs" sounds cool, but I don't think it matters for street riding.
Same with saying you have a "KAT Shock". Something to say, but for 115 pounds, stay stock. Even me - I removed a KAT shock and gave it away. Put a new stock shock back on the bike and I am much happier with the ride.
:D It sure pays to ask the experienced crowd. She is still learning to ride since she got her licence in August in Wisconsin. She bought the bike in November, didn't ride it yet. But just getting it on and off the trailer I could tell the forks are mush. I thought something was wrong with the front end! It sounds to me that Progressive springs will be the way to go for her since she is far from the track at this time. And I'll adjust the stock shock for her. If anybody has any other suggestions please don't hesitate. Any ideas where to get springs for cheep (she's a college student on a budget)? Thanks
OK front spring may only be one possible solution too. The most $$$ solution ...
A proper seal job, correct oil level and weight of oil will be a good first step, followed by maybe extra spacers if needed.
I would seriously not plonk the $$$ with a 120 lb rider into the FE either.
Of course a crappy FE can be more unsafe, but tires and brakes are more important there.
At the very least, seal and oil before putting in springs.
Cool.
Buddha.
Sonic springs are about $85.
What year is the bike?
If 1989-2000, switching to the 2001+ springs might be enough for 115 lbs. I have some of those from 2 bikes I put 0.85's in.
if bike is 2001+, then you need better springs. By you saying you thought something was wrong, must be 89-00.
As the buddha said, proper oil, seals and extra pre-load can help for 115 lbs. If 89-00, then try the newer springs. Can send for postage.