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VetRacer75

11 YZ450 Stock Suspension settings

15 posts in this topic

Hi, was just wondering how many clicks out some of you guys are running on stock suspension.

I have found that I had to keep clicking in the rear rebound till I was one to two clicks out before it felt settled and didn't kick back too fast on hard landings. Also the compression on the shock is only about 5 clicks out too stop it blowing through the stroke seat bouncing, landings etc.

Also now that I'm pushing the bike a lot more and going faster I've had to come in a few clicks on both the rebound and compression on the forks aswell.

I was able to get my sag right by tightening the shock spring.

But I can't help wondering if the standard springs are too light.

Also have you guys that have raced, found an improvement by having you suspension revalved and resprung.

I'm 93 kgs no gear, intermediate rider..

Thanks, Chris.

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Inadequate rebound response is pretty common to most Japanese bikes. I stiffen the valve stack up quite a bit on the YZ/YZF's I do. I haven't heard too many complaints of the compression being weak on the new ones yet. However, at 93 kg, you are a bit heavier than the standard springs are intended for. 85 kg is about the max. Sounds like at your level you need the suspension tailored to your needs/style.

Try these guys:

AUSTRALIA - Suspension Matters - Queensland - David Burnett - Phone: 0417 382 583 Email: info@suspensionmatters.com.au

AUSTRALIA -West Coast Dirt Werx - Western Australia - Mat Day - Phone: 08 9337 3641 Email: twobros@bigpond.net.au

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we run more sag than normal on the same bike. cc though not moto. read that a different lower link helps or compensate with the sag. front is ok stock, adjustable so far. rider is 175 with no gear, Open Expert class.

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Inadequate rebound response is pretty common to most Japanese bikes. I stiffen the valve stack up quite a bit on the YZ/YZF's I do. I haven't heard too many complaints of the compression being weak on the new ones yet. However, at 93 kg, you are a bit heavier than the standard springs are intended for. 85 kg is about the max. Sounds like at your level you need the suspension tailored to your needs/style.

Try these guys:

AUSTRALIA - Suspension Matters - Queensland - David Burnett - Phone: 0417 382 583 Email: info@suspensionmatters.com.au

AUSTRALIA -West Coast Dirt Werx - Western Australia - Mat Day - Phone: 08 9337 3641 Email: twobros@bigpond.net.au

Thanks Grey, I've read a lot of your posts, you are a very helpfull man.

I'm going to call David asap.

Do you know what fork rates I will require for my weight by any chance?

Should I source them first do you think?

Cheers, Chris.

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The consensus on the '11 seems to be that the springs are mismatched front to rear in stock form. Recommendations for your weight run pretty close to the stock 5.7 kg/mm rate, although some do call for around a 5.8. The front's another thing. Stock is 0.47 kg/mm, but most tuners would call for between 0.49 and 0.50 for you.

Whenever I see guys who are out of the stock weight range, I always tell them that the first most important thing is to get the spring rates right. Without that, the suspension has no chance of working as it should. With the right rates, on the other hand, a lot of people find the bike is OK in stock form, and don't go any farther. For you, at the the level you describe, I'd say you'll end up doing more to the forks and shock beyond that, and you could either start with the springs or just go ahead and get the whole thing done.

Dave's kits are phenomenal. There's no way I'd be doing what I do with my bike at my age without the stuff. The two listings I posted are from his authorized installer list. If you'd rather talk to him, you can, of course, but those guys would at least save you some of the expense of overseas shipping.

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The consensus on the '11 seems to be that the springs are mismatched front to rear in stock form. Recommendations for your weight run pretty close to the stock 5.7 kg/mm rate, although some do call for around a 5.8. The front's another thing. Stock is 0.47 kg/mm, but most tuners would call for between 0.49 and 0.50 for you.

Whenever I see guys who are out of the stock weight range, I always tell them that the first most important thing is to get the spring rates right. Without that, the suspension has no chance of working as it should. With the right rates, on the other hand, a lot of people find the bike is OK in stock form, and don't go any farther.

+1 Gray's comments on getting spring rates correct.

I went stock fork springs but lighter shock spring (I weigh only 163 lbs, 74Kg) and it balanced everything out nicely.

The stock suspension is good enough (for me anyhow) to leave it alone.

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I'm about your weight and have ended up with a Factory Connection 6.1 rear spring that is pretty close to perfect for me.

The stock 5.7 was good initially at the max preload of 15mm but softened up after a few hours. I find the biggest problem with springs is getting a true accurate rating. I find there's a lot of variation and unless you check it yourself you have to trust the source as to it's true rating.

I could not get a FC 5.9 to deliver less than 100mm of sag with 15mm of preload. It behaved exactly like the stock "5.7". That tells you either the stock "5.7" was stiffer than 5.7 or the FC 5.9 was softer than advertised. You just don't know.

What you're describing sounds like you might have preloaded your stock spring too much (more than 15mm). Spring manufacturers stress very strongly not to compress the spring more than that to obtain proper sag. FC recommends between 5-10mm.

The fork springs are a matter of opinion. I'm happy with the stock ones. Others have gone stiffer. I'm hesitant to do that for reasons described above and I don't mind riding a little low in the stroke up front as it only improves turning feel. Plus, I've landed very hard on these SSS forks and they have never bottomed hard. Proper (max) oil level is key on the front.

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...I've landed very hard on these SSS forks and they have never bottomed hard. Proper (max) oil level is key on the front.

The KYB twin chamber resists actual bottoming unusually well. The oil locks in the lower lugs are very effective. Oil level has a little less to do with it than you might imagine, but it does have an effect since, obviously, it controls the effect of the captive air in the outer chamber operating as a spring, and the air "spring" is very progressive. Oil viscosity, on the other hand, has a pronounced effect on bottoming, and the use of one grade heavier oil in the outer chamber is a good means of retaining or improving bottoming control while at the same time lowering the oil level to reduce the deep stroke harshness that comes from a too small volume of air.

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The consensus on the '11 seems to be that the springs are mismatched front to rear in stock form. Recommendations for your weight run pretty close to the stock 5.7 kg/mm rate, although some do call for around a 5.8. The front's another thing. Stock is 0.47 kg/mm, but most tuners would call for between 0.49 and 0.50 for you.

Whenever I see guys who are out of the stock weight range, I always tell them that the first most important thing is to get the spring rates right. Without that, the suspension has no chance of working as it should. With the right rates, on the other hand, a lot of people find the bike is OK in stock form, and don't go any farther. For you, at the the level you describe, I'd say you'll end up doing more to the forks and shock beyond that, and you could either start with the springs or just go ahead and get the whole thing done.

Dave's kits are phenomenal. There's no way I'd be doing what I do with my bike at my age without the stuff. The two listings I posted are from his authorized installer list. If you'd rather talk to him, you can, of course, but those guys would at least save you some of the expense of overseas shipping.

Thanks guys, so I rang David from suspension matters and he had a couple options depending on how much I am willing to spend.,

First off, get the whole hog, to get the front and rear resprung for my weight, gold valves in my forks, another mod to reduce the shim stack, can't remember on compression I think.

For the shock he recommends installing a rebound separation valve for more direct/precise adjustment, also so clicker settings won't effect the other, as well as modifying the shim stack. Also commented on the bike being unbalanced, forks too soft and shock spring just too soft for my weight and speed in mx. If I was trail riding would leave springs the way they are.

About 1k or less 350 without springs.

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Thanks guys, so I rang David from suspension matters and he had a couple options depending on how much I am willing to spend.,

First off, get the whole hog, to get the front and rear resprung for my weight, gold valves in my forks, another mod to reduce the shim stack, can't remember on compression I think.

For the shock he recommends installing a rebound separation valve for more direct/precise adjustment, also so clicker settings won't effect the other, as well as modifying the shim stack. Also commented on the bike being unbalanced, forks too soft and shock spring just too soft for my weight and speed in mx. If I was trail riding would leave springs the way they are.

About 1k or less 350 without springs.

Dude, I'm not saying I agree with Motocross Action magazine all the time. But one thing they say you can take to the bank. That is the Kayaba SSS suspension is the best production suspension ever put on a motorcycle. Better than anything else on the market today.

To go out and spend that kind of money to modify the best suspension available just doesn't make sense. My advice. Spring it. Adjust it. Ride it. Enjoy it. It's close to perfect right out of the box.

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Dude, I'm not saying I agree with Motocross Action magazine all the time. But one thing they say you can take to the bank. That is the Kayaba SSS suspension is the best production suspension ever put on a motorcycle. Better than anything else on the market today.

To go out and spend that kind of money to modify the best suspension available just doesn't make sense. My advice. Spring it. Adjust it. Ride it. Enjoy it. It's close to perfect right out of the box.

I hear you, thanks FZ, it is a lot of money, but did you say that you only beefed up the shock spring? Do you ride or race mx mate?

How much and what weight oil did you add to your forks, because of bottoming I have flat spotted the rims on rough square edged hard landings front and rear dammit. I think with stiffer springs this will be avoided.

I see some of the pros around here getting the whoops wrong etc, and their suspension just soaks it up and doesnt seem to kick them around like its very forgiving.

Because is it already good doesnt mean it can't be a lot better.

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...the Kayaba SSS suspension is the best production suspension ever put on a motorcycle. Better than anything else on the market today.

To go out and spend that kind of money to modify the best suspension available just doesn't make sense.

It is very good. But it really can also be better.

One of the things at work here is the difference between the US and Aussie dollar, and the price of stuff down under. Look at the price Chris mentioned for the springs; $350. Those we sell genuine KYB springs here for $220-250 front and rear. At that rate, $1000 becomes more like $700, which is a lot closer to reasonable.

And as I said, re-springing first is a good way to start, and a lot of people are happy with that alone. Not long ago, a guy won a vets race at Loretta Lynn's on stock YZF suspension using no modifications other than the SPI suspension oil from SMART Performance. It can be done, but speaking from my own experience, the suspension is even better when gone through (if it's done right), and there's no better place for a real racer to put money in a bike.

David Barnett , by the way, is not Dave Johnson, the owner of SMART Performance, who I was talking about calling earlier. You may want to consider asking Mr. Barnett why he is recommending the gold valves over the SPI kits.

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It is very good. But it really can also be better.

One of the things at work here is the difference between the US and Aussie dollar, and the price of stuff down under. Look at the price Chris mentioned for the springs; $350. Those we sell genuine KYB springs here for $220-250 front and rear. At that rate, $1000 becomes more like $700, which is a lot closer to reasonable.

And as I said, re-springing first is a good way to start, and a lot of people are happy with that alone. Not long ago, a guy won a vets race at Loretta Lynn's on stock YZF suspension using no modifications other than the SPI suspension oil from SMART Performance. It can be done, but speaking from my own experience, the suspension is even better when gone through (if it's done right), and there's no better place for a real racer to put money in a bike.

David Barnett , by the way, is not Dave Johnson, the owner of SMART Performance, who I was talking apout calling earlier. You may want to consider asking Mr. Barnett why he is recommending the gold valves over the SPI kits.

Grey those spring prices will only save me $100-$130 minus freight and there is prob not much diff.

I will ask why he would he would use gold over SPI kits.

I was talking to another pro riding the same bike, actually he has two, about a month pago he told me how he was riding over in theo states and rode a crf 10 model and said it felt more planted than his yzf. Then I spoke to him couple weeks ago and he had his suspension worked on and said "the bike feels way more planted and I can go faster and hit obstacles knowing the bike will soak it up, the wheels feel like they are touching the ground more"

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Grey those spring prices will only save me $100-$130 minus freight and there is prob not much diff.

I understand that. I was trying to explain it to FZ. You guys are stuck with paying those prices. But you're all rich, aren't you? :thumbsup:

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I would love to get this done to my bike.  Anywhere in California not aussie I can accomplish this?  Sacramento area.

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