Fork maintenance?

7KALITT4KRAZY7

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Feb 8, 2023
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20
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Dothan, AL.
New fork oil will help, but the S10 comes stock with soft progressive springs that contribute to the dive you are experiencing.
A good set of straight rate springs will greatly help with your issue. Stoltec Moto or Sonic springs sells a replacement set of straight rate springs for $120/pair and are worth every penny.

A short term fix is to dial in some more preload on the fork caps. This will pick up the front of the bike slightly and help reduce the diving you are experiencing.
Another question from my deep and astounding ignorance. Is the ratio aspect based off of rider weight or ride quality desired? (Stock to Stiff)
 

jrusell

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Aug 23, 2017
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Dartmouth, Nova Scotia, Canada
I am not sure what you mean by "ratio aspect"?

Do you mean is the desired Spring rate based off weight or ride quality desired?
For the most part spring rate is determined by weight of rider/gear normally carried.

You should select a spring that will give you proper rider sag. Just because a spring has a higher spring rate does not mean it will make the bike feel stiff or harsh. Adjusting compression and rebound damping is used to control the suspension movement when compressing and extending and are a large component to making the bike feel planted and also comfortable.

I do not know your weight, but I can give an example.
I am 220lbs. I purchased a set of 0.95kg/mm springs and was very happy.
I would suggest 0.95kg springs would be good for a rider between 185-260lbs. Based on the measurement I have seen I think someone less than 180lbs could go as low as 0.90kg/mm.
I am sure others can let you know their weight and what they used.

Accessories/ passenger or whatever you add to the rear when traveling will have an effect on selecting a rear shock spring rate, but little to no effect on the desired fork spring rate so don't worry about those when thinking about your forks.
 

7KALITT4KRAZY7

New Member
Joined
Feb 8, 2023
Messages
20
Location
Dothan, AL.
I am not sure what you mean by "ratio aspect"?

Do you mean is the desired Spring rate based off weight or ride quality desired?
For the most part spring rate is determined by weight of rider/gear normally carried.

You should select a spring that will give you proper rider sag. Just because a spring has a higher spring rate does not mean it will make the bike feel stiff or harsh. Adjusting compression and rebound damping is used to control the suspension movement when compressing and extending and are a large component to making the bike feel planted and also comfortable.

I do not know your weight, but I can give an example.
I am 220lbs. I purchased a set of 0.95kg/mm springs and was very happy.
I would suggest 0.95kg springs would be good for a rider between 185-260lbs. Based on the measurement I have seen I think someone less than 180lbs could go as low as 0.90kg/mm.
I am sure others can let you know their weight and what they used.

Accessories/ passenger or whatever you add to the rear when traveling will have an effect on selecting a rear shock spring rate, but little to no effect on the desired fork spring rate so don't worry about those when thinking about your forks.
You answered my question precisely. I’m 215 dressed and carry between 0 and 40 lbs. of gear, depending on what/where I’m riding. The set of 0.95 kg/mm adjusted properly, sound like the solid absorption and comfort I’m looking for. Thanks!
 

MattR

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Nov 16, 2019
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North Hampshire UK
You answered my question precisely. I’m 215 dressed and carry between 0 and 40 lbs. of gear, depending on what/where I’m riding. The set of 0.95 kg/mm adjusted properly, sound like the solid absorption and comfort I’m looking for. Thanks!
Blimey! That’s confusing! Mixing the old fashioned imperial measures with the modern metrics. Does the output come in kg or lbs?


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Bombadier36

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Aug 8, 2019
Messages
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Location
Florida Panhandle
So…. Fork seals replaced and I went on a test ride - no leaking. I’m now 330 miles from home and both forks are leaking. Trying to limp home today while stopping to wipe them off as I go (concerned of oil on the front brakes). Hope to make it!

My only thoughts on what went wrong is not seating seals completely (or damaged on install - but both?), seals installed upside down, or to much oil in the forks. Not sure what else would cause both to leak.
 

jrusell

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Dartmouth, Nova Scotia, Canada
So…. Fork seals replaced and I went on a test ride - no leaking. I’m now 330 miles from home and both forks are leaking. Trying to limp home today while stopping to wipe them off as I go (concerned of oil on the front brakes). Hope to make it!

My only thoughts on what went wrong is not seating seals completely (or damaged on install - but both?), seals installed upside down, or to much oil in the forks. Not sure what else would cause both to leak.
What brand seals ? Did you use All balls seals? Some of the worst out there IMO. Don't try to save a buck when buying seals. Use Yamaha or SKF seals and you don't need to worry about quality.

Also it only takes a small nick on the chrome to cut a new seal. Always a good idea to thoroughly inspect the chrome tube for pits or nicks in the tube. If you find any use a very small file to knock down any sharp edges that can cut a seal. Make sure the tube are perfectly clean. Dried bugs or dirt will damage seals quickly.

Also when installing the seal on the chrome tube it is a good idea to use a plastic bag or Saran Wrap over the end of the chrome tube. This protects the seal when sliding over the sharp edges of the tube and the upper bushings which can easily cut a new seal.

But both leaking would make me think what you stated. Seals installed upside down. Let us know.
 

Bombadier36

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Aug 8, 2019
Messages
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Location
Florida Panhandle
What brand seals ? Did you use All balls seals? Some of the worst out there IMO. Don't try to save a buck when buying seals. Use Yamaha or SKF seals and you don't need to worry about quality.

Also it only takes a small nick on the chrome to cut a new seal. Always a good idea to thoroughly inspect the chrome tube for pits or nicks in the tube. If you find any use a very small file to knock down any sharp edges that can cut a seal. Make sure the tube are perfectly clean. Dried bugs or dirt will damage seals quickly.

Also when installing the seal on the chrome tube it is a good idea to use a plastic bag or Saran Wrap over the end of the chrome tube. This protects the seal when sliding over the sharp edges of the tube and the upper bushings which can easily cut a new seal.

But both leaking would make me think what you stated. Seals installed upside down. Let us know.
Use Yamaha seals and did a good job cleaning the forks well before install. Used a glove over the top of the tube to push it over.

Definitely will let you know! Going to order new seals today and do it all again :(
 

tntmo

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Nov 10, 2017
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San Diego, CA
I'd try cleaning the fork seals before taking it all apart. You can buy a fancy cleaning tool, make one from a plastic bottle or even just use a couple business cards.
 

Bombadier36

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Messages
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Florida Panhandle
I'd try cleaning the fork seals before taking it all apart. You can buy a fancy cleaning tool, make one from a plastic bottle or even just use a couple business cards.
About an hour into my ride home and saw your post. Just wiped off the oil and tried cleaning. Didn’t see anything come out but I’ll stop every hour to check them.

Trying to watch and see if the front is sagging as I lose oil. Cut a zip tie to length as a measuring stick. Not sure how much I can lose before it’s an issue.
 

holligl

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I replaced the fork oil in Dec. While trailering to AZ, the right fork leaked quite a bit. Unloaded and tried cleaning. Still leaking and tried cleaning again. Ordered parts and a seal driver. Kept riding while waiting for parts. Now it has stopped leaking after some more aggressive riding. At least I now have everything to do it. I should recheck the level, guessing I lost a couple ounces. But once it's off, I'd probably rebuild. You do one, why not two. Or just go ride!

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TenereGUY

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I replaced the fork oil in Dec. While trailering to AZ, the right fork leaked quite a bit. Unloaded and tried cleaning. Still leaking and tried cleaning again. Ordered parts and a seal driver. Kept riding while waiting for parts. Now it has stopped leaking after some more aggressive riding. At least I now have everything to do it. I should recheck the level, guessing I lost a couple ounces. But once it's off, I'd probably rebuild. You do one, why not two. Or just go ride!

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Many times forks can be blown if you compress the front suspension while trailering. That's a major reason I went to a Condor Chock. Front isn't compressed. How do you know it is only a couple of ounces?
 

holligl

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Many times forks can be blown if you compress the front suspension while trailering. That's a major reason I went to a Condor Chock. Front isn't compressed. How do you know it is only a couple of ounces?
It was only compressed about half way on the trailer. Guessing on the loss by the size of the residual spot on the trailer.
 

tntmo

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That's not really true, compressing forks doesn't cause seals to blow.

Lots of dirt bike riders says the same thing and use those fork block deals when trailering them. Funny how the bike can come down off a 50 foot jump over doubles on the track all day long with no issue, but then people worry about slowly tightening down some straps to bring it home.
 

TenereGUY

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I just know racers don't like to compress the front if trailering. Can mess up your suspension. I understand your logic.
If it leaked out excessively it probably would have also splattered in the slipstream too... but if your bike isn't showing oil anywhere else then maybe it was just a few ounces. You'll never really know until you pull that fork and put the oil in a container where you can measure it. The only downside is performance and if really low on oil it will wear off the Teflon coating on the bushings and You'll have steel rubbing on your fork tube which will wear it out faster and can cause you to have to buy a new fork upper. Do you feel lucky?
 

holligl

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If it leaked out excessively it probably would have also splattered in the slipstream too... but if your bike isn't showing oil anywhere else then maybe it was just a few ounces. You'll never really know until you pull that fork and put the oil in a container where you can measure it.
It was well tarped so the slipstream was limited. I would measure the height rather than dumping, unless I go ahead with the new seals and bushings. Will probably check next rainy day. Performance seems good.


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TenereGUY

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It was well tarped so the slipstream was limited. I would measure the height rather than dumping, unless I go ahead with the new seals and bushings. Will probably check next rainy day. Performance seems good.


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Sounds like the best way to go!
 

Mad_Matt

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Nov 15, 2023
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Colorado
I'm gathering the parts to refresh the front forks on my 2014 ES with 55k miles. Currently, both forks are puking fluid when I ride but not when chilling in my garage. I have tried cleaning the seals multiple times, but it hasn't seemed to fix the issue.

What is the consensus on the parts to replace when doing the refresh? I ordered the Yamaha OE Fork seal kit, which provides a new Oil Seal (13) and Dust Seal (10), but when I looked at the factory service manual, it calls for a lot more parts to be replaced. Swapping out the additional "New" parts highlighted in the diagram would add about $120 to the refresh cost. Is it worth it?

Screenshot 2024-01-05 at 9.24.12 AM.png
 

thughes317

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The Bluegrass, KY
I'm gathering the parts to refresh the front forks on my 2014 ES with 55k miles. Currently, both forks are puking fluid when I ride but not when chilling in my garage. I have tried cleaning the seals multiple times, but it hasn't seemed to fix the issue.

What is the consensus on the parts to replace when doing the refresh? I ordered the Yamaha OE Fork seal kit, which provides a new Oil Seal (13) and Dust Seal (10), but when I looked at the factory service manual, it calls for a lot more parts to be replaced. Swapping out the additional "New" parts highlighted in the diagram would add about $120 to the refresh cost. Is it worth it?

View attachment 107885
You're welcome.....

and definitely due the bushings.

 
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