2010 SG Front End Dives When Braking
Banned
Joined: Jul 2009
Posts: 3,719
Likes: 1
Dunno about any 'heavier fluid bs', but I'm runnin Bel Ray 30# as suggested by local indy. Took the dive out, and still rebounds well. Front end doesn't raise so much on quick starts as it did with the OEM oil. Although, next change I will probably drop down to something lighter, because the 30# is just a tad too stiff for my liking.
Former Sponsor
Joined: Feb 2009
Posts: 117
Likes: 0
From: Las Vegas
Dunno about any 'heavier fluid bs', but I'm runnin Bel Ray 30# as suggested by local indy. Took the dive out, and still rebounds well. Front end doesn't raise so much on quick starts as it did with the OEM oil. Although, next change I will probably drop down to something lighter, because the 30# is just a tad too stiff for my liking.
Ultimate HDF Member
Joined: Mar 2008
Posts: 5,788
Likes: 203
From: SW Florida
Well after installing the Progressive Drop-in lowering kit along with the SE "Heavy" fork oil, I decided to try some lighter 10W fork oil. And instead of adding 10.8 oz, I added 11 oz. Much like Howard suggested. Took a short ride yesterday and notice a little more brake dive, but not bad. Nowhere as bad as stock. The ride is definitely smoother. Will be taking long ride tomorrow to see how they react.
Road Warrior
Joined: Apr 2009
Posts: 1,258
Likes: 114
From: Jackson, Ohio
The SE 1" lowering kit has much stiffer fork springs than the stock springs.
It lowers the bike to help keep the stock stance after you install the 21" and it will help with your diving as well.
It lowers the bike to help keep the stock stance after you install the 21" and it will help with your diving as well.
Ultimate HDF Member
Joined: Mar 2008
Posts: 5,788
Likes: 203
From: SW Florida
What fork oil did you use with the SE kit?
Former Sponsor
Joined: Apr 2007
Posts: 5,360
Likes: 453
From: Davie, FL
I have written and showed via photographs what a 1" or measured 0.7" lowered HD kit is. They ride horribly and how they get the drop is by reducing the stroke by 0.70". The springs resistance are increased in order to slow the decreased stroke down in time so it does not bottom out. What is inside of your fork OEM and the HD lowering kit next to it (minus springs)
Differences not including the top out springs which you re-use the same.
There you have it as this is the stuff they do not tell you about until you have already spent your money.
If you look closely you will see holes. Back in the day when racing and no aftermarket suspension was available to buy, we would weld up the holes, turn the welds round, than drill different size holes (larger will allow more fluid to pass and smaller will allow less).
When heavier oil is used, stiction is created. Put a shaft into 2 oils (heavier and lighter). Watch how slowly the heavier oil comes off the shaft than try wiping it off of the shaft with your fingers. Than do the same with a light oil. That resistance is called stiction in suspension speak.
The (intended) lighter the oil the easier/properly the suspension works, add/replace heavier oil the harder it is to move the suspension therefor you can guess the rest (harder ride). You can slow the rate of travel/time by adjusting the flow of the light weight oil through various means starting by what you already have. There you have it, think prior to doing.
Ohlins suspension theory is to only use the correct resistance springs to overcome gravity and set the piston in the proper position inside of the body (in this case fork tube). The actual suspension does all of the work and not the springs. Again: Just overcome gravity and not be a spring on a stick.
Experiment and do for yourself, much more rewarding when it works out for you. Remember the air spring!
Differences not including the top out springs which you re-use the same.
There you have it as this is the stuff they do not tell you about until you have already spent your money.
If you look closely you will see holes. Back in the day when racing and no aftermarket suspension was available to buy, we would weld up the holes, turn the welds round, than drill different size holes (larger will allow more fluid to pass and smaller will allow less).
When heavier oil is used, stiction is created. Put a shaft into 2 oils (heavier and lighter). Watch how slowly the heavier oil comes off the shaft than try wiping it off of the shaft with your fingers. Than do the same with a light oil. That resistance is called stiction in suspension speak.
The (intended) lighter the oil the easier/properly the suspension works, add/replace heavier oil the harder it is to move the suspension therefor you can guess the rest (harder ride). You can slow the rate of travel/time by adjusting the flow of the light weight oil through various means starting by what you already have. There you have it, think prior to doing.
Ohlins suspension theory is to only use the correct resistance springs to overcome gravity and set the piston in the proper position inside of the body (in this case fork tube). The actual suspension does all of the work and not the springs. Again: Just overcome gravity and not be a spring on a stick.
Experiment and do for yourself, much more rewarding when it works out for you. Remember the air spring!
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Cruiser
Joined: Feb 2009
Posts: 107
Likes: 0
From: Las Vegas NV
I have written and showed via photographs what a 1" or measured 0.7" lowered HD kit is. They ride horribly and how they get the drop is by reducing the stroke by 0.70". The springs resistance are increased in order to slow the decreased stroke down in time so it does not bottom out. What is inside of your fork OEM and the HD lowering kit next to it (minus springs)
Differences not including the top out springs which you re-use the same.
There you have it as this is the stuff they do not tell you about until you have already spent your money.
If you look closely you will see holes. Back in the day when racing and no aftermarket suspension was available to buy, we would weld up the holes, turn the welds round, than drill different size holes (larger will allow more fluid to pass and smaller will allow less).
When heavier oil is used, stiction is created. Put a shaft into 2 oils (heavier and lighter). Watch how slowly the heavier oil comes off the shaft than try wiping it off of the shaft with your fingers. Than do the same with a light oil. That resistance is called stiction in suspension speak.
The (intended) lighter the oil the easier/properly the suspension works, add/replace heavier oil the harder it is to move the suspension therefor you can guess the rest (harder ride). You can slow the rate of travel/time by adjusting the flow of the light weight oil through various means starting by what you already have. There you have it, think prior to doing.
Ohlins suspension theory is to only use the correct resistance springs to overcome gravity and set the piston in the proper position inside of the body (in this case fork tube). The actual suspension does all of the work and not the springs. Again: Just overcome gravity and not be a spring on a stick.
Experiment and do for yourself, much more rewarding when it works out for you. Remember the air spring!
Differences not including the top out springs which you re-use the same.
There you have it as this is the stuff they do not tell you about until you have already spent your money.
If you look closely you will see holes. Back in the day when racing and no aftermarket suspension was available to buy, we would weld up the holes, turn the welds round, than drill different size holes (larger will allow more fluid to pass and smaller will allow less).
When heavier oil is used, stiction is created. Put a shaft into 2 oils (heavier and lighter). Watch how slowly the heavier oil comes off the shaft than try wiping it off of the shaft with your fingers. Than do the same with a light oil. That resistance is called stiction in suspension speak.
The (intended) lighter the oil the easier/properly the suspension works, add/replace heavier oil the harder it is to move the suspension therefor you can guess the rest (harder ride). You can slow the rate of travel/time by adjusting the flow of the light weight oil through various means starting by what you already have. There you have it, think prior to doing.
Ohlins suspension theory is to only use the correct resistance springs to overcome gravity and set the piston in the proper position inside of the body (in this case fork tube). The actual suspension does all of the work and not the springs. Again: Just overcome gravity and not be a spring on a stick.
Experiment and do for yourself, much more rewarding when it works out for you. Remember the air spring!
Nice post, very accurate explanation. I am not knocking those who are happy with stiffening up their front suspension by using heavier fork oil. As you said, it just does not make good suspension sense to minimize both compression and rebound to minimize an excessive front end dive issue. Yes it will do it, but at the expensive of greatly limiting rebound. Perhaps those who only ride on relatively smooth roads, or dont push their bikes very hard can get away with it. For most it will create a bone jarring experience with increased road inputs being felt in the front.
Ohlin suspension theory is actually very good suspension theory and has been around for a long time. Use the springs to hold your ride up,( bike, auto, truck, racing vehicle.. whatever) or as you say gravity and let the suspension components handle the road inputs, and do not restrict those components with heavy fork fluid.
Great pics with a great write up. Again for those that heavier fluid has worked for and you are happy with your results thats great, but not something that any real suspension guru would recommend doing.
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