Installed Ohlins on 2010 Road King
Ultimate HDF Member
Joined: Dec 2010
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From: wet coast BC
I think we've confused each other! I was talking about nominal length, not compressed length. Some of the Ohlins have an adjuster that enables them to be shortened overall by around 1/4", which is what I've done to mine, so I have reduced them from 13" to 12 3/4" overall. With sag of just over an inch compressed length is around 11 3/4".
I am trying to show why I went to the 13" instead of the 12" JRI. The stock 12" does not compress much and then it reduces the 2" of compression travel. whereas the 13" JRI drops the 1" with rider weight making it 11 7/8" when riding.
For those wanting to lower the ride height on an SG the 12" JRI will drop to 11".
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Tourer
Joined: May 2013
Posts: 297
Likes: 12
From: Los Angeles County
I think we've confused each other! I was talking about nominal length, not compressed length. Some of the Ohlins have an adjuster that enables them to be shortened overall by around 1/4", which is what I've done to mine, so I have reduced them from 13" to 12 3/4" overall. With sag of just over an inch compressed length is around 11 3/4".
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Joined: Jun 2007
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From: Bedford UK
I installed the shocks as part of a rear end overhaul, so only set belt tension after I had completed everything. I didn't install the shocks as the only change I made. I would guess that you won't need to change belt tension, although it is worth checking after they are installed.
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Tourer
Joined: May 2013
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From: Los Angeles County
Shocks have two very different functions. The first is to hold up the weight of the bike, which is the job of the springs. Setting sag achieves that, but also provides enough movement up and down to allow the dampers to do their job.
The dampers provide control over the motion of the vehicle, once you start moving, which is where you can achieve a "nice ride"! With sag set correctly make small adjustments to your dampers to fine tune the quality of your ride. If the damping is too soft you may bottom out, if it is too stiff the ride will feel hard and unforgiving. Adjust the dampers, not the springs!
You have put behind you messing with preload! That was when you had low grade shocks with mediocre damping and no damper adjustment. Look back and give thanks, look forward with eager anticipation!!!!
The dampers provide control over the motion of the vehicle, once you start moving, which is where you can achieve a "nice ride"! With sag set correctly make small adjustments to your dampers to fine tune the quality of your ride. If the damping is too soft you may bottom out, if it is too stiff the ride will feel hard and unforgiving. Adjust the dampers, not the springs!
You have put behind you messing with preload! That was when you had low grade shocks with mediocre damping and no damper adjustment. Look back and give thanks, look forward with eager anticipation!!!!
And the preload setting makes a LOT of difference in ride. The less preload, the better. I almost got the seamless freeway ride with preload at the minimum possible. No way to get the rider sag in the 25-30mm range and enjoy the ride.
I also did a comparison of the spring rate of the Ohlins compared to the Harley air shock at my air pressure setting ... about 30% lighter rate on the HD.
Putting a call in to my vendor ...
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Tourer
Joined: May 2013
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From: Los Angeles County
Thought I would post another update on putting the Ohlins shocks on my ride. (HD159 model)
I am not completely done yet, but I learned something I hadn't seen posted here yet.
With these shocks, the most important factor is the one I can't easily adjust ... spring rate!
I have been through two different rates of springs, and the rear end ride went from "not harsh but way too firm" to "almost disappearing". The preload / rider sag plays quite a role in stiffness, but there is only one sag setting on my shocks that really works - 30mm (minimal harshness and not bouncy). So I set the sag there, the response is optimum for the springs, but it is either too firm or not. With 27N/mm springs (about 155 lbs/in) it was just plain bumpy. I could tell there was a good shock under there, but it was just too much. I have heard a lot of guys describe this on their Ohlins and JRIs, and try all kinds of obscure messing around to fix it.
I switched to 25 N/mm (~140 lbs/in) springs, and wow, what a difference. Again 30mm sag, the shock is much more pleasant to ride, just about disappears, much more balanced with the front end.
My stock Harley air shocks have a measured rate of about 120 lbs/in where I set them (all riding is one up, I'm 210 lbs). They give a nice balanced ride but not the quality I get with the Ohlins.
So I am planning to go with 23 N/mm (~130 lbs/in) springs and see if that is ideal. If the change between the first two is any indication, I may be done!
So I have to say - Installation is easy and not at all sensitive, doesn't change squat with the ride; good preload / sag is easy to adjust and optimize; finding a good rebound setting is straightforward (no compression setting on mine). If you think your fancy shocks are really nice but just can't get them adjusted right, TRY DIFFERENT SRINGS.
I am not completely done yet, but I learned something I hadn't seen posted here yet.
With these shocks, the most important factor is the one I can't easily adjust ... spring rate!
I have been through two different rates of springs, and the rear end ride went from "not harsh but way too firm" to "almost disappearing". The preload / rider sag plays quite a role in stiffness, but there is only one sag setting on my shocks that really works - 30mm (minimal harshness and not bouncy). So I set the sag there, the response is optimum for the springs, but it is either too firm or not. With 27N/mm springs (about 155 lbs/in) it was just plain bumpy. I could tell there was a good shock under there, but it was just too much. I have heard a lot of guys describe this on their Ohlins and JRIs, and try all kinds of obscure messing around to fix it.
I switched to 25 N/mm (~140 lbs/in) springs, and wow, what a difference. Again 30mm sag, the shock is much more pleasant to ride, just about disappears, much more balanced with the front end.
My stock Harley air shocks have a measured rate of about 120 lbs/in where I set them (all riding is one up, I'm 210 lbs). They give a nice balanced ride but not the quality I get with the Ohlins.
So I am planning to go with 23 N/mm (~130 lbs/in) springs and see if that is ideal. If the change between the first two is any indication, I may be done!
So I have to say - Installation is easy and not at all sensitive, doesn't change squat with the ride; good preload / sag is easy to adjust and optimize; finding a good rebound setting is straightforward (no compression setting on mine). If you think your fancy shocks are really nice but just can't get them adjusted right, TRY DIFFERENT SRINGS.
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Joined: Dec 2008
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From: Rhode Island/Pensacola Florida
Good information, sel53. Thanks for the review. I will be installing the Ojlin 159 this winter along with the new Ohlin front suspension. I do about 80% two up riding (total weight between us is about 380 lbs). I'll let you know how it goes.
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Joined: Dec 2010
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From: wet coast BC
Once I came across a graph/table of the spring rate choices and how they applied to weight. I did not bookmark and have not been able to find it again. It visually showed what sel53 changes relate to.
your post goes a long way to show how off the shelf shocks no matter brand do not fit everyone.
your post goes a long way to show how off the shelf shocks no matter brand do not fit everyone.
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Joined: Jan 2008
Posts: 6,532
Likes: 132
From: SoCal
The very first thing you do when installing shocks is to determine whether or not the installed spring rate is correct. If you had done the 3 shock length measurements after installing the shocks(or after the break-in) you would have known where you stood as far as the spring rate spring rate goes. When you received the shocks do you get a detailed sheet on how to go about this? If not you need to contact whomever you bought the shock from to get the details on these 3 measurements and how they relate to spring rate. Sure beats changing springs at a whim and guessing at spring rates and sag settings.
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Tourer
Joined: May 2013
Posts: 297
Likes: 12
From: Los Angeles County
qtrracer, I would not be posting this info here for others if I had found the information in Thede & Park's suspension book, along with Trevitt's suspension tuning book, along with every post known to mankind on this forum, along with everything Ohlins publishes, to be adequate for a simple setup.
The range of free sag vs rider sag that Ohlins (and others I have found documented) covers quite a large range. [5mm < free sag < 15mm; 25mm < rider sag < 35mm] That yields a possible preload range of 10mm, and a range of "acceptable" spring rates covering a rider-minus-free-sag difference of 10mm to 30mm. Using simple math I can compute what the spring rate change might-should be, yet a rate change that is a small fraction of that makes a dramatic difference--> To me it seems that it takes riding!
So even working with a knowledgeable & cooperative seller 300 miles away, and Ohlins being 1-1/2 weeks shipping away, it takes time, patience, a lot of measurement, and even more riding to get it right.
The Canadian gentleman is right, these are not buy and use shocks ... I wanted to pass along some info to make it easier for the next person. If you know an analytic way to determine spring rate, please post it so we can all learn.
1Canuck, that table you mention sounds interesting, if you come across it.
The range of free sag vs rider sag that Ohlins (and others I have found documented) covers quite a large range. [5mm < free sag < 15mm; 25mm < rider sag < 35mm] That yields a possible preload range of 10mm, and a range of "acceptable" spring rates covering a rider-minus-free-sag difference of 10mm to 30mm. Using simple math I can compute what the spring rate change might-should be, yet a rate change that is a small fraction of that makes a dramatic difference--> To me it seems that it takes riding!
So even working with a knowledgeable & cooperative seller 300 miles away, and Ohlins being 1-1/2 weeks shipping away, it takes time, patience, a lot of measurement, and even more riding to get it right.
The Canadian gentleman is right, these are not buy and use shocks ... I wanted to pass along some info to make it easier for the next person. If you know an analytic way to determine spring rate, please post it so we can all learn.
1Canuck, that table you mention sounds interesting, if you come across it.
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Joined: Jun 2007
Posts: 45,429
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From: Bedford UK
You have put yourself to a lot of unnecessary trouble and effort. I installed mine, set their sag, and Mrs B and I have been happily riding on them ever since! Simples.
Last edited by grbrown; Nov 27, 2013 at 03:37 AM.