After reading a number of encouraging reviews on the Ricor Intiminators and Fabrick8Rs excellent posts I decided to get a set to improve the ride quality of my standard Sportster forks. I live in the UK Lake District where the roads are famously undulating. Hence, any improvement in suspension is noticeable at relatively modest speeds. I was getting numb hands with the standard Harley damping! I fully rebuilt my Sportster forks when I installed the intimidators and found an immediate improvement in ride quality. However, all was not well. The UK had a cool summer in 2015 and using the recommended Amsoil 5W low (209) VI oil, I did not get full travel unless I reduced the oil level. This resulted in too much dive.

Having read many of the reviews on the intimidators and the various modifications suggested, I thought I would first try a faster moving oil before modifying the valving. Typical UK riding temperature are in the range of 10-25C; doubtless many parts of the USA are warmer. I changed to Silkolene Pro RSF 2.5w, which has a claimed high VI of 460 and found that it works much more consistently in cooler temperatures. The Amsoil and Silkolene fork oil has fairly similar cst at 40C (15.7 v 13.8) and 100C (4.4 v 5.8). However, if my estimates are correct, the viscosity @10C would be around 25cst for the Silkolene and 45cst for the Amsoil, based on their claimed VI. I anticipate that has an appreciable effect on the damping! I was able to adjust the Silkolene oil volume so the final 1/2" of compression ramped up while still retaining excellent mid stroke compliance. I can offer no better compliment than to say I no longer notice the front suspension. It does its job so well. The bottom line is that Silkolene RSF 2.5 (or possibly Redline light) might be a more suitable oil to use in cooler climates due to the higher VI.

 

Hello old chap, from just down the road, and welcome to HDF. You've been venturing out around the Lake District in recent weeks, through the floods?! Jolly brave. For members from further afield there have been terrible floods and damage done in that area over the last 2-3 weeks.

Great post, but can I make a suggestion? You will find suspension threads all around HDF, the subject is so common, and the Sportster section will appreciate learning about your experience, so kindly start a new post over there.

 

Thanks Mr Brown. I may just do that. The reason i wanted to add my experience to this particular post was that it was by a long way the most detailed on the subject of setting up the Ricors. I found it very helpful.

Hopefully, trying a higher VI oil will help others. It is simple to do before you modify the valving and there is a reasonable rationale for doing so in cooler weather.

{Thanks for asking; I was lucky with the floods but some of my friends were made homeless}.

 

You did the right thing posting here and you are quite right, this thread is very special. The significance for Sporty owners is that news of an inexpensive forks upgrade should be well received.

 

I suspect that the difference in VI of these oils at lower temperatures would be noticeable on heavier touring Harleys as well if you ride in cooler weather. I weigh about 120KG and my Sportster has Performance Machine brakes. The differences I noticed with the higher VI Silkolene oil were much better bump compliance, smoothness and being able to use all the travel without excessive brake dive. Pretty much what the valve modification is aiming to achieve

 

Did you modify the valves themselves in any way, or just install them as supplied? Mrs B and I have a Sporty and that could do with some help up front. We have single-rate Race Tech springs in it, which I'm happy with, plus Emulators, which I'm not. If Intiminators are going to improve damping up front I may well be tempted to try them.

 

The valving was left as delivered from Ricor but I changed the oil to Silkolene RSF Pro 2.5 which has a claimed VI of 460 compared to Amsoil at only 209. Since this is about how higher VI oils flow at lower temperatures, the same approach could be helpful for touring Harleys when ridden in cooler weather.

To recap: I rebuilt my 39mm forks and cleaned them out very carefully to remove old sludge. The intimidators were left standard so I could first try them as Ricor supplied with the recommended Amsoil 5W. It was much better but not ideal. The fork felt over damped on bump compression, so I then tried the Silkolene and as explained it has a higher VI and at ambient temperature we had in the UK summer meant that it is much faster flowing than the Amsoil based on claimed VI. (UK summer temp in 2015 was only about 16C so the baseline viscosity of the oils would be roughly 22 cST for the Silkolene and 35 cSt for the Amsoil). The difference in viscosity was such that I could get the ride I wanted without disturbing the valving. I just set the sag/preload and then fine tuned the final ramp up on the last 1/2" of travel by adding 10cc of oil to both forks at a time (within manufacturers height limits). Very happy with it now.

I have tried to post a viscosity/temperature diagram for the two oils to illustrate the varying viscosity rates but can't find a format that this site will upload. Anyone able to help?

 

Fabrik8r:

Your mailbox is full - not surprising

I was convinced by about page 20 and did not read any further...............

Are you still doing the Ricor cartridge emulator mod, and if so are you willing to do a set for me?
If so then do I need to have a set shipped to you or do you still have them pre-modded?

Great work and thank you for sharing with other enthusiasts

 

You will not be let down
http://www.progressivesuspension.com...u-2013-touring
No need to fiddle/fart around @least for me.

 

The thing with this mod discussion is, Ricors were designed to be used with stock, soft springs. When you install with the proper spring rate, stiffer springs, you get a stiff suspension. Even Ricor told me you get 80% of the benefits using stock springs. I had Ricors. They do some good things, using stock springs. However, using Race Tech Springs with Gold Valve Emulators makes for a far better suspension.