YSS emulator size?

[soupdragon]

I'm thinking of improving the front end on my 2012 f700gs. The rebound damping feels like it needs to be increased. I'm hoping YSS emulators (£88 from Brooks http://www.brooksuspension.co.uk/fork-internals/yss-fork-emulators.html) will do this along with heavier oil - say Silkolene sae 20?).
Trouble is they say they are not listed for this model and need to know the diameter I require. I don't really want to do a strip down to measure myself - presumably it's the same as the diameter of the top of the damper rod that they will sit on or in other words just a little bit smaller than the inside of the stanchion?
Has any one done this mod with YSS or similar and can tell me what size to order?

 

[Bem]

back in a mo, just having a look in the garage for the packaging.

 

[Bem]

Just when I thought I knew what was going on, and then I check the facts! The YSS only go up to 36mm
I have Ricor Intiminators fitted, from the label of which I think mine are 41mm (658 rather than 700, but the fork legs appear identical)
Checking on their site confirms this http://store.ricorshocks.com/bmw_s/47.htm
and also found the following suggestion
"Changing to a higher viscosity will add resistance to compression but it will also slow down rebound, which would be undesirable. Use only the recommended 5wt Amsoil fluid"

If you gently prise off the plastic caps from the fork top then you will be able to get a reasonable measurement across the fork using a Vernier.

And I started a thread somewhere on here about this.

 

[Bem]

http://www.ukgser.com/forums/showthread.php/288887-Improved-650-front-end?highlight=intiminators

and here is Ivors take on the same thing some six months later

http://www.ukgser.com/forums/showth...IR-OF-RICOR-INTIMINATORS-TO-A-F650-GS-(2009)?

 

[soupdragon]

Emulators

Thanks, Bem for your info. Brooks want me to measure the damper diameter but I'm not going to do that in case they can't supply the part. The largest they list is 36mm, as you say. As the OD of the fork tubes is 41mm and assuming they are about 1.5mm thick and allowing for 1mm clearance for the valve, than I should think 36mm would do. I see Intiminators are twice the price of YSS emulators which is too much for me to pay.

 

[Bem]

Thanks, Bem for your info. Brooks want me to measure the damper diameter but I'm not going to do that in case they can't supply the part. The largest they list is 36mm, as you say. As the OD of the fork tubes is 41mm and assuming they are about 1.5mm thick and allowing for 1mm clearance for the valve, than I should think 36mm would do. I see Intiminators are twice the price of YSS emulators which is too much for me to pay.

Er no, unless I have missed something you have said here.
If you do not measure the ID of the tube then how can you know what is and isn`t going to work?
Essentially these need to be a "tightish fit" that is able to move freely within the tube, but not so slack that they allow oil to easily get all around, ignoring the valves in the middle. A 36 in a 41 tube is slacker than slack.
Suggest you at least re-measure the OD which by my reckoning is nearer 45mm (bit dark and cold to measure up now)

Brian

 

[soupdragon]

Emulators

The OD of the top tubes is 46mm and the ID is 36mm. I would think 36mm emulators would be a bit tight so perhaps the next size - 33.5mm - would be right. YSS say a clearance of 0.75mm - 4mm is adequate. The 33.5mm valves would give a clearance of 2.5mm. Emulators are different to Intimidators - they dont need to be a tight fit - thet dont require a perfect seal and can move around a bit.

 

[Bem]

Ok,Ok, but don`t forget to write something about its benefits after fitting!