Monday, January 23, 2012

Suspension Mods

Since Ohlins no longer sells a rear shock for the 885i or 955i, I decided to build one based on the original Ohlins specs. You can take these specs to your suspension tech to build you a shock with similar valving characteristics:

The Ohlins model for the 885i was TR852 (or TR 8520) based on a 46mm diameter piston, monotube body with adjustable rebound, piggy back adjustable compression, and a hose mounted hydraulic preload adjuster: Ohlins model 46PRCS. Preload is not adjusted with the collar.

I went a step further and built a 46HRCS with both a remote compression adjusterand a remote hydraulic preload adjuster. Rebound is still adjusted at the base of the shaft. This build is similar to the current Ohlins TR709 S46HR1C1S for the 1050.

The shock specifications are different for a Steamer, 955i, or 1050. The Ohlins catalog only lists a TR704 for the 1050  which is a S46HR1C1S with 350mm length and a 120 N/mm (12.23 kg/mm or 685 psi) rear spring rate

The 2001-2006 955i (T709EN) had a 1" longer eye-to-eye length, but same stroke and spring length as the 1999-2000 885i T709. Best way to tell them apart other than VIN is paint scheme, no eye lashes on T709, exhaust collecter box, and vertical mounted oil cooler on right side (885i) vs. across 955i.

So if you have a 955i just change the eye-to-eye length. Or for the in-seam challenged, build the shorter shock to lower the seat height. I recommend dropping the fork tubes through the triple clamps to 20mm+.

Build Specifications:
Total length (eye-to-eye): 370mm (14.5", the 955i is 15.5")
Stroke 69mm

Parts (Ohlins part numbers) used on a TR852:
Head 870-55
Body: 1010-34
Shaft: 5500-16
End-eye 1054-21 (Note the top shock mount is a Torx M12 X 64MM; and the bottom shock mount is a  Torx M10 X 111MM holding a sleeve.)
Resevoir tube: 302-01
Internal spacer 1069-02 (2x)
Gas piston: 305-01
Shaft Jet: 5665-18
Adjustment valve: 5655-04
Valve stop: 519-04
Piston: 1114-14
Adjustment shaft: 566-41
Internal stop: 5115-01

Valving Specifications:
Compression: 520-38 (5x), 540-36 (2x), 525-34, 525-32, 525-30, 525-26, 530-22, 530-20, 530-18
Rebound: 530-34 (4x), 525-32, 525-30, 525-28, 530-26, 530-22, 530-18, 519-07, 578-01 (5x), 539-01 (Note the 2 stage blow-off)
Compressionadjuster (Preload): 186-12, 185-12, 186-18, 186-16, 186-14, 186-12
Spring 1099-74 220mm or 8.7 inch spring (The 1028 psi spring rate was a suprise.  180 N/mm or 18.35 Kg/mm) Much stiffer than the OEM spring . 1050 uses a ~640 psi (11.35 Kg/mm) rear spring. Ohlins spring rate provided is based on a 155-170 lbs. rider with gear.
Preload 18mm
Bearing, cylinder head: 536-02, 1018-02 (2x)
Bearing, end-eye: 3097-02 (2x), 1049-02 (2x)
preload adjuster: 3681-01, 1042-06
Spring clip: 516-01
Bump ruber: 563-04
Bracket: 1164-02 (for preload adjuster)
Spring position: 3mm
Gas pressure: 12 bar

Initial Settings:Compression 10 clicks
Rebound: 12 clicks

To balance out the rear suspension, and eliminate fork dive, I installed Ricor Intiminators, with Amsoil 5W suspenion fluid to 107mm air gap.

Oddly, Triumph uses fluid volumes and not the air gap measurments with spring removed and fork fully compressed. Measurement based on fluid volume and not air gap are extremely inaccurate!

The following air gaps are provided: 720cc cc (107mm air gap) for VIN 198875 and after (955i).  Prior VINs had 682cc (119mm air gap). The increase in fluid volume was to reduce the fork dive. Front fork spring rates were increased from .400 kg/mm  to .600 kg/mm on T709EN and 1050.  '06 955i use 655cc (146mm air gap).  Interesting note: Steamers used .460 kg/mm spring rates.

You can also install Speed Four preload adjustable fork caps on the 43mm KYB forks. Do not use the fork caps for the Scrambler (41mm KYB forks).


  1. So the 855i 1999-2000 rear shock is shorter than the 955i 2001-2006 model ? I wont to lower height of bike I hear this will do that by an Inch or so,( WILL THE 99 SHOCK FIT THE 955I REAR) and what is a cowling 'eyelashes' ?


  2. This is not a SAFE Mod, for the following reasons
    1. All adventure ability is gone (as bike is lowered by about 2 inches and bottoms out very easily.)
    2. Ride high view is traffic is gone
    3. Handling is not as good (yes i did drop the front as well)
    4. Had to take off centre stand
    5. And the spring sits on the rear swing arm (not cool)
    I will be converting back (DO NOT PUT THE 855 SHOCK IN A 955 TO LOW)