Yamaha TRX850 Enthusiasts Forum

Over time I have ended up with a miss match of front end bits; including gold valves, standard and modified damping cartridges of different lengths, stanchions with different internals as well as standard and 0.85 springs of different lengths.

Now I need is a base point from which to set up the bits I've got.

What I need from you guys are some representative measurements:

1. Length of fork from wheel spindle to bottom of triple clamp on STANDARD TRX suspension

a) loaded
b) unloaded

2. Length of fork from wheel spindle to bottom of triple clamp on MODIFIED TRX suspension

a) loaded
b) unloaded

All assistance greatly appreciated!

Fluro

There are a few links on this on a few other threads on this subject or google up setting sag on your motorcycle. Start at std with the forks through the top tree and clip on by 18mm. Take all the preload of the spring adjuster then wind it down 2 lines. Place a small cable tie around the front fork so it can slide up and down as you press on the forks. Lift the front wheel off the ground and push the cable tie down onto the dust seal on the forks. Measure from the cabletie to the bottom tripple tree...Place the wheel back on the ground without pressing on it and it should drop just with the weight if the bike around 10mm. If it drops further then add spacers on the spring or if close you may take this up with 1 or two more lines on the preload by winding more preload on... .85mm/kg spring will suit an 80/85kg rider for the street. (.7 is std so fine for a 65kg rider) the sit on the bike and with your weight on the bike measure to the cable tie again and if your around 30mm (10mm + 20mm) from your original measurement . That's a good starting point. Use the modified damper rods with the emulators.. The emulators will address the compression on the bike and rebound is adjusted by the weight of oil used. Air gap with emulators around 120mm. Measure this by removing the spring, press the fork leg all the way down and take the measurement to the oil from the top of the fork leg while fully compressed...

Thanx for that succinct summary Cobba, it gives me something to work from.
However, my main problem is that the modified dampening rod is longer than the standard one,pushing the slider further down the fork leg.
I plan to drop the stanchions thru the yokes to compensate.
If I have an idea of how far the front wheel should be from the bottom yoke I can set the bike up with something close to the origional geometry.
Ta. Fluro.

To modify the std TRX damping rod check out this link below. .
the extra length can only be with the emulator/gold valve sitting ontop of the damping rod. If the spring is too short this will cause the fork to be shorter so just space it up with a metal sleeve or some hard plastic tubing.. (not brittle PVC or a soft flexible tubing like waterpipe).

.http://www.trx850.com/phpBB_forum/viewt ... +emulators

Setting sag

http://www.motorcyclistonline.com/howto ... ion_setup/

what I do on the rear is tape a bit of masking tape to one of the attatchment pins for bungee straps on the frame and lift the weight off the rear suspension using a ratchet strap to the frame and roof truss.
Mark this to a point on the masking tape (either centre of axle or put a small dot on the swingarm as a reference point) when the bikes weight is off the rear suspension (unladen sag) .

the lower the weight of the bike down on the rear suspension and mark this point again.. (around 10mm is a good ) this sets the correct spring rate for the bike. if a little higher just bump up the preload on the spring) TRX rear spring is rated for a 76kg rider..

then when your weight is on the bike mark the tape again and take the measurement..