TRX850 suspension adjustment help

Hi guys, I just sold my bandit 250 and got a TRX850. On the test ride I noticed
that the front suspension was very soft (compared to bandit). If I adjust the
preload to stiffen up the front, what effect does this have on handling?

On the test ride I didn't get a chance to get out of second gear. The current
front sprocket is a 17 tooth. If I change it to a 16 tooth, will this help
much? Should I go down to 15 tooth if available?

thanks.

 

1 tooth down and a suspension rebuild is standard TRX fare

where is JL ???

check google

 

Not sure where you hail from Fat Ho, but a suspension rebuild sounds on the
cards. Well, not quite rebuild, more of an upspec. Sounds like you need
stiffer front springs and revalving to suit. They can probably work their
magic hands over the rear shock for you too. If you're in Sydney, give Frank
Pons at Biketek a call (highly reccomended .. by me!!!), umm, if you're in
Melb I think Promecha is the go down there. Other than that, not sure where
to go to. It'l be the best money you've ever spent.

As J5 said, you can change down the gearing if you like, I haven't ridden
em.

Cam
'03 954

 

Been busy mate - 700 odd unread aus moto emails in a couple of days - you lot
sure are prolix !

Yeah like Glen said - gearing it down makes it a lot more fun in the twisties
and a little nicer around town - you can either go 1 down at the front or a
couple up at the back. Wouldn't go any further than that. I actually ended up
going back to the stock gearing.

Gold valve the front and replace the springs if you're more than 75 Kg (stock
springs are suitable for about 65-75Kg) knock on a bit of preload but don't
crack it up all the way or it'll remove your fillings - you can go up a bit on
the oil weight as well. DEF worth the money for goldvalves though - huge
improvement.

1 thing that's a must do, and one thats highly recommended:
Must do: Slide the forks up the triple clamp (or the triple clamp down the forks
depending on your viewpoint) - sharpens the steering no end, from memory go an
inch (25mm) first up and test from there. They steer like a truck until you
steepen them up. They also don't have enough weight on the front stock, so you
need to do it to get them in balance (if you're 7 feet tall you can jack up the
rear via dog bones but they have so much clearance there's no real need
otherwise)

Recommended - put a set of blue spot calipers (or even goldies from the new
model if you can get them) off an R1 or R6 (or I think a couple of others now).
Makes a huge difference.

Going from the baby bandit to the TRX you'll have to get used to two things -
it's not a high revver with a peaky torque band so don't wring the tits off it -
ride the torque - get used to a lazy left foot And the other thing is it's a
corner speed bike - a big four* you ride slow in fast out and use the HP, the
TRX has oodles of ground clearance the lack of hp means you can get on the
throttle real early

JL
*not the baby bandit - I mean things like R1s

 

that the front suspension was very soft (compared to bandit). If I adjust
the

It is a popular misconception amongst bikers that increasing the preload
somehow stiffens the suspension. Changing the preload doesn't do anything to
the rating of the spring, it merely changes the sag by adjusting the length
of the spacer above. Only adjust it by measuring the sag when you are
sitting on the bike. It should sag about 25 to 40 percent of the full
travel. Most road bike forks have about 120mm, so the sag should be between
30 and 48 mm and that is your sensible adjustment range. Wheels go over dips
as well as bumps and you don't want the suspension to bottom out or top out.

Increasing the preload raises the front end which changes to geometry to
slow down the steering. It will increase stability but make it more
difficult to change direction. If you increase the preload because you have
too much sag then you should also change the rear to compensate for the
different geometry.

Thinking that you need to make a change because the suspension feels
different to your Bandit sounds a bit silly. If I was picking a bike to use
as an example of suspension perfection it wouldn't be a Bandit. Why do you
think it is too soft? Is it bottoming? I like my suspension to be as soft as
possible, without causing any handling faults..... it's comfy.

Cheers Frank.

 

This is not true if you're using progressive springs.........................

 

springs.........................

I think you will find it is.

Richard

 

OK.

I'm sititing here with my poor little flu'd out fevered brain trying to
understand:
http://www.progressivesuspension.com/fork-springs.html

So - if the spring is already compressed 2 inches, it is harder to compress 1
more inch than it was originally?
Surely that means that preloadint the springs changes the initial stiffness??

??

I know preloading the springs does nothing with linear springs except change
ride height

Compressing the springs to "harden" the suspension does mess with how much you
can load them before getting coil bound.......

K

 

It's a sad, sad reflection of just how bored I am that I'm reading a "yes it
is/no it isn't" thread about inconsequential suspension adjustments to an
irrelevant bike.

I just have to get a life.

Anyone know of one that's not being used (apart from my own)?

 

While true, there's a bit missing - changing the preload changes the
range of motion (travel) the spring has available to work through
hence it has less travel before it bottoms out (at which point it *is*
really stiff , and in the case of progressive rate springs you have
less movement in the suspension before you hit the higher rated part
of the travel

Errm sorry ? Care to explain how that works ? You're basically turning
a screw that extends a lump of metal down the fork leg to compress the
spring - how does that change the geometry ? You sure you're not
thinking of the rear (where change in preload will affect geometry by
changing the amount of sag when you sit down). Willing to be corrected
but I can't figure how that could work...

If your front preload is wrong then you probably should be correcting
your rear, but not because of geometry, because you want the spring
operating in its ideal range

well I can tell you for a fact that the TRX *IS* too soft for nearly
all riders - even with a 55Kg female on it it's rather softly sprung
for a sports bike, and fixing the front end on it is de-rigeur. The
baby bandit has reasonably good suspension - far better setup than the
1200 in my opinion (which is pretty ordinary stock)

As for the liking it to be soft - yes, well, squidgy suspension goes
hand in hand with crap handling, pogo-ing your ways through the
corners is good news if you're on a poorly maintained back road, but
it'll screw your corner speed on a decent road or race track.Not to
mention the amount of dive you'll get from the front when you brake
hard into a corner, which dramatically increases the rake at the
front, dramatically changing your steering geometry in an inconsistent
way as you brake and then release.

The point of suspension is to keep the black bits in constant
connection to the road - suspension that is too hard or softly sprung
prevents that, as does incorrect damping. There's a reason the race
teams spend zillions on suspension.

JL

 

*about to ask a stupid question, but then realises the answer*

phew.

Mike.S