Revisiting Rear Suspension

[jbfla]

I have read SpudRider's suspension tutorial thread several times, watched YouTube suspension videos, and read Race Tech's Suspension Bible.

There appears to be no clear answer (to me) how to alleviate the quick, sharp, up and down motions that, IMO, give a harsh ride. I cringe when I see road patches and potholes ahead.

I return from a ride with my spine and internal organs (kidneys) aching.

I was hoping that as I rode the bike more miles, the suspension would soften up.

At 2,700 miles, it hasn't.

Some of you may be aware I have been posting about this problem on ADV.

I was hoping to appeal for assistance from a wider audience.

So far, some good suggestions, but no answers.

Here is my last post. I'm at an impasse as to what to do next:

Originally Posted by pyoungbl, post: 28787595, member: 55971

Yep, you are spot on. Now, what amount of sag did you measure?

Here are the numbers, remembering they are for my riding weight and bike:

All numbers are rounded to the nearest whole number.

Rider in full riding gear = 188#
RX3: no top case, no rear rack, 5# in side cases, 2# tank bag, 1/2 tank of gas, hand guards, all other stock items.

Published travel of the RX3 rear shock = 5.6" = 142 mm (rounded).

Target sag (per RT Suspension Bible) of 1/3 of full travel = 47 mm.

Preload was measured as the number of full turns of the shock collar.

I have read that 1 full turn is equal to 1 mm, but I haven't verified this for the RX3.

preload.........................static sag (race sag)

0 turns (no preload)......56 mm
3 turns.........................54 mm
6 turns.........................47 mm
9 turns.........................44 mm

IMO, this suggests that the 6 turns would conform to 1/3 of total travel.

And is in agreement with the chart in the RT Bible.

And that the spring is NOT too stiff ?????

I haven't fully test ridden the RX3 in all combinations of preload and damping settings.

The road testing is very time consuming.

At this point, I'm puzzled; is it the spring, preload, damping or ???

The only bike to bike comparison at hand is the Indian Scout (other bikes are in NC).

The Scout, with only 3 inches of travel, and mediocre suspension at best, rides the same poorly maintained roads with far less drama than the RX3.

I'll try a few more preload/damping settings over the weekend....... and then order the Progressive shock?

I am sure there is a solution.

Any educated suggestions are welcomed.

jb

[pete]

static sag is not race sag....
static sag is the suspension compression under the bikes own weight
with out rider....

race sag or rider sag is the bike with rider on...

Static sag should be around 30/35mm

race sag , rider sag ... 33% or 1/3rd of travel....

[jbfla]

Originally Posted by pete

static sag is not race sag....
static sag is the suspension compression under the bikes own weight
with out rider......

Not according to the Race Tech Suspension Bible.

According to Race Tech, static sag is the difference between the shock fully extended and the bike with rider and all gear on board.

Static sag and race sag are the same (according to Race Tech).

The sag between the fully extended shock and with only the weight of the bike is called "free sag" or I have also seen it called "bike sag".

I think that is the cause of some of the suspension confusion...different terms for the same thing.

jb

[pete]

Originally Posted by jbfla

Not according to the Race Tech Suspension Bible.

According to Race Tech, static sag is the difference between the shock fully extended and the bike with rider and all gear on board.

Static sag and race sag are the same.

The sag between the fully extended shock and with only the weight of the bike is called "free sag" or I have also seen it called "bike sag".

I think that is the cause of some of the suspension confusion...different terms for the same thing.

jb

It depends what world you live in I surpose....
we will have to agree to disagree on this one...
As yer said to meany terms for the same thing...



..

[jbfla]

Originally Posted by pete

It depends what world you live in I suppose....
we will have to agree to disagree on this one...
As yer said to meany terms for the same thing.....

Pete, yes, I have found many terms used differently.

I was going by the RT suspension book's term.

Just today, I was watching another suspension video that used "static" sag as you have, "the suspension compression under the bikes own weight with out rider...."

Race Tech calls that "free" sag.

Regardless of what it is called, my sag numbers were calculated by measuring the fully unloaded shock number and subtracting the fully loaded number (bike, rider and gear).

It would be a lot easier if everyone would use the same word for the same thing.

Thanks for your response.

jb

[Jay In Milpitas]

I know that the shock pics were taken during warmer weather.

Having said that, am I the only one wondering why Spud's pants are under the shocks?

JB, I agree with you about springs being matched to rider & machine. As far as the cost, I know that GS owners are known to put an aftermarket shock on their $20k+ bikes. Then again, I've known HD owners that put complete new engines in their bikes around the second scheduled service.

Heck, I think ALeong has already bought a couple thousand dollars of goodies and hasn't even received his bike yet.

[SpudRider]

I properly adjusted the spring preload for the Chinese shock absorber, and it was still punishing. Even if the spring is the problem, no aftermarket shock springs are available. Sadly, Chinese motorcycles are not noted for their excellent suspensions.

Therefore, I strongly recommend you purchase the aftermarket, Progressive shock absorber sold by CSC. Along with an increased suspension travel, the Progressive shock outperforms the Chinese shock on all surfaces, both paved, and unpaved.

http://www.chinariders.net/showthread.php?t=15567

[jbfla]

Originally Posted by SpudRider

.....
Therefore, I strongly recommend you purchase the aftermarket, Progressive shock absorber sold by CSC. Along with an increased suspension travel, the Progressive shock outperforms the Chinese shock on all surfaces, both paved, and unpaved. ....

Thanks, Spud. That's the conclusion I'm coming to.

The $4,000 bike is quickly becoming a $5,000+ bike...

However, some of my riding pals have ordered custom shocks (Ohlins) and had the springs matched to their riding weight.

Is the spring on the CSC Progressive shock "one size fits all rider weights"?

Doesn't seem logical.

I hope you don't mind if I borrow your picture of the two shocks.

jb

[SpudRider]

Originally Posted by jbfla

Thanks, Spud. That's the conclusion I'm coming to.

The $4,000 bike is quickly becoming a $5,000+ bike...

However, some of my riding pals have ordered custom shocks (Ohlins) and had the springs matched to their riding weight.

Is the spring on the CSC Progressive shock "one size fits all rider weights"?

Doesn't seem logical.

I hope you don't mind if I borrow your picture of the two shocks.

jb

CSC is selling the Progessive shock with two different springs. I have the heavier spring on my shock absorber. Talk with Ryan, and he will recommend the correct spring for your riding weight, et cetera.

Of course, you are welcome to borrow my photos.

[Tranberg]

The sag from the bike's own weight is irrelevant, since it's not going very far on its own.

[jbfla]

An update on the rear suspension:

After riding my RX3 200 miles (all pavement) since I spent all that time "tuning" the rear shock, I am pleasantly surprised at the improvement of the ride on the rough surfaces.

For someone younger and in better physical condition than myself, the ride may be perfectly acceptable.

I'm still getting the Progressive shock, but would suggest that you adjust your rear shock to your riding weight and style, and ride a few hundred miles on different road, and off road, surfaces before purchasing another shock.

jb

[SpudRider]

Originally Posted by jbfla

An update on the rear suspension:

After riding my RX3 200 miles (all pavement) since I spent all that time "tuning" the rear shock, I am pleasantly surprised at the improvement of the ride on the rough surfaces.

For someone younger and in better physical condition than myself, the ride may be perfectly acceptable.

I'm still getting the Progressive shock, but would suggest that you adjust your rear shock to your riding weight and style, and ride a few hundred miles on different road, and off road, surfaces before purchasing another shock.

jb

Yes, you definitely need to adjust the spring preload properly to get the maximum performance from any shock absorber. Even the Progressive shock won't perform best , until you also adjust it for the proper spring preload.

[detours]

My progressive shock was pretty stiff when Gerry first installed it and I finally got around to checking the sag.

I was surprised to see the preload was cranked almost to the max! No wonder it didn't feel much better than stock!

So I've spent the last several days moving the adjuster. It's taking forever because I can only move it a couple of notches at a time with my tool. I'm about halfway up the shock threads now. Tonight's ride was an improvement, but it's still way too stiff.

I'll get there eventually but to anyone who buys the progressive shock, adjust the preload to about 1/4 or 1/3 down the threads BEFORE you install it (on the light side), so you have less to adjust when it's on the bike.

BTW, I highly recommend this Ohlins shock spanner wrench. It can either push or pull the adjustment rings and it's narrow so it fits in tight spots.

http://www.amazon.com/Ohlins-Shock-S.../dp/B00415XAH0

[pete]

Originally Posted by detours

I'll get there eventually but to anyone who buys the progressive shock, adjust the preload to about 1/4 or 1/3 down the threads BEFORE you install it (on the light side), so you have less to adjust when it's on the bike.

never preload the spring more than 20mm (3/4").... If you need to the spring is to
soft....

Just a thought... with the RX3 having limited travel & the setting you are trying for being
more suited to bikes with round 300mm / 12" of travel..
Maybe you should be looking at a soft road bike set up..
is 10mm static sag & 25% rider sag..


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[pyoungbl]

Detours, Thanks for pointing out the lighter spring! I weigh just a few pounds less than you and have had a similar experience with the Progressive shock. I have almost no preload dialed in. If I have the bike loaded down for a camping trip the suspension works just fine. Without that extra load the rear is too stiff for my taste. That new spring option sounds like exactly what I need.

Peter Y.