ChinaRiders Forums - View Single Post - Tutorial: Adjusting the Shock Spring Preload for the RX3

Bob Kelly · 05-16-2022, 07:05 PM

Although this thread is mainly about the RX3 I have some info on the RX4 to share
after the initial "first ride" I took out all the preload on my RX4 it has 2 nuts on the shock not a locking collar I just moved the nuts to the top of the shock... I did this to LOWER the bike which it did ! by 2" at least..... but the ride was still as bad as the first ride and it beat me to death.... I put on 121 miles like that and finally decided to attack the harsh ride issue.... I ordered a spring from Race tech and got a 10" long 2" i.d. by 500lb rate spring.... It rode just the same so I pulled off the shock put it in the vice and studied it a while the stock shock is 17" long eyelet to eyelet... it has a progressive or double rate spring on it that is exceedingly stiff... so I thought replacing the spring with something weaker was the answer. I was told that the spring rate of the stock shock was 650lbs so I thought I'd try 500lbs
I was wrong..... the problem was that the shock has a mear 2.1" of travel in it !
and the threads on the upper part of the shock that adjust the pre-load are about 4" long..... as you raise the nuts you lower the piston in the shock so in reality what I did by putting the nuts all the way to the top was bottom out the shock ! because of it's short stroke.... when I realised what I did and how I screwed up I put the stock spring back on and extended the shock all the way UP and then ran the nuts down to the top of the spring....
this will give me maximum shock travel and maximum seat height to my chagrin...
I can no longer flat foot that bike i could when I had the shock bottomed out but the ride was horrible ! I had to run 28 p.s.i. in the rear tire just to be able to ride it !
the only way I can get the seat height down is to buy a lowering kit or make a new horseshoe/dog bone that is longer so if anyone knows of a lowering kit for the RX4 please say so, I'm desperate !
..... the RX4 I have is a 2021 that I got from CSC and the weather is finally good enough to ride it... but it is definitely too tall for me with it lowered 2" I could flat foot both feet as a stop sign and I will have it like that again one way or another.... even if I have to fabricate up my own suspension bracket !.... it won't be the first time !
....
sense the shock on the RX4 only has a 2.1" travel the preload is a joke ! because if you set the preload to the normal sag etc.etc. you stand a real good chance of bottoming out the shock ! and that is probably why they put in such a heavy spring in the first place......
sitting on my bike is like sitting on a park bench there is no give at all....no flex when I get on it or jump up and bounce on it it is rock solid ... and that is the way it came !
....I am trying to change that as the roads around here are rough to say the least !
....
Bob...

05-16-2022, 07:05 PM	#95
Bob Kelly Join Date: Jan 2022 Location: Weed, California. Posts: 271	Although this thread is mainly about the RX3 I have some info on the RX4 to share after the initial "first ride" I took out all the preload on my RX4 it has 2 nuts on the shock not a locking collar I just moved the nuts to the top of the shock... I did this to LOWER the bike which it did ! by 2" at least..... but the ride was still as bad as the first ride and it beat me to death.... I put on 121 miles like that and finally decided to attack the harsh ride issue.... I ordered a spring from Race tech and got a 10" long 2" i.d. by 500lb rate spring.... It rode just the same so I pulled off the shock put it in the vice and studied it a while the stock shock is 17" long eyelet to eyelet... it has a progressive or double rate spring on it that is exceedingly stiff... so I thought replacing the spring with something weaker was the answer. I was told that the spring rate of the stock shock was 650lbs so I thought I'd try 500lbs I was wrong..... the problem was that the shock has a mear 2.1" of travel in it ! and the threads on the upper part of the shock that adjust the pre-load are about 4" long..... as you raise the nuts you lower the piston in the shock so in reality what I did by putting the nuts all the way to the top was bottom out the shock ! because of it's short stroke.... when I realised what I did and how I screwed up I put the stock spring back on and extended the shock all the way UP and then ran the nuts down to the top of the spring.... this will give me maximum shock travel and maximum seat height to my chagrin... I can no longer flat foot that bike i could when I had the shock bottomed out but the ride was horrible ! I had to run 28 p.s.i. in the rear tire just to be able to ride it ! the only way I can get the seat height down is to buy a lowering kit or make a new horseshoe/dog bone that is longer so if anyone knows of a lowering kit for the RX4 please say so, I'm desperate ! ..... the RX4 I have is a 2021 that I got from CSC and the weather is finally good enough to ride it... but it is definitely too tall for me with it lowered 2" I could flat foot both feet as a stop sign and I will have it like that again one way or another.... even if I have to fabricate up my own suspension bracket !.... it won't be the first time ! .... sense the shock on the RX4 only has a 2.1" travel the preload is a joke ! because if you set the preload to the normal sag etc.etc. you stand a real good chance of bottoming out the shock ! and that is probably why they put in such a heavy spring in the first place...... sitting on my bike is like sitting on a park bench there is no give at all....no flex when I get on it or jump up and bounce on it it is rock solid ... and that is the way it came ! ....I am trying to change that as the roads around here are rough to say the least ! .... Bob... __________________ It's too late when you've gone too far !
	0