Removing the rear shock ?

pyoungbl · 05-08-2022, 09:08 AM

Bob, when I was swapping springs on my RX4 I tried 650 lb/in...too stiff, then went down to a lower value....maybe as low as 500 or even 450. It has been a while. Lucas is giving you good advice, you should be looking at about 1/3 suspension travel suspension sag when the bike is unladen. The correct spring will get you there. At the same time, you need to have a shock that works with the spring. The OEM shock is bargain basement, a common place to save money. The valving is dead simple, just fixed holes for the oil to pass through. That's OK for gentle bumps but will lock up when you try to force fluid through those holes at a velocity higher than minimal. Of course grease will help the suspension a bit. There is grease present on the new parts, just not a lot. The grease is more to keep rust at bay than anything else since the parts run on needle bearings.

At some point Joey sent me the specs for the rear suspension. The OEM spring is rated for 142 n/mm...that converts to 810 lb/in. You can immediately see why the ride is so stiff. Add in the fact that the spring is progressively wound, meaning that as it compresses the rate goes up! Don't forget that the shock itself has progressive resistance due to the gas being compressed. Now you have doubled down on rising resistance as the shock compresses. All this is great if you are using the bike as a pack animal at low speed, not so good for the way we use the bikes.

We bought bikes that offered affordable fun. If you want the suspension to work to your satisfaction you'll have to decide how badly you want that result. Earlier I mentioned Cogent Suspension's custom shock/spring. You balked at the price. That's understandable if you think of a $5K bike needing a $700 upgrade...a might big % of the cost of the whole bike. Think of it another way. If you buy a well used BMW, KTM, Ducati and get it for a bargain price (even free) the consumables still cost the same as a brand new machine (assuming the sizes are the same)...I'm talking about tires, brake pads, stuff like that. The parts are not discounted because of the age of the bike. Suspension is the same thing, high quality is going to cost. Cogent's price is competitive, even inexpensive compared to some stuff from Ohlins. Oh, Ohlins would not even consider building a shock for my RX4...I tried. Not enough market for their effort.

All of the above is not to bash your efforts. I went down the same path. Health issues have given me lots of time to think about your suspension problem. My thoughts are offered for free. Feel free to ignore, no problem here. I'd just like to see you happy with the bike.

Peter Y.

05-08-2022, 09:08 AM	#14
pyoungbl Join Date: Feb 2016 Location: Portsmouth, Virginia, USA Posts: 632	Bob, when I was swapping springs on my RX4 I tried 650 lb/in...too stiff, then went down to a lower value....maybe as low as 500 or even 450. It has been a while. Lucas is giving you good advice, you should be looking at about 1/3 suspension travel suspension sag when the bike is unladen. The correct spring will get you there. At the same time, you need to have a shock that works with the spring. The OEM shock is bargain basement, a common place to save money. The valving is dead simple, just fixed holes for the oil to pass through. That's OK for gentle bumps but will lock up when you try to force fluid through those holes at a velocity higher than minimal. Of course grease will help the suspension a bit. There is grease present on the new parts, just not a lot. The grease is more to keep rust at bay than anything else since the parts run on needle bearings. At some point Joey sent me the specs for the rear suspension. The OEM spring is rated for 142 n/mm...that converts to 810 lb/in. You can immediately see why the ride is so stiff. Add in the fact that the spring is progressively wound, meaning that as it compresses the rate goes up! Don't forget that the shock itself has progressive resistance due to the gas being compressed. Now you have doubled down on rising resistance as the shock compresses. All this is great if you are using the bike as a pack animal at low speed, not so good for the way we use the bikes. We bought bikes that offered affordable fun. If you want the suspension to work to your satisfaction you'll have to decide how badly you want that result. Earlier I mentioned Cogent Suspension's custom shock/spring. You balked at the price. That's understandable if you think of a $5K bike needing a $700 upgrade...a might big % of the cost of the whole bike. Think of it another way. If you buy a well used BMW, KTM, Ducati and get it for a bargain price (even free) the consumables still cost the same as a brand new machine (assuming the sizes are the same)...I'm talking about tires, brake pads, stuff like that. The parts are not discounted because of the age of the bike. Suspension is the same thing, high quality is going to cost. Cogent's price is competitive, even inexpensive compared to some stuff from Ohlins. Oh, Ohlins would not even consider building a shock for my RX4...I tried. Not enough market for their effort. All of the above is not to bash your efforts. I went down the same path. Health issues have given me lots of time to think about your suspension problem. My thoughts are offered for free. Feel free to ignore, no problem here. I'd just like to see you happy with the bike. Peter Y.
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