A question about progressive suspension recommendations.

Hello again everyone,

[Main question is at the bottom if you want to skip the details, but there's some important info before that.]

My project is turning into a nightmare, but I'll try to only cover one thing at a time to maintain my sanity (and my wallet).

Following advice I found on the forum, I got a set of progressive 412 low buck heavy duty (HD) shocks for my '82 XJ750J.

I am now beginning to think that the advice I read was wrong. I heard that for the 650's and above the HD shocks were recommended as regular replacements to the OEM shocks.

Unfortunately what I found was the new shocks are much, MUCH too firm, even on the lowest preload. My original shocks did very little to absorb potholes and the like, but this new set might be even worse. It honestly feels like I've installed a slightly springy metal bar in place of my old shocks. During a couple test rides I found that on some bumps I was being bucked out of the seat and my feet struggled to stay on the pegs at times (this happened with my old suspension too).

Following some other advice I found (on the forum, of course) I checked the swingarm bearings by removing the shocks and moving/lifting the rear wheel to feel for issues. I'm assuming the sort of bearing failure that would cause stiff suspension would be pretty obvious. Unfortunately(?) I found the bearings to be smooth as silk and tight (side to side) throughout the full up and down range of the swingarm. To my untrained hands, they felt fine.

I'm not going to say the bearings don't need to be replaced, they probably do, but I don't think they caused both my old and new shocks to feel harsh. I'm now wondering if the HD shocks are just way to firm for me, or if there could be something else wrong here. Again, my old shocks also felt really harsh, but they never bottomed out and the damping adjuster actually still worked to some extent.

Standing next to the bike while it rests on the side-stand, I used to be able to push the bike down several inches in the rear very easily. Now I can barely get it to budge even throwing my entire weight on the pillion seat.

Some info about me and my riding style: I am about 155 lbs. I have never carried a pillion, although I might in the future. The gear I carry, beyond helmet, jacket, boots, etc., is just a small backpack with some water, snacks, and first aid type stuff. It probably weighs about 5-10 lbs.

I think I might be too light for the HD suspension, even with a 750. Should I return the shocks and buy the standard duty version? Could something else be wrong in the swingarm/final drive area that could cause suspension to feel harsh?

Thanks for reading.

 

I have an 1982 XJ750J Maxim.......

I bought Progressive Suspension Springs Part # 11-1107.........they work great......

available thru Summit Racing Equipment or Amazon....

 

I used the model 12 with standard spring rate, have the heavy springs for 2 up riding and I'm 190+

 

I'm talking about the rear suspension, specifically the 412-4221c part number.

Having said that, I am planning on getting progressive springs in the near future. I've heard great things about them.

 

If you are able to return the springs for the standard version I would do so. 155 is pretty light for the HD springs as a solo rider.

 

I'll look into returning them.

I was under the impression that when the stock suspension failed it would bottom out and start bouncing instead of damping, but mine seemed to feel really hard instead. My bike has over 26,000 miles on those shocks. Shouldn't they feel too soft (when not bottoming out)?

 

if you still have the old ones, see if the old springs will fit the new shocks

 

I would rather not hurt my chances of getting a return by taking anything apart.

I think I'll try to get the standard duty shocks and see what those do.

 

Side note, did you change tires recently? There are a number of members on here that have commented on the difference in rough road riding when going from one tire to another.

 

I put Michelin Commander 2 tires on a little over a year ago. They're tires intended for high mileage. Could that cause the suspension to feel really stiff?

 

Changing the rear tire from a "high mileage" Dunlop (can't remember which - Elite or something?) to a Dunlop D404 softened my ride considerably. I'm sure treadlife is also considerably shorter, but it rides better.

 

I think I'll be switching to the Michelin Pilot Road 4 tires at my next tire change. While high mileage was important when I replaced them last, in the future I'll have the money for safer lower milage tires.

 

I believe that is a radial tire intended for much wider wheels. OEM XJ sizes are not available.

 

Thanks for the advice but I've already set the heavy duty shocks up to be returned and ordered the standard ones.

I'm going to replace the steering stem bearing and fork oil soon (already have the parts). After a paycheck or two I'll get springs.

Speaking of which, the Progressive springs for the '82 XJ750J are discontinued. I see Chacal still sells springs, but doesn't say what they are. Does anyone know what chacal is selling for this bike?

 

I purchased the delux fork rebuild kit from Chacal back around February and it came with new progressive springs.

 

Do you know the Progressive part number for those springs?

 

I still have the box can post part# when I get home tomorrow.

 

That would be great!

 

Shoot Chacal a message, he'll give you a straight up answer about what he has etc.

 

I think the Progressive part # is 11-1107.

 

I just realized Fiveofakind posted the part # in the second post of this thread.

 

I was hoping you had a different number than what he provided. The 11-1107 springs are discontinued. I guess Chacal has some "NOS" or something.

 

The box had a 2013 date on it so I guess it was NOS.

 

Hi, I am lookintg to replace my sagged fork springs. Anyone had any experience getting a set of springs from ebay?
The bike is an 1980 xj650 seca.
I was looking at these https://www.ebay.com.au/itm/Progres...355438&hash=item5450a86b40:g:HKoAAOSwoVFZ3-ox
They say they are for an 1982 XJ650R Seca.
That should be right for mine shouldn't they?

 

This might help you.
https://www.motorcyclistonline.com/suspension-setup-101-part-i-setting-sag

I don't know what's available to you, but I bought custom wound springs for mine. They cost me less than $125 and they're just right for me. I don't prefer progressive wound springs. I bought mine from www.traxxion.com