[Bilgemaster]

What "GSS" says has the ring of truth and wisdom. My old Norton "Desert Sled" came to me as a basket case with only one very worn out original Girling shock. I poached a pair of nice enough but non-descript chrome shocks off some broken down old Honda UJM that someone had shoved off into a creekside ditch off South Congress Avenue in Austin, slapped 'em onto the Norton, and they never gave me cause for the least complaint, and they're still nice and shiny. I'm clearly not that picky though. Still, it seems to me that there must be millions of perfectly good cheap shocks out there in breakers' yards that could be interchangeable with those OEM ones to experiment with.

[Jako]

True preload will not change the spring rate or travel but it moves the ride  height,    in my case my weight  was using up  half the downward  travel with  sag,  so  sitting on the bike I would have  about half the available travel in each direction ,  by preloading the springs with  18mm spacers  I changed the rider sag to 32mm , that's  30% of the  travel . So I moved the rider height from around the middle of the available travel to  30% , from the top, leaving  70%  downward travel , still the same spring rate and the same amount of travel  but repositioned to give more downward travel where I was bottoming and less upward  . This went a long way to eliminating the bottoming and clanging I was experiencing and made the bike much more enjoyable . I knew I needed upgraded springs for optimum  performance but  I rode around 3000 km  like this and found it satisfactory I found the rear shocks are good  once  front is sorted . I  finally upgraded shocks , fork springs and emulator valves just this weekend, still.dialing that in . I think everybody should check the rider sag and adjust preload to.suit, it's easy ' free and reversable and might be rewarding.

[twocoolgliders]

The stuff about preload was directed at another member...preload will not solve my problem(s)


I agree that I need to change stuff....

I plan to install fully adjustable rear shocks, and probably a fork cartridge kit of some kind....

It's only money...


Cookie

Ok.  So by increasing your preload, you are reducing your sag and increasing your ride height.  Again, this will not change the spring rate one ounce.  It will not keep the bike from doing the bouncy bouncy thing others have mentioned.  It will not keep the suspension from harshly bottoming out.

If you want control over the performance and ride quality of your bike, you must be able to control the damper itself.  The balance of how quickly a shock will compress or rebound is the real work of a shock assembly.  Too little damping in either direction wil cause that bouncy ride, too much will cause the damper to pack up, as it's orifices are too small or the oil too heavy to react.

Honestly, the spring is really only along for the ride to hold the bike up.  To maintain ride height.

So, IMHO, if you think the bike's suspension sucks, the only way to fix it is to modify it through open it up and modify it or replace it with something that will work for you.  As it sits, your fork is rebuildable.  Those pretty shocks are not.

Race tech has springs and emulators for your forks.  They also have the knowledge to guide you how to setup and use their products to improve your crappy suspension.  it'll cost you around 350.00 for the products, but if it alleviates your issues...  They could also be able to build you rear shocks that'll fit your bike and you.  Expensive, but again, that's what they do.

I'll leave y'all with this.  Even guys who buy nearly race ready bikes for double or triple the cost of an Enfield, will spend thousands dialing in their suspension to suit them.  Everything is a compromise.

[gizzo]

Hope it work out for you. It's be a shame to give up on an otherwise nice bike because of lousy suspension. I'm in a similar boat with my 535 CGT about now. Rear shocks getting tired. I'll replace with adjustable Ikons when a few $ make themselves available. Recommend by another forum member who knows his stuff.  The forks are OK on mine. Springs are about right for my light weight and oil is easy to change. Good luck mate.

[9fingers]

Hi Twocool, certainly try different fork oil first, something heavier will give you both more compression damping, and more rebound damping, which seems to be what you are complaining about.
as for the rear shocks, you mentioned that they are "rebounding quote slowly", so it seems they have plenty of rebound damping, which is what you want. If compression damping is to light and rebound to slow, the rear shocks can "pack Up" in a series of bumps and end up basically fully compressed. The same goes for the front. I think Harris Performance and RE did really fine job with the suspension, so there must be something wrong with yours. My bet is that the forks oil is low, contaminated, out of spec, or whatever. Companies like Hagon and Falcon make good rear shocks for not that much money. I use Falcons, tuned for my weight, on all of my trials bikes. I get them directly from Falcon in the UK. You missed a spectacular 180 mile ride up to the Catskills today, and a great BBQ lunch.
And ice cream on the way home! Next time.
9fingers

[Farmer_John]

Hope it work out for you. It's be a shame to give up on an otherwise nice bike because of lousy suspension. I'm in a similar boat with my 535 CGT about now. Rear shocks getting tired. I'll replace with adjustable Ikons when a few $ make themselves available. Recommend by another forum member who knows his stuff.  The forks are OK on mine. Springs are about right for my light weight and oil is easy to change. Good luck mate.

The Ikons are a nice product.  I ran some Koni dial a rides for a long time and I believe Ikon still makes that ancient ancient design.

[NVDucati]

For what its worth:
On one of the 650 twin forums from India ( just a civilian like us) I see that fork caps with preload adjuster for most 41mm forks fit the RE. Here is the post:

"These are generic preload adjusters for a 41mm fork. While you may not find many (or ones moderately priced) for the INT 650 exclusively, there are plenty of good quality and affordable ones out there for the Yamaha R3. And here's a little secret, any of those would do too - it's a direct fit"

[gizzo]

The Ikons are a nice product.  I ran some Koni dial a rides for a long time and I believe Ikon still makes that ancient ancient design.

They are, and made locally for me. That's a plus. I'm a bit over the made in China thing right now. My old pantah is wearing some ancient Koni shocks too. It's probably time to have them freshened up. Too bad the forks are rubbish.

[NVDucati]

Curious: Does anyone know (or use) these rear shocks?
https://www.racingbros.com/EN/product-detail/149
$900 USD

[cyril31]

True preload will not change the spring rate or travel [...]

In theory you are right, we learned that K is a constant. But like a lot of stuff in physics, it is a convenient simplification to base theories.

I did some testing while trying to understand how supposedly similar rated springs acted differently when aging and preloading them, and found spring rates are actually never constant; the more they are loaded, the more their rate increase.

To my knowledge there is ONE spring maker in the world that makes nearly constant rate springs: swift. I have not yet tried them, but it clearly is the next modification i will do on the race car. They are not expensive either and can do custom work, so if you are looking for a spring change, you might want to get some from them.

I did not make a write up of my experiment but someone else made a similar testing, with a dyno spring (my testing involved various weights, and a ruler, not a dyno). You can find it here:
https://www.northamericanmotoring.com/forums/suspension/157535-swift-springs-dynoed.html

[twocoolgliders]

follow up:

So this morning I visited Ron at Washington Cycle Works....He is the top suspension guy in the area (and beyond)

I explained the symptoms to him.  He came outside and bounced the front end a round a bit, and said...you're right this suspension is crap, how do you even ride this bike?

He says the only way to "get it right" is to install fully adjustable fork cartridges and fully adjustable rear shocks.

He also assured me that the difference would be "night and day"....and that the ride would be "wonderful".....provided not only the right parts installed, but with a proper and correct set up.  He showed me his shop full of bikes with great suspension parts, but that ride like crap because nobody knew to set them up.

Fridays and Saturdays he does nothing but set-ups!


This is going to cost me a small fortune!!!!

But my motto....pay up front, do it right the first time, and then you only cry once...!

This won't get done any time soon....he is booked up for almost two months now...plus we need to order lots of parts....some companies are working with a "Corona Virus small staff"....so deliveries are slow.  I also need some RE parts (OEM) from India...who knows when they will arrive?

http://washingtoncycleworks.com/

Cookie

[rowdyyates]

I really do not have any issues with the suspension at all. Then again, I don't have anything to compare to and I am a novice.

[NVDucati]

I really do not have any issues with the suspension at all. Then again, I don't have anything to compare to and I am a novice.

No, it isn't "crap". And I think a lot of folks will be just fine with it. Mind you all front suspension periodically needs fresh fluid.
Plus, the actual frame / wheel geometry on these bikes is spot on.
The term "crap" might have been born from other folks who want it to be different.

[9fingers]

I still think you should try changing your fork oil before you spend a lot of money on custom suspension set up and parts. We used to modify Showa forks on our Hondas back in the 70s and 80s, by enlarging the oil holes on the compression cycle and going to slightly heavier oil to cure the pogo stick effect that they had. Not hard to do, cheap, and can be very effective. Most reviewers thought the suspension was pretty good until pushed really hard. I still think yours is an anomaly.
9fingers

[twocoolgliders]

Well....maybe....

I'm an "all or nothing" kind of guy.....

so now I'm "all in"....


Cookie

By the way, riding around today in hot weather...the front end turned into spaghetti!  Super soft and bouncy!

I still think you should try changing your fork oil before you spend a lot of money on custom suspension set up and parts. We used to modify Showa forks on our Hondas back in the 70s and 80s, by enlarging the oil holes on the compression cycle and going to slightly heavier oil to cure the pogo stick effect that they had. Not hard to do, cheap, and can be very effective. Most reviewers thought the suspension was pretty good until pushed really hard. I still think yours is an anomaly.
9fingers