Suspension and other settings, for a light weight rider

[piotrek]

On 1/20/2022 at 12:15 AM, howie333 said:

Hopefully this suspension is salvagable and adjustable. How often should I be changing fork oil, manual states use Yamaha fork oil, but doesn't state what weight for climate and how I ride. I'm @ about 12.5 K miles now.

Get the suspension into the right sag numbers first. I agree with @OZVFR that straight rate fork springs are the way to go. They have more predictable action and damping will also be easier to tune. Yamaha uses Yamaha 01 oil, which is ~15 cSt@40C. The 'w' is inconsistent across brands, so just be mindful of that.

The higher the cSt@40C number, the 'thicker' the oil. This is useful to know if you want to adjust your damping range. Compression damping is fixed on your bike I think, so altering oil viscosity will have an immediate effect on that. Your rebound damping adjustment range will also move, so it's all being affected to some degree.

I would change the fork oil and install straight rate springs in the front, if you can spare $100 and do it yourself. Some tools required. YT is your friend. If you can get the suspension into the right sag numbers then I would try and experiment with rebound damping and maybe oil viscosity and levels in the forks. You only have one active fork (LH side is just a spring with preload), so the oil viscosity won't matter in the LH fork.

OR... see a suspension/MC shop as @betoney suggested, and they could offer some options for you. Setting up sag and damping is a basic service most offer for not much money, and at least you will ride away with a proper baseline. You can do a bunch of things, but get the basic setup right and then move on from there.

Edited January 21, 2022 by piotrek

[OZVFR]

I should also add that when I first got the bike, I changed to a 10 weight oil (or cst32@40 from memory, and piotrek is right, W weight is not a standard and is very inaccurate. CST is the way to compare oil) and added 15mm of fork oil height which helped a lot until I reworked the forks properly. 
 

[howie333]

I used the Motool to set total sag(static and rider) @ aprox. 35mm rear, and 40mm front( best I could get). Right now front fork preload is maxed and bottoming out, and rebound damping is all out to right feel, and  rear shock is set @ max soft w/ rebound 1-1/2 turns out; feels right. Rider sag is 40mm for the front, and rear is 35mm. I talked with K Tech suspension today; said not to use Maxima 5w, (already bought), but to use motul 5w for proper flow rate, change springs to a .85Nm, and the razor R rear shock $$ (not the Light). and be better to get their fork cartridges $$which come w/ the springs. Says preload not as imoprtant as dampening when setting up suspension.    can anyone comment on these recomendations please 

 

Thank You...

[OZVFR]

Maxima 5 is 15.9cst@40, Motul 5 is 18.3cst@40 so slightly heavier but not much in it, for proper flow rate with what?

The stock valving is badly under damped, so I would be going closer to 25cst@40, but that is just my preference.

0.85 springs are fine, I went with 0.9 but it's just my preference as I often load the bike up for long trips.

You will definitely get better suspension the more you spend, but you can also get the front working reasonably well with new springs and a new shim stack. Even better if you opt for high flow valves.

Not much you can do with the rear shock except throw it in the bin. It must have cost Yamaha around $15 for that metal tube with a toilet plunger in oil.

[piotrek]

16 hours ago, OZVFR said:

Not much you can do with the rear shock except throw it in the bin. It must have cost Yamaha around $15 for that metal tube with a toilet plunger in oil.

This ^. I was in denial for a bit, and then I got the sh*t beaten out of me on a trip up north (frost heaves). Ordered a new shock as soon as tears stopped. The Gold Valve and new springs were great... but the new shock really made a difference.

[howie333]

A few questions: 

should I stay w/ the stock Cst rating oil with upgraded forks ?

Will High flow valves, springs, and new shim kit come with new fork cartridges, and is this what I should be installing ?

For rear shock; should I use the Razor R light or go with the Razor R w/ compression damping (cartridge)type ?

W/ 165lb. rider, riding gear and tank and side bags which spring rate .85nmor .9nm is recomended for proper spring rate and how and why do you figure or calculate this rate ?

Someone recomended a .9nm spring set, Racetech or K-tech gold valves w/ custom shim stacks and high flow valves, and raise forks 15mm in triple tree to put more weight on front wheel. Opinion ? My forks now are raised 10mm in triples as is other bike I own w/ good results. I guess I'm ready to spend money where needed. I'm also learning alot thanks to these replies. 

 Thank You for replies...     

 

 

 

[betoney]

10 hours ago, howie333 said:

A few questions: 

should I stay w/ the stock Cst rating oil with upgraded forks ?

Will High flow valves, springs, and new shim kit come with new fork cartridges, and is this what I should be installing ?

For rear shock; should I use the Razor R light or go with the Razor R w/ compression damping (cartridge)type ?

W/ 165lb. rider, riding gear and tank and side bags which spring rate .85nmor .9nm is recomended for proper spring rate and how and why do you figure or calculate this rate ?

Someone recomended a .9nm spring set, Racetech or K-tech gold valves w/ custom shim stacks and high flow valves, and raise forks 15mm in triple tree to put more weight on front wheel. Opinion ? My forks now are raised 10mm in triples as is other bike I own w/ good results. I guess I'm ready to spend money where needed. I'm also learning alot thanks to these replies. 

 Thank You for replies...    

Asking for individual suspension settings is kind of pointless as its very subjective, its like asking for a screen height setting, its going to vary greatly based on a riders preference.

The very best thing you can do is call a qualified suspension shop and ask questions, many questions.  Any competent suspension technician can offer advise on oil viscosity and spring rate based on your intended usage.  If you intend to commute or want highway comfort they will recommend very different advise than if you want a track day setup.

If you intend to upgrade the shock and are committed to spend the money -IN MY OPINION- I would suggest spending a little more over the price of a base emulsion shock and get a shock with remote reservoir (separate nitrogen and oil) as well as compression and ride height adjustability. 

For the forks, you can get an amazing upgrade with correct springs and a piston kit (revalve) which might be a cheaper option than cartridges, however a cartridge swap will be a simpler upgrade if you are doing the work yourself.  I have never bought complete cartridges, I have only ever had the factory parts upgraded with springs and revalve, so I cant comment on a performance difference between revalve and full cartridge.

 

[howie333]

Fellow from 2 wheel obsesion has an in depth video on You tube that explanes fork and shock upgrade. He uses Stoltec Moto which sells the tools and parts needed to revalve and spring exististing forks. The rears he uses Penske rear shockw/ cartridge. I'm not sure if worth the extra money over a K-tech shock of same type.  He uses the MT09 for example that has compression damping forks. Would I notice any improvement of added front and rear compresion damping w/ the fJ-09 for street riding ?  

thnx...

Edited February 19, 2022 by howie333

[howie333]

12 hours ago, KellyL said:

@howie333 I think you would get a lot out of reading this book. It's worth the $30.

Book will inform you about shock differences, independent of brand hype (which are just variations on the fundamental).

• Twin tube (Koni/Ikon, those dual shocks on a Royal Enfield or Ural)
• Emulsion (your factory shock, Penske 8900E, Hyperpro 460)
• Single tube DeCarbon (K-Tech Razor Lite, Penske 8975, Nitron NTR-R1)
• Remote reservoir (K-Tech Razor R, Penske 8983, Nitron NTR-R2 and above)

I'd base brand choice on access to after-sales support.

The correct answer is "it depends"

I agree. Depends on where you ride, how you ride, how much you and your luggage +/- passenger weighs, how much you want to spend, etc. Sky is the limit.

I put Nitron TVT cartridges + NTR-R1 rear into another bike and yes it improved it heaps, but for about 20% of the bike's purchase price. I purposely budgeted for a cheaper bike + suspension mods rather than more expensive bike, so I could have it exactly as I wanted.

In the meantime I can live with the crappy rear shock on my Niken as it's fine for how I ride it.

(Noticed in your other post that you might be getting an Aprilia RS660... AFAIK the springs on that are pretty soft too 🤣 )

Thanks for info; I just ordered the suspension Bible. sounds like a 1st step. I'm still on fence about the Aprilia RS660, with oil leaks, computer glitches, but you'd just have to demo that bike to experience the Total fun factor; I figure a great 2nd backroad bike. The Truimp Street Triple, or other similar nakeds not great @ speed w/o a fairing/sheild or ride position. The R7 doesn't do it for me either w/ feel or looks.