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suspension modification


RADU

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Hello,

 

I have a 2002 VTEC VFR model and for quite a while now, i am not very satisfied with its stock suspensions. Although i have adjusted the rear suspension to make it more hard, i still have the feeling the moto feels "like a boat" if you know what i mean. The suspensions (both front and back) leave the impression that may be very soft. The feeling gets even more real when i load the motorcycle with luggages and passanger. A mechanic adviced me to install progressive springs on both front and rear suspension.

My questions:

1-would progressive springs make a difference; will the suspensions get more stiff and ferm?

2-if yes, what brand to choose?

3-are there available progressive springs for rear shock as well, because i haven't seen any ?

4-my model does not have an adjustment knob for rear shock absorber (soft-hard). Is it possible to mount one of these on it, or should i get a totally new shock absorber which has this feature (very expensive)? If yes, what brand/model suggestions do you have?

My purpose is to ride the motorcycle in a sport touring fashion; touring with some confort, but also in certain situations (like accelerating, braking, entering curves), i want to feel the suspensions a bit more sport, stiffer, with less "boat" effect.

 

Thanks

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Progressive springs are initially soft for comfort and touring, then get PROGRESSIVELY firmer as they are compressed. They will not help with your floating, boat feeling. I am pretty sure the factory suspension is a progressive rate, front and back.

 

Linear rate springs like race tech would be better at removing the floating feeling, especially when the correct rate for your weight is selected. The factory ABS shock has an adjustable preload knob on it.

 

You should talk to Jamie Daugherty at http://www.daughertymotorsports.com/ about modifying your forks and an abs rear shock for you. The guy is a total VFR suspension GURU and I would put money on it that he knows a lot more than your mechanic, especially when talking about VFRs.

 

If you are not partial to the linked brakes, you could always do a front end swap, but I am pretty sure that that is out of the scope of your mechanics abilities.

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Hyperpro in the Netherlands sell true progressive spring kits (front and back). You can get either a rear spring or a complete shock.

 

I'm pretty sure they are an improvement over stock but they are still a one size fits all approach which is really the main issue with OEM suspension (well, that and the cost of a premium shock).

 

BTW, you can adjust the damping on the OEM shock but the main issue IMO is that it has too soft a spring and too much compression damping (to compensate for the soft spring) which means that there is simply no setting on which it will perform in a firm and controlled but compliant fashion. 

 

It's either wallowy or harsh on bumps when it's not both. 

 

It needs to be resprung and revalved but most suspension tuners don't want anything to do with the OEM shock.

 

Daugherty does it but he's in the US. A couple of reputable specialists in the UK do it as well. 

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I have used parts supplied by Jamie Daugherty in the US and have been very happy with the result. I wouldn't let the distance from Romania to the US put you off, the world is a much smaller placer with internet shopping around.

 

I'd suggest you look at a new straight rate springs and replace the compression valve body and shims in the front, and get a modified re-sprung CBR600F4 shock for the back. Very good value for money, and you'll have a bike with suspension tailored specifically to you.

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Although not a necessity if you plan on having someone build your suspension for you but it will come in handy to maybe help understand and/or explain what you want out of your suspension. I read this and keep it on hand, even though I did go to Jamie Daugherty for all my suspension upgrades.

 

Racetech Suspension Bible

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23 hours ago, RC36Rider said:

Hyperpro in the Netherlands sell true progressive spring kits (front and back). You can get either a rear spring or a complete shock.

 

I'm pretty sure they are an improvement over stock but they are still a one size fits all approach which is really the main issue with OEM suspension (well, that and the cost of a premium shock).

 

BTW, you can adjust the damping on the OEM shock but the main issue IMO is that it has too soft a spring and too much compression damping (to compensate for the soft spring) which means that there is simply no setting on which it will perform in a firm and controlled but compliant fashion. 

 

It's either wallowy or harsh on bumps when it's not both. 

 

It needs to be resprung and revalved but most suspension tuners don't want anything to do with the OEM shock.

 

Daugherty does it but he's in the US. A couple of reputable specialists in the UK do it as well. 

 

 

Linear > Progressive rate springs

 

Too much compression dampening? That is the first time that I have heard of this lol. If there was too much compression dampening (there's not) and too soft of a spring, you could easily solve the problem by fitting a heavier spring and adjusting the rebound to compensate, but it is not that easy, because that is not the case.

Time to have Jamie Daugherty build you a proper shock or just buy an Elka etc...

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51 minutes ago, CandyRedRC46 said:

 

Linear > Progressive rate springs

 

 

That's very debatable on a road bike designed to handle anything from solo riding to two-up touring with luggage. 

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55 minutes ago, CandyRedRC46 said:

 

Too much compression dampening? That is the first time that I have heard of this lol. If there was too much compression dampening (there's not) and too soft of a spring, you could easily solve the problem by fitting a heavier spring and adjusting the rebound to compensate, but it is not that easy, because that is not the case.

 

- I don't think you can adjust rebound independently of compression on the OEM shock. I could be mistaken since I haven't opened the thing myself but I do think the (rather crude) adjuster restricts the low speed circuit which flows in both directions.

 

- There is pretty much unanimity on this board on the stock springs being too soft.

 

- Spring and damping are not interchangeable. You can (to some extent) compensate for a soft spring by increasing compression but you certainly cannot compensate for too much compression by fitting a heavier spring !

 

Let's see what the experts have to say. Meanwhile, I stand by my assessment. :wink:

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22 minutes ago, RC36Rider said:

 

- I don't think you can adjust rebound independently of compression on the OEM shock. I could be mistaken since I haven't opened the thing myself but I do think the (rather crude) adjuster restricts the low speed circuit which flows in both directions.

 

- There is pretty much unanimity on this board on the stock springs being too soft.

 

- Spring and damping are not interchangeable. You can (to some extent) compensate for a soft spring by increasing compression but you certainly cannot compensate for too much compression by fitting a heavier spring !

 

Let's see what the experts have to say. Meanwhile, I stand by my assessment. :wink:

 

The VFR800 VTEC shock is adjustable for preload and rebound, but lacking compression adjust-ability...

 

I will agree that the stock spring is too soft, but I will take it further and say that both the spring and dampening (compression and rebound) are too soft as well, so if you fit a heavier spring, the stock shock will just be even more underdampened.

 

I am aware that spring and dampening are not interchangeable, I was simply making a point.

 

I also stand by my assessment:
Stock VTEC shock is preload/rebound adjustable, undersprung and under dampened.

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To clear up any possible misunderstanding, I was not advocating for Hyperpro or giving them my endorsement (which you would be wise to ignore anyway). 

 

I was merely answering questions 2 and 3 from the OP.

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Many members here have gone to DMr to improve their suspension, and most, it not all are very happy. On a performance & value comparison, the full work up of front and rear (rebuild of existing OEM forks and shocks) is hard to beat. Simply re-springing existing suspension won't give the owner the big jump in performance they most likely had in mind either.  If money is no object and brand name is important, do the complete Ohlins rear shock and fork kit. If maximum performance for value is high on the list of priorities, go DMr because it's proven by many VFR members already. I'm sure one can find an equivalent in Europe as well because the VFR is very popular there.  I think we're all in agreement the stock suspension is only adequate if you don't push the bike's handling too hard.

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To get back on topic... :goofy:

 

Since budget seems to be a concern, a possible way to go might be to procure an OEM shock from an ABS version (for the remote preload adjuster) and have it revalved and resprung.

 

1. I'm not 100% sure it fits a non-ABS without any fuss.

 

2. Shipping to Romania and most importantly EU taxes might add quite a bit to the bill if you go with DMr (Daugherty Motorsports). :blush:

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Just now, RC36Rider said:

To get back on topic... :goofy:

 

Since budget seems to be a concern, a possible way to go might be to procure an OEM shock from an ABS version (for the remote preload adjuster) and have it revalved and resprung.

 

1. I'm not 100% sure it fits a non-ABS without any fuss.

 

2. Shipping to Romania and most importantly EU taxes might add quite a bit to the bill if you go with DMr (Daugherty Motorsports). :blush:

I put an ABS model shock on my 6 Gen and helped fellow forum member Duccmann do the same. In my case, the mounting holes for the remote adjuster mounting bracket needed to be threaded but on Duccmann's bike the bolt holes were already threaded. Other than that potential issue, the shock is a direct bolt in. I also sent it to DMr before I installed it.

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33 minutes ago, RC36Rider said:

To get back on topic... :goofy:

 

Since budget seems to be a concern, a possible way to go might be to procure an OEM shock from an ABS version (for the remote preload adjuster) and have it revalved and resprung.

 

1. I'm not 100% sure it fits a non-ABS without any fuss.

 

2. Shipping to Romania and most importantly EU taxes might add quite a bit to the bill if you go with DMr (Daugherty Motorsports). :blush:

Shipping parts from the US to New Zealand usually runs to US$40-60 for an item like a shock. Not cheap, but not a deal breaker either. 

 

Don't tell the Feds, but sellers are usually willing to mark down the declared value of parts to minimise local taxes...

 

And I'll jump on board with the too much compression damping thing too. The HMAS pistons that Honda use (especially the fork but I assume the shock too) have relatively small ports to the shim stacks; this means that you get orifice effects when the shim should be controlling the flow, so the forks are harsh on big bumps and mushy on smaller ones, no matter what you do with the shims. Daugherty replaces the shock pistons when he modifies them, and supplies new valve bodies for the forks with large ports.

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1 hour ago, Terry said:

 

Don't tell the Feds, but sellers are usually willing to mark down the declared value of parts to minimise local taxes.

 

 

:goofy:

 

EU customs just might let the package through but if they don't, they'll apparently slap it with 20% VAT (or whatever is currently applicable in Romania) plus 4.5% import duty, plus a customs clearance fee of ??.

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Guys, thank you all for the suggestions here.

 

3 hours ago, Rogue_Biker said:

Simply re-springing existing suspension won't give the owner the big jump in performance they most likely had in mind either.

This is exactly what i want to avoid. Since i want to invest in better suspensions, i would rather give my money on something that really worths it. Nevertheless, the budget is an important parameter here and so, i don't want to buy very expensive Ohlins or other brands; i don't say they don't worth the money but i don't want to invest in suspensions more than the motorcycle's value.

 

On 26.09.2016 at 6:07 PM, RC36Rider said:

Hyperpro in the Netherlands sell true progressive spring kits (front and back). You can get either a rear spring or a complete shock.

Yes, i can see they also have Street Box kits, including front and rear suspension, but are really OK, or just a normal rear shock with a stiffer spring?

 

On 26.09.2016 at 6:07 PM, RC36Rider said:

Daugherty does it but he's in the US. A couple of reputable specialists in the UK do it as well. 

Do they have a site to check out more details?

 

1 hour ago, RC36Rider said:

To get back on topic... :goofy:

 

Since budget seems to be a concern, a possible way to go might be to procure an OEM shock from an ABS version (for the remote preload adjuster) and have it revalved and resprung.

 

What would be the benefit of buying a ABS version of rear shock and revalve/resprung it? Isn't it the same shock absorber as the one on the non ABS version? I know that it has preload adjustment knob, but besides this...?

And also, if i would do this, wouldn't i end up in the same situation as: Simply re-springing existing suspension won't give the owner the big jump in performance they most likely had in mind either.

 

17 hours ago, Duc2V4 said:

Although not a necessity if you plan on having someone build your suspension for you but it will come in handy to maybe help understand and/or explain what you want out of your suspension. I read this and keep it on hand, even though I did go to Jamie Daugherty for all my suspension upgrades.

 

Racetech Suspension Bible

Thank you very much. I will start and read it right away, because indeed, i need to understand better what i want and what i get.

 

You guys all speak about Daugherty and it's not quite clear for me what do you suggest:

-to send my rear shock absorber to them in order to tune it, or just ask them for a completelly new shock absorber already tailored for me? What brand would be this one?

-also to buy fork suspension springs from him or to send my fork to him in order to tune it.

 

The option of sending them my suspension for tunning and then ship it back to me would be very expensive. Does not worth it.

I will send an email to them asking for the options, but first i want to be clear about your suggestions, guys.

 

Once again, thanks a lot.

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Yeah but both local suspension specialists I contacted here in Belgium gave me the non-rebuildable BS, including one who advertises rebuilding Showa OEM shocks. Apparently, it applies only to MX bikes and CBRs. :491:

 

Both were more than willing to sell me a fine aftermarket shock. For top $$$ of course and without hydraulic preload. :blush:

 

Besides, the VFR is a bit special with its inordinately high leverage ratio so I'm a bit leery of even reputable tuners being able to get it right first time without having the bike in their shop.

 

JD knows his Viffers. 

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And I'll jump on board with the too much compression damping thing too. The HMAS pistons that Honda use (especially the fork but I assume the shock too) have relatively small ports to the shim stacks; this means that you get orifice effects when the shim should be controlling the flow, so the forks are harsh on big bumps and mushy on smaller ones, no matter what you do with the shims. Daugherty replaces the shock pistons when he modifies them, and supplies new valve bodies for the forks with large ports.



So not to much overall compression, but more specifically, too much high speed compression and too little low speed compression. I can get on board with that on the forks, not sure about the shock, but sounds good enough for me.

Sent from my Nexus 6 using Tapatalk

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20 minutes ago, RADU said:

 

What would be the benefit of buying a ABS version of rear shock and revalve/resprung it? 

 

ABS version is for hydraulic preload. Otherwise, no difference AFAIK.

 

Most of the basic Showa components are actually fine. Once tuned more specifically for your weight and style of riding, they can be pretty nice. This is what DMr (Daugherty) does. Fit a spring that is chosen for your weight and modify the damping characteristics accordingly. 

 

http://www.daughertymotorsports.com

 

I also know of MCT in the UK :

http://www.mctsuspension.com

 

You'll have to call or mail to see what they can do and how much they charge. No details are given on their website except that they are happy to work on OEM shock modifications. 

 

No personal experience with them but they seem to have a good name.

 

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Hyperpro spring kits and Street Box:

 

Probably just FYI. No matter how good their progressive spring is, if it has to work with stock damping, the improvement can only be limited. 

 

Their basic shock (the one in the Street Box) is an emulsion type I think. Not top notch. They make higher end shocks but they're just as pricy as anyone else's. 

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RADU, the reason why DMr (ie Jamie Daugherty) is highly praised here is his willingness & ability to take your existing VFR suspension, replace the springs to your weight and intended use/riding style, replace most of the internals, meaning new valves and shim stacks, and high quality fluid.  Doing that to the OEM rear shock requires drilling a hole on the shock to drain/replace the fluid.  Race Tech also does this by the way.  It's not uncommon practice.  By replacing not only the springs and the shock/fork internals, your suspension is now able to provide a level of damping that simply transforms your bike from being just adequate for the job, into something that feels BETTER than new.  I have a '15 CBR600RR with the fairly new big piston front fork and fully adjustable rear shock.  And when I ride my DMr suspended VFR back to back versus my CBR, there is almost very little difference in the way the bikes handle. The CBR flicks into corners quicker because it's over 130 lbs. lighter.  The CBR's front forks are also more compliant (that's due to the BPS fork's ability to absorp small bumps easily).  But the damping qualities are almost identical.  Keep in mind I asked DMr for a sporty ride/handling.  I also asked for a suspension that will accommodate some additional weight when I'm touring.  So the springs I got have plenty of preload adjustment for touring weight.  The front forks also got rebound damping adjustments (OEM front forks are spring pre-load only).  Having that rebound adjustability up front allowed me to fine tune squat under acceleration AND control spring rebound if/when I turn up the spring pre-load when I'm loaded down for touring.  In a nutshell, my VFR suspension now has firmness, control, and smooth damping when I hit bumps all at the same time.  The steering is also lighter and the bike steers faster.  Finally, there is now very little brake dive or rear squat under acceleration.  Both ends feel VERY planted even under harsh road conditions while leaned over.  These characteristics simply were NOT a possibility with the stock suspension even when it was new.

 

The cost to me was USD1,000 including shipping to DMr, and shipping back to me.  Here is his VFR800 specific web page: http://www.daughertymotorsports.com/vfr800.html

 

In my humble opinion, there is no middle ground to get what you REALLY want.  It has to be new linear rate springs to your weight, new internals (high performance valves, fluid, new shim stack, etc.), professionally done.  There is no need for any brand name shock when your existing shock is capable of doing most of what a pricey new shock will do.  I still believe there has to be someone in the EU who can do what DMr in the USA can do.  I find it hard to believe the market that so loves the VFR has nobody capable of rebuilding your existing suspension at a reasonable price.   

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Although not a sixth gen, I had Jamie do my front and rear on my '01 and it was better than new. It transformed my riding experience, for the better. Rogue_Biker nailed it. Until the DMr upgrades I did not realize how much I did not trust my suspension; it did not inspire confidence. Now it seems like I know just what the machine will do given the inputs I deliver and it feels like the bike does what I think before I make a move. Telepathic is the word.

I was the best $900 I've put into her.

 

Who said money can't buy happiness?!  :-) That's one place it did.

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48 minutes ago, Rogue_Biker said:

Keep in mind I asked DMr for a sporty ride/handling.  I also asked for a suspension that will accommodate some additional weight when I'm touring. 

This is exactly what i want to achieve.

 

48 minutes ago, Rogue_Biker said:

 There is no need for any brand name shock when your existing shock is capable of doing most of what a pricey new shock will do.

So the best option with the highest ratio cost/performance, is to have the stock forks and shock absorber tunned, correct?

 

48 minutes ago, Rogue_Biker said:

I find it hard to believe the market that so loves the VFR has nobody capable of rebuilding your existing suspension at a reasonable price.   

 

This is my biggest problem now. There surely must be mechanics or companies that can do this, but i don't know none of them.

RC36Rider suggested MCT in the UK, but for the beggining i rather search for local nearby solutions; i would prefer to have this services reachable in order to make any kind of tests if required.

So i am still searching now in local forums for suggestions indications.

 

Rogue_Biker, thank you, you have explained in your previously post, EXACTLY what i want o obtain from my VFR as well.

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1 hour ago, CandyRedRC46 said:

 

So not to much overall compression, but more specifically, too much high speed compression and too little low speed compression. I can get on board with that on the forks

 

 

Unlike the shock, I've been in the forks myself so I know what's in there and, no, they don't have too little low speed compression. At least not for the road.

 

The low speed bleed is 1 mm and the stock oil viscosity is 37 cSt.

 

Race Tech who have a firmly established reputation for hard setups recommend a 1 mm bleed for racing and 1.3 mm for road use and that's in conjunction with their 16 cSt viscosity oil!

 

To save you the calculation, 1.3 mm means 69 % more flow area than 1 mm and the effect of the viscosity difference between 37 and 16 is massive.

 

The closest I could find locally was 19 cSt oil and that change alone turned my stock forks into a mushy pogo stick instantly. Not recommended. 

 

The wimpy stock springs need all the help they can get and that help comes in the shape of very strong compression damping and a high oil level. 

 

The result is forks that perform reasonably well on smooth tarmac but react harshly on the smallest bump while still feeling a bit mushy on the brakes or gentle undulations (very low speed movement so very little damping force).

 

I firmly believe that the shock is setup in pretty much the same way. 

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