Comfort vs performance?

[Nat]

I'm thinking of upgrading the suspension on my 2004 Honda VFR800. At the moment I'd say that the bike generally handles very well. However going over big bumps or where the road surface changes the bike is uncomfortable.

So my question is: if I upgrade the suspension with the aim of improved comfort over the bigger bumps, will my performance or handling suffer as a result? OR is there an aftermarket shock or some adjustment I can do that will take the dge off these bigger bumps and not leave the bike wallowing in high speed corners?

Thanks in advance,

[FJRider]

Contact Robert Taylor in the Members list and ask him.

[caspernz]

Don't think comfort vs performance, think compliance...as in proper damping control and correct spring rates front and rear. And yes, you could do worse than get in touch with Dr Robert Taylor at KSS :niceone:

[Robert Taylor]

Contrary to popular misconception it is entirely possible to have both. I will explain it all tonight

[FJRider]

Contrary to popular misconception it is entirely possible to have both.

Another popular misconception destroyed ... <_< Well done that man .. :niceone:

[Nat]

Contrary to popular misconception it is entirely possible to have both. I will explain it all tonight

Great to hear this. I'll try giving the stock shock a bit of a fiddle in the next few weeks to see if I can dial in a bit more comfort without making the bike wallow. Now to figure out what to do and how to do it...

[FJRider]

Great to hear this. I'll try giving the stock shock a bit of a fiddle in the next few weeks to see if I can dial in a bit more comfort without making the bike wallow. Now to figure out what to do and how to do it...

There is no one suspension setting that will fix/suit all issues ... all the time. A compromise (at best) ... is all you can wish for.

Different roads, different loads, and different speeds can make previous changes worse.

[F5 Dave]

its not necessarily the 'big' bumps that are the problem, its the 'sharp' bumps that give low rent suspension the fits. They are the ones that cause higher speed shaft movement. Either way the stock shocks have a lifespan & could be pretty soggy by now.

[Robert Taylor]

I'm thinking of upgrading the suspension on my 2004 Honda VFR800. At the moment I'd say that the bike generally handles very well. However going over big bumps or where the road surface changes the bike is uncomfortable.

So my question is: if I upgrade the suspension with the aim of improved comfort over the bigger bumps, will my performance or handling suffer as a result? OR is there an aftermarket shock or some adjustment I can do that will take the dge off these bigger bumps and not leave the bike wallowing in high speed corners?

Thanks in advance,

The reality with the Showa shock in the VFR800 is that it has a VERY restrictive main piston. It has circumerentailly arranged and tiny holes acting as the main compression ports. The rebound ports are just as tiny. Because of the small overall flow area these ports will just not flow enough oil from one side to the other when an abrupt bump tries to deflect the shock shaft at high velocity. As F5 Dave very correctly points out its not neccessarily the size of the bump, its the shape of the bump. So railway lines that are installed above flush, sudden and ''sharp'' seal lip changes and badly installed manhole covers are about the worst offenders

So the shock goes into a semi hydraulic lock situation, it just cannot react fast enough. You feel it in your back, moreover the tyre also feels it as it has to absorb more of the bump than it should ( which it cannot ). The extra ''implosion'' imparted to the tyre and the scrubbing it causes wears it more rapidly than it should. If we take an example of a really bad shock absorber system such as the old Suzuki TL1000S fiting an Ohlins shock almost doubled rear tyre life, and of course because it was more responsive also helped mechanical traction ( grip ) somewhat

In fact you could in theory completely remove the compression shim stack off the piston in that Showa shock, aside from the fact you would lose ride height control this shock would still fail abysmally to absorb abrupt bumps. BECAUSE the ports are too small and choke off in flow rate at deflection velocities.

So the next question is ''why not put an aftermarket piston inside that shock?'' Yes that is possible but there is a HUGE compromise involved in this. Inside the shock there is a seperating plate with a restictor hole in it to ( in this case crudely) provide what we call ''pressure balance''. It is irrrevocably located in position by radially displaced indent grooves impressioned on the outside of the shock. So you can drill and tap a hole to accept a gas charge nipple but as you cannot remove that plate how can you remove all of the drilling and tapping swarf? Also, how can you remove the seperating gas piston to check the integrity of its piston ring / o ring? You cannot... There are a number of Heath Robinson ''suspension technicians'' in NZ that will do such a shoddy job but that is a line we totally refuse to cross.

REAR SPRING If the rear shock spring is a little firm for you a lighter spring will provide a small improvement, but when the abysmal and restrictive hydraulics are at least 75% of the issue its spending money largely fruitlessly to respring it. Some suppliers may be happy to sell you just a spring but it shouldnt be about making money when the result is negligible.

SO, ONTO THE BIGGEST MARKETING LIE IN THIS INDUSTRY....''the suspension is fully adjustable'' COMPLETE AND UTTER BOLLOCKS!

Part 2 to follow

[Robert Taylor]

Part 2

Approximately 87% of the mass flow is from one side of the main piston to the other, through the shim stacks and ports. There is a small amount of flow through the rebound adjuster needle ( through the middle of the main shaft ). These unless they are check valved will ''cross talk'' i.e they will flow in compression direction as well as rebound.

There is a reasonable response range on the rebound adjuster, there always is when a stiff and non responsive rebound stack is fitted. Where there is a compression adjuster circuit ( into a reservoir ) thats in a flow path that only accounts for around 13% of total damping force, initiated by shaft displacement. 13% of that flow is part needle passage but mostly through the shim stack on the small compression adjuster piston. In real terms the response range on the compression adjuster is very very narrow. If anyone wants to challenge me on that then lets please exchange dyno graphs.

If you open the compression adjuster out more and more it ends up being a vain attempt to gain some compliance. All it achieves is you now have so much bypass bleed the initial chassis control ( low speed shaft velocities ) becomes very sloppy. As you have already noticed! Moreover, because there is now so much free bleed the point at which the ( highly restrictive ) shim stack and piston combination moves ( engineered by an accountant ) actually happens later. The bike is a sloppy rocking horse or wobbly jelly that is incapable of absorbing the abrupt bumps that our roads dish up with regularity. These shocks also have a huge amount of unwanted hystersis, that in laymans terms further manifests the sloppy response that happens

Its pretty much a waste of money trying to rectify that stock ''chassis gap filler''. There are also a number of cheap aftermarket shocks available, each to their own but if you want a serious improvement with a quality shock that can also be easily customised then you have to spend in excess of $1000. Dont let any of the keyboard experts on here tell you otherwise as their ''sampling base'' will be somewhat narrow. The best youve ridden is the best you know!

Aside from careful and complimentary selection of materials and very precise tolerancing a quality afterrmerket shock will have very very low friction, making it more responsive. Development and dyno plus road testing is a LOT more lengthy and comprehensive than budget level shocks. The main piston is a large port design so that when the shim stacks open there is more than ample flow to absorb those nasty bumps. The real trick here is that the valving shims are arranged to give what we call a digressive damping force curve. There is a very good amount of low speed damping force but when the shock encounters an abrupt bump the shim stack lifts an appreciable amount to provide ample flow area to iron out most of those bumps.

Point of fact with our favoured Ohlins product we customise for every customer in respect of fitted spring and internal valving, as added value. If you buy off the parasitical US resellers ( who indiscriminately sell around the world but put nothing back into our local economies ) they may fit a spring rate that they think is right for you but certainly there will be no valving work. If you are dissatisfied they are half way across the other side of the world, which is a handy ''filter'' for them. Believe me we regularly get such shocks to sort out ( of varying brands ) that the customer has bought offshore with the promise that it will be set up for the conditions ( which these parasites usually know nothing about )

New Zealanders are largely more savvy about what they want and expect compared to most other markets. As an unashamed sales pitch we are here to provide such service and our committment to the local market is huge. Aside from spring rate testers and a huge inventory of tooling we also have invested in over $35000 worth of suspension dyno in order to help optimise suspension for the local market. No one else in the motorcycle suspension industry in NZ has such a huge commitment.

There are a couple of options for that model, if you PM me Ill come up with some good pricing, we hate losing sales to offshore resellers and will meet the market as much as is possible without prostituting ourselves. But above all we provide huge added value

[vifferman]

Don't think comfort vs performance, think compliance...as in proper damping control and correct spring rates front and rear. And yes, you could do worse than get in touch with Dr Robert Taylor at KSS :niceone:


Contrary to popular misconception it is entirely possible to have both.
Yup. I have both, and it's easily adjusted for when I ride two up - just dial in more preload and that's it!

Don't do what I did and try and do it yourself. I was intending to save some money but instead wasted time and money doing that. Fitted an Elka shock in the back (this surprisingly had an Eibach spring of exactly the right springiness), and Sonic Springs in the front. The front end was then fettled by Robert to match the springs, but as the springs recommended by Sonic were too springy, it ended up harsh, so I had to have the springs replaced and the damping rejigged to match. The Elka was much better than the Showa, but I could never get the damping quite right.
Then I had to get the rear end refettled to match the front.:rolleyes: Had the Elka gutted and Ohlins internals fitted by Robert, as by happy coincidence (or whatever) the shock body matched that of an Ohlins, so Robert fitted an appropriate set of shims and seals from what worked on an Ohlins for a VFR800. It now rides like a real bike, and is the best money I've spent on the bike.

The surprising thing for me is that I had it adjusted by Robert for my weight, but forgot to ask him about what to do for the ride home, with the vifferbabe and all our luggage on the back, and panicked at first because it seemed all soft and wallowy two-up. Worked it out for myself: it was as simple as winding on more preload until it felt right! The damping was still pretty much right, even with the extra weight, so only a click or two of compression damping was required.

[Nat]

Wow thanks Robert for such a detailed piece. Will PM shortly.

[F5 Dave]

yeah its always an education & an insight to some shock's inability to be modified

[Dodgy]

Yes, go and see Robert, simply the best around for suspension.

My 2000 VFR has clocked up 100,000 and was treated to an Ebay special CBR929 shock at 98,000km (the original shock was still awesome(ly bad)). The 929 shock really improved the ride as it is a far better shock than the standard one, but of course not nearly as good as Ohlins. Three of my bikes have Ohlins shocks and two of those were from Robert - can't speak highly enough of his expertise and service.

[AndyR1]

Part 2

...
Point of fact with our favoured Ohlins product we customise for every customer in respect of fitted spring and internal valving, as added value.
...


Even buying the most advanced Öhlins racing fork works only half as good as one customised one fitted to your bike, your riding style and weight. Coming from Europe I know that even in bigger markets only few people have the knowledge and ability to tune your suspension accordingly but much fewer people are willing to pay even additional money to get the job done perfectly. What makes you faster, what saves tires, what gives you feedback and confidence on your bike? An exhaust, 20bhp more or the new gadgets of a HP4?

For sure not - just the SUSPENSION. Having more than 5 years a stock Öhlins fork and shock in a bike with stock linkage and stock swingarm and huge bearings tolerances I know how it feels to get adapted and re-valved, re-shimed, re-needled etc. fork and shock back in addition to different linkage, different progression settings and perfect matching springs.

No need even to change the setting for street riding or for trackdays - you will have such a wide range of repsonse even for pretty fast driving.

The suspension needs to be set up so it's operating range is for your weight, your bike and your riding in the middle range so you have plenty of room to make it more comfortable if necessary or even little bit harder. Also a good suspension should be not more than a few clicks away from it's finally designed range of use ... then it works perfect. I'm quite amused to see fork indicators on track bikes 4-5cm away from the bottom fork leg - what this should tell us?? :no:

So keep up this kind of approach Robert and no way to change my 1999 R1 against a 2013 one - neither suspension vise nor for other reasons :first:

Cheers

[dipshit]

So my question is: if I upgrade the suspension with the aim of improved comfort over the bigger bumps, will my performance or handling suffer as a result? OR is there an aftermarket shock or some adjustment I can do that will take the dge off these bigger bumps and not leave the bike wallowing in high speed corners?

Stuck inside with the rain today doing some web browsing and came across your question.

If the suspension gets sorted on your bike properly then you can most certainly gain control and comfort. This is exactly what I experienced with my bike.

A few years ago I bought a brand new K8 GSXR600. Great bike apart from my 75kg body getting launched out of the seat on any decent bump. Very unsettling for the bike too. Felt like the tyres were only floating over the top of the road surface with little grip. Also closing the throttle mid corner made it feel like the bike wanted to run wide.

Decided to give the 600 the Robert Taylor treatment with a secondhand reconditioned Ohlins rear shock and a front fork re-valve job. Cost about the same as what a noisy aftermarket exhaust would have cost.

The result was a bike that didn't squat under power or dive when closing the throttle or moderately braking or wallow when going through a dip in the road. The pitch of the bike feels ironing board flat. It doesn't matter if you want to brake/decelerate mid corner, power on mid corner or change line mid corner... it just responds to what I want to do without hesitation or protest. Now you would think that firmness in the pitch of the bike came at the expense of a rougher ride over bumps. Not so. The 600 is now also much more settled over bumps and feels more stuck to the road. My backside isn't getting launched out of the seat over bumps and makes for a much more comfortable ride.

It is most definitely a case of you get to gain both and it doesn't have to be one or the other.

[dipshit]

The real trick here is that the valving shims are arranged to give what we call a digressive damping force curve. There is a very good amount of low speed damping force but when the shock encounters an abrupt bump the shim stack lifts an appreciable amount to provide ample flow area to iron out most of those bumps.

The couple of sentences hear from Robert are very much the heart of the matter as to how I was trying to explain how my bike feels now in the post above. (that and of course having the correct spring rates for your weight)

To have a much firmer bike in terms of ride height at both ends but at the same time have a much more compliant/absorbent ride over harsh bumps makes riding my 600 a sheer pleasure. Before I got the suspension work done, a couple of experienced riders and motorcycle mechanics told me that it wouldn't be worth it for a street bike unless I was going to go racing on it. They couldn't have been more wrong.

PS... BTW... I know the personal feelings of a Suzuki dealer down my way advises against a GSXR as a road bike because the rider will get hammered by the suspension too much on our bumpy roads. He feels a more touring orientation bike or a less cutting edge sports bike makes a better street bike for this reason. Shame as the only reason they are like that for most people is because of inadequate setup.

[F5 Dave]

Been a while since he was young then. I had no issue that I had to stand up over gnarly bumps on my 750SP, it was a small price to pay.

Later I spent money on kits both ends and redid the seat and got better handling and much more comfort to boot.
now I'm older I did it the other way around with a softer bike and suspension to aid control.

[Robert Taylor]

The couple of sentences hear from Robert are very much the heart of the matter as to how I was trying to explain how my bike feels now in the post above. (that and of course having the correct spring rates for your weight)

To have a much firmer bike in terms of ride height at both ends but at the same time have a much more compliant/absorbent ride over harsh bumps makes riding my 600 a sheer pleasure. Before I got the suspension work done, a couple of experienced riders and motorcycle mechanics told me that it wouldn't be worth it for a street bike unless I was going to go racing on it. They couldn't have been more wrong.

PS... BTW... I know the personal feelings of a Suzuki dealer down my way advises against a GSXR as a road bike because the rider will get hammered by the suspension too much on our bumpy roads. He feels a more touring orientation bike or a less cutting edge sports bike makes a better street bike for this reason. Shame as the only reason they are like that for most people is because of inadequate setup.

Hey thanks. The whole reality is that the suspension thing has become a trade in its own right and is also very dependent on experience. Plus, in reality continued off shore training and a high level of equipment. You cannot just do a 2 day Race Tech seminar and be an overnight expert, its a start only. When I trained to be a motorycle mechanic ( back in the 70s ) the training for suspension was VERY rudimentary. It still is, to this day. And VERY inadequate for a modern world where technology ( and expectations ) have moved on in leaps and bounds.
Misconceptions abound. For example ''Im not fast enough for an Ohlins ( or other excellent ) shock''. When in reality its actually about improving ride quality, control, response to adjustment and tyre life.
Or ''throw in a set of progressive springs, that'll sort it''. Now thats a 70s ''solution'' if ever there was.
The less you know the simpler it is....