The Robert Taylor suspension thread

[et al]

Point of fact I have 5 proper suspension technicians spread across the country who I entrust to do this work and converse closely and transparently with them. No egos, no bull...t, just get in and do the job properly.

Hi Robert,
I appreciate the good stuff you are contributing on this Forum. Regarding your suspension technicians referred to - are you able to post here who/where they are, or should people approach you in the first instance?

[Robert Taylor]

Hi Robert,
I appreciate the good stuff you are contributing on this Forum. Regarding your suspension technicians referred to - are you able to post here who/where they are, or should people approach you in the first instance?

Yes, can be a ''tetchy'' subject because so many shops think that they can service suspension, but the cold hard fact is that we demand a whole load more overall committment than most are prepared to sign up to. Add to that continuity problems as so many mechanics are transient.It is for all intents and purposes a seperate specialised trade in its own right.
This is not a skill you are born with and to that end I have trouble with the term ''guru.'' It takes many years of experience, solid study and the willingness to put in the hard yards and hours learning. If it becomes all consuming ( as it has for me ) then factor in tens of thousands of dollars in overseas trips and the same in equipment, including a sophisticated shock dyno.

I will elaborate further in a future post, my issues are not too disimiliar to other distributors of many technical products who are actually prepared to provide back up. Suffice to say send me a pm and I will direct you to the most appropriate guy for your needs.

Empirical information submitted on this forum is to help people to help themselves. There is no one magical setting that works well on every road and every track, so if we can help many to understand to a higher level then all the better.

We need to touch on tyres and how the supension and tyres should work in harmony, and how they very often dont. For example we can double the rear tyre life on the TL1000 S/R models. A heavy workload precludes doing so now but will come back to that.

[saul]

Blimen heck brilliant cheers

[Tim 39]

While we're on the subject of talking about ohlins...I have an ohlins steering damper on my RS125...how is that better than a standard HRC one? Robert?

[F5 Dave]

Interesting point containing 2 posts (ie: the Suzuki rotary damper), Tim are you talking about the Rotary steering damper that originally came from the Scott steering damper? Or the traditional slide damper?

The problem with most dampers is trying to get them without wicked freeplay. Which reminds me my Ohlins str dmpr needs bleeding or a decent service.

I suppose most early/simple dampers are just orifice devices comprising little more than the adjustment needle hole. Never thought about it much.

Speed activated sounds like a good idea, but really you may be better with a variable damping to movement angle. I guess traditional dampers do this to an extent as they have to react by opening the shims which will only happen after a certain amount of travel. Hold on that's the reverse, Duh.

I wonder if the top of the line ones are nitrogen charged to avoid cavitation?

There had been talk of suspension fluid that became more viscous as you passed current through it, imagine the possibilities of uP control, but I guess that never got anywhere or was impractical.

Sorry Robert I guess you will feel a bit like you are explaining simple things to the masses who seem unable to grasp the concepts fully enough. But have enjoyed your past articles in KR. Which is good as they are otherwise totally lacking in the sort of expertise to produce said articles.

[imdying]

There had been talk of suspension fluid that became more viscous as you passed current through it, imagine the possibilities of uP control, but I guess that never got anywhere or was impractical.

Magnatrac is the working name of the shocks with similar tech fitted to HSVs. I've only read one review on it, but they reckon it was the ducks nuts.

[boomer]

Magnatrac is the working name of the shocks with similar tech fitted to HSVs. I've only read one review on it, but they reckon it was the ducks nuts.

one of the motors on top gear had it, i think it was the audi. press a button and the magnets turned on or off and .. voila.. sports style suspenders

[imdying]

I think the HSV has a wee computer that adjusts them 1000 times a second Pretty sure that the Audi would be similar though.

[Tim 39]

it's the slide type, basicly I'm wondering if its worth swapping over to my new bike or not. (the shaft is a bit long I reckon)

[F5 Dave]

yeah read about the idea in the early 90s but heard little more about it.

Having a simple harder/stiffer may be of little use as the valving would have to exponentially change with the increase in viscosity, unless the change was pretty subtle it would leave the high speed damping too stiff on 'sport setting' and low speed too soft on 'comfort'. Heck my stepmahs Laser car had dash push button (orifice) adjustment in early 90s

Actually depending on use maybe around town it wouldn't matter too much if the compression damping was bugger all in your people mover. On a bike it would be a drag as lack of low speed compression damping makes the bike fairly unsettled esp in side to side transitions.

[slowpoke]

one of the motors on top gear had it, i think it was the audi. press a button and the magnets turned on or off and .. voila.. sports style suspenders

Who needs magnets, I'm getting stiff just thinking about it........

[Robert Taylor]

First off, as already mentioned, thank you for your contribution so far to KB, I read with much interest what you have to say, which is well thought out, and written so I can understand it... even Boomer understands!.
Wish I knew about you when I had my TLR... FFS what were Suzuki thinking with that rotary damper??! I never understood the concept, and still dont.. well kinda, but 3000 kms from a Rennsport (the shizz tyres at the time)?? That was very costly.



Too right mate, you got a set of K7 front forks to sort out comin your ways tomorrow... or the next day, stupid couriers!!

The basic concept of the rotary damper is very sound, just ask Michael Schumacher, Kimi Raikonnen or Felipe Massa.

The Japanese of course ''invented it'' and found a way of destroying potential benefits by passing it through the PCD or ''product cheapening department'' Excess internal friction ( in fact heaps of friction ) that creates heat and overstresses the already very limited fluid capacity. Small diameter low resonse shims and the internal calibration from hell. Because in practice the damper is so non compliant the tyre has to cope with absorption duties rather more than it should.

Tyres and suspension should work in harmony. The suspension units are there to absorb bumps and to maintain chassis stability and ride height control, among other duties. Simplistically;

1) If the suspension is too firm and has heaps of stiction and then friction ( i.e TL1000S / R and VTR1000 as some of the worst examples of many diabolical oem shocks ) then the sidewall compliance of the tyre is overworked because it is compensating for the lazy shock. That means a lot more scrubbing action is occuring on the contact patch surface. Result, accelerated tyre wear. Playing with the clickers isnt going to help, the problem is too fundamental.

2) If the suspension is too soft and / or the springing is too soft for the overall loading the overall end result of rapid tyre wear again occurs. Just sitting on the bike uses up a good part of the suspension travel alone, so there is less available for absorption and chassis stability duties. On a single shock rear end with a linkage system soft springing / settings can actually feel firm. That is because you arrive at the rising rate part of the curve a good deal earlier.

ETC ETC....That so many people are prepared to put up with such poor suspension and instead spend their money on noisy pipes amazes me. Cynically....''look at me, the noise I am making is drawing attention to my ill handling bike'' Okay, thats a bit rough but examples like that do exist on a daily basis.

This is a motorcycle forum but lets think about the drift car culture that has permeated onto the streets. Drift cars are very ''tied down'' Stiff spring rates, lowered ride height and radically reduced travel ( very often actually on the bump stops ) and any external compression and rebound clickers wound nearly if not all the way in. Stiff anti-rollbar settings, if fitted. Very low profile rims with little sidewall compliance in the tyres. All to initiate breaking traction easily to drift. SHOULD DAMN WELL BE FOR CIRCUIT USE ONLY. So you see these things bouncing around the streets and all I can think is ''you brainless plonkler''...and dont you come anywhere near my teenage daughters! Given our bumpy and often greasy low grip roads that can be a cocktail for disaster, especially as many of the twits that drive these attention grabbers havent yet worked out that the throttle can be moved in two directions. Something that LTNZ should clean up but its probably in the too hard pile, that or any Government wouldnt touch it for fear of losing votes.

The point is poor suspension compliance and over-firm ( and as we have said too soft suspension ) compromises tyre life and also mechanical grip.

A few years back Brian Bernard was regularly racing a TL1000R during the winter series races that regularly visited the old Taupo circuit. We fitted an out of the box Ohlins shock to that bike and he shaved 2 seconds per lap instantly off his lap times around that short little circuit. I can remember it well because another competitor who thought he had that years series in the bag unsuccessfully protested.

The improvement in lap times was because the suspension actually responsively moved to track surface changes as it should and kept the tyre firmly interlocked with the grain of the pavement.....more mechanical grip.

With the stock ''gap filler'' he had been ( sounds corny ) ''dry aquaplaning''.

[imdying]

1) If the suspension is too firm and has heaps of stiction and then friction ( i.e TL1000S / R and VTR1000 as some of the worst examples of many diabolical oem shocks ) then the sidewall compliance of the tyre is overworked because it is compensating for the lazy shock. That means a lot more scrubbing action is occuring on the contact patch surface. Result, accelerated tyre wear. Playing with the clickers isnt going to help, the problem is too fundamental.

Is that why a friends GSXR1000 went from a tyre shredding machine to barely even scuffing it after fitting an Ohlins shock (both round the track)? I was astounded at the difference I don't mind saying... you'd get your moneys worth out of the shock in rear tyres alone I'd guess

[Robert Taylor]

While we're on the subject of talking about ohlins...I have an ohlins steering damper on my RS125...how is that better than a standard HRC one? Robert?

I am not so familiar with the HRC one but am guessing that it is a single tube type with a deliberate air bubble ( which homogenises ) to allow for heat expansion.

The Ohlins damper has a seperate chamber to compensate for oil expansion and it also gives it a slight pressurisation effect. So straight off it doesnt cavitate.

A top mount transverse type has a small bleed bore and needle because it must provide a lot of damping within a very short stroke and technically is ridiculous. But that is fashion.

Sidemount dampers for the same amount of handlebar arc have a longer stroke, which is easier to modulate accurately. The bleed bore is larger with a less aggressively tapered needle, often with a cross bore processed into it.

There are 20 clicks or more of adjustment range but it is rare to require the setting further inward than 8 clicks out

[slowpoke]

Thanks Robert.
It must feel like you are talking to a bunch of cabbages sometimes but rest assured this stuff is gold to most of us.....even if some of it does get lost in the translation. You know better than anyone how much crap is spruiked by salesman so it's a rare and much appreciated opportunity for us to pick your brain for unbiased information. I'm off to scrub the top mount transverse type steering damper off my list of trademe/ebay searches, thanks mate.

Now, about those teenage daughters.....