mallory 1000 old bikes and even older riders

[Jamiec_c]

Pask, with the rear ride
height i found substantially more than 9mm totally transformed the handling. Here in Aus, the guys that ran the RC45 race bikes back in the day won the Aust superbike title back to back in 94/95, i have talked many times to the team engineer over the years, they took the experience they had from the rc30 and directly took that to the 45, they won aust superbike title in 93 on the 30. anyway with the 30 they would raise the rear 70mm AND drop the forks thru the clamps! They did the same with 45, I originally got specs from them on setting up mine and i run ALOT of rear ride height and it works great(way more than people would contemplate!)

[roger]

Keep going guys, this is getting very interesting.

Regards,

Roger.

[Busy Little Shop]

Pask, with the rear ride
height i found substantially more than 9mm totally transformed the handling.

Jamie what rake and trail numbers are you running with 9mm???

[Jamiec_c]

Hi Pask, I personally am not running 70mm I was just stating what the aust superbike team had to run, many years ago I talked to Clyde Wolfenden and asked why the 45 had a bad wrap for handling, he said " we've never had a problem with handling it's a sweet thing". I am actually running around 20mm of ride height, I used to have an Ohlins but now running HRC.

It was Clyde who said how to set the bike up giving it lots of rear height, I have stood next to standard 45's and they appear very low whereas standing next to mine give the impression of a larger bike as its raised up quite a lot compared to a standard bike, but it works for me, so I'll leave it.

Your set up of ride he adj and B linkage is probably best set up to have without replacing the shock.

Larry I have no idea of that the trail is, sorry.

[Jamiec_c]

Paso FYI, when I was running the ohlins it had been built with a longer shock piston rod for more travel in droop. Also currently the sssa I'm running is the longest at 555mm centre to centre as opposed to 535mm of the stock one. So the wheelbase isn't as short as the ride height would give the impression of.

[arsey30]

Not really RC45 related but RC30 ride height according to Maxton for the TT was 540mm , which is around an extra 20 mm on standard, when 17" wheel is fitted and measured with the bike on stands.
6mm sag on its wheels will give a ride height of 534mm.

Spoke to a factory rider and he said the best ever handling bikes around the TT circuit was the RC30, although he thought that the 1991 RVF was even better, if he was able to race it after running it in.
RC45 was the worst, [Hislop and Phil Mc did confirm that, and think M D uhamel did as well ]

However, he did say that front fork offset was the key to good handling.

Watched Steve at the top of the Baggarow in 1994 and wondered how his tank slapping bike would finish.
Can Larry post some details of the above observastions please.

[Busy Little Shop]

Can Larry post some details of the above observastions please.

I loved my iconic RC30 but it had 2 problems HRC corrected with
evolution of the 1994 RC45... namely not enough weight on the front and
no tune flex in the frame... as a cure HRC moved the RC45 engine
forward 10mm and developed long flexy engine mounts like you see on
the current MotoGp tune flex frames and this orthodoxy in frame design
is why the RC45 still feels modern today whereas the RC30 feels well
past its sell-by date...

Quote Carl Fograty

Formula One
"The RC30 was as fast as anything out there in 1989 and 1990, but very
difficult to ride. It didn't suit my style but I was able to ride
round the problems with the front end of the bike, by holding it up
with my knee. Jamie couldn't do that and, whenever he tried to get
anywhere near me, he came off."

WSBK
"The TT Formula One championship had been scrapped, so there were no
distractions from Superbikes. The stage was set to make a big
impression on the world stage. I just hadn't bargained for the speed
of the Yamahas, Ducatis and Kawasakis! Or the fact that, not only was
the Honda still handling badly, it was now one of the slowest bikes
and well past its sell-by date. It was to be a very tough year."

IOM TT
"when 1 sat on the RVF for the first time, it was like a live
wire and 1 couldn't stop it jumping all over the place. 1
brought it back to the pits, my face as white as a sheet after
a hairy ride.
'I don't like this thing at all. What do you think, Steve?'
1 asked.
'Mine seemed to be handling fine, actually.'
'Bloody typical!' 1 groaned. 'I get the one you can't ride.'

Technically speaking...
Both the RC30 and RC45 use aluminum beam frames as the basic chassis
design but what has evolved is the sensitivity to deflection when
leaned right over... The RC30 employs short stiff front engine mounts
where as the RC45 employs long flexy front engine mounts... Honda
found that the longer the engine mount the more a rider can feel the
limits of traction while leaned over... especially when the front
contact patch is held more true in line with the rear contact patch
due to the inherent superior stiffness of up side down forks...

The goal of tuned chassis flex is very much in evidence in MotoGp
today... starting with the 990 and the 800s and finally 1000 every
manufacture employs some form of a long flexy front engine mounts...
short ones are no longer a design option by the engineers even with the
latest electronics...

RC30 no tune flex by virtue of the short ridged front engine mounts


RC45 tune flex by virtue of the long flexible front engine mounts


With tune flex a rider can find his way into a slide and more importantly
find his way out of a slide as Duhamel demonstrates with the AMA RC45

[jayRC3045]

Can Larry post some details of the above observastions please.

You had to ask didn't you , why dave why !!!!!!!!

[arsey30]

Larry,

Does the engine/engine mounts flex allow the main [rigid] frame to flex?

I was told the long engine mounts resisted vibration fatigue, and took the load/stress away from the cylinder heads.

[roger]

On Wed Sep 18, 2013 7:39 pm I posted:

Keep going guys, this is getting very interesting.

At that point the thread could have gone one of two ways, either onward and upward into the realms of high interest and practical usefulness, or downward into the realms of pitch black darkness and nonsense… guess where it’s descending?....... Damn, I’ve used an easy word and given the game away!

This talk about RC45 designed-in frame-flex is post-product-release retrospectively argued nonsense (invented by a few to somehow elevate the RC45 into the realms of utterly flawless uber-super-duper-bike).

Any degree of RC45 chassis flex is going to be outwith the physical domain of the rigidly fixed block of metal known as… the engine. In fact flex is going to be about two points:

1: The headstock.

This forward located flex (when the bike is not running straight and level*) is torsional. That is the headstock contorts relative to the normal* vertical centre plane of the bike. This is why the HRC chassis strengthening - headstock - kit is applied to (rarely upright) race bikes.

2: The swing-arm.

Specifically a lateral bending flex (thus through the plane perpendicular to the vertical plane of the bike*) along a line rearward from the swing-arm pivot centre. This lateral flex is why the HRC swing-arm bracing kit, then subsequent kit swinging-arm, then subsequent double-sided swinging-arm, came about.

As Arsey 30 has supposed, long engine mounts resist vibration fatigue because vibration operates along an increased length, nothing more.

The key issue (relating to any bike/model) has been (inadvertently?) exposed by Larry with:

Quote Carl Fograty (Fogarty)

Formula One
"The RC30 was as fast as anything out there in 1989 and 1990, but very
difficult to ride. It didn't suit my style but I was able to ride
round the problems with the front end of the bike, by holding it up
with my knee. Jamie couldn't do that and, whenever he tried to get
anywhere near me, he came off."

Conclusion:

You need to set the bike up (whatever the bike) as best you can to suit the rider - and the ride, and then the rider needs to ride it… and if racing to win ride it on ‘the ragged edge’.

If there’s going to be ‘a dive into ‘technophilia’ with this thread, I’d personally rather hear members own thoughts/experiences on ‘set-up’, rather than read what (I consider to be) the broken record of historical falsification being played to convert a pig’s ear into silk purse’.

No offence meant, but if you don’t recognise fault where there is fault in the RC45 design (as Honda did – to its credit) how are you ever going to (modify/set-up) to get the best from what you have?!

So for a (newish) start how about 'thoughts' on what rake, trail, and offset are for, and how making individual changes to them, and changes in combination - specifically with regard to the RC45 - will translate into the riding experience (or better yet, how real changes to them have actually translated into the riding experience).

Regards,

Roger.

[arsey30]

Quite Roger,

This site is for the exchange of information, is it not?
How it rides is more useful to me than design philosophy.
Read Phil Mac and Hizzies books to see what they thought of the RC45.

However, the 1000cc twin opposition in WSB spurred on HRC to produce the finest 750 race bike ever, it only needed the brilliant little John K to win the title.

I wish this and other sites were going when I was setting up my suspension, carbs, and fitting new parts. [1992]

[Busy Little Shop]

Larry,

Does the engine/engine mounts flex allow the main [rigid] frame to flex?

I was told the long engine mounts resisted vibration fatigue, and took the load/stress away from the cylinder heads.

True... long arms allow the headstock to flex ever so slightly and no
the long arms are not primarily designed to deal with cylinder head
stress... remember Honda dropped the I4 in favor of the V4 in Gp
racing because it don't vibrate as much and the V angle makes for a
rigid cube block design which fights against internal friction...

Short history of Tune Flex...
In the 1980 as tires improved and engine outputs increased, the forces
involved in braking and accelerating started to overwhelm the old
flexy steel chassis and so frame builders started to make their new
aluminum frames stiffer and stiffer thinking there was no limit to the
degree of stiffness a rider could handle... thats why some riders
prefer the stiff as marble feel of the RC30 chassis but it comes at a
cost of nervousness at speed...

In the 1990s the chassis builders started to encounter the oppostie
problem of flex as their frames got stiffer and stiffer, the bike
started chattering and vibrating, making handling terrible, especially
when leaned over, when the suspension of a bike ceases to work, being
in the wrong plane. And so the concept of flex was introduced, adding
sufficient flexibility to allow the bike to absorb some of the bumps
while leaned over, but still stiff enough to keep the chassis stable
in a straight line and under braking. Since the late 1990s, and
especially since the four-stroke era began, a huge amount of work has
gone into engineering in exactly enough flexibility in specific areas,
while retaining the stiffness in the planes where it is needed.

As tuneable flexibility has become increasingly important, the
attractiveness of alternatives to aluminium has also grown.
Traditional aluminium has the benefit of being light and easy to work
with, but as chassis designers push the limits, they also run into a
few limitations. Engineering in flex is a matter of designing chassis
elements with a specific thickness and shape, but the underlying
properties of aluminium mean that at some point, achieving the precise
amount of flexibility required means sacrifices strength. The way to
get around this problem is to by making elements longer, allowing a
mass (usually, the mass of the engine) to use the greater leverage
provided by a longer element (such as an engine spar connecting the
engine to the main chassis beam) to provide the flexibility without
sacrificing rigidity. The RC45 got the benefit of this latest
engineering in tune flex which is why it still feels modern...

Ironicly Yamaha started MotoGp in 2002 with a frame without tune flex
feel but after Rossi signed in 2004 he and Burgess schooled Yamaha on
the benefits for long flexible front engine mounts...

Quote Jeremy Burgess in 2004 on Yamaha's lack of tune Frame Flex:

"We identified fairly early what the problems were. The bike was
developed by two very good 250 riders. No slur on them, but what you
want for a big bike, a 500 or a four stroke, is something different.
All bikes operate within a circle, and the circle wasn't anywhere near
where I felt it should be... To ride one of these things, you need to
have enough feel to get the bike to slide; you must be able to feel
your way into a slide and then back out again safely. The chassis
set-up was radically changed - the bike being made longer and higher,
the forks extended by nearly 25mm and the swingarm stretched by the
same amount. These modifications were made to a chassis
that had even more radical front engine mounts than the prototypes
seen at the end of 2003 at Valencia. Front forks don't work
so well when leaned over, and to try to maintain grip the new chassis
allowed the whole head stock to flex a little when the bike was deep
into a corner and leaned right over."


Yamaha M1 Tune Flex Evolution notice the 2002-2003 frame is like the
RC30 whereas the title winning 2004-2005 frames are like the RC45...


Aprilia's new RSV4 sports a tune flex frame which looks a lot like RC45

[Busy Little Shop]

Roger's eloquent reply translated...

Well, Dave, if the man I know chivvies along and gives it some welly,
he can still grasp the nettle and win back the man on the Claphman
omnibus. But it’s plain as a pikestaff that if he goes off his chump
and faffs about with all the cobblers and codswollop, he’ll be gone
for a burton and end up Nobby No-Mates.”

[roger]

Hello Larry,

As Joey Dunlop once said to John McGuiness, “just grit yer f*****g teeth. That advice is on the record.

I presume your latest (frankly, offensive) post is designed in the hope that you’ll have insulted me so much that I’ll respond no further to the thread; thus leaving the floor to you, so enabling you to pedal your complete nonsense in an entirely unopposed way….

Well Larry “thanks” (really), for your most childish, puerile, pique laden NPD* response. Though I suppose when you’ve ‘nailed your colours to the mast’, and nailed them, and nailed them, and…. nailed ad nauseum - when ‘your mast is then shot to pieces by your very own side’** there’s nothing more to do other than throw an infantile tantrum (and I knew it would happen sooner or later – quite predictable*).

But, just to get to the bottom of your problem with a (my) dismissal of your third hand, fourth rate, ultra plagiarised, projectile vomited claptrap, regarding (so called) RC45 chassis tuning…… was it my mentioning that to race the RC45 successfully a chassis/swingarm (b)racing kit was required**… so, this reality, from Honda itself, sort of gives your broken record guesswork about (none-such) designed-in RC45 chassis flex the big F-?

NPD* = No Point Discussing, or whatever.

Finally for you Larry, I suggest you give-up on trying to translate my posts, as it’s quite obvious (to me) that you’re incapable of success with such a process (unless and except when my posts happen to concur with your own).

For everyone else:

Any useful information, feedback, pointers, recommendations, whether experience or science based (as opposed to ‘throwing chicken bones into the air to see how they land’) would be gratefully received – by me at the very least... But I do appreciate that what might work for one might not for another.

Regards,

Roger.

[Busy Little Shop]

Hello Larry,

Regards,

Roger.

Hiya Roger...
It don't matter what you scribe my dear friend I just love reading your
responses... so don't change a thing even when you thank me for my
"most childish, puerile, pique laden NPD*" reply...