ESE's works engine tuner

[Brian d marge]

Spend 29 euros on tony foales software

will save u lots of frustration


Stephen

[jasonu]

With the rider in position the weight distribution should be clearly biased towards the front. Judging from the pictures I can hardly imagine this is the case.

That is mostly because of the ( crap (IMO sorry TZ)) chassis they chose to use. Even with extra bracing, better wheels and slicks it is still basically a fancy commuter chassis with plenty of weight and crap geometry. With all the time and effort that has gone into the engine surely a TZ125 or NX4 RS125 chassis is in order. I am sure that once the motor is properly up and running and reliable they will perform a chassisectomy transplant.

[F5 Dave]

Attachment 262748

heres that photo I said I knew about and have one of a matching sidecar for it aswell

Crumbs, that brings back memories! Been a long time since I've seen it like that. Had its front brake on my H100 for some time. Wonder where that went?

[F5 Dave]

My silly assumption about engine positions was based on the fact that the weight distribution of the Aprilia RSA turned out to be worse than that of the preceding RSW model because the RSA engine had to be moved further back because of the front-exiting exhaust pipe. So in the top picture the engine already is too far to the rear...

None of the rest of us think it was a silly assumption, i think the lads get a bit enthusiastic. But on the other hand, don't those spoked wheels look retro cool?

One of the battles we face placing commuter engines into frames they were never intended for is the sprocket ends up quite far from the sw pivot. It is a compromise but I go for having to deal with running a loose chain & getting the engine as forward as can.

The 250/4 chassis TZ has makes the compromise a step further, but at least it looks more comfortable than me squeezing onto my NF4.


TZ one wonders if you limited the travel on your road set up suspension (that has to deal with pot holes & pillions) the SW variation would be less so you could cope with sprocket distance if you desired.

[bucketracer]

In the picture below, if the engine is moved still a bit further back, you might be able to fit a straigth trombone pipe between cylinder and front wheel. And who cares about front wheel load; that only affects handling...

None of the rest of us think it was a silly assumption,

It was silly to assume Chambers and TeeZee wouldn't have thought about engine position and handling, sure they might not have it right but they would have thought about it.

What offended me was the mocking tone. Would have been better to ask then suggest a suitable ratio.

Any way TeeZee has told me I have "Won" the job of re measuring the Beast.

[F5 Dave]

Please don't offend the world renownd GP expert over internet 'tone', remember he is here by choice

[bucketracer]

Ok ......



A picture speaks a thousand words.



Bike without rider, 48kg front and 48kg rear for 50/50% weight Bias.



Bike with rider, 87kg Front and 104kg Rear for 46% Front 54% Rear.



Engine has to move forward.

Now that begs the question, what is an appropriate weight distribution for a small race bike that doesnt go all that fast?

[F5 Dave]

Perhaps I can answer that question with another;

What pushes the front more?;
- A bike at high lean angles on a Kart track with really tight corners taken at lowish speeds running 4yr old production slicks underinflated to increase temp, or,
- A late 80's RS 125 (to get power closer) on a longer track higher speeds with same tyres but higher pressures?


No, I don't know the answer either.


both answers make me want to get the weight forward though.

[husaberg]

Ok ......



A picture speaks a thousand words.

Bike with rider, 87kg Front and 104kg Rear for 46% Front 54% Rear.


Engine has to move forward.

Now that begs the question, what is an appropriate weight distribution for a small race bike that doesnt go all that fast?

I abandoned the NSR frame for the same reason as to get the weight distribution right would entail cutting the spars to do that. Well it is easier to start fresh.

Have you asked Crazy for a replica rs geometry frame quote?

But wight distribution is effected by the rider placement as well as he (TZ)is far heavier than the power plant.
TZs frame this is .....The tank is huge and set far back(no doubt most of it was airbox) the subrame looks heavy the clips ons are high.You can lower the forks raise the arse etc.....
but handling is subjective. find some bike with handling you like and replicate it as close as you can.(All of it)

Or put a radiator on it at the front that would help. Maybe a rule change to ballast the 2 strokes will be on the cardsthen you can add ballast.

No idea on the best weight distribution but if you reverse yours it will be equal to a 1990 RSV250 Aprilia.
54% front 46% rear Although it was modded later to......no idea what.But as the riders complained at the time about it being too lively under braking.....

[Yow Ling]

Does it have a handling problem or are you guys just inventing one?

Before you go crazy moving the engine why not put 5kg of lead over the front wheel ?

What is the loaded weight distribution for a RS framed bucket ?

[richban]

Does it have a handling problem or are you guys just inventing one?

Before you go crazy moving the engine why not put 5kg of lead over the front wheel ?

What is the loaded weight distribution for a RS framed bucket ?

My bike is 50/50 without rider and 50/50 with rider. I thought I had some sort of chatter problem at the GP. Next race I just leaned forward into a more aero position through the same corner. Fixed. he he.

[richban]

Bike with rider, 87kg Front and 104kg Rear for 46% Front 54% Rear.

That does seam quite a big difference. Is that in a tuck position?

[kel]

Have you asked Crazy for a replica rs geometry frame quote?

TZs frame this is .....The tank is huge and set far back(no doubt most of it was airbox) the subrame looks heavy the clips ons are high.You can lower the forks raise the arse etc.....

Re the crazy frame, I asked, its about a months wages. When you factor in the mortgage, single income, kids etc it works out to be two years savings in real terms. I want one!
Husaberg your comments on the frame are pretty much spot on with my thoughts but as I know next to nothing about chassis set up (cant even set the preload right ) then its guaranteed not to be that simple. Before it died last time out we dropped the forks, I was wanting to add preload to lift the rear as well, and that tank well it sure is big and does stop a skinny bugger like me from getting the weight over the front although I think my weight distribution would have more forward bias than the scales test. Dave M was making speedpros bike boogie so the FZR certainly can be riden hard, but then he probably would have disapeared into the distance on an RS chassis.

Seems I've upset people re crazy price (no pun intended). I wasnt stating that its over priced, rather the limitations of my meagre salary and family commitments! Considering the time, effort and quality its extremely good value - note the comment "I want one!" Very sorry, thank you, carry on.

[Henk]

I loved the Crazy frame with Bert's motor in it at Kaitoke. I'd ask him to PM me a rough price but with all the associated RS bits to make it all work I'd probably cry.
Lovely bike to ride though.

[husaberg]

Re the crazy frame, I asked, its about a months wages. When you factor in the mortgage, single income, kids etc it works out to be two years savings in real terms. I want one!
Husaberg your comments on the frame are pretty much spot on with my thoughts but as I know next to nothing about chassis set up (cant even set the preload right ) then its guaranteed not to be that simple..I was wanting to add preload to lift the rear as well

Ouch that hurts....

One other simplistic idea as well is to add a link to the chain would would be surprised.
One other one was too bring the steering head back with eccentric cups the NSR have huge bearing not sure about the FZR's
But yes they were simplistic but Honda, Yamaha and Suzuki have all made howlers of 500GP bike frames.With huge budgets. these include a YZR500 that was reputedly un-ridable it think it had a coaxel swingarm from memory that one in the mid 90's.So bad it was KR had to go get some ROC frames (that were a copy of the dimensions of the old YZR's) Honda with the upside down bike and well pretty much any four to 1991 ish and Suzuki with the frame 2 inches out for Kevin.Luckily for him they hadn't crushed the old ones and were able to use the old ones.
Yet the euros seem to get it right it is an art but you can paint by numbers as well.
Me well i brought a NF4 frame and forks (Co-incidentally from Crazy)for less than a Weeks wages seeing as the NSR125 and NF4 are reasonably similar. i am confident of not upsetting the handling too much. I would rather have had a NX4 but couldn't find one.Or a crazy frame replica.
I seriously started to make a CF one one but too much time and too hard work and the ancillaries killed the cost.

Oh yeah adding more spring preload actually makes the rear suspension effectively softer BTW.The best handling tip is simple ride the bike lots.

And if i had a Disk valve single, and if i couldn't live with a RS frame couldn't afford a Crazy frame i would probably do a spine frame. or sell a kid?