Balance Factor

madero said:

Hello all,

I have seen that normal factor is about 70% or +10 or -10%,without the counterbalencer.

But when do you have to take 80% and when to take 60%??

What with a small displacement---bigger displacement?? (400-450---550-650cc engine).

Thanks in advance,

Madero

Click to expand...

Hi Madero,

Too many variables and no "scientific" data to support any one calculation.
This remains a cut and try "Black Art" arena.

Chassis design, spring rates, handlebar style, riding position, primary rpm range , primary load characteristics, riding style, etc. etc. influence the end result.

Read "Tuning For Speed" written by Phil Irving is the best advice I can give the inexperienced crankshaft tuner.

Dale

Hi Mathieu - by shear co-incidence that .pdf about balencing that I sent you the other nigh was straight out of Tuning for Speed look at the top of the scanned pages. I swear I didn't read this post before I sent it.

A fine book written a long time ago.

Ben

got my copy and it's VERY old!

regards

Taffy

Last printed in the late fifties, early sixties "Motorcycle Engineering" by Phil Irving is also chocked full of great information.

Dale

Just ordered "Tuning for Speed" from an Amazon Marketplace seller for $44.95. Thanks all for the recommendation. His books are all out of print and can be quite expensive. "Rich Mixture" goes for $475-$499 :shock:

Any other good books on tuning and motorcycles in general? I never would have found this title on my own.

I don't have the second book Dale mentions though I have seen it somewhere I guess a friend must have it. My copy of Tuning for Speed is a second edition 1951 copy which was until I pitched it years ago my farthers. I also have a 1987 copy which was the last print of it I know of I bought it in a secondhand book shop for the outrageous sum of 10 pence.

PS - Motorcycle Tuning Two Stroke ISBN 0-7506-1806-X & Motorcycle Tuning 4-Stroke ISBN 0-7506-1805-1 - both by John Robinson are good basic books, nothing to technical but pretty much all areas covered.

If you are into 2-strokes Cesare Bossaglia is a very good author as is John Dixon - but they both get technical and are not light reading, they are more focused on design than tuning thought the boundaries blur once you start replacing major components.

While backpacking around australia in the early months of 1980 I noticed a ad in a motorcycle paper(Revs ?)that a Mr P.Irving was to speak at a motorcycle club meeting near where I was.After much searching I found this little hall on the outskirts of Melbourne where he was to appear.Only about 15-20 people were there and the man himself spoke at length of his days at Vincent m/c and his time with Brabbam.
One of the most interesting evenings I ever spent,for sure.
My copy of" tuning for speed"always graces my night stand ,a fifth edition.. .

Through a mutual friend I have had the distinct pleasure of getting to know Tony Foale.

If ever the chance attend his seminar or the least, purchase his book.
http://www.tonyfoale.com/

Dale

not to mention tonys software