Lucky Phil

With respect to the piston motion the crank isn't accelerating/decelerating it's the piston that is for a constant crank speed not the other way around. At low engine speeds like idle the crank in a 90 deg V twin with have varying acceleration during the 2 cylinders full cycle but at 3000 rpm of so it will be on no consequence to the cam drive chain. Ciao

Well non of those mentioned have harmonic dampers and seem to work just fine. Probably because they don't have a massive long train of gears from the crank to the cams, not sure. Ciao

It's all geometry docc. That's why there's a practical limit to the capacity of a traditional flat plane crank 4 cylinder engine before you need balance shafts. It's generally around the 2.0 litre mark give or take. Doesn't mean you can't have a 2.5 4 cylinder engine without a pair of balance shafts turning at 2X engine speeds but the secondaries get a bit much for a DD. Some engines don't need the cam drive dampers such as VFR Hondas and MV Agustas and the Guzzi. Ciao

Yes thats what creates secondary vibrations. The piston travel in the first and last 90 deg of crank rotation is greater than the second and 3rd 90 degs. Ciao

It's worth bearing in mind that you can't as a general principle translate everything in engineering across all installations and applications. What works perfectly fine in one application can have issues and problems in another. From my sketchy memory gears weren't favoured by NASCAR engine builders because in the operating envelope they ran at harmonic vibrations were an issue with gear driven cams. Chain driven cams dampened this out. Remember though this is/was pushing an original design to it's limits and a lack of rigidity in cranks combined with sustained high rpm introduced it's own issues unique to those engines. It's what makes engineering interesting and challenging and keeps designers awake at night. It worked here on that, so it "should" be ok on this, then it turns out it's not and back to the drawing board, testing and investigating. Rolls Royce engineers and designers spent 5 years of the war on a merry go round like this developing the Merlin and Griffon engines among others. Quite often it was a minor modification required or a materials change and the issue was solved. Ciao

Ciao

Yes my experience too docc. Ciao

These are actually a bona fide secondary sealing mechanism in the aviation business. As opposed to the automotive world where they are seen as a dust excluder. Ciao

Yea thanks docc, I saw that one. It looks a little ropey and with shipping is very expensive for a $10 item. Cleared out my messages. You were right, full inbox. Ciao

What could be the reason for this docc? Too much stuff in my PM box? I kinda figured I wouldn't be able to available docc but thanks anyway. Who knows the call in the new year might be "lucky"lol. Ciao

I need one too if anyone has one. Ciao

Maybe I was explaining it wrong docc or we are at crossed purposes. Ciao

So if I string line a bike from the rear wheel using a pair of stands at the front or use a parallel and I measure the gap from the parallel or string to both sides of the front wheel and get a measurement of 20mm on one side and 30mm on the other side what is the track deviation? In my world it's a bike that's track is 5mm out of alignment. What about you? Ciao

I don't see the minor variation in crank speed due to the firing order having any meaningful effect on vacuum balance or cylinder filling. There are too many other variables involved for this to be a significant contributor. It's something that looks better in theory than actuality. Same as measuring exhaust temps on idle, what meaningful information does that give you within realistic parameters? Small EGT variations could be due to many things. Ciao

Forget the tyre's, tyres are variable. So you place a pair of straight edges on each side of the rear rim and they run forward past the front rim so you can measure the gap differences on each side of the front rim aft and fwd. Lets assume the frame is perfectly straight the measured gap between the sides of the front rim aft and fwd will be exactly the same. Now lets assume you move the "centre line" of the front wheel one way by 5mm the measured gap between the sides of the front wheel to the straight edges will now be a 10mm "difference" in measurement. So the measured "difference" between the sides is twice the actual centreline track offset. Ciao

I've never had any issues with side stand components loosening myself. Most side stand issues I've seen have just been a lack of maintenance and foolish owners that think sitting on the bike while it's on the side stand is a "think to do" or pull the bike over on the side stand and use it to pivot the bike around to point the other way or to rotate the back wheel to lube the chain. A lot of side stands aren't engineered for those sort of actions and stresses. Guzzi did upgrade the V11 Sport side stand support bracket secondary bolt from 6mm to 8mm. Yes they way the Italians design a side stand you'd think they consider it a bonus item. The self retracing unit on my 851 looked like an afterthought and some I've had were almost impossible to extend without being an expert in Yoga, on or off the bike. Only Vehicles category LC (motorcycles) manufactured after 1 July 1988 require a stand in any form per the Australian Vehicle standards. Prior to that you can register them leant against a wall or propped up with a stick you carry in your jacket. Ciao

Or so the coils don't interfere with each other on extension/retraction so the stand operates smoothly. At the end of the day it's a spring loaded metal stick with foot on the end of it so it doesn't pierce soft ground. I doubt harmonics is a factor really. Especially an Italian side stand. The fact you get one in the first place from the Italians is a bonus. Ciao

Yea, I had a feeling there were quite a few makes out there that were offset for one reason or another. Harleys don't surprise me as handling doesn't seem to be on top of their agenda. It's better to be aligned of course but within reason it's not an issue. It's also worth remembering that the track difference when measuring from the side of the rims as a differential is twice the actual centreline offset so say a 5mm side to side difference is only 2.5mm centreline offset which doesn't seem as bad. Ciao

Ok docc looks like I misinterpreted "again" I'll change my post. Thanks. Ciao

I want a TIG welder. Can someone buy one for me for Christmas:) A really, really good one, lol. Are you listening Santa? Ciao

It's about increasing the area under the foot not the overall length of the stand. Ciao

It has a piece of string tied to it and looped over the l/h bar grip. Get on the bike, retract the sidestand and pull up the string wrap it around the stand plate and put it in your jacket. That's what I'd do. Just off to patent that now. Ciao

There're marketing people not Historians, lol. Ciao

Not quite, she's a bit older these days:) I met Barry about 30 years ago. We were racing at PI and he was staying at the same Motel. Ciao

Barry Sheene helmet and leathers and boots. Ciao