Chuck

Yeah, I just cracked up the first time I saw it. In related news, 155520 downshifts and upshifts on the seriously overstressed .071 spring as we speak. I'll let it run a while longer and test it to see if it's lost it's ju ju.

I very seldom watch movies.. and almost never watch one again. I've seen O Brother several times. One of my all time favorites.

"We.. thought.. you was a toad.." Gotta watch them si reens.

Ok, back at it. It was too cold to play this morning. Welded a couple of wear pads on the lever, and am currently testing the limit of the .071 spring wire. It has 28 degrees of preload, and maximum safe travel is 60 degrees, according to the spring calculator. 28+39=67, so we'll see if this sucker breaks or takes a set. The Guzzi 080 spring with 1 1/2 coils has 1250 grams of pressure on the pawl in neutral, and essentially nothing at the limits of the upshift. This spring has 1150 grams in neutral and I haven't measured at the limit of travel, but it's substantial. The .071 spring with 5 degrees preload has 700 grams of pressure, and still has positive pressure on the upshift. I'm thinking that we'll probably end up with an .071 spring with 10-15 degrees preload. We'll see how well the over stressed test works out. 2017-12-01_12-05-29 by Charles Stottlemyer, on Flickr I hear the Scura calling. Time to go for a ride.

Docc's method worked a treat for me. The Odyssey battery on the Aero Lario had "issues." No more. Discharged it, blasted it with 10 amps for an hour or so. It's been fine ever since.

Well said. Believe me, brother.. I feel your pain, and know *exactly* what you are talking about.

this engine is amazing. When I bought the project, it had the original engine. 1800 hours since new, 300 since a top overhaul, and had been sitting for years. Because of the cam sitting high in the case, they rust cams and lifters when not in use. It was of practically no value. cheap. (Guzzi content) I pulled it apart, cleaned light surface rust off the cam and lifters, reassembled with all new gaskets, put an oil filter mod on it, and it runs like new. Burns a quart in 14 hours. Doesn't leak. (!) Sometimes, you get the bear.. Sound like you got a good one there Chuck, unlike the old P&W radials I worked on as an apprentice. They used to leak more oil than they burnt. If they weren't leaking you got worried:) Ciao Oh, I have a radial in the shop. It's a 90 hp Lambert. 1930. It was overhauled, test run, oil drained and pickled in the late 90s. Supposedly, there's no oil in it, but there are a *lot* of oil spots under it.

this engine is amazing. When I bought the project, it had the original engine. 1800 hours since new, 300 since a top overhaul, and had been sitting for years. Because of the cam sitting high in the case, they rust cams and lifters when not in use. It was of practically no value. cheap. (Guzzi content) I pulled it apart, cleaned light surface rust off the cam and lifters, reassembled with all new gaskets, put an oil filter mod on it, and it runs like new. Burns a quart in 14 hours. Doesn't leak. (!) Sometimes, you get the bear..

Candy is dandy, but likker is quicker. I've never tried the rose thing..

I can send you my best guess spring if you want to do some real world testing. Right now, I'm riding (fabulous day today) and doing an annual inspection on the Colt. My lovely assistant helped me get the cowling off without damage this afternoon to start on the "powerplant" part of the inspection. 2017-11-29_08-08-00 by Charles Stottlemyer, on Flickr

Sorry, I've been slackin today.. and will continue slackin until this stretch of warm weather goes away.

Well.. she *is* Italian.

One thing that is difficult to design against is vibrations. Could the spring buzz itself to death? Are there any wear marks where the spring sits in the shifter mechanism? If, for example the spring resonates at 4000rpm, then the fatigue cycle count could get into very high numbers without much shifting. Changing the resonance frequency could make a steel spring last forever if the design stresses were below the fatigue limit. A resonance change could come from different thickness wire, different length spring, different oil in gbox. Just a thought. I know it doesn't help your design, but it may explain why you can't break that spring by shift cycles alone. Interesting thought, but beyond my meager ability to test. Wear marks? Very subtle. I had to look at the used one with a 10X glass to make sure it wasn't new when I first looked at it. Then, when I took the new one out of Scud's preselector, I could see the old one was sacked when placed side by side.

That's the long and short of it.

True.. but apparently *some* springs don't break. This is probably one of them. I've also tested many variations with my gram scale in the neutral position. *Nothing* is as powerful as the Guzzi spring, but I doubt this much torsion is necessary. After all, the spring only has to hold the pawl against the pin at the start of the upshift. The eccentric will take it from there. I should take that back. The .071 spring with 25 degrees preload is about the same.. 1600 grams. Comma But 25+39 degrees is getting back to the "beyond safe travel" of that spring. Make sense? Even the weakest .071 spring still has positive pressure on the up shift, compared to a stock spring that is sacked. My gut feeling is that the .071 spring with 10 degrees preload is the one we want. It's what I'd put in my bike at this point. Third from the top in this picture. 2017-11-25_05-45-36 by Charles Stottlemyer, on Flickr Testing will continue, just the same. I'm afraid of the .080 spring stock with another active coil. Theoretically, it should be the best, but with tolerance stack up, it *might* not fit all bikes. .080" X3 equals .240". Scud's shifter gizmo measures .240". It works, somehow. If someone else's measures .230" it probably wouldn't. Do I see any eyes glazing over yet? Sorry. I've dealt with manufacturing tolerances all my life, and I'm ruling out the .080 wire with extra coil.

Gave up this afternoon at 289386. It wasn't going to break. 2017-11-27_03-50-39 by Charles Stottlemyer, on Flickr Cleaning things up reveals the reason. 2017-11-27_05-06-32 by Charles Stottlemyer, on Flickr The cam had eaten it's way into the lever. That combined with the spring doing the same thing, it's not been twisted the entire 39 degrees. More like 34. The best laid plans and all that. I need to insert some 4130 into the lever, and try again. This spring is still in great shape, though.

I noticed in some of the shadows there was a girl following you closely. How'd she like the Duck?

Uh oh. Be careful, it's a slippery slope. I started cheating on a silver Ducati with a grey Centauro, and haven't had a duck since.

207360 and counting at 6 o'clock this morning. Still showing no obvious sign of fatigue. (!) We need an energizer bunny emoticon. In related news, after filling the little gearbox with rear drive lube, it's quieter and the motor and box are running much cooler. (Guzzi content.)

Honestly, Docc.. I don't know. *Assuming* it's still going tomorrow morning, it'll have more than 200, 000. I didn't expect it to last his long.

No. (!!) Believe me, I'm surprised. I toyed with putting it in the preselector and testing how much spring pressure it had, but decided to wait until tomorrow morning if it hasn't broken. Honestly, I would never have believed it would go this long. It's eating up my steel lever, and just keeps on clacking..

Scud.. if you had installed the spring you sent me, you wouldn't have broken it. It now has over 100000 shifts, and seems to be indestructible. I'll let it go all night and see what happens.

No, it is almost completely relaxed on the upshift.

Stop the presses. I went out to check on it before going to bed, and had a squeak from the gearbox. Maybe (hopefully) just low on oil, and not a gearbox rebuild. At any rate, shut it off and will look at it today. At that point, the Guzzi spring still looked good, surprisingly enough to me. 5 hours so far.

Yes, they do. Generally, it's for the better, though. In aluminum. Not so much for spring steel. Stress relieving temp is about 350-400 F. I seriously doubt that the spring in a transmission gets that hot, though. That reminds me, It's been a little over 17000 shifts, now.. maybe I better go out an take a look.