Wow Sixth@9k, hopefully that's on a track lol.
Upgrade the springs and put a washer in to add in some more pinch, is what I hear really helps. If you're truly daring and have a mechanical engineering background like myself. Try to calculate a die spring that would work.

HEFTY™ Die Springs | Heavy Duty Metal Compression Springs
(Could model one in creo or solidworks and run a simulation.)

 

The only track we have here in Massachusetts is the highway. I was just running out through its paces and seeing how well the carbs were synced and jetted. So talk to me about the washers...how thick? I would guess a diameter large enough to cover the spring...

I'm a pilot, an engineer's worst enemy. I figure out ways to undo your hard work in seconds.

-Michael

 

Yeah, 9k in 6th on public roads is probably not something we want to talk about too much around these parts.

Just bear in mind, at those kinds of speeds, the bike is shifting an enormous amount of air, as it comes up to maximum torque any weakness in the drive train will be exposed.

Of course maybe one alternative; might just be, to maybe not go that fast on public roads?

I know it's a cop-out option, but when I see the behavior of foreign rental car drivers around here; I have learned to treat every blind corner or brow as a potential killer.

OK, boring old fart advice over.

But I didn't get to be a boring old fart without recognizing some of the dangers involved in being a biker.

 

Thank you for the advice. If we could shift back to the clutch questions...

 

Nah I'm a production engineer, meaning I've run CNC and manual machines. Always figured to be a good engineer you had to have some hands on experience. Anyways you know what I'll see what I can find out and what would be best. Even might post photos results,btw FYI while trained to use mpa & NM I prefer psi and ftlbs. Guess it's an American thing lol.

(And hopefully there won't be a debate about Honda knows best. Sorry to say physics is the same for every one big or small.)

 

Okay limited by the clutch hub and spring. Since it's aluminum, I could be wrong but mine feels and weighs as if it's aluminum. The thread Honda used (m6x1.0) with the aluminum is ~9ftlb torque(ref 3000lbs clamping force) is max normally(oil in the threads) they are set to 6ftlbs (ref 2000lbs clamping force). That's from the service manual (read closely it's 9NM which is 6ft). At 9 ftlbs or more you risk the bolt failing; but could try 8ftlbs (10.8nm). That being said that would increase the clamping force from ~2300lbs to ~2800lbs.

Optionally and better(simpler) is using a 316L SST spring. Which would be ~23% pressure increase. But would cost more and wear faster.
Btw it would be 2.5-2.6mm wire diameter 20-19mm OD, 47mm free length, 8 coils.


C0850-098-3000-X is the spring you're looking for and it's about 14$ a piece.

alternatively you could add in 96475K238(mcmaster) between the head of the bolt and the washer which will increase the preload. In theory increasing the applied force and while not relevant to this less time between engagement.

So far the best thing is applying 8-9 ft-lbs and adding in a belleville washer. Most extreme is to change the threads from M6x1.0g6H4 to 5/16-24 UNEF-1B(2B) whiching increases your clamp load to ~4000lbs(13ft-lbs) along with adding in belleville washers. But that would be one hell of a fist pump like riding a Harley (SS of course). But combined with clutch-less shifting may give you the results you want but may cause premature failure of the clutch hub if stressed for to long. So many Varibles but main issue is that clutch hub the and the torsion stress. Maybe could change the clutch basket out with a yamaha R1 which has 6 points instead of the 5 points (Sorry going off on a tangent). Anyways, you being a pilot i only assume you know a few engineers, could ask them to confirm about the extra torque on the bolt and adding in belleville washer.

(edit; Also could retap as M8x1.0 and buy matching M8x25 bolts and torque down to 11ft-lbs and add in 1/16" copper washer. All this just the same will affect the friction plates, causing a possible premature wear. Sorry so many variables, when we change one things it affects another and my mind is calculating all the factors even down the added stress on the bearing to case. Most often it's the male post with the female threads that fail from the torque. if we had some way to reinforce them the possibilities are quite extraordinary i think. Even setup a dual pressure environment allowing for engagement to be at a higher pressure but when the clutch lever is in a collapsible spring wash would alleviate the need for such stain.)

 

Anyways clean the threads really good make sure they have as little oil on them as can be.
(the internal thread will have oil in them which is fine this lowers the k factor to ~.15 vs ~.12 for both threads having oil)
A ~1/16" washer
McMaster-Carr
under the head of the screw but before the original washer. (should now have a bolt + new washer + old washer + spring into hub into clutch basket)
Torque to 9 ft-lbs.

As i do not know the condition of your bike i do not assume liability for anything. But all information is based on material properties (grade 8 bolts, beryllium copper springs, sst washers, & aluminum alloy hub) and T=k*F*D thread properties there should be no problems.

(And fyi a 1/16" washer will give an ~9% increase in pressure on the spring.)

 

Fatigue reports for fun to add into my portfolio, something different then the stuff i normally do
(Reference only as the information is from simulation studies)
https://drive.google.com/folderview?...Wc&usp=sharing

Ouch adding a 1/16th washer drops the usage down to 30,000-50,0000 life cycle. Wear starts only after ~5400 cycles, probably why only racers do it they can afford to replace springs after each race. You'd be lucky if the springs last more than 4 months. Best to buy better springs lol.