In a previous thread I made about clearence issues in the clutch (solved by dave, the hub face had worn away) I was left with some questions about the pushrods.

Specifically, why do we have three different lengths? it's my understanding that the middle length rod is what the bike comes with stock, and it seems to be at this point understood that using the shorter pushrod can compensate for plate wear -- in my case, i was compensating for clutch hub face wear. But under what circumstances would someone want to use the longest rod?

I've contacted Suzuki corp. directly, at least the western devision of suzuki, and they could not give me an answer. I've asked every gearhead I know around my area what they think and have not been able to find any answers.

Any ideas?

Dave,

This makes sense and I think you're correct once again but it seems problematic to me that you pretty much need to bolt the thing back up to find out if you have the correct rod for whatever aftermarket pack you're installing. It's generally just frustrating this isn't in the clymers book but I guess that's why we have this forum!

In some of the older forum posts about the rods and people trying out different rods there seems to be mixed reports of longer rods keeping the clutch in the sweet spot, I'm guessing there's factors at play people haven't fully communicated at the time.

By this point, haven taken the thing apart and put it back together more times than I can count I feel very confident the shorter rod compensates for wear when the arm is nearing or below the bottom indicator mark, it seems plain as day.

What surprises me about the hub wear I've had is that I haven't found me tion of it anywhere else in the forums. I'm guessing because I'm year round daily driving in stop and go city traffic holding the clutch in I was more prone to hub wear than others may be, as the hub face/pressure plate should only really be wearing when the clutch is disengaged/partially engaged.

Fun puzzle overall

Vers,

From my perspective: as the clutch disks wear, the distance between the hub and pressure plate decreases, as spring force is compressing the pack.

Where rod length comes into play is that the length of the rod, with the clutch fully engaged, can cause slippage due to the inherent pressure it puts on the plate from the cam on the actuating arm, extending the springs ever so slightly. A shorter rod puts less pressure when fully engaged than the longer rod. This is evidenced by, when the arm is below the indicator marks on the clutch cover and nearing the bottom mark, a shorter rod brings the arm back towards the middle point of the marks. A longer rod would force it down below further the bottom mark.

Now I do think under normal circumstances, as the clutch wears the arm should always be between the two marks on the clutch cover, and I don't think anyone should need necessarily to use a rod other than the middle length unless something weird is going on -- in my situation, clutch hub wear led to me putting the shorter rod in, which fixed the slip but in tandem with the over-compression of the worn hub along with shorer rod had the spring bolts came in contact with the actuating arm inside the cover causing a buzzing sound and also for the bolt heads to start wearing down. I bought a new clutch pack and put the middle rod back in which fixed the interference issue but now the clutch was slipping worse than ever before because in the time I used the shorter rod the hub continues to wear. This is when Dave pointed out the possibility of a worn hub or pressure plate and I found that he be correct upon inspection.

I'm now back to the middle length (stock) rod, new hub, new plates and no slippage.

Want to point out I'm using Barnett clutch disks, metal disks and springs. Which may have contributed in some way to the above.

Wow that's a way more succinct explanation than the novel I wrote.

What dave said...

Och, my only thought is that with the new clutch pack and shortest rod, the clutch would have difficulty disengaging -- you can test this by putting it in gear and holding the clutch lever down, if it's pulling, it's not disengaging fully because the shortest rod is not allowing the pack to separate fully. I think with a new clutch pack you should be using the stock (middle length) rod or perhaps even the longer one.

If the clutch is disengaging fully, I think there may be something else going on with either the transmission or possibly the shift lever or perhaps the clutch was assembled incorrectly.

Just my 2 cents.

Well, truthfully I don't think there's a direct answer to that question because it's based on how the clutch is wearing. For instance in my case, I put a brand new clutch pack in but my hub was worn pretty significantly. The shorter rod kept it from slipping and kept me on the road, but also caused the spring bolts to hit the actuating arm inside the cover because the whole pack was pushing out too much when engaged.

I think under normal circumstances only the stock (middle) rod should be used. I think there is an argument to be made about using the longer one if you get an aftermarket pack with more thickness than stock, like Dave mentioned. I think yo technically can use the shorter one if it's slipping like I did but doing so I ran into issues.

If I were in your shoes I would crack it open and put the stock rod in, along with the Barnett springs, and see if that solves it.

https://photos.app.goo.gl/VVaunN6MMh86k7Bs6

Had to make a Google link. The pressure plate face is more worn than the hub actually and this was a brand new plate because I broke a bolt off on a previous clutch replacement.

Weird right? I will say I abuse the everloving sh*t out of my bike -- every light is a drag race, lots of short trips, lots of long trips, roughly 10k miles a year in daily driving.