XS650 Clutch Pushrod experiment & tidbits

Did not read through the entire thread but I thought I should post this:

mikes_vs_stock_pushrod.jpg


On the left is the Mikes one piece rod after one summer (6000km's) and on the right the longer part of the original 2-piece rod (probably after 30 summers of riding). The ball bearing beetween the two rods seems to work wonders. Or the Mikes rod was not hardened?

I'll be using a two piece rod with a hydraulic actuator next summer (testing it...)

Pekka
 
I managed to snag a N.O.S. one piece rod off eBay, surprisingly for less than Mike's sells their re-pop. I will be swapping that in next season. It will be interesting to see if my Mike's rod has worn as much as yours. I've got 8 or 9K on the Mike's rod.
 
When I received my MikesXS pushrod last week, I noticed that the 'narrowed' end was eccentric, and the rod was slightly bent. During the straightening, recentering, and pre-dimpling operations, I noticed that there was no hardening of the ends like I experienced on my factory stock rod.

Made up a couple of rods from straightened 304 stainless, gave one to DogBunny to play with. This 304 stainless is a little harder to machine compared to the replacement MikesXS rod.
 
I've been using the long pushrod from Mikesxs, for the last 5 years. When I checked it a few months ago, it shows no wear that I can see, so it must be hardened. This is a pic of the original dimpling, and it still looks the same.
 

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  • Dimpling push rod and worm screw.JPG
    Dimpling push rod and worm screw.JPG
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I want to thank TwoMany for the beautiful one-piece rod that he gave me. I don't want to appear insensitive to TwoMany's thread and his great work, but I hate to admit that I am a little reluctant to use it, because I am an advocate of the two-piece. 5twins and retiredgentleman, aren't your clutches constantly going out of adjustment when your engines get hot with your one-piece rods?
I remember a post that 5twins made where he pointed out that over time the engineers tend to improve their designs by simplifying where they can, but that in the case of the push rods, they changed from a one-piece to a more complicated two-piece, so they must have had a reason?
I gave TwoMany a two-piece push rod, and will be interested to see how he likes it.
 
When I first got my bike instead of a ball inside the adjuster there was a disk, same diameter as the rod and maybe 1/8" thick. It worked fine. Might want to try it if your balls are wearing out your rods...
 
DogBunny said:
I want to thank TwoMany for the beautiful one-piece rod that he gave me. I don't want to appear insensitive to TwoMany's thread and his great work, but I hate to admit that I am a little reluctant to use it, because I am an advocate of the two-piece. 5twins and retiredgentleman, aren't your clutches constantly going out of adjustment when your engines get hot with your one-piece rods?
I remember a post that 5twins made where he pointed out that over time the engineers tend to improve their designs by simplifying where they can, but that in the case of the push rods, they changed from a one-piece to a more complicated two-piece, so they must have had a reason?
I gave TwoMany a two-piece push rod, and will be interested to see how he likes it.
Click to expand...

I've used the stock 2 piece rods(aluminum with steel tips) , and I now use the Mikesxs single long steel rod. The 2 piece rods are much better at staying in adjustment, but they have more wiggle and the bushing does eventually wear and need replacing.

The single steel rod, after 5 years use, has no wiggle and still feels very tight in the bushing. This keeps the pushrod seal from leaking oil. Yes, because of the expansion difference, I have one adjustment of the adjustment nut at the lever, when the engine is first started (cold), and a second adjustment when the engine is hot . As the engine heats up, the free play increases at the lever, and I simply readjust to keep the freeplay at about 1/16". I do this while I'm riding.

The perfect pushrod would be a one long piece rod made of aluminum, with steel ends.

A case could be made to use the 2 short pushrods, and when the outer rod starts to wiggle to much, its time to replace the bushing. If the bushing replacement was only needed every 8 to 10 years, then that would be a good trade off to allow using the 2 short rods.
 
I'm not sure why Yamaha went to a 2 piece rod on the 650. They used a one piece alloy/steel rod on the XS500 which you would think is the best of both worlds - long rod to ease bushing wear and alloy to expand the same.

When I got my 650, of course it needed a new pushrod seal. The new one leaked as bad as the old one because the bushing was worn. Even with a new bushing, the short outer rod still wiggled side to side quite a bit (that was new as well). The bushing and seal cured the leak but I figured it wouldn't be long before the new bushing wore a little and it started leaking again. I put the long rod in and that was nice and solid with no wiggle.

I set my adjustment very tight cold with pretty much zero freeplay at the lever. As soon as the bike begins to warm up, freeplay develops at the lever. This way, I don't have to fool with the adjuster at the lever and do different hot and cold settings.
 
I suspect the one and two-piece wiggle about the same when one end is trapped in the worm gear assembly in actual use. The rod flops all over without the case cover on, but it isn't going to do that once the case cover is on.
 
retiredgentleman and 5twins, thanks for answering.
5twins, good strategy on the adjustment. Will try it when I use the one-piece rod that TwoMany gave me.

xjwmx, I pretty much think the same thing, within limits. I think there is a greater "buckling" effect with the short rod.

I also think that that some of the slop in the worm gear assembly and some of the slop in the rod is necessary for the rod to find its alignment with the worm gear ball bearing.

Regarding bushing wear, I think there is a trade-off. The one-piece probably rubs less. However, it spins in the bushing, while the two-piece shouldn't.

In any case, I view periodic bushing replacement as inevitable maintenance, like changing oil. I've done it enough times that it is now no big deal. I have a bunch of the longer McMaster-Carr bushings, and look forward to trying them.
 
Check the "wiggle" on your short rod before and then after installing the longer bushing. Who knows, maybe that extra 2mm will add support and reduce it.
 
I have my doubts that the wiggle in the actuating rod has anything to do with a worn bush.
My feeling is that it is the worm mechanism being off centre with the axis of the rod that will wear the bush and oil seal.

The worm mechanism is fitted to the crankcase cover and then the cover is fitted to the crankcase but the centre of the worm is never aligned with the axis of the clutch actuating rod.

If the centre of the worm is slightly excentric with the axis of the rod then the end of the rod will wear one side of the bush and oil seal more and be a source of friction on the Rod and bush.

It might be interesting to experiment with a clutch actuating rod that had the worm braized to it and the worm mechanism fixed to the crankcase instead of the cover . If the worm mechanism was inline bored and matched to the crankcase or had alignment pegs to locate it accurately when fitted , it should reduce friction and wear considerably and make for a smoother operation.
 
When I first got my bike the bushing was extremely worn compared to the Mike's that I eventually replaced it with. There was no leaking. Somebody had replaced the seal.

So I wonder if a worn bushing really contributes to wearing the seal out. Seems like a bunch of intuitive hunches and no real evidence. Sending the poor bushing to jail when it's innocent :)
 
peanut said:
My feeling is that it is the worm mechanism being off centre with the axis of the rod that will wear the bush and oil seal.

The worm mechanism is fitted to the crankcase cover and then the cover is fitted to the crankcase but the centre of the worm is never aligned with the axis of the clutch actuating rod.

If the centre of the worm is slightly excentric with the axis of the rod then the end of the rod will wear one side of the bush and oil seal more and be a source of friction on the Rod and bush.

It might be interesting to experiment with a clutch actuating rod that had the worm braized to it and the worm mechanism fixed to the crankcase instead of the cover . If the worm mechanism was inline bored and matched to the crankcase or had alignment pegs to locate it accurately when fitted , it should reduce friction and wear considerably and make for a smoother operation.
Click to expand...

Bingo! My thoughts exactly. I fitted a 12" rod, then the sidecover (minus worm), to see if making an alignment jig would be worthwhile. But this would have to be done on each bike, on an individual basis, in a way that would be do-able by any owner. AND, accomodate the worm sloppiness. My brain fried, and decided that an undimpled flat/square adjuster screw was best for now.

Something else to consider, the pushrod seal is fixed to the crankcase, but the bushing rotates with the mainshaft. The only time the mainshaft isn't turning is when the bike is in gear, clutch pulled, not rolling. Even in neutral, clutch pulled, the mainshaft may be rotating...
 
xjwmx said:
So I wonder if a worn bushing really contributes to wearing the seal out. Seems like a bunch of intuitive hunches and no real evidence. Sending the poor bushing to jail when it's innocent :)
Click to expand...

Another good one! The exposed pushrod gathers grime, and being plain steel, rust. That's gonna cut into that seal too. When I get around to making the experimental bi-metal rod, the outer portion will be 304 stainless, polished.

The pushrod only moves no more than 2mm, could also try a spring-loaded sheath, to keep it clean...
 
rockhead said:
I've never seen this one done before.
Click to expand...

The left cover looks like a mirror, but the right cover looks like mine...

but I'm determined to get somebody to polish mine next time I have the right one off. There's a polishing and powder coating place down the street.
 
I'm curious about something. On my bike, the first clutch pull in the morning has a little catch in it. Builds up tension and then lets go. It's always just the very first pull and it's always there, and it's always been that way. Something is settling in overnight, just for that first clutch pull.

It's been there through many changes, so I wonder if it's universal? It's been there through a new cable, through a new lever, through filing on the lever to smooth it on the cable, through a worm gear disassembly and regreasing, through a bushing change and a seal change, through many cover removals,

I don't consider it a problem but I wonder if anybody knows what I'm talking about...
 

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