On the road again at 40.............the bike that is

Excellent front guide comparison there, robinc. This thread has the links to y'all's guide discussions, including the SR500 front guide, and discussing re-angling the newer guide for the early XS1 tensioner system, which would be better if done on the OEM guide, due to the better bolt angles...

http://www.xs650.com/threads/front-cam-chain-guide-wear-out.50727/
 
Thanks 2M.

And, thank you for posting that link. Lots of great info in those threads and albums. Much appreciated!
 
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Nice comparison study, Robin !
Glad you were able to get yourself an OEM guide.
This is all relevant to me, as I'm in the midst of the teardown and inspection of my '78 engine which I got with that $100 barn find (with 15k on the odo) last year.
A quick look at the guide in the cylinder before closing up shop last night seem to reveal it was OK , but I just now pulled it off, and it seems to be toasted:
78 Teardown 003.JPG


Therefore, I'll be interested in what Jim has to show us when he gets his today from Mike's.
.
 
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As far as I can see, there are two issues with the Mikes part:
  • The angle & depth of the holes (which could possibly be fixed by drilling them out to a larger size (likely 8mm) and re-tapping);
  • The hardness/durability of the slipper pad material.
The second issue is, in my view, more of a challenge. If the new pad wears faster than the OEM, then you’d be right back where you started in short order. OTOH, the Mikes part might be just fine for the occasional Sunday morning ride at moderate speeds etc.

I wonder if setting the timing chain a teeny bit loose would help it survive...

Given all of that, I like the notion of checking out one of the SR/XT 500 parts with an appropriate mounting spacer. It will have the corrrect pad mat’l and if the geometry is correct - it ought to work like new.

Has anyone checked the guide from an XS400, XS750/850 triple or even an XS11 (although, the bigger multis may have used a Hy-Vo timing chain). Simple parts like chain guides may have been recycled.

Pete
 
Thanks Dude. Ya yours has sure suffered the all too common problem of the rubber face delaminating. Hopefully Jim finds evidence of a better batch in the U.S.

On my old one the face appears to be intact (except for the wear grooves) and still adhered well.
A piece of the raised edge at the top broke off when I removed it, and that edge is loose and ready to break off for about half of it's length.

IMG_20180323_173434.jpg


IMG_20180323_173247.jpg


This part might still be usable in spite of not having half of the right side raised edge. I'm not sure. But If the edge is coming away I wonder how long before the rest does as well?
While it wasn't cheap, I figure putting in a new part is a lot cheaper than having to tear it down again, including the time involved, if that old one kept failing.

Got everything I need now to put er back together.......except for warm weather!
 
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MaxPete said:
As far as I can see, there are two issues with the Mikes part:
  • The angle & depth of the holes (which could possibly be fixed by drilling them out to a larger size (likely 8mm) and re-tapping);
Click to expand...

Yes I guess that would be a possibility Pete if one has the equipment to ensure the correct angle is maintained. Or use helicoils if there is enough wall left there after drilling?

MaxPete said:
  • The hardness/durability of the slipper pad material.
Click to expand...

Back in post #699 5twins mentions us finding a way to repair the originals. That would certainly be the best solution.
I'm sure getting the remaining rubber off of these wouldn't be too difficult on most of them but how can we then reface them?
Maybe someone who knows industrial coating products would be aware of something that could be applied as a new facing material?

I'm also wondering, IF the cam chain is properly adjusted and maintained, how much rubbing/wear would the guide receive?
Or, does the chain continually rub against the guide?
 
I don't think the chain rubs hard on this thing. I've never found one worn through or even badly worn. Some show virtually no rub marks at all. They just seem to fall apart. Apparently it's not easy to bond rubber to aluminum. The SR's guide bracket is steel and like I said, I've never heard of one failing. Bonding rubber to steel must be easier and work better.

I've been giving more thought to adapting one of these and the bracket or mounting block required. Here's a pic from 2M's album showing the SR guide atop the XS one. I've drawn in a simple mounting block. The mounting tabs on the SR guide could both be shortened a little bit and the top one bent in to mate with the mount .....

FrvEkS1.jpg
 
robinc said:
Back in post #699 5twins mentions us finding a way to repair the originals. That would certainly be the best solution.
I'm sure getting the remaining rubber off of these wouldn't be too difficult on most of them but how can we then reface them?
Maybe someone who knows industrial coating products would be aware of something that could be applied as a new facing material?
Click to expand...

I'll betcha somebody in the industrial community has a process that can do this. Cam timing chain slipper pads were a problem on many bike models for many years in the past - and yet, now, they don't seem to be a big deal (at least in the auto industry) and so someone has sorted this out.

A chain is a chain and so what works for one engine should work for any other.
 
5twins said:
I don't think the chain rubs hard on this thing. I've never found one worn through or even badly worn. Some show virtually no rub marks at all. They just seem to fall apart. Apparently it's not easy to bond rubber to aluminum. The SR's guide bracket is steel and like I said, I've never heard of one failing. Bonding rubber to steel must be easier and work better.

I've been giving more thought to adapting one of these and the bracket or mounting block required. Here's a pic from 2M's album showing the SR guide atop the XS one. I've drawn in a simple mounting block. The mounting tabs on the SR guide could both be shortened a little bit and the top one bent in to mate with the mount .....

FrvEkS1.jpg
Click to expand...
A profusion of gratitude awaits the person who constructs this mounting block and produces it for us XS owners.
 
YamadudeXS650C said:
A profusion of gratitude awaits the person who constructs this mounting block and produces it for us XS owners.
Click to expand...

Indeed - and in the meantime, I will call around and see if I can find someone who can re-surface the OEM pad with a modern slipper material.

Pete
 
MaxPete said:
Indeed - and in the meantime, I will call around and see if I can find someone who can re-surface the OEM pad with a modern slipper material.

Pete
Click to expand...
Maybe Elon Musk would be interested in taking on this challenge.
Last March a 5th grader wrote to him, and he replied by twitter to the student, "Great idea!" he said.
 
OK, Mikes order is in and I must say.... I'm more than a little disappointed..... OEM part is in the foreground, Mikes new part is behind it....

1.jpg


You can clearly see that the holes are drilled and tapped way off of perpendicular to the mating face. And that's just the half of it. The part is actually cast wrong. Look at this....

2.jpg


This is the OEM part. The mount boss is cast perpendicular to the mating face as shown by the red arrows. Now look at Mikes...

3.jpg


The bosses are cast perpendicular to the guide itself. Why is this bad? Look where the red line leads....

4.jpg


If we try to drill and tap it for a helicoil or the next size fastener, we will either bust through the bottom of the boss or make it so weak that the casting will eventually shatter.
Unless I have an epiphany... this ones going back to Mikes with a strongly worded letter about the ethics of charging 36 bucks for an unusable part. There's really no excuse for this....
Modding the 500 guide intrigues me. Time to ponder....
 
JimD54 said:
OK, Mikes order is in and I must say.... I'm more than a little disappointed..... OEM part is in the foreground, Mikes new part is behind it....

View attachment 115529

You can clearly see that the holes are drilled and tapped way off of perpendicular to the mating face. And that's just the half of it. The part is actually cast wrong. Look at this....

View attachment 115530

This is the OEM part. The mount boss is cast perpendicular to the mating face as shown by the red arrows. Now look at Mikes...

View attachment 115531

The bosses are cast perpendicular to the guide itself. Why is this bad? Look where the red line leads....

View attachment 115532

If we try to drill and tap it for a helicoil or the next size fastener, we will either bust through the bottom of the boss or make it so weak that the casting will eventually shatter.
Unless I have an epiphany... this ones going back to Mikes with a strongly worded letter about the ethics of charging 36 bucks for an unusable part. There's really no excuse for this....
Modding the 500 guide intrigues me. Time to ponder....
Click to expand...
Bummer.
Thanks for posting your observations, Jim.
 
Yikes!!

Jim: that’s just sloppy - what a shame.

But - what would the prospects be of “simply” drilling the hole at the proper orientation - tap-drill size for an M8 and then tapping it? A larger thread could be torqued to hold the shoe in place more strongly even if the engagement depth was shorter.

Now, about the brass idea - the issue I see with that would be that any brass material that is worn off by the timing chain would then be floating around in the lube oil and that could be hard on bearings, piston rings etc.
 
MaxPete said:
what would the prospects be of “simply” drilling the hole at the proper orientation
Click to expand...
The problem Pete is that the boss isn't cast (oriented) correctly. If we drill perpendicular to the mating face, the hole's angled towards the edge of the boss. Not only that, the bosses are so skinny, I don't believe there would be enough metal left there if we oversize it.
 
Dangit Jim. Had my fingers and toes crossed for you. Looks like both our parts came out of the same poor quality run. Your arrows clearly illustrate what I was thinking in terms of running out of boss wall material.

Not home right now but I'll measure the available flange width to see if there might be enough material to try Paul's brass strip idea. I just don't think there's a lot of room for rivets.

If so maybe would could find a hard rubber/plastic strip to rivet or glue in place with some kind of chemical and heat resistant adhesive?
 
I am someone who believes in the effectiveness of group pressure.
If Jim sends Mikes a well-documented letter, I will follow up with my two cents on the matter.
If they get 25 messages of complaint, perhaps modifications will occur.
.
 

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