Shifter arms

[Shipper]

Just beginning my total rebuild of the original bottom end so that I am able to match serial numbers with frae on my '75 650xs that I have been riding extensively with a top notch second engine bought five years previous. (see pic). I found some excessive wear in the jaws of #5 arm and ordered what I thought was a legitimate replacement on line to find that there are subtle differences. First, the numbers do not indicate #5 but #6 with a 256-1 indicator above. Second,, the face of the original arm has a distinct profile around the opening for the drum whereas the replacement is shaved clean. Other than that, they appear exact. Anybody know if that is going to be a problem if I use it in #5 position?

In addition, my #4 arm also shows jaw wear, anyone know where I can find a good one?

Thanks,

OK, not often I'll post a thread and get no response at all - first time for everything. So I need your input and I'll try it this way.

Attached are pics of the shifter forks I'm dealing with. The one with the most meat on it is the one i mention above with the *#6 on it. The super worn one is the number 5 i'm trying to replace (no luck anywhere so far) and the other is the number 4 which I think is still of useable quality. If I can't get replacements and if the popular opinion is that these are not of any use, I guess Im screwed.

 

[Shipper]

 

[spungle]

Hello, for reference from a spare engine. the number 6 looks very different near the hole for the shift drum to number 5. The machined part dimension of your #6 is completely different to #5.

The numbers 256-X (1,2,3) are the indicator on which place it should be. the other numbers (your mentioned #5 and #6) are often different from gearbox to gearbox.


I've read somewhere the top end which engages the dogs are in spec if they are minimum 4,9mm thick. English is not my best, sorry... good luck

 

[Shipper]

Thanks Spungle - how many euros for those three forks?

 

[gggGary]

I have a tranny or two in the bins, help me out with good pics marked as to what you need? You might try @lakeview too, he's north of the cooty wall.

 

[spungle]

Sorry shipper, but this bottom end is my winter project, not to sale.

 

[Shipper]

Sorry shipper, but this bottom end is my winter project, not to sale.

I have a tranny or two in the bins, help me out with good pics marked as to what you need? You might try @lakeview too, he's north of the cooty wall.

Hey G's, great to hear from you on this project. The forks are from the tranny on a 650xsB 1975 (447 variety) and the 4 and 5 have significant wear with the five being the worst. I am really interested in obtaining forks that will serve the purpose in my rebuild so if you have those available, I'm definitely interested.

The pics below show best possible profiles/wear etc. As you hopefully can determine, the wear is significant with #5 being the most severe. Let me know if more info/pics are required to ensure a match. Thanks again for getting involved, always appreciated.

Shipper

 

[gggGary]

At least that one is kinda worn looking, all the others look fine, just polished not worn.

 

[Shipper]

Thanks Gary. Just another example of my inexperience but every event is a learning experience. So, I was more concerned about the "inner" surface wear as opposed to the tip of the arm thickness. The smallest reading I get on the #5 fork (most worn) is 48.2mm. Are you advising that regardless of the inner wear, the tip of the arm thickness is sufficient for proper operation? In hindsight it actually sounds right. (Sorry about the poor lighting).

Thanks again,

 

[gggGary]

just got a set of shift forks from another motor back they LOOK brilliant but need to look them over.
We prolly need to look into "bent" also that has always been a "popular" tranny problem.

 

[spungle]

Sorry, have written it wrong. The shifter forks should be thick 4,7 not 4,9mm. Have it from this german blog:http://www.cco-classicracing.de/motorradumbau/xs650-motor/xs650-motor-instandsetzung/

But couldn't find another reference to crosscheck this. Is there another known reference to this value?

 

[gggGary]

I still need to do some more checking have two sets of forks on the bench now. Looks like the one marked in red is thin/bent. The rest seem to all measure <> 4.85mm

 

[Shipper]

Sorry, have written it wrong. The shifter forks should be thick 4,7 not 4,9mm. Have it from this german blog:http://www.cco-classicracing.de/motorradumbau/xs650-motor/xs650-motor-instandsetzung/

But couldn't find another reference to crosscheck this. Is there another known reference to this value?

Holy crap Gary - that blog you sent is exactly what I've been looking for - but i don't speak German. Is there a translated version somewhere?

 

[Shipper]

Holy crap Gary - that blog you sent is exactly what I've been looking for - but i don't speak German. Is there a translated version somewhere?

Sorry Gary - my mistake, that blog came from Spungle - not you.

 

[Shipper]

Sorry, have written it wrong. The shifter forks should be thick 4,7 not 4,9mm. Have it from this german blog:http://www.cco-classicracing.de/motorradumbau/xs650-motor/xs650-motor-instandsetzung/

But couldn't find another reference to crosscheck this. Is there another known reference to this value?

Hey Spungle - would really like to see that blog in english - any possibility it has been translated somewhere?

 

[Shipper]

just got a set of shift forks from another motor back they LOOK brilliant but need to look them over.
We prolly need to look into "bent" also that has always been a "popular" tranny problem.

Gary, my thinnest arm tip (number 5) is showing 4.72mm. From what I'm getting, they should be ok for use. Again, my concern was the inner curve wear which apparently is not a concern. Do you agree? Plus still interested in what you have on the bench if mine are not serviceable.
Thanks,

 

[gggGary]

Well with two sets on the bench all but the one showing obvious wear are 4.8(2-7) that worn looking one 4.68ish My suspicion would be a messed up shift bent the fork a bit, forcing one face into constant contact with the side of the slot in the gear. Guess I gotta take a better look in the slot also.
Note how the shift forks are hard chromed out there. Once the chrome is gone, wear will accelerate.
Couple comparo's tween a normal and that worn one.

 

[spungle]

Hey Spungle - would really like to see that blog in english - any possibility it has been translated somewhere?

You can try deepl.com to translate. Just copy and paste the text. Deepl is a fine tool to translate...

This blog is my only source of this 4,7mm. I love to know if this is mentioned elsewhere in a service bulletin or manual. But the main failure you should look for are wear and bent like gggGary mentioned.

 

[gggGary]

Google translate did a good job on making that readable.

 

[Shipper]

Well with two sets on the bench all but the one showing obvious wear are 4.8(2-7) that worn looking one 4.68ish My suspicion would be a messed up shift bent the fork a bit, forcing one face into constant contact with the side of the slot in the gear. Guess I gotta take a better look in the slot also.
Note how the shift forks are hard chromed out there. Once the chrome is gone, wear will accelerate.
Couple comparo's tween a normal and that worn one.

Holy crap Gary, really appreciate the input as always but fact is - my forks look new compared to these pics. Again, I was more concerned about the "inner curve" wear as opposed to the tip thickness. Again, the minimum thickness I have on the worst worn fork is 4.72 mm. From everything I'm reading, that should be adequate, no? What's your opinion?