Japanese manufacturers, can we have an honest conversation about your chain guide mounting please?

Nate_Ferderer 2/19/2020 11:59am
2/19/2020 11:59am
Bret wrote:
The manufacturers definitely have the expertise to mount the guide better. That makes me think that the minimal welds were intentional. This would allow the guide...
The manufacturers definitely have the expertise to mount the guide better. That makes me think that the minimal welds were intentional. This would allow the guide to break off and cause zero damage to the swingarm if it made contact with or got caught on something. If the welds were stronger and the guide beefier, the damage could be transferred to the swingarm instead, resulting in undetected cracks or deformities since the guide remained in place. The engineers are pretty smart. I doubt that this is something that was done for cost savings or something they simply overlooked.
You're implying the guide brackets are designed to break away from the swingarm rather than build them stronger and have some 'worse' failure mode to the swing arm? Both failure modes result in a junk swing arm. If it were the chain guide breaking away, I'd buy into this logic. As stated above, it isn't only a Japanese welding issue, it also happens to Euro cast mounts. Surely these parts went through an FMEA, but I don't work for these companies and can't speak for the designers. As a design engineer, my opinion is the guide bracket is not designed to break away to prevent an alternative failure mode. We don't know the truth and that's why we can argue about it on the internet Sideways
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FWYT
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FWYT 2/19/2020 12:01pm
2/19/2020 12:01pm
TKL965 wrote:
I'd almost consider doing a 3d printed bracket the wraps around the swing and incorperate a guide into that, have the whole thing just bolt on...
I'd almost consider doing a 3d printed bracket the wraps around the swing and incorperate a guide into that, have the whole thing just bolt on in 2 halfs? be cheaper and more cost effective than maching something out of billet. thats if you can get a hard wearing plastic? food for thought
I've thought this might be a good solution, as well. Something that wraps around the swingarm. Probably would not
win a beauty contest but NFG.
JM485
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JM485 2/19/2020 12:25pm
2/19/2020 12:25pm
Bret wrote:
The manufacturers definitely have the expertise to mount the guide better. That makes me think that the minimal welds were intentional. This would allow the guide...
The manufacturers definitely have the expertise to mount the guide better. That makes me think that the minimal welds were intentional. This would allow the guide to break off and cause zero damage to the swingarm if it made contact with or got caught on something. If the welds were stronger and the guide beefier, the damage could be transferred to the swingarm instead, resulting in undetected cracks or deformities since the guide remained in place. The engineers are pretty smart. I doubt that this is something that was done for cost savings or something they simply overlooked.
If that their line of thinking then someone needs to have their head examined. One of the times I had this happen was at an EX race (yes I understand that’s a little tougher on them than a moto track, the issue is the lack of thought and effort here), and it happened right on the landing of the big finish line jump, taking out my rear hub as it wrapped its way around the rear sprocket and brought me to a sudden halt. Had this happened on the takeoff I might have an extremely different story to tell that doesn’t have a very happy ending.

Obviously nothing is perfect and there will always be failures from extreme events, but for anyone to honestly sit there and think that how they mount these things is adequate is either blind or delusional. The fact that it’s been going on like this for so long is just mind blowing to me.
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JM485
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JM485 2/19/2020 12:28pm
2/19/2020 12:28pm
TKL965 wrote:
I'd almost consider doing a 3d printed bracket the wraps around the swing and incorperate a guide into that, have the whole thing just bolt on...
I'd almost consider doing a 3d printed bracket the wraps around the swing and incorperate a guide into that, have the whole thing just bolt on in 2 halfs? be cheaper and more cost effective than maching something out of billet. thats if you can get a hard wearing plastic? food for thought
FWYT wrote:
I've thought this might be a good solution, as well. Something that wraps around the swingarm. Probably would not
win a beauty contest but NFG.
For an extremely vulnerable part like this I have my doubts about being able to print something strong enough. I may just take another posters advice and buy the bulletproof mount, I didn’t realize at first that they made a YZ version so that would be the easiest route. We’ll see, when I get the new swingarm in the next couple days I’ll decide if I want to design my own mount or just use what’s available.
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soggy
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soggy 2/19/2020 12:43pm
2/19/2020 12:43pm
8tensolutions wrote:
Not to change the subject, but this is a great example when someone asks why a high end MTB costs as much as a moto. It's...
Not to change the subject, but this is a great example when someone asks why a high end MTB costs as much as a moto. It's amazing how "cheap" some things are on motos whereas other pieces are F1 level. It's all about controlling costs where they can.
The first thing that came to mind when i saw this was is a narrow wide style that has become ubiquitous in MTB would work in a similar fashion for rear sprocket?
Bret
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Bret 2/19/2020 1:35pm
2/19/2020 1:35pm
Bret wrote:
The manufacturers definitely have the expertise to mount the guide better. That makes me think that the minimal welds were intentional. This would allow the guide...
The manufacturers definitely have the expertise to mount the guide better. That makes me think that the minimal welds were intentional. This would allow the guide to break off and cause zero damage to the swingarm if it made contact with or got caught on something. If the welds were stronger and the guide beefier, the damage could be transferred to the swingarm instead, resulting in undetected cracks or deformities since the guide remained in place. The engineers are pretty smart. I doubt that this is something that was done for cost savings or something they simply overlooked.
Or maybe it is just not an issue. Other than the photos in this thread I have never seen one broken off. Honestly, I am very surprised that radiators and rotors and levers survive tip overs and crashes as well as they do and they are far more exposed than the chain guide. Until one of us talks to the swingarm engineer we may never know.
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FWYT 2/19/2020 10:45pm
2/19/2020 10:45pm
HondaMan66 wrote:
Anyone have a pic of the Bullet Proof Designs swing arm guard installed?
Here you go. This guy has wiped so many chain guides off of swingarms in Baja that he keeps an inventory of good, used swingarms (sourced when a good deal pops up on Craigslist or eBay) on hand ready to swap out. So far no failures with the Bullet Proof guard. So far!!!!! Laughing Laughing Laughing




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kkawboy14
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kkawboy14 2/20/2020 7:47am
2/20/2020 7:47am
Rotaholic wrote:
You are running an after market chain guide, the foot pegs are worn flat, you modified the front case saver and never put in shorter bolts...
You are running an after market chain guide, the foot pegs are worn flat, you modified the front case saver and never put in shorter bolts, lower linkage looks like its never been serviced and I doubt the wheel is tracking straight. I've never seen that before, but can now see how it could happen lol
MxKing809 wrote:
Cool story Bro..... try again [img]https://p.vitalmx.com/photos/forums/2020/02/19/405282/s1200_84DA2E85_667E_45CB_AB05_9CCB50F9A275.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2020/02/19/405281/s1200_0AFFEE6F_CB85_4DEE_9034_13C29A36062B.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2020/02/19/405279/s1200_208093F7_4065_4BE0_B5F3_AA3C6ECA25FD.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2020/02/19/405280/s1200_C113D1D6_495F_4F7C_B223_9393EBF9475E.jpg[/img]

Cool story Bro..... try again





Rotaholic wrote:
Have you ever thought about not casing those doubles and clearing them instead....
😂
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MxKing809
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MxKing809 2/20/2020 9:43am
2/20/2020 9:43am
MxKing809 wrote:
Cool story Bro..... try again [img]https://p.vitalmx.com/photos/forums/2020/02/19/405282/s1200_84DA2E85_667E_45CB_AB05_9CCB50F9A275.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2020/02/19/405281/s1200_0AFFEE6F_CB85_4DEE_9034_13C29A36062B.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2020/02/19/405279/s1200_208093F7_4065_4BE0_B5F3_AA3C6ECA25FD.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2020/02/19/405280/s1200_C113D1D6_495F_4F7C_B223_9393EBF9475E.jpg[/img]

Cool story Bro..... try again





Rotaholic wrote:
Have you ever thought about not casing those doubles and clearing them instead....
kkawboy14 wrote:
😂
I don’t get it. What jump did I case?
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soggy
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soggy 2/20/2020 9:50am
2/20/2020 9:50am
Rotaholic wrote:
Have you ever thought about not casing those doubles and clearing them instead....
kkawboy14 wrote:
😂
MxKing809 wrote:
I don’t get it. What jump did I case?
these morans think you can hit the chain guide casing a jump Pinch
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jeffro503
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jeffro503 2/20/2020 10:06am
2/20/2020 10:06am
FU2 wrote:
Better ask the question, why and how does this happen to u and not to any one else. Is it a yahama thing or just a...
Better ask the question, why and how does this happen to u and not to any one else.

Is it a yahama thing or just a rider thing or just bad luck...

Well searching for parts can be fun so have fun with it sir..
I have seen 2 brand new Yamaha's get their guides ripped off. One of them , was within the first 15 mins it had ever been ridden on a track. The welds had not even penetrated the swingarm at all. The guiode had the weld attached , and like Josh mentioned , it looked bird shit. Yamaha shop replaced it that very same day after they pulled one right off a brand new bike. Bike was a 2017 YZF450.
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Jeff_Crutcher 2/20/2020 8:06pm
2/20/2020 8:06pm
When I rode Kawi’s my chain guide was an absolute liability every 5th ride. Switching to the TM Design helped. Never had this problem on KTM.

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