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I picked up a bike that had a terrible vibration from 1500-2900. It didn't smooth out till 3K! It finally sheared one of the bolts that attach the motor mount to the frame and broke my exhaust into 3 pieces. I went down and bought the new Harley-Davidson C style motor mount to replace the alloy Art. When I pulled the AA I notice it had a 1/2" center sleeve for the motor mount bolt but whoever installed it used the stock 3/8" bolt. I emailed Alloy Art and they said it probably should be a 1/2" bolt...lol. Probably? Anyway, the stock Harley motor mount cleaned the problem up.
Just a heads up and was wondering if anyone else has experienced this?
 

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I just replaced my front mount on 1985 FXRS, I assumed it was the original.
But the old one and the new one had the 1/2" bushing in the mount. The old mount had a 3/8" bolt, I installed a new 3/8" bolt with a heavy thick under the head.
I wonder if I should go replace it with a 1/2" bolt, or if it is supposed to have the 3/8", even though it is a 1/2" bushing???
 

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My 1999 FXR2 motor mount had a 1/2 bushing and a 3/8 bolt. When I started experimenting with motor mounts, I changed to a 1/2 bolt. However, my factory parts manual specified a 3/8 bolt, so I went back to that size. I never saw that the bolt size had any effect on vibration. Cinch either one too tight and you’ll feel more vibration, but it’s not the bolt size. Every motor mount I’ve had (HD, Glide Pro, Kinetic Structures, Drag Specialties) all had 1/2 bushings.
 

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I've had a few motor mounts on my '85 FXRS over the years. I bought her brand new so I know everything she's ever had. Currently running Kinetic Structures, and love it. ALL have used a 3/8" bolt. One thing I would add to the conversation regardless of which mount you choose is to make sure that all the other mounting points on the bike are in good shape and everything is properly aligned. Before you torque it down, that 3/8" bolt should slip up and down in the mount without resistance.
 

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One thing I would add to the conversation regardless of which mount you choose is to make sure that all the other mounting points on the bike are in good shape and everything is properly aligned. Before you torque it down, that 3/8" bolt should slip up and down in the mount without resistance.
True. I might add Glide-Pro recommends loose installing the front mount then starting the motor and running it for a couple of minutes to allow everything to find its’ place, (Alignment) then shutting down and torquing the fasteners in place. Easy on the center bolt. I have found this to be a valid procedure, no matter whose mount is being installed.
I too, have a Kinetic Structures mount in place at the moment (about a year, now) and am having good results. I’m thinking, hoping that it might last longer with less degradation over time due to its construction.
 

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In talking with guys that have used the Alloy Art, it's more show than go.
I have no experience with the Alloy Art product, but have to admit..it is a pretty thing, that's for sure.
Of course..I don't know how often I've ever had folks squat down to admire the beauty of my front motor mount..!! :rolleyes:
During installation, more than just idling the motor with the center bolt loose, I tightened mine to a little less than "finger-snug", no more...and rode the bike around the block, doing a few gentle starts and stops along the way. Found the bolt still loose when I got home and then torqued it down.
FWIW: I've only run 17,000 mi on my Kinetic Structures SS-mesh front motor mount, but will say that so far...it's doing just great.
 
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