New Motor Mount Stiffness Causes Vibration!
bigtone, thanks for that explanation, I understand how the forces at work in that scenerio could have an undesireable effect on handlung. I actually used the Glide-Pro front mount, it is of a softer material and probably would not work in that situation with the steep shock angle. I did pay close attention to the note about aligning the center bolt, I even made an alignment dowel a few thousanths oversize so the bolt would have no binding. Great product, Sta-Bo is about the same with an additional cliam of some adjustability.
Hi guys, lots of good points made today, and Thank You. I did call Kevin at Stabo this morning and did buy his front motor mount. For $60 I'm willing to be the guinea pig.
Kevin is an enthusiastic salesman that points out the differences between his and the Velva Ride and other similar urethane units, and based on what I experienced before
(in the first 80,000 miles,) I thought I'd give it a shot. Hopefully will have it Wednesday and will install it Thanksgiving Day. I'll post everything right after.
He points out that the urethane he uses is much harder than Velva's and yet more comfortable because the sleeve isn't "attached" to the urethane. The adjustment comes with an optional extra washer placed between the mount and the big washer we all have under all our front mounts. I explained that with me commuting 20,000 miles a year down here I didn't want to be replacing his mount every 6 months. He assured me that wouldn't be the case, as it would be with units such as Velva. ( We'll see.)
As far as the strain on the mounts, I bumped the driveline forward a bit and got off the bike. I could see on the front plate where the top washer had been vs the 1/8" forward it seem to have skidded. While off the bike and no further pressure on the mounts, I tightened all 3 locations evenly.
The rear mounts still touch the "cup" in the frame, including the third ring on the new isolators. (So did the second ring on the units that I removed as the rubber had worn completely away where it had rested on the frame in that cup, exposing the steel.)
Since I'm waiting for a couple of days now, I thought I'd loosen all the bolts on the brackets and front mount and start the motor and let it find it's 'sweet spot.' Really can't see what I have to lose in trying. Thursday morning I'll go back to starting from scratch anyway!
Kevin is an enthusiastic salesman that points out the differences between his and the Velva Ride and other similar urethane units, and based on what I experienced before
(in the first 80,000 miles,) I thought I'd give it a shot. Hopefully will have it Wednesday and will install it Thanksgiving Day. I'll post everything right after.
He points out that the urethane he uses is much harder than Velva's and yet more comfortable because the sleeve isn't "attached" to the urethane. The adjustment comes with an optional extra washer placed between the mount and the big washer we all have under all our front mounts. I explained that with me commuting 20,000 miles a year down here I didn't want to be replacing his mount every 6 months. He assured me that wouldn't be the case, as it would be with units such as Velva. ( We'll see.)
As far as the strain on the mounts, I bumped the driveline forward a bit and got off the bike. I could see on the front plate where the top washer had been vs the 1/8" forward it seem to have skidded. While off the bike and no further pressure on the mounts, I tightened all 3 locations evenly.
The rear mounts still touch the "cup" in the frame, including the third ring on the new isolators. (So did the second ring on the units that I removed as the rubber had worn completely away where it had rested on the frame in that cup, exposing the steel.)
Since I'm waiting for a couple of days now, I thought I'd loosen all the bolts on the brackets and front mount and start the motor and let it find it's 'sweet spot.' Really can't see what I have to lose in trying. Thursday morning I'll go back to starting from scratch anyway!
Last edited by Stiggy; Nov 21, 2011 at 05:41 PM.
UPDATE: Installed the StaBo front motor mount Thanksgiving morning. Immediately noticed the lack of handlebar vibration at cruising speed on a short run.
The floorboards still carried some vibration which I attribute to the new rear stabilizers still breaking in. So after a short 5 mile ride I inspected the rear bushings and loosened the front mount as I checked the rear units, tightened down the rear first,(they're dead nuts centered BTW,) then tightened down the front.
(As I tightened the rear exhaust flange I noticed a crack developing just beneath the flange on the rear jug (!), so the exhaust system just got pulled for tomorrow morning repair and I'll be checking out the vibration, or lack thereof, tomorrow afternoon.)
First impressions of Stabo: Wow! The lack of the handlebar vibration was awesome.
With the rear biscuits softened up, I've got my old bike back better than before! If this thing last 20,000 miles I'll be a happy camper.
Thanks again for all the help and opinions everyone!
The floorboards still carried some vibration which I attribute to the new rear stabilizers still breaking in. So after a short 5 mile ride I inspected the rear bushings and loosened the front mount as I checked the rear units, tightened down the rear first,(they're dead nuts centered BTW,) then tightened down the front.
(As I tightened the rear exhaust flange I noticed a crack developing just beneath the flange on the rear jug (!), so the exhaust system just got pulled for tomorrow morning repair and I'll be checking out the vibration, or lack thereof, tomorrow afternoon.)
First impressions of Stabo: Wow! The lack of the handlebar vibration was awesome.
With the rear biscuits softened up, I've got my old bike back better than before! If this thing last 20,000 miles I'll be a happy camper.
Thanks again for all the help and opinions everyone!
UPDATE: Installed the StaBo front motor mount Thanksgiving morning. Immediately noticed the lack of handlebar vibration at cruising speed on a short run.
The floorboards still carried some vibration which I attribute to the new rear stabilizers still breaking in. So after a short 5 mile ride I inspected the rear bushings and loosened the front mount as I checked the rear units, tightened down the rear first,(they're dead nuts centered BTW,) then tightened down the front.
(As I tightened the rear exhaust flange I noticed a crack developing just beneath the flange on the rear jug (!), so the exhaust system just got pulled for tomorrow morning repair and I'll be checking out the vibration, or lack thereof, tomorrow afternoon.)
First impressions of Stabo: Wow! The lack of the handlebar vibration was awesome.
With the rear biscuits softened up, I've got my old bike back better than before! If this thing last 20,000 miles I'll be a happy camper.
Thanks again for all the help and opinions everyone!
The floorboards still carried some vibration which I attribute to the new rear stabilizers still breaking in. So after a short 5 mile ride I inspected the rear bushings and loosened the front mount as I checked the rear units, tightened down the rear first,(they're dead nuts centered BTW,) then tightened down the front.
(As I tightened the rear exhaust flange I noticed a crack developing just beneath the flange on the rear jug (!), so the exhaust system just got pulled for tomorrow morning repair and I'll be checking out the vibration, or lack thereof, tomorrow afternoon.)
First impressions of Stabo: Wow! The lack of the handlebar vibration was awesome.
With the rear biscuits softened up, I've got my old bike back better than before! If this thing last 20,000 miles I'll be a happy camper.
Thanks again for all the help and opinions everyone!
Very cool. Kevin explained to me the compression tunability function of his mount and I was intrigued but I had already installed the Glide-Pro front mount. I realize you just got it installed, but did you mess with "tuning" of the front mount, or do you have any opinion about it? I got over 15k on mine and no sign of wear or indication of deterioration, that's the beauty of this design, with the floating core there is nothing to "break".
By eliminating that washer, you preload the block a bit which holds the motor tighter to the frame so to speak, but according to Kevin that might transmit more vibration to the frame / bars, so what's the point? ( Unless a tighter front mount might 'support' the rear isolators in some way?)
I probably won't do it as the motor still pretty much just sits there anyway,
( there's no bouncing at idle like you might get on a Dyna chassis,) and I'm all about the 'smooth.'
Again though, it blows me away that the handlebars at cruise speed just stopped vibrating - completely. That's even more obvious because the floorboards still shook which made the compairison so obvious.
I am so looking forward to a ride this afternoon so I can learn more about how it's working and I want to thank you again, fabirk8r for turning me on to the folks at StaBo!
Sounds like the Stabo is a good product. I may have to check one out next time I need a replacement. Still, I don't understand why your floorboards are vibrating. My floorboards/pegs/bars on my rubber mount bikes have just about zero vibration at cruising speed, even the bike with the 96" S&S engine.
Sounds like the Stabo is a good product. I may have to check one out next time I need a replacement. Still, I don't understand why your floorboards are vibrating. My floorboards/pegs/bars on my rubber mount bikes have just about zero vibration at cruising speed, even the bike with the 96" S&S engine.
Just finished my new improved improvised exhaust system rebuild and took the bike out for 35 miles of varied country riding. Tracking is still dead on, handlebars are still quiet and now at 3000 to 3500 rpm, everything is smooth, floorboards included. ( Wasn't like that yesterday morning.)
I'm hoping that the isolators will continue to settle down and will report as they do.
Its weird for me too because the bike had no vibration for the first 11 years of it's life and the vibration doesn't seem to be anything related to the motor directly, ( crank runout,) because as I said the vibes are now gone over 3,000. We'll see!
And neither do I completely. This is the first time I kept a bike so long that at 100,000 miles I start replacing "stuff," ( wheel bearings, isolators, plug wires etc,) because it seems like a good idea to do so. So I'm in virgin territory myself.
Just finished my new improved improvised exhaust system rebuild and took the bike out for 35 miles of varied country riding. Tracking is still dead on, handlebars are still quiet and now at 3000 to 3500 rpm, everything is smooth, floorboards included. ( Wasn't like that yesterday morning.)
I'm hoping that the isolators will continue to settle down and will report as they do.
Its weird for me too because the bike had no vibration for the first 11 years of it's life and the vibration doesn't seem to be anything related to the motor directly, ( crank runout,) because as I said the vibes are now gone over 3,000. We'll see!
Just finished my new improved improvised exhaust system rebuild and took the bike out for 35 miles of varied country riding. Tracking is still dead on, handlebars are still quiet and now at 3000 to 3500 rpm, everything is smooth, floorboards included. ( Wasn't like that yesterday morning.)
I'm hoping that the isolators will continue to settle down and will report as they do.
Its weird for me too because the bike had no vibration for the first 11 years of it's life and the vibration doesn't seem to be anything related to the motor directly, ( crank runout,) because as I said the vibes are now gone over 3,000. We'll see!
Your new exhaust system may have effected your tune. In my tuning adventures I've found that a good "equalized" individual cylinder tune has big impact on vibration. I recently put my OEM 2:1 headpipe back on after I sent my FM pipe in to get repaired and I picked up a lot of vibration. After a few datalogging sesions and some map tweaking, it settled back down. No way of knowing if that might be what you are experiencing, but it is a possibility. I'm sure your new rear isolators are part of it though.
Since last Sunday I logged just over 400 miles so that maybe seems to be the break in window.
( The exhaust DOES make a difference. The pipe that cracked was a 2 into 1 White Bros 'E' Pipe that did not have equal length headers. The replacement header is an equal length header 2 into 1 Supertrapp - now hooked up to the 'E' pipe muffler. The motor still runs strong, but slightly different. I think I'm going to like it.)
I'll go out again today...
Mounts don't cause vibration, engines do. New mounts translate more vibration because they are firmer. Chances are your front mount steel sleeve was cracked free from the rubber for a long time thats why it felt smoother. Replace with either Glide-Pro or Sta-Bo urethane mounts. they both have a "floating" core design, similar to a worn out mount, and they translate a lot less vibe. Either mount is about the best you can get. The new rear bushings will also translate more vibe, they will settle down after you get some mileage on them. Double check to make sure the moulded in metal rings around the outside edge of the new rubber isolators are not making contact with the chassis, just behind the brackets, that will translate a lot of vibe.
Last edited by John Rocky rococo; Nov 16, 2023 at 11:16 AM.
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