Adjustable Front Motor Mount

Goat Herder said:

I did much the same..and while I hated this bike so I never cared to do it right it was my proving grounds. I cracked the engine block casing where the J Shaft plates go on this bike.I let something else loose get though...[rattling did it ] The rattling motor stole horse power too. Why I never cracked the frame where I did the cheesy front mount is beyond me but I will never do it that way again I guess I live and learn

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I guess you mean not screwing up the main mounts to start with, because I don't know how doing a crappy job in the first place pertains to this.

Cracked the block? Loose parts rattling because of poor rear mounting? Not tightening the two nuts at each end of the keeper shaft together so they don't move? What, you were expecting a front mount to compensate for all that?

This thing didn't vibrate at all. Zero, none, and it didn't even have padded grips so you feel everything.
The only vibration I felt was the cheesy front tire starting to show it's 'out of roundness' at 40MPH.

In fact the the 50 something year old doctor I did the JS upgrade for called, he wanted to verify my address to send me a Christmas card with a tip.
He took it out and ran 1/2 a gallon of gas through it, said it does 45 in 7th gear, and LOVES it!

Then he asked about the 6 U clamp nuts I told him to check often and he wanted to know how tight to make them as they felt very tight after his rides. In short, still perfect. No vibration, no loosening, no frigg'n rattling or broken blocks or mounts.

Scoff all the heck you want, I love this mount and about to put a bigger motor in my JS'ed bike and going to use the same design for it's front mount, just slightly modified design and material.

Corgi1, the motor pull via the JS is straight down to the BB, the frames BB and drive sprockets have the right right side pull on it to the wheel, not the motor. The only pull the motor itself from the JS out is to the right by the JS out and BB connection which is next to nothing.

And Vince, thanks for the 'good luck' wish even as snide as it was meant.
You and I got off on the wrong foot but we both think the same way, not lame one build fixes for problems but universal ones and the same philosophy about how lame a drive side tensioner is.

'Nuff said.

Thanks Goat, I just share my thoughts and idea's as I go, if I get some good advice great! If they help someone else, great too.

I asked Dr. Mike to come by the middle of next month for a free tuneup, I can evaluate how that initial one is holding up, and I am rebuilding my own bike starting today using beefier (3/16th) metal and a slight design change so I will be able to evaluate it on a daily basis.

A couple of things are for sure, some of the stock kit mounting options are just junk 'solutions'. Drive side tensioners top the list, but drilling a frame hole and using a single bolt for long front mounts is a close second followed by having to bend the tailpipe to fit around using the second U block and longer studs kit extender if you use that option.

All 3 of those come down to your front mount. It needs to be adjustable and not get in the way of the tailpipe on the left side, and for direct drive bikes with a stock back mount, prevent the motor from twisting left.

I figure an inch and a half of travel is more than enough, and just have 2 lengths for the long side of the 'L'. One for close mounts, one for longer mounts.

Between Norms (I was trying to type 'Venice' short for Venice Motor Bikes before), seat post side mount shims and being able to move the motor up and down maybe drive side tensioners will go away forever and sure make life easier to build bikes and adjust chains.

Or not, I guess we'll see because all I can do is try ;-}

I promised an update as to how well my adjustable front motor mount held up on a Jackshaft bike.

The customer, Dr. Mike, just called me out of the blue, so I will tell you what he said while it is fresh in my mind.

His bike is running perfect, he said that as I had pointed he would need to raise the motor a tad to take out a little slack out in the chain between the Jackshaft and the Pedal sprocket as it wore.

He made me blush.

He said he was "amazed how simple it was to do" and the "twist up motor support shaft and adjustable front motor mount were shear genius engineering design".
I told him the Jackshaft motor support adjuster was part of SickBikes Jackshaft kit and agreed with him, and that I just made the front mount to work in tandem with it.

He went on to talk about his engineering background, and how most people don't take the time to do things right, he went off on a tangent saying he has been trying to teach his adult daughter that making the extra effort pays off in business, used me as an example, etc, etc.

"I just had to call you KC and tell you what a fantastic job you did!"

I told you it made me blush.
And I am still sitting here grinning from ear to ear while I type this, it really feels good to get calls like that ;-}

So, go ahead and say I suck at motor mounting.
If sucking when I design and use something and it works perfectly I will continue to suck along.