Fat Bike Down Tube Is Too Fat To Allow Studs. Best Solution Needed. (Video Clip)

yuckfoo

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What's the best way to tackle this problem? Should I file the sides of the tube? The distance between the studs when I thread them in (engine off the bike) is 43.36mm. The width of the tube is 44.65. I'd only have to file down about 0.7 mm or so on each side.
 
What's the best way to tackle this problem? Should I file the sides of the tube? The distance between the studs when I thread them in (engine off the bike) is 43.36mm. The width of the tube is 44.65. I'd only have to file down about 0.7 mm or so on each side.

You need a small piece of plate steel and a muffler clamp to fit over your frame. Drill two holes in one side of the plate to fit the engine and two more holes in the other side to fit the muffler clamp. Mount the engine to the plate and rest it on the down tube and secure it with the muffler clamp.
 
I ran into that problem 3 times... You need this... Big frame motor mount . (y)
I'll try this. The problem is the studs won't fit around that tube. But I guess with this you cut the studs down so they only stick out enough to get a nut on there? That way they never pass the full diameter of the tube(?)
 
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You need a small piece of plate steel and a muffler clamp to fit over your frame. Drill two holes in one side of the plate to fit the engine and two more holes in the other side to fit the muffler clamp. Mount the engine to the plate and rest it on the down tube and secure it with the muffler clamp.
This is what I do, if I need a mount I make it, every frame is a little different. Find a u-bolt that fits the frame tube tightly and it works good. On a beach cruiser I can add a offset to the mount for the large space. This one I made.
 

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This is what I do, if I need a mount I make it, every frame is a little different. Find a u-bolt that fits the frame tube tightly and it works good. On a beach cruiser I can add a offset to the mount for the large space. This one I made.
I've done it that way before too, but have found that not all U-bolts are made the same and they bend and break. That's why I like the muffler clamp and you can get any size of U-bolt that you need from 1" and up. The muffler clamp has two parts to grip your down tube perfectly, I just weld the saddle to the plate. Of course on some bikes you can't use the saddle because of clearance issues.
 
On my Mongoose , which is a Malus , I used the big tube motor mount adaptor plate like mentioned , but still had to get Allen pan head bolts , cause with hex headed bolts , the hex hits the frame tube and doesn't let the mount sit flush against the tube
 
It should have come with the kit a four-hole plate with a U bolt.

Also, is what I have to do to get a good fit on the rear mount is grab some mini-files and file down the grove usually on both sides until it's a snug fit, prevents vibration, and other things.
 
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