CNC Motor Mounts?

O

oceanotter

New Member
I was thinking about putting CNC Motor Mounts like these on my next 2stroke build.

http://www.kingsmotorbikes.com/scar...roduct_preview&id=4059&uid_temp=19&detailed=1

I'm actually building off a walmart bike that I liked. http://www.walmart.com/ip/26-Kent-Del-Rio-Men-s-Cruiser-Bike-Red/22899852

My last build has had a -lot- of issues with vibrations breaking motor mounts and bolts... I wanna try and avoid this using better mounts, bolts, and a better frame than my last one (which wasnt really great for a motor last time)

Has anyone used these? Do I need two of them or just one? I thought I might need two for both mounts on the engine, but if I'm wrong I'd love to know!


How do you keep your 2 cycles in place?
 
You want the rear of the engine to bolt directly to the seat post tube if possible then use a single mount up front, but a word of caution that these come in only one size so measure your front tube and get the size of the mount before ordering. I got one of those mounts at the shop and I can measure the hole size to see if it matches your frame tubing size.
I got mine to mount an engine in an aluminum specialized mtb frame but my bottom tube is about 1/4" larger diameter than the hole in the billet mount. With mine I'm going to set it up on my lathe and bore the hole out to fit the frame but I know most people don't have a lathe or cnc router in their garages. You could buy it if the hole is smaller and take it to a machine shop and ask them to bore it out so it fits your frame perfectly.
If the hole is bigger than your bottom tube you will need to make a set of split shims or have a set of shims made so it'll fit. It needs to fit so that when the 2 allen bolts are torqued down there's a slight gap between the 2 halves as you don't want it to fit loosely.
 
I used one on my build and the diameter of the mount was slightly bigger then my frame so I used a piece of metal wrapped around the frame and it's a tight fit now.the motor feels very secure.
 
never felt a need to do other than a bit of modification on standard mounts - after market mounts might be easier tho

looking at the frame, I'd be more concerned about getting the gas tank on solidly
 
Just a couple strips of metal with two holes wrapped around the frame and the tanks mounted. That's what I did for my tank and it's solid.
 
Stock mounts work well. Just don't do this:

$T2eC16ZHJGsFFMlgNbf3BRzOYz6,Iw~~60_12.JPG
 
even if you do purchase one on them billet mounts ...with or with out a shim
its all for not if you dont use decent steel bolts , not the stock supplied ones
 
Davezilla said:
You want the rear of the engine to bolt directly to the seat post tube if possible then use a single mount up front
Click to expand...

Is there a reason why the rear should be a direct mount? I'm using the CNC mount in question with a 1/4" thick rubber PVC pipe coupler as a shim. It feels rock solid. I haven't finished the build yet though...

attachment.php
 
Get rid of that aluminum thing and the rubber and mount the engine as it was designed to be mounted. That is, directly to the seat tube with the mount parts provided. After the rear mount is on and tight and the engine centered in the frame you'll need to do whetever is necessary to mount the front of the engine. Depending on the frame that could be an aftermarket mount or one you fabricate.

Once the engine is mounted it should not be able to be moved and feel as if it is part of the frame/bike. The way you have it now looks like 'trouble brewing'.

Tom
 
jeffyh said:
Is there a reason why the rear should be a direct mount? I'm using the CNC mount in question with a 1/4" thick rubber PVC pipe coupler as a shim. It feels rock solid. I haven't finished the build yet though...

attachment.php
Click to expand...

Use the stock rear mount on the rear only, & use that custom mount on the front of the engine! ;)
 
I've used the original Manic Mechanic mounts http://www.mmbikeparts.com/Default.asp
and they're pretty great.

Those ones that KMB sells are knock-offs, they probably work just as good, but I like to support the original manufacturer. The MM ones are only about $20 more and you get a nicer finish and one that's tried and true (guaranteed to work!).

I also say this because I'm biased against KMB, I paid $200 for a Huasheng engine and never received it. After multiple phone calls to no avail, I just faced the fact I threw away the money.
 
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