Need a motor adapter for an 09 Electra coaster 1crusier

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Tmoney

New Member
Apr 28, 2011
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california
Its a very good bike. Comfortable, reliable and good looking. Only problem is the engine compartment is a little weird compared to the traditional V frames on most cruiser bikes. The front end mount wont reach the bottom front pole of the frame. Right now my engine is on a nothing special every day old road bike. Got the road bike for free. But I have always hoped to motorize my 09 Electra. I want to know where to get a motor mount adapter or how to build one for an Electra bike.
 

AslansMonkey

Member
Oct 2, 2008
194
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I have a motorized Electra Coaster 7D and I mounted my motor by attaching the front to the down tube as usual (this avoids muffler clearance issues) and fabricating a simple rear mount using bar stock and some U-Clamps. The major issue with this frame is that the extension needs to be so long that you need both horizontal AND vertical support. The photo (I know, it's not very good) shows what the completed mount looks like. Note you may need to extend your chain for this to work.

The steps I took are basically...
1) have someone hold the motor to the frame so you can make a cardboard template of your mount.
2) Bend bar stock to fit leaving a tab on the bottom and back to run your U-clamps through
3) Drill holes for the motor mount and the U-clamps. The bar stock I used was just barely wider than the frame and matched the motor mount width pretty closely so the U-clamp holes were really notches in the mount.
4) Bolt the mount to the motor (paint it first if you wish) and install.

Since the Coasters use aluminum frames I cut copper tubes that matched the bike tube diameters in half and used the half on the curved part of the u-clamps (between them and the frame) to provide some additional support and spread the load out.

I'm sure a reverse of this idea would allow you to mount the back of the motor to the seat tube, but then you'd have trouble getting the exhaust to fit.
 

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Tmoney

New Member
Apr 28, 2011
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california
this is the bike i plan on motorizing
As you can see the engine compartment is different compared to the usual style people use for bicycle motorization.
 

Tmoney

New Member
Apr 28, 2011
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california
I guess its stretched at the engine compartment for the bikes comfort. It is a comfortable bike. Now I just need to mod my engine brackets to help the fit. It would be a big help if someone can provide me a link that sells adapter kits for motorizing that type of bike.
 

AslansMonkey

Member
Oct 2, 2008
194
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Again, that bike is the exact same frame as the bike I showed, only mine is the 7 speed version. No one makes adapter kits for that frame, you have to adapt it yourself, but as I've demonstrated it's not hard to do and frankly, is a big part of the fun.
 

MotorBicycleRacing

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Jul 28, 2010
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I guess its stretched at the engine compartment for the bikes comfort. It is a comfortable bike. Now I just need to mod my engine brackets to help the fit. It would be a big help if someone can provide me a link that sells adapter kits for motorizing that type of bike.
Mount the motor solidly on the seat post tube then post a pic if you
still need help with the front mount.

You can use one or two rear mount blocks on long bolts for a front mount
or use clamps off the front down tube.
Or go a little more custom. I don't think anyone makes a specific mount for
that frame.

Where in LA do you live? I am in north OC and are making a lot of custom mounts
right now for a few bikes.
I have most of the parts needed on hand to make them.

Actually with that big of a frame you can do a "Bairdco Style" reversed engine
with the carb in the front and exhaust coming out the back.

Would help to know how far you need to extend the front mount.
 
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stickerbush

New Member
Jun 22, 2011
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Pacific Northwest
I also have an Electra Cruiser build going, with a Grubee G2A 48cc Skyhawk. Here are some pics for reference.





My plan for the front mount is to get the small universal front mount from sickbikeparts.com and use aluminum spacers/standoffs in the space between the engine and front mount. Once I have the sizes of everything I will post them here. I think I'll need around 1.5" to 1.75" of spacers, depending on how I adjust the height of the mount on the seat tube.
 

nidyanazo

New Member
May 25, 2010
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SoCal
When we @ Motovelo build an electra we make a proper mount to do it right:
We also made the muffler extension..





 

stickerbush

New Member
Jun 22, 2011
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Pacific Northwest
OK, got the engine mounted in my Electra Cruiser finally.


The rear mount just uses what came in the kit.


The front mount is constructed from a front mount kit from Sick Bike Parts and a couple of 1" aluminum spacers.



Parts list:

From Sick Bike Parts
1 x Front Engine Mount - Small Universal
- Down tube width: 1 3/8 to 1 1/2 inches
- Engine stud width: 1.9 Inches

From widgetco.com:
10-14-1000-AS 1/4" x 1" Aluminum Spacers (2 reqd.) .258" ID x .500" OD x 1" L

From Ace Hardware:
M6x1.00x30 cap head bolt (2 reqd.)
 

MarkSumpter

New Member
Nov 27, 2010
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Ohio
Looks good with plenty of room for the carb and it looks fairly level for the float to travel freely. Since the mounting bolts are so long I would make sure to go to a heavy grade bolt or maybe drill out the stud holes for bigger diameter. You might also want to take a piece of 3/4" EMT conduit and split it in half and slightly flatten it to go between the front and back of the front clamp you got from SBP to spread out the load and decrease the chance of cutting into your frame from vibration. Most people say this is only necessary on aluminum frames but I do it on steel ones too. Oh and use Nylock nuts on you U clamp or the standard ones backed up with nylocks if you have enough thread on the U bolt. It just helps to keep them from vibrating loose...
 
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MotorBicycleRacing

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Jul 28, 2010
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Looking good but the front mount looks a little weak with all the
offset on the plate.

How about using another frame clamp below the motor and a
bent metal plate between the 2 clamps which the motor bolts too?
 
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AslansMonkey

Member
Oct 2, 2008
194
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Looks like a good mount, Stickerbush, kind of interested in what you plan to do with the exhaust with that set up. You might get more engine vibration than you expect and may need to add some form of vertical brace somewhere but you'll discover that soon enough when you ride and with your mount it may not even be a problem. I had to brace the back of mine, but then I mounted the front mount directly to the tube so I had an extra long rear mount. This solved any exhaust mounting issues but, as I said, created a vibration one and I had to extend the chain a little.
 

htownrnr1

New Member
Jun 14, 2011
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Houston, TX
Stickerbush -

Could you let us know how the bike is working out? I'm seeing lots of solutions to the motor mount problem, and yours looks the easiest. You put any miles on the bike yet?