81 CM400T brat build

hello, new to the site and the riding world, just bought an 81 CM400T, so far i have spent my time getting it running and stripping it down a bit. Now im ready to take the plunge and get started on the build, the plan:

-shorty rear shocks with rear frame rails curved upwards towards shock mount ala: typical bratstyle
-16" rear shinko 270 whitewall (old firestone look) on 16" wire wheel
-21" avon speedmaster on 21" wire wheel
- narrow ribbed rear fender
-narrowed and frisco mounted sportster tank
-set of narrow (22" or so) t bars, turned down 20 degrees or so at the grips
-5 1/2" bates headlight
-32 ford "stop" tail light
-chinese aluminum master cylinder
-car style ignition switch

i have all these parts so far (tires no wheels) and am getting ready to get my hands dirty. i have all the parts figured out for the basic rolling chassis and stance that i am after, but i am getting stumped on some of the harder to find stuff. here is what i am looking for details on:

7/8" dual cable throttle - is it a push/pull style? i cant find info anywhere
front and rear wheel axle sizes - i would like to keep the front disc so i need a different brand wheel
when i change the rear frame section to the curved style tubes do i need to brace them back together somehow?

Hey Dan, sound like a great project. Do you have any pics? As far as your questions, the dual cable throttles (as far as I have seen) are a push/pull system. I personally do not have one on my rig but my buddy's is like that. And for grafting the rear loop to the rear of the frame, I just bent a smaller piece of tube and welded it in between where your butt joints are going to be. I also welded a cross brace so that I could mount my seat. Mine has worked like a champ. Hope that helps.

Thanks for the info, I will get that throttle ordered up, I am kinda building
More of a narrow Frisco style bobber mixed with a soft tail bratstyle look.
I will probably brace the frame ahead of the shock bolts and leave the rear parts separated
And hide the brace under the seat, I will get som pics when I can

a couple of shitty pics from last night

and a bit of inspiration

hi bloke, i got a cm 250 with the twin throttle cables i just removed the pull close cable. i havent had any big rides like that but running in shed seams fine as it has a heavy throttle return spring!

thanks for the info, there seems to be quite a few push pull setups available, i will probably just buy one of those. hopefully my cables and sleeves will be the right length, fingers crossed.

does anyone know if the tank must be higher than the carbs so it will gravity feed? will a fitting on the bottom of the oil tank ie: 2-4" lower than the carbs be too low? i am planning on using a round oil tank as auxillary gas tank, the sportster tank i bought is only 2.1gal. if i could connect the two tanks in series that would be alot easier than pumping it back into the fuel tank. i was planning on using one of those priming bulbs off an outboard motor and a 3 way valve to pump it back

I've got a CM400 also and eliminated the pull cable as well. I dont think you'll have the volume to push the gas up into the carbs if the fuel level is below the fuel input.

hillbilly said:

hi bloke, i got a cm 250 with the twin throttle cables i just removed the pull close cable. i havent had any big rides like that but running in shed seams fine as it has a heavy throttle return spring!

Click to expand...

So the push cable is just a return cable, I assumed
It pushed on the opposite side of the throttle arm to help
Open the carbs, I think I will just run the one cable in that case.
I figured the tank would be too low, thanks for that info

Dont discount your vision just yet, you can always find a small electric fuel pump to help move things along!

dannyrds said:

So the push cable is just a return cable, I assumed
It pushed on the opposite side of the throttle arm to help
Open the carbs, I think I will just run the one cable in that case.
I figured the tank would be too low, thanks for that info

Click to expand...

I'm definitely going to have both tanks, I thought about using a priming bulb from an out board motor as a manual pump. They have a one way check valve so it won't run back between squeezes of the bulb, and I can use a brass 3 way selector valve to connect carb and both tanks, and just fill thru the oil fill neck. Although, maybe a fuel pump and check valve would be easier, I'll get it mocked up and decide then

Love the direction you are headed sir. That black bike is sick, looks good with the Sportster tank on it.

Picked up a dirt bike wheel locally and mounted my Avon speed master

I also recieved some stepped bungs I ordered from bungking.com and went to the local metal store, I picked up some 1" to go over the bungs to create the risers, and some 1 1/8 for the top bar as well as some 7/8 to sleeve into the 1 1/8" for all my bar controls. I also ordered up a switch box for the bars to hold 2 micro switchs, on for signals and other for high beam and horn.

got some work done in the last couple weeks






pegs: before and after



caliper bracket

Looking very nice. Bookmarked

heres a pic of the mocked up handlebars, top tube is electrical conduit, easier to work with to get a good template for final piece

more work done, welded up all the rear frame mods, mounted the fender, trimmed and mounted the seat pan, made a battery box and cut it into the round oil tank i am using to house all me electronics, if im lucky there may be room left in there for wallet/phone/keys as well, or tools, who knows. need to mount the oil tank to the frame and grind off unused bungs, as well as cut a hatch into the top of the tank for access. next up is the fuel tank, using a stock sportster tank, 10 3/4" wide at the front and 8" wide or so at the back, going to cut a wide patch out of the center and put the two halves back together, hopefully ending up with about 5 1/2" wide at back and 7" wide at front. not much left after that, which is good i need to get it torn down soon if im gonna be riding it this summer.

Awesome build, I like the head light bracket, I still need to figure something out for the headlight I am thinking of ordering. Are the shocks the 11" shortys from DCC ?