subframe fun has begun

 

 

The piece of wood is a mock up battery. The top rails also get some more bends.

 

that battery gonna be happy sitting on top of the valve cover?...

 

Hi Thruxton,
Just my opinion, but I think once the seat padding is on, the rear sub-frame will be too high. I am enjoying this thread, I wonder if it will catch up with the "Post Whoring Newbie Thread" More useful information in this one already.

 

there will be an 1/8" gap and heat shielding, so I dont see it as a problem.

The subframe will sit about 32.5" and Ill have around an inch of padding, so it wont be too high.

My legs are long enough even though im only 5'11", Thanks for your concern though.

 

The subframe will sit about 32.5" and Ill have around an inch of padding, so it wont be too high.

My legs are long enough even though im only 5'11", Thanks for your concern though.[/QUOTE]


With the VFR tank my seat is at 34" and I'm 5'11" as well.
......and I have a 30" inseam.
So unless your legs are shorter than mine it won't be a problem.

Have you considered placing the battery behind the steering neck ?
Since you're fabbing your own tank, you can move the air intake to accomodate the battery in that area. ( Nothing worse than somebody else telling you how to build your bike..............)

Kai Ju

Kai Ju

 

all my electronics are going behind the steering neck. The battery wouldnt fit anyway.

I dont see anything wrong with the location. My monster's stock battery location is similar.

As long as I shield it from the heat it should be fine.

Carbon fiber with aluminum tape should shield from about 95% of the heat.

OPINIONS?

 

Ive been building the subby to fit a VTR radiator. I dont have the radiator yet, so if it doesnt fit I may have to cut this one up.

6.25" between the lower rails. Will it fit?

 

Yes it will.
Stock radiator is 1 3/4x6x13 if you ignore all the miscellaneous brackets and spigots.
With your fabrication skills that shouldn't be a problem.

Kai Ju

 

alright. someone measured one for me today and came up with 6.75".

Ill remove all the brackets and move the inlets and outlets.

Kai Ju do you have any predictions about the running temp of my bike?

 

I just remeasured and, using the endcaps as the largest dimension, I stick with the numbers I gave you before. Consider that this is as small as you can make the rad and will require removal/relocation of spigots and mounting brackets.

As far as predicting what the running temp will be depends on the amount of airflow you will get.
If you look at my bike you'll see my side intakes on the rear cowl.
In hot weather they help, in cold weather they don't.
My bike's cooling system works because I have two fans.
It only needs one for around town, canyon work and constant speeds below 75-80.
Once speeds stay above 80, especially in high ambient temps, the second fan is needed.
That said, with both fans going, my bike runs cooler than most VFR's and RC51's, with high temps being in the 230's.
I routinely hear of VFR's and RC51's running in the 240-250 range.

You will be using half the surface area of a stock VTR in a location that doesn't promote airflow.
I've tried ducting to force air in, which didn't work.
If you can configure ducting that extracts the air from the radiator you'll be way ahead of me.
My goal was to make the bike look as Factory as possible which has limited my options, yours aren't. Have fun and go with it.
Like probably the rest of us, I hit your thread several times a day and wish I had your skills, kudos to your dad for teaching you, kudos to you for running with those skills.

Kai Ju

 

Looking good! I am curious what you will come up with for your air filter / airbox situation.

 

 

 

did you tap the inside of the frame to mount the front of the sub frame?

big time kudos out to you!!! i too check this thread several times a day. i'm hooked. better than the dukes of hazzard when i was a kid! yes truck, i'm a lot older than you!

 

Yes I drilled and tapped the inside of the frame. I also made aluminum bungs that are threaded that will make the mount alot stronger. I just have to weld them to the frame now. Ill weld them next time I drop the engine.

Also gonna gusset the subframe with some plate to make it more rigid.

 

Did you leave yourself enough room to the get the valvecover off without unbolting the subframe in the front ?
On the other hand, you only have to do so every 16000 miles.
So it's not that big of a deal, except for the plumbing, maybe.
Can't wait to see your radiator solution.

Kai Ju

 

nope. Unbolt the subframe at the front and tilt it back a little. Im using every inch of space on this thing.

 

gusset patterns



gussets done. I got lazy, Ill weld them in tomoorrow

 

I don't know how much it will help, but remember that hot air naturally rises and that fighting that natural flow will work against you in your fight to keep things cool. I don't know what your plans are for a tailsection, be it stock, R1, Gixxer, etc. If there's any way to run the fan(s) to take advantage of the natural airflow then that would be the way to go, having the fan(s) pull the air up and out rather than blowing down and out. Also, don't forget about a hugger to help keep the rad clean and prevent busted fins.

PS It'd be interesting to see the mockup with the tank installed and you sitting on the bike. My initial thoughts are "ouch"!

 

I posted this on another thread a while back. Puller fans, heat exits out the low pressure area behind the back.

I will NOT be running a hugger as I hate the way they look. Ill protect the radiator in other ways.

And Im not using any stock style tail, gsxr, r1, anything like that. Im designing and building my own.