Topic: * UPDATED* CAN I CUT THIS OFF AND NOT DIE ? * DIDNT DIE - BUT I TOOK SOME PICS !

[ProTeal55]

Hello fellow Cb'ers...

I was out in the garage today just looking at my CB from different angles, seeing where I could improve it's looks , function , etc..
I do this once in awhile to get a grasp of what I have going on the bike, and what I want to have the bike look like as a whole.

Anyways, I decided I want to clean-up under the rear of the seat.
Looks cluttered , and thats not a good thing on a motorcycle...
Like cut-off the stock rear fender mounting tabs (which I have my lights bolted too at the momment), and so on.
Less weight + A cleaner looking bike =  A more happy owner 

My main question is , whats the deal with the "brace" thing going from one frame-rail to the other ?
You know, the piece of metal that has two bolts for the stock inner fender to attach too ?
Does this serve any purpose what-so-ever besides maybe support a rear passenger ?
If I cut it off will the bike turn into a mess of twisted metal and black spraypaint , or will I be fine...?

I am curious, and VERY sawzall happy lately 

[Tim.]

My $0.02 - give it a shot

Seriously, I've considered the same thing, but have only seen it done on hard tail conversions.  I'd seriously consider replacing it with other cross-bracing under the seat or somewhere.

[aptech77]

I cut EVERY unneeded oz. I could from my 400F. I love my di-grinder.

[ProTeal55]

Well , if any of you know me, you know I usually DO first then ASK later  
The cuts were allready made eariler today , and below is what I came up with.
(Pardon the wiring - as of 9:03pm CST it has all been re-done )

I cut off the stock rear fender tabs, which forced me to re-mount my running/brake lights.
This was the main reason why I wanted to do this, cause I felt that the lights stuck out too far, and didnt flow
with the rest of the bike. I removed the stock brace thinge  , and angle cut the frame tubes to make them look decent.
Trimmed the stock inner feinder so you wouldnt see it from the side with the seat on...
I made a small bracket to mount the lights right behind the shock mounts, and ran the wiring thru the
frame tubes for a clean look (came out pretty nice). After that I filled the end of the open tube with paintable
silicon, which I will paint black after it has cured (the white dots in the pics)..
The once chorme housings were sanded and painted black. I sacrificed the amber lenses for painting purposes, and kept my red
ones nice and clean...
Now with the seat on you dont see anything under the seat like you did before, it's nice and clean as it should be...

I really dont think their will be any issue without that brace back their , as the distance from the one brace to the end of the tubes is
less than 5 inches, but tomorrows test ride will find out if I am right or not..If their is some sort of wicked flex, I will just weld up some tubes and make my own bracing...

We shall see...

[mlinder]

You are gonna need to brace from shock to shock back there. You\ve got stress points with only free ends beyond em now. Say hello to bendy subframe if you dont.

[DiscoEd]

PT...Bring on the pics! The suspense is killing me!

Regards,
DiscoEd

Edit: Doh! There are the pics. I guess they didn't load the first time.

[ProTeal55]

You are gonna need to brace from shock to shock back there. You\ve got stress points with only free ends beyond em now. Say hello to bendy subframe if you dont.

Even with less than 5'' of tubes behind the shocks ?
Their is a brace right in front of the shocks - which I didnt touch/hack/cut/modify/etc...
I have seen TONS of bikes with the rear section hacked off right behind the factory shocks (IE the bike below)....

[mlinder]

The brace in your pictures is 5 inches or so infront of your rear shocks. You are looking at 300 lbs of force on some little metal tubes that are braced only in one dimension. To top it off, they are now much more free to travel up and down (as well as every other direction) at different rates.
You need a brace right at the point where the shocks meet the frame. A rigid one, welded, would probably work better than the original, actually.

[750goes]

How are you going to hold up the inner fender???

where is your brake light bolting to ??

I think there should be some sort of "brace" across the frame, but I'm not an engineer, so I hope it works - go for it....

[Leemata]

This is slightly off-subject, but what is the width of that rear tire?  Seems much wider than stock.  Any handling differences?

Terry

[05c50]

I don't think you will have any problem with the brace gone. I removed mine about 2 years ago and have many miles on it since with no problems. after I cut it out, I had to fit a new fender in between the frame. I tried to spread the frame with a port a power and it was very hard to spread. I have noticed no difference in handling or frame flex without it.

[ohiocaferacer]

I don't think you will have any problem with the brace gone. I removed mine about 2 years ago and have many miles on it since with no problems. after I cut it out, I had to fit a new fender in between the frame. I tried to spread the frame with a port a power and it was very hard to spread. I have noticed no difference in handling or frame flex without it.

Ditto.....I removed the rear fender brace(rear of the shocks) on my CB350 years ago and have ridden the hell out of it with no problems. The only time you would have a problem with frame twist is if you are doing some road racing and loading the frame hard while cornering.

Looks good PT!!

Greg

[ProTeal55]

How are you going to hold up the inner fender???

The inner fender was not removed, just "trimmed" alittle.
It actually stands erect on it's own , so I don't think I have to worry about mounting it to anything
so to speak....

where is your brake light bolting to ??

Brake light bolting ?
The two lights on either side of the frame act as both running AND brake lights.
These lights are bolted to a bracket I made, and then attached to the frame right behind the rear shocks.
The wiring was ran inside the frame rails for a clean look, so you can barely see any wires going to or from the lights.
Once the "putty" sets up and can be sanded and painted, you will never know the tubes were ever hollow...

This is slightly off-subject, but what is the width of that rear tire? Seems much wider than stock. Any handling differences?

The rear tire on the bike is a 16incher with a 130mm Avon Venom tire. I did the swap to a 16'' more for looks than anything, and the added sidewall does help with the bigger bumps. As far as handling goes, I cant really tell ya. When I went to the 21'' up front, my bike handles far less than a stock bike does. Best way I could describe it would be to go ride a 12foot chopper - then take that heaviness of the steering and add that to your CB. Def. not for the faint of heart but I have become accustom to it...

Ditto.....I removed the rear fender brace(rear of the shocks) on my CB350 years ago and have ridden the hell out of it with no problems. The only time you would have a problem with frame twist is if you are doing some road racing and loading the frame hard while cornering.
Greg

Thanks Greg, you should see it with the seat on the bike. The lights almost dissapear into the rear now, and don't stick out like before.
I doubt this bike will be getting any roadracing done to it, as it basically cruises around town, bar to bar, etc..
I am gonna take it out tonight and see how it works - and keep a close watch for cracks and such.

[mlinder]

I guess I ride a bit harder than you folks saying its ok. I also like to visit the track now and then.
Even If I didn't, I'd never compromise the integrity of my frame like that. Having stress points with bracing on only one end goes against both common engineering rules and common sense. Bur hey, not my bike. For your own sake though, a simple bar inbetween shock mounting points should be put in, better safe than sorry.

[ProTeal55]

MLINDER -->
I appreciate all that you have said, and I thank you.
The last thing I wanna do is have the bike collapse/break out from under me.
I plan to run some 1/2 metal from side to side to give some kinda support later today.

Thanks for all the posts...

[wardmoto]

How about saome lube for your poor chain!  I bet that think is soaking you for 3-4 hp.

[nickjtc]

Always best to err on the side of caution....you wouldn't want to find yourself sliding on your a##s because of catastrophic frame failure....

[Bodi]

I think that rear cross member was just a fender mount, not structural. You still have the shock mounts in the frame web, and the cross bracing just ahead of them. The extended tubes just hold up the lights from what i see.
Welding on a crossover bar will reduce vibration in the lights at least.

[ProTeal55]

How about saome lube for your poor chain! I bet that think is soaking you for 3-4 hp.

New chain is on order , so no worries 

I think that rear cross member was just a fender mount, not structural. You still have the shock mounts in the frame web, and the cross bracing just ahead of them. The extended tubes just hold up the lights from what i see.
Welding on a crossover bar will reduce vibration in the lights at least.

That's kinda what I was thinking.
As my weight is directly over the battery, so I cant see this being an issue.
I am gonna take it for a ride tonight and see if anything moves/feels sloppy/etc...

[marvsho17]

My buddy who works at cycletech in loves park built a cafe honda a few years ago and they cut that brace off.  Not sure what happened with the bike because it was sold on ebay.  They did not weld any other support back there. 

[ProTeal55]

Finshed up the rearend project, got the seat back on , and took for a spin..
No difference in ride what-so-ever from before.
I even did some "manuevers" that I would never do on the street, and felt no added flex or
loose-ness at all. I will keep a watchfull eye - but I think I am gonna be ok.

The rear of the bike looks so much cleaner than before.
I went from this (look under the rear of the seat)

To this

And this

And this..

The entire rear looks cleaner, and less clutterd than it did with that brace under their.
The lights (now painted black) mold into the bike more, and with them tucked in more, arent so noticeable.
I am happy with my work - now onto the front-end project 

[nickjtc]

How much crap gets thrown up at the back when it rains? Just curious.

[ProTeal55]

How much crap gets thrown up at the back when it rains? Just curious.

You would be surprised, but none actually...
The rear part of the seat hang off just enough to catch i would say 90% of the road crap.
It acts as the rear fender enough for me, plus I totally dig the non-fender look (as u can tell)

[caferacer550]

Proteal.

I'm pretty sure you mentioned it before - but where did you get those lights from?
Are they street legal?

Thanks.

[Tim.]

Looks like the rear end of a 550 - the before pic isn't there - I can't remember how much frame there was showing - looks great now!  In the second picture below you can see my home-made seat and my questionably safe or legal signal lights.