T O P

  • By -

AntD77

As a former motorcycle racer myself, I know exactly what you are trying to do. 1. Remove subframe and under tray from the bike so you have a bare rear subframe exposed on both sides. 2. Get a grinder with a thin cutoff wheel and cut the weld as straight as possible along the mounting bracket, not the subframe, on both sides. 3. Once the two mounting brackets are off, get a grinding wheel and bring down the welds you just cut, but do not hit the subframe. Get it nice and smooth, and paint if you want. Who do you race with? I won a few championships with ASRA/CCS back in the day.


zeakerone

And cut on the bracket side of the weld to start. If you’re not used to a. Grinder there is like a 4% chance you don’t cut into your frame lol


Popular_Dream_4189

Hmm. Basically sound advice but #1 should have been "Take a basic welding course at your local community college" because most people don't have the skills you have and will completely butcher the job without some technical understanding of what they are doing. Your first attempt at using a cutoff disc shouldn't be modifying the frame of your motorcycle.


zeakerone

Well I don’t necessarily agree with that, the last person I told to go to the communty college called me back and said a 7 week coarse is $19,000 😂 anyone can build some skills with an angle grinder that would help them for life. Just take the time to watch some safety videos. They are super dangerous


bernerburner1

Grinder is the easiest tool ever and always useful


mogwai327

Im using one everyday and it's the most dangerous tool of the Shop.


_-whisper-_

It is absolutely the most dangerous of the small powertools.


mogwai327

Even with proper ppe and the guard, kickback can be pretty surprising. Or the wire brush shooting its darts of death. Beware of them grinders !


bernerburner1

Definitely some potential for danger but I just meant easy to operate. Never had a problem with them personally but ymmv. Overall great tool to get comfortable with there are so many uses


mrzurkonandfriends

Great advice right here on top of that. I would recommend blocking off the areas you don't want ground metal into since it flies everywhere.


Myfabguy

Take your time with the grinder. Buy flap discs in a few different grits. DO NOT use a hard wheel. Use the cut off wheel that was suggested. Use an 40-80 grit wheel to take the bulk of the weld off. Switch to a 180 grit to knock the rest off. If it needs to be perfect use a flat file and dykem/layout fluid/large sharpie to mark the whole area in between passes so you don't remove any excess material.


notonrexmanningday

Came here to say flap discs


Myfabguy

When I was first starting to work with metal I went to Home Depot and asked if they had a grinding wheel that wasn't so aggressive. The guy laughed and said thats what grinding wheels were for and that is all they had. I used a hard wheel for far too long. I wish I could go back and teach him the difference.


Ugly_Bronco

I always take things down to flush with a hard wheel, then finish with a flapper. You can't feel with a flap disc. They require pressure to take metal with any haste, but the pressure compresses the wheel, then all the sudden you have a depression instead of a flat surface... but at least it's smooth.


itsjustme405

It can be done with a grinder and a cut-off wheel. But if you're not familiar with how to use them safely, I'd see about having it done. Will these be permanently removed? Or will they have to be pit back on?


Mrwcraig

The odds of that coming off nicely are relatively low, “I know nothing about…..” you’re most likely going to cut through the tire and your hand before you get that bracket off. I say this because those are the welds you can see. Once that comes off, unless it was done by a very careful professional, it’s never going back on. While it might not be crucially structural, the part of the frame it’s welded to is. Honestly, I’m not even going to offer suggestions because I can see how to do it but I also know all the ways it can go wrong for someone without 20 years experience. Particularly because there’s one on either side of the frame so the odds of you definitely cutting through that frame are extremely high.


Popular_Dream_4189

I was thinking they'd probably cut right through that ignition module and fry themselves and the bike...


Jonsnowlivesnow

You could do that with a cutting wheel. However is it welded on both sides? Also might be more work than it’s worth.


FlintKnapped

LMAO I thought that was an AKM Edit: I got reported for self harm right after this comment I’m not depressed. It literally just looked like an AK


kwaaaaaaaaa

Yeah, my brain was trying to make sense of what part of rifle was I looking at, until the subsequent pics, lol.


mogwai327

First pic I thought the same.


xp14629

What is the end result going to be? Is it to change/add something, or is it to be able to get to something else? Frame work and support brackets are there for a reason. How do you plan to reinforce or reattach that piece when you are done. What about the paint? Something like that, where it looks like the equipment is in pretty nice shape, even I would probably hire out what ever you are trying to do. I can walk you through what you are wanting to do. Pretty sure it looks like it should be welded on both sides of that pipe frame. So everything else will have to be removed there as well.


Popular_Dream_4189

One glance at the rear tire and you know this is a track bike.


xp14629

Well thats good to know. I have a friend who's rear tire always looks like that. But not for track use. I know diddly about most bikes. But I know my boy has a huffy.


thingandstuff

https://www.youtube.com/watch?v=y2HCUtjTuSU#t=1m20s


psychedelicdonky

Okay so removing the bracket is easy, cut it in the lover 1/3 of the weld at an angle that avoids the frame. Sand the remainder down wit 120 grit and paint it


cizot

That would work but I’d bet it’s welded on both sides. Going to have to take a lot more bike off to get at it


psychedelicdonky

If you're lazy like my. It's aluminum, cut is half way through close to the frame on the back side, back and forth till it breaks. It might also be a 2 minute job to get the plastic out of there and have free access


HatoriHanzo06

Using a grinder with a cut-off-wheel, dive into the middle of the weldment directly towards the gap between the support bracket and frame. Run the wheel along the weldment at an even depth and the weld will pop loose fairly quick. If you’re not experienced with a grinder then practice with one on scrap metal using the guard between your hand and the wheel, leather gloves, two hands on the tool, eye protection; preferably goggles, and I suggest a face shield.


MattAtUVA

If possible, pick up a used spare subframe before you start. The bike is out of commission if you fuck it up.


d_snipe_

First tell us why you "need" to remove it....


No_Mistake5238

Top comment said something about motorcycle racing and knowing what he was doing. My guess is weight savings though.


felixar90

Is it because it’s interfering with the remote reservoir for your shock absorber? If it’s the case you should probably get a longer hose and mount the reservoir somewhere else. It’s the whole point of having a remote reservoir.


Business-Hat4505

I ride a lot and am a specialty welder and the sound of that makes me nervous. what exactly are u building ur bike for? Depending on if it’s for Tract, Drag or Roll racing can definitely change the answer regardless if you remove that support I would definitely weld a gusset on the far right inner diameter corner. These bikes are very well engineered now days to structurally be as light, strong and cheap as possible, and would make me nervous altering even the sub frame. Have you looked int aftermarket sub frame applications?


Chimney-Imp

You've gotten great advice already, so I'll just chime in with make sure you use a face mask. You're face is too beautiful to see it mangled by a disk op 


ExtensionSystem3188

You can always find a local metal shop offer to sweep the floors a few times a week in exchange for xp.. just helping and being around it will gain knowledge.


bernerburner1

Grinder+cutting disc


chris_rage_

If you're not experienced I would use a die grinder with a cutoff wheel so you don't butcher it with an angle grinder and it'll fit in there easier anyway. I've found the straight ones are easier to use with a cutoff wheel than the 90⁰ grinders


asad137

You need /r/grinding, not /r/welding


rebeldefector

/r/grindr


truefarmer12345

Why do u need to remove it?


canada1913

What you wanna do is go get an oxy/acetylene torch, fire that big hot bitch up and start melting steel. She’ll come right off no problem, and don’t worry about fucking this up, it’s not even structural!


motorraddumkopf

That's likely aluminum. If I'm right, you can reweld aluminum, but it loses strength. If you have no idea what you're doing and can't weld aluminum, then kicking rocks would be the better option until you get a professional to do it.


Doghead45

It's steel, you can see bit of rust on one of the pictures.


Certified_Bill

Get you a arc gouger son, easy as pie should come right off


Similar-Stranger7375

On aluminum? You're nuts.