if i were u i would just go ahead and look into a new subframe. as far as the forks go...that is something that u want to look at closely. i would def pull the axle and make sure nothing is bent that u cant see. if the forks just shifted then u should be able to loosen them up like u said and straigten them back up, but just give everything a really good once over. also check the brake lines since they do bolt to the forks.

 

The stresses on the steel frame from bending it back (and even a minor wreck for that matter) are minuscule. Unless you have rusting issues, there will be no issue with strength when repairing the frame. Refuting this is comparable to saying straightening a car frame on a frame machine with thousands of pounds of force will cause undue stress. Also, it would be more dangerous, in my opinion, to cut off the bent subframe and weld on a new one. You have no way to guarantee the integrity of your welds short of professional inspection.

 

its not steel though, if im not mistaken its an aluminum alloy or something like that. but the reason i said that was because if it is a larger bend then there is a chance of cracking when u bend it back. i dont think if it is a small bend that it will matter but i wanted him to know that it is a possibility being that the frame isnt steel. and as far as a new subframe, if u read some of the threads on doing it i believe alot of guys make brackets to bolt up like the newer style bikes.

 

I'll be sidling up to cajunlowrida here.... a little strain hardening in the steel subframe and residual stresses aren't going to hurt anybody. I essentially bought a bike in EXACTLY the condition p8ddy describes and fixed it. I had bent forks, and a bent subframe and plastics were sad...

On fork repair...
Don't just assume that because you can get your wheel to point forward means that your forks aren't bent. It's absolutely necessary after a wreck to disassemble the forks and roll the upper tubes across a smooth table to assure yourself they haven't been tweaked. It takes a surprisingly small amount of force in an unexpected direction to set them off. It may be (and probably is) more than just the forks slipping in the triple tree.

On subframe unbending...
If it's twisted, you'll need to tear the rear of the bike down to the frame and work on it with nothing attached to it. Much easier to see what happened/what you're fixing that way. I took a 2x4 piece of wood and put one end below a main subframe rail, and one side above, so I could just have a buddy hold the bike and torque it back straight. If you notice the frame is off side-to-side, (shifted off the centerline of the bike) you'll need to find a buddy (like me!) that has two rather beefy utility poles in his front yard.

 

claim it on ins and get a new bike its worth it

 

i wasnt totally disagreeing with him. i was saying that it depends on the severity of the bend. u dont wanna be crankin on it if its bad enough to crease it or something. minor bending wouldnt really affect anything like i said b4. i would probably try it to b4 i spent alot of time and money on changing subframes.

 

Good advice, thanks.

I looked over the bike again - and this time with a friend, just so I didn't get consumed with "cut bits off and get things welded" mode. :-)

The subframe is bent about 25mm on the left hand side, so we're gonna try and straighten it out and see what happens. If we can't get it right, then welding is the way to go, but trying to control the budget a bit, straightening it will be the no1 choice - as long as it's safe.

I had another look at the forks, and one stachion has been pulled a little, so all things going well, it's just be a matter of loosening up and re-setting. I'll be careful and check that everything is as it should be though. Safety first.

By way of luck, I have an f2 engine cover that will work with the f3 engine - it's the left hand cover, for the stator. So, it'll just be a matter of dumping the stator into the the other case and getting a gasket.

So....hopefully I'm looing at - New fairings, left foot peg and a gasket. Hopefully.

Next weekend will the bike torn down and the rebuild start. :-)

I still need to get the pictures uploaded, which I'll get done tonight when I get home. :-)

Thanks! It's great getting this advice, without you guys I'd be thinking of giving up on my poor CBR.
Pat

 

Regarding the forks - the only real force they got was from the handlebars hitting the ground and turning sharply - I don't *think* that should cause any bending, but I take your point - I'll tear them down and check. Better safe than sorry.

I've roped a friend into helping out next weekend with the subframe - I've not got a utility pole, but I do have a wall with a fence on it - I think that's give us enough stability - especially since I don't need to worry about the engine cover or fairings! :-)

One thing - Is the tyre in that picture a Pirelli Diable Rosso? That's the tyre on my bike that let go! Only 400 miles old too. I'm thinking I might not like this tyre! :-)

thanks - again, I have lots to think about and getting the full picture regarding what to look for is invaluable. You guys on CBR forum are life savers!

pat

 

The thing is this - the book price on a bike of this vintage is so low it's not worth doing - and they simply take more money from you in increased premiums for the next 6 or 7 years.

And I love the CBR. It rides really nicely, is economical and great looking. There is no need to dump a perfectly good bike. And I'm as poor as a church mouse - The amount I'd need to spend to get a significantly better bike doesn't make sense financially.

 

that tire looks like the dulop qualifyer. thats what i have and its not too bad. and def dont give up on her. we need to keep the f2s of the world alive. thats the problem these days, some people are too eager to just get something new and forget about such an "old" bike. its ashame.