Repairing cracks in fairings? | GTAMotorcycle.com

Repairing cracks in fairings?

M

MaksTO

Well-known member
So I got my 2007 cbr125. A few miles on it, and obviously it's been used like a beginner bike and has been dropped a bunch. I have two main cracks on the fairings on both sides just above the turn signals on the top of the fairing. Maybe 1-2 inches long. Everything is attached and holds fine, but I was wondering if there are any ways to fill in and buff out cracks like that? I can attach photos of them later to make the reference a bit easier. I was thinking I could pull them off, and use a two part epoxy from the inside to bond the cracks (I'm not sure if epoxy will fuse or melt the plastic though, since it's largely a thing used on fiberglass from my knowledge). Probably won't repaint since it will probably be hard to find a perfect match, but if its possible to touch up, I'd consider that as well.

This isn't an urgent thing for me. But I figured if the bikes been beat up, it might be a fun project to try and clean her up a little bit in my spare time.

Would appreciate any thoughts and feedback :)
 
I've used CTC shiny muffler tape on the back and JB Weld 2 part plastic epoxy on the outside.
If you're careful it will hardly show.
 
I'm with Evo. I may put a stitch in each crack to try to keep them from getting larger, but just ride it. The chance it tips over again is high and unless you do a really great job on the repair, the crack will pop open again (and be harder to repair the second time).
 
I personally haven't dropped the bike yet. Been close, but its light enough that I could save it while maneuvering around the garage. It's not so much a value thing for me, as I don't believe the materials for this repair would exceed $20 and change. My perspective is that while I have something busted, it might be fun to try to learn to repair it on my own. Moreso for my personal knowledge rather than the bikes wellbeing.

First bike, yes. But I am not sure how long I will be sticking with it for. Could be a season, could be a few years until I am 25 and able to get something bigger for less insurance. Unless my paycheck doubles in the next year I will probably be happy with this for the time being.

I just plan on doing small/inexpensive work on the bike to make minor improvements. So far I want to fix up the fairings to remove a bit of the buzz, and will likely change my clutch springs for a heavier one to put down power a little better off the line (supposedly these bikes have very weak springs from the factory which wears the clutch fast and causes power loss). That's a discussion for another thread though.
 
MaksTO said:
I personally haven't dropped the bike yet. Been close, but its light enough that I could save it while maneuvering around the garage. It's not so much a value thing for me, as I don't believe the materials for this repair would exceed $20 and change. My perspective is that while I have something busted, it might be fun to try to learn to repair it on my own. Moreso for my personal knowledge rather than the bikes wellbeing.

First bike, yes. But I am not sure how long I will be sticking with it for. Could be a season, could be a few years until I am 25 and able to get something bigger for less insurance. Unless my paycheck doubles in the next year I will probably be happy with this for the time being.

I just plan on doing small/inexpensive work on the bike to make minor improvements. So far I want to fix up the fairings to remove a bit of the buzz, and will likely change my clutch springs for a heavier one to put down power a little better off the line (supposedly these bikes have very weak springs from the factory which wears the clutch fast and causes power loss). That's a discussion for another thread though.
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If you want a great guide for things to poke and prod in a 125, search through Brian P's threads. He's had a few and posts very detailed descriptions of things that get maintained/upgraded/setup differently.
 
GreyGhost said:
If you want a great guide for things to poke and prod in a 125, search through Brian P's threads. He's had a few and posts very detailed descriptions of things that get maintained/upgraded/setup differently.
Click to expand...

Thanks for the recommendation! I have been reading on cbr125world and watching Marvin Millers videos, which is where I plan on getting the HD Clutch Springs and maybe the performance pack if I am bored. Though I think clutch springs/plates/gasket/oil will be a nice all in one maintenance journey for me and will probably make the 23,000km mileage seem less noticeable.
 
get some lego or black ABS pipe, break into small bits, get some acetone, mix together, on the back side of panel dremel out the crack a bit so it has a V shaped notch, apply the slurry to the area, let dry, and your good to go, on the outside, you can apply a bit of bondo to the crack to fill it in, sand and paint, or if it's a thin crack, just put in the bondo, and leave it, there is stuff for filling in cracks, it's thin and spreads very easily..

the above slurry will bond the panel together

it all depends on how far you want to go with the repair....

I will assume the body panel is an ABS type of plastic
 
GateKeeper said:
get some lego or black ABS pipe, break into small bits, get some acetone, mix together, on the back side of panel dremel out the crack a bit so it has a V shaped notch, apply the slurry to the area, let dry, and your good to go, on the outside, you can apply a bit of bondo to the crack to fill it in, sand and paint, or if it's a thin crack, just put in the bondo, and leave it, there is stuff for filling in cracks, it's thin and spreads very easily..

the above slurry will bond the panel together

it all depends on how far you want to go with the repair....

I will assume the body panel is an ABS type of plastic
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Definitely a cheap plastic of sorts.

The acetone/plastic seems interesting. Though I will likely just go for a pre-designed gap filler from CT or something for the sake of ease.
 
I found the clutch springs a good upgrade. Best mod I did was -1 on the front sprocket and +1 or 2 on the back. I hardly ever used top gear before that

I like working on my bike as a learning experience. Taking the fairings off the first time is a pain. Keep some ziplock bags handy and or masking tape to keep track of all the screws
 
jeff96 said:
I found the clutch springs a good upgrade. Best mod I did was -1 on the front sprocket and +1 or 2 on the back. I hardly ever used top gear before that

Sent from my SM-A500W using Tapatalk
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Does it run out or revs or power after the gearing swap?
 
jeff96 said:
I found the clutch springs a good upgrade. Best mod I did was -1 on the front sprocket and +1 or 2 on the back. I hardly ever used top gear before that

Sent from my SM-A500W using Tapatalk
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I know the performance pack comes with a front sprocket. Is it a -1? I'd assume so?
 
Also read through some of @Brian P 's posts. Seems he mentioned a tire and suspension upgrade on his 2007.

Current I am running Pilots, which I assume are better than the stock whatever that came on it.

No idea what he was meaning about changing suspension. Would be curious to find out more but can't seem to find it on the forum yet (brand, site, etc).
 
Home Hardware used to have some stuff called Plastex.

It came with some other stuff you could use as a mold and you could rebuild bits and pieces as well as repair holes.

I saw it at the motorcycle show one year.
 
MaksTO said:
Definitely a cheap plastic of sorts.

The acetone/plastic seems interesting. Though I will likely just go for a pre-designed gap filler from CT or something for the sake of ease.
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but you don't want to just fill the crack, it will just fall out, you need to bond the crack back together, or it will just continue to crack

if you just make the slurry and spread it along the back of the crack, this will at least stop the crack from spreading as it will fuse the panel together

filling from the front side will not do this it will just fill the crack, with vibrations and such it will just fall apart

have a look here.....

1985 YAMAHA FZ750 Rebuild Project

.
 
Poke a series of holes either side of the crack and stitch it together with zip ties, that is the only repair that really holds. Is ugly as sin but it works, you can add material to the back side real easy and stitch that in too.
 
GateKeeper said:
but you don't want to just fill the crack, it will just fall out, you need to bond the crack back together, or it will just continue to crack

if you just make the slurry and spread it along the back of the crack, this will at least stop the crack from spreading as it will fuse the panel together

filling from the front side will not do this it will just fill the crack, with vibrations and such it will just fall apart

have a look here.....

1985 YAMAHA FZ750 Rebuild Project

.
Click to expand...
Is that photo just the acetone/plastic combo on the back? I was thinking either exhaust tape inside, epoxy outside, or maybe this can work too. Just not sure what the proportion of plastic to acetone should be? I would assume until its just a goop of sorts?

I also see it's common to dremel out the crack sometimes on the outside for filler, but I hope that with the acetone solution that might not be needed? Just maybe sanding the outside before touching up the paint if I do so.
 
MaksTO said:
Is that photo just the acetone/plastic combo on the back? I was thinking either exhaust tape inside, epoxy outside, or maybe this can work too. Just not sure what the proportion of plastic to acetone should be? I would assume until its just a goop of sorts?

I also see it's common to dremel out the crack sometimes on the outside for filler, but I hope that with the acetone solution that might not be needed? Just maybe sanding the outside before touching up the paint if I do so.
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Think about the surface area inside the crack. That's why people grind it out, you can triple your effective area to give the adhesive a chance. If you don't grind it out, you could build it up, but a)doing that on the outside would look terrible and b) the crack will still exist behind and serve as a stress riser to crack your patch.
 
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