Topic: CB750K0 Side Covers - Advice?

[StockRider]

Regarding my side covers (multiple 1/2"-1" cracks around studs/edges), I'm debating several options for next year:
1.) Ride naked.
2.) Attempt self-repair. Install with fresh grommets.
3.) Pay for professional repair. (Likely no paint job since that will be needed on all body parts down the road.) Install with fresh grommets.
4.) Get repros and store the originals. Install repros with fresh grommets.

Advice?

Cosmetics have never been a big concern on this bike. Dad had the cracks in the side panels "reinforced" with electrical tape.

It got to the point several years ago that I stopped riding with the right hand side cover after I lost it on the interstate going 80+ and didn't even know it. I still don't know how it got around the oil cap! I spent a night thinking that someone had swiped it in a parking lot. Amazingly, it happened to catch my eye the next day on my way home from work, chillin' on the side of the interstate with just a bit of road rash.

The pictures don't show it clearly but the factory date stamps are legible to the naked eye..., don't want to wipe that evidence out. (691209.1, 700214.3)

[StockRider]

More pics.

[754]

Where are the  date stamps, what area ?

[StockRider]

691209.1, 700214.3

Inside, centered, just below the holes/studs for the badges.

[StockRider]

Closeups...

[Stev-o]

I'd vote for #4, buy repops and store the originals.

I just happen to have a pair for sale! Was going to put them on my K1 but decided against it.

[newday777]

Repairs on the backside won't show and are easy to do.
1. Wash area well of all grease/oil.
2. Clean with denatured alcohol.
3 sand all paint off down to clean ABS(the plastic is ABS) where the repair will be done so the cement adhesion is good.
4. Clean again with denatured alcohol.
5. Lay down mesh tape to strengthen across the cracks.
6. Lay down thin layers of ABS pipe cement. 24 hrs between layers to fully off gas. 5 layers will be a good strong repair. You can sand it after it fully cures in 7 days to smooth it out.

[newday777]

I actually had to cut out a lower pin from a really busted cover and Dutchman it on as this cover has a custom paint job. It turned out well. I also strengthened a couple bad cracks further up too. He'll try and have the paint blended later

[Prospect]

I'd repair them if I were you. There is no substitute for original.

[Don R]

 I've often wondered if there's something we could spray on the inside to restore the flexibility or lessen the brittleness of the old abs plastic.

[seanbarney41]

not gonna hurt anything or cost much to repair them...then if they hold up and make you happy you are good to go.  If not, buy some repro's.  I don't see availability going away in the immediate future, at least.  I would not spend the money to repaint the damaged originals though.  No matter what you do, get some new grommets.  Removal attempts with the old hard ones is probably what caused the cracks in the first place.  Grease the tabs for removal in the future.

Are you sure those castings are date codes?  I am certainly not a sandcast/K0 expert, but I have never heard of this with Honda side covers or any other parts I can think of.

[jlh3rd]

eh....this is an original 550F cover......don't know what the horizontal # is
but vertically you can see 74, 75, 76, 77, 78....?

[ACK777]

After repairing the fronts I tape them off completely and then sand the entire back by hand focusing on any cracks and then scuff the cracked/repaired areas (and pretty much all over) with some lower grit sandpaper to boost adhesion. Once they are fully prepped and ready to go I spray them with an epoxy bed liner building up a rigid backing over many coats which can get surprisingly thick (just make sure your tape game is on point with any louvres and around the edges).

The one caveat is that not all bedliners are the same with some, like Line-X, being way more rigid and giving a lot of support to pieces where others are super flexible so you want to make sure you get the right one that will compliment the state of your covers.  Also knowing how many coates and all the minutiae behind whichever system can be a pain.  If you have the pleasure of living on the mainland in the real world there are probably a couple of different places you could drive to that would spray them for you.  Some of these liners can get up to 3/8"s thick but especially on dished out pieces like covers it adds a lot of strength and was reassuring after repairs.

[Old Moe Toe]

I really like the faded color and patina on those side covers.
+1 for a fibreglass and mesh repair on the underside. I did that with my K0 cracked sidecover and no one would ever know looking at it.

[bryanj]

No matter what repair the will still be 50 yr old degraded and brittle plastic, repair them to keep as originals and fit new supple ones to ride with

[StockRider]

not gonna hurt anything or cost much to repair them...then if they hold up and make you happy you are good to go.  If not, buy some repro's.  I don't see availability going away in the immediate future, at least.  I would not spend the money to repaint the damaged originals though.  No matter what you do, get some new grommets.  Removal attempts with the old hard ones is probably what caused the cracks in the first place.  Grease the tabs for removal in the future.

Are you sure those castings are date codes?  I am certainly not a sandcast/K0 expert, but I have never heard of this with Honda side covers or any other parts I can think of.

Fairly sure. There was a reference that I will have to dig up that mentioned the parts bins in the factory. Depending on where they were in the production cycle you could end up with parts from several weeks to months apart on the same bike assembly.

My frame tag is dated 02/70, so the two "dates" from the side covers made sense to me. Could be an incorrect assumption all around.

There are a few threads over at the sandcastonly.com site:
http://cb750sandcastonly.com/smf_forum/index.php/topic,1748.0.html
http://cb750sandcastonly.com/smf_forum/index.php/topic,837.msg5646.html#msg5646

[StockRider]

I appreciate all of the input so far!

Part of my dilemma is not having a clear, long term plan for this treasure.

My youngest daughter decided at a young age (when it was still her grandpa's) that it would be hers some day.

She's 17 now and still serious about taking it over in the future.

Pictured below at 4 y.o., already the boss.

[newday777]

I appreciate all of the input so far!

Part of my dilemma is not having a clear, long term plan for this treasure.

My youngest daughter decided at a young age (when it was still her grandpa's) that it would be hers some day.

She's 17 now and still serious about taking it over in the future.

Pictured below at 4 y.o., already the boss.

😜
Remember.....
Leave it better than you got it....

[StockRider]

I really like the faded color and patina on those side covers.
+1 for a fibreglass and mesh repair on the underside. I did that with my K0 cracked sidecover and no one would ever know looking at it.

Pulled the emblems off today. I was surprised by two things:
1.) The weight of the emblems. I wasn't even aware they were metal until I pulled them off. That explains why the studs have survived so long.
2.) The paint color underneath. I knew it wouldn't be faded like the rest of the cover but the contrast is crazy.