nknudsen was asking about my frame rust in my parts for sale thread, and so I thought it might be a good idea to start a fresh thread to discuss it, and as a slight warning to others 
Filling in the back story, I bought my '01 EC200 a couple of years ago, with the intention to get into green laning. I never really got round to much off road so it's spent much of lit's life with me as a supermoto.
Last week I was working on diagnosing a running issue (turned out to be cracked reed petals) and I noticed this worrying looking hole in the frame where the down tube splits into the two smaller tubes that run under the engine.
I spend a lot of time around classic cars, so I'm well used to rust, and quite a competent welder. So I figured it looked a simple enough repair. I stripped the bike down so I could get a better look at the frame, and after a bit of poking about with a screw driver the rust was clearly a bigger issue than I first thought.
Still, not a difficult area to patch and repair, so the next step is to get in there with a grinder and cut it back till we have clean metal to work with.
Oh? After cutting back the area around the two obvious holes in the previous photo, I could see inside the box section down tube. Inside were 2-3 handfuls of mud and rust flakes. The box section down tube had completed rotted away in some places where the two lower frame tubes join up. In this picture I had got in with a screw driver and poked around a bit to find out what was paper thin and flexible and what wasn't so it looks a bit more exaggerated that it did when I first opened it up.
Lifting the frame up, I could hear mud/rust flakes siding around inside most of it. With that in mind, I have the whole frame a bit more of a prodding with the screw driver and found a couple more small holes in one of the lower frame tubes, underneath where the engine sits. So I decided to cut into it and open it up to look inside.
Again large amounts of mud and rust flakes came out, and it's clearly weakened in there.
At this stage, it's clear to put the strength back in this frame would be a very large job, certainly requiring serious jigging, if not just ending up with the standard headstock and a completely rebuilt rest of the frame! So it's going in the bin.
From the outside the frame really didn't look so bad, it was clearly rusting from the inside out. Now that I've got the frame upside down in the garage and can study it, I can see that most of the frames tubes have got small drain holes in them, all of mine were completely blocked up with mud, so the frame wouldn't have drained properly. From my 4 wheeled experience I know just how much damage that trapped moisture can do.
Hopefully someone can read this, clear out their drain holes and save their frame before it rots out like mine has!
Filling in the back story, I bought my '01 EC200 a couple of years ago, with the intention to get into green laning. I never really got round to much off road so it's spent much of lit's life with me as a supermoto.
Last week I was working on diagnosing a running issue (turned out to be cracked reed petals) and I noticed this worrying looking hole in the frame where the down tube splits into the two smaller tubes that run under the engine.
I spend a lot of time around classic cars, so I'm well used to rust, and quite a competent welder. So I figured it looked a simple enough repair. I stripped the bike down so I could get a better look at the frame, and after a bit of poking about with a screw driver the rust was clearly a bigger issue than I first thought.
Still, not a difficult area to patch and repair, so the next step is to get in there with a grinder and cut it back till we have clean metal to work with.
Oh? After cutting back the area around the two obvious holes in the previous photo, I could see inside the box section down tube. Inside were 2-3 handfuls of mud and rust flakes. The box section down tube had completed rotted away in some places where the two lower frame tubes join up. In this picture I had got in with a screw driver and poked around a bit to find out what was paper thin and flexible and what wasn't so it looks a bit more exaggerated that it did when I first opened it up.
Lifting the frame up, I could hear mud/rust flakes siding around inside most of it. With that in mind, I have the whole frame a bit more of a prodding with the screw driver and found a couple more small holes in one of the lower frame tubes, underneath where the engine sits. So I decided to cut into it and open it up to look inside.
Again large amounts of mud and rust flakes came out, and it's clearly weakened in there.
At this stage, it's clear to put the strength back in this frame would be a very large job, certainly requiring serious jigging, if not just ending up with the standard headstock and a completely rebuilt rest of the frame! So it's going in the bin.
From the outside the frame really didn't look so bad, it was clearly rusting from the inside out. Now that I've got the frame upside down in the garage and can study it, I can see that most of the frames tubes have got small drain holes in them, all of mine were completely blocked up with mud, so the frame wouldn't have drained properly. From my 4 wheeled experience I know just how much damage that trapped moisture can do.
Hopefully someone can read this, clear out their drain holes and save their frame before it rots out like mine has!
