Rear broken frame repair - 1100GS

[dancata]

Hi all,

Here are some pics of my bike, where the rear frame connects to the gearbox, on the right side. This has been broken by the PO, from a trip to Norway. He said the repair was made by a trained BMW mechanic while working after job hours. It looks ok, rigid and I had no problems with this so far, for the past 32k km since the bike has been mine. Hope this helps someone.

Thanks,
Dan.

 

[Stewart H]

That looks like a strong repair, probably a lot easier than alloy welding too.
Stewart

 

[dancata]

F%ck! Just saw this now, in the picture...

Does the pivot pin (6) look OK to you?

 

[John Armstrong]

I can see threads on mine too, which is either good or bad

 

[Timolgra]

F%ck! Just saw this now, in the picture...




Does the pivot pin (6) look OK to you?

The pivot pin won't be located fully in the bearing and you need to remove it and measure how much thread is going into the paralever...else it'll collapse

 

[Vern]

The plate is cut around the pivot pin,so it won't make any difference to it

Now try and keep up and look at the pretty picture again

 

[Mac]

A most excellent repair

 

[dancata]

The plate is cut around the pivot pin,so it won't make any difference to it

Now try and keep up and look at the pretty picture again

Yeah, I know that the plate doesn't make any difference to the pin, but the screw probably needs adjustment... Will read the manual and see what needs to be done. The thing is that I kind of feel the bike while loaded with passenger and bags like a old bus, the one that bends from the middle.

Also, I have a new telelever front pivot that needs to be replaced, but I don't have the time to change it :|

 

[dancata]

According to this,

it says screw in fixed bearing journal; doesn't that mean it should go all the way in, an no threads remain vizible?

Dan.

 

[Vern]

Dan,nothing needs adjusting there.The pin is fully home,and the plate fits around it,so don't worry to much

What you can feel that is like a bendy bus,is just the steel plate moving a bit,but it will probably be fine for the next 100 years.

Good fix I think

 

[Timolgra]

The plate is cut around the pivot pin,so it won't make any difference to it

Now try and keep up and look at the pretty picture again

I'll just keep quiet in future

 

[zarly]

Doug in Victoria

Hi there, I just registered here due to a converstaion I'd been having with Dancata, I have a similar break at the rear subframe mount on the transmission housing, and have been searching for a fix. Here's what I've found as possible fixes.

1 - Weld a mass of metal onto the housing and re-drill it for the bolt to attach.
2 - Fix with super metal plate like Dan has done
3 - get a used transmission

I'm full of questions because I have as much mechanical experience as my grandmother has spitting, so please be patient with me.

New transmissions are expensive, used M97's aren't very common. What would you do? The fix Dan has on his bike looks strong and sturdy and simple'ish compared to the other options. Aluminum welding sounds like a hit or miss operation from other things I've heard. And would I really have to have the transmission removed to have the welding done?

- Is aluminum welding that hard to get done, and if done correctly would it be strong?

- Dan, is your "bends like a bus" a really noticeable feeling?

- Vern, Would metal really move like that when it's bolted on in three places?

- My insurance company wants to write the bike off rather than try to help me fix it. Are they taking drugs?

Thanks everyone!
Doug Walker
Victoria, BC
Canada

 

[Vern]

Hi Doug,

Ally welding would be fine and plenty strong enough,if done properly,BUT I wouldn't fancy the chances of doing all that welding without stripping the gearbox out completley.Al the rubber seals and bearing cages would suffer one way or another,especially if your bearings are caged in nylon supports.

The metal would bend easily enough.The three fixing points on the gearbox,and the one on the subframe have got a big radius bend inbetween them,so plenty of flex available there.

I'm going to have a look and see how feasible it is to make a "get you home kit" tomorrow.Watch this space.

If the insurance want to write it off,then let them and buy it back off them if that's how it works there,and then mend it your self

How's that for starters

And welcome to the site as well

 

[zarly]

Thanks Vern! So when you say "there is a big radius bend" between the three mounting bolts and the fixing point on the subframe... does that mean that because the stress is now going to be on the lower three mounting points rather than on the top of the gearbox, that will make the steel plate bend earthward when it's under stress.. is that what you're saying sort of?

OH... and also, stripping out the gearbox, do you mean removing the gearbox from the bike, or remove the gearbox from the bike and then take the guts (gears) out of it?

And which would you do, if you were me... since you sound as though you know what you're talking about?

Hi Doug,

Ally welding would be fine and plenty strong enough,if done properly,BUT I wouldn't fancy the chances of doing all that welding without stripping the gearbox out completley.Al the rubber seals and bearing cages would suffer one way or another,especially if your bearings are caged in nylon supports.

The metal would bend easily enough.The three fixing points on the gearbox,and the one on the subframe have got a big radius bend inbetween them,so plenty of flex available there.

I'm going to have a look and see how feasible it is to make a "get you home kit" tomorrow.Watch this space.

If the insurance want to write it off,then let them and buy it back off them if that's how it works there,and then mend it your self

How's that for starters

And welcome to the site as well

 

[Pekkavee]

One way to avoid this kind of failures is to install Touratech Hard Parts in the first place.
http://tinyurl.com/yb2jxwv

I did it, but too late. The gear box mounting was broken allready.

Pekka

 

[zarly]

One way to avoid this kind of failures is to install Touratech Hard Parts in the first place.
http://tinyurl.com/yb2jxwv

I did it, but too late. The gear box mounting was broken allready.

Pekka

Yep. Me too. How did you fix it?

 

[dancata]

Hi there, I just registered here due to a converstaion I'd been having with Dancata, I have a similar break at the rear subframe mount on the transmission housing, and have been searching for a fix. Here's what I've found as possible fixes.

1 - Weld a mass of metal onto the housing and re-drill it for the bolt to attach.
2 - Fix with super metal plate like Dan has done
3 - get a used transmission

I'm full of questions because I have as much mechanical experience as my grandmother has spitting, so please be patient with me.

New transmissions are expensive, used M97's aren't very common. What would you do? The fix Dan has on his bike looks strong and sturdy and simple'ish compared to the other options. Aluminum welding sounds like a hit or miss operation from other things I've heard. And would I really have to have the transmission removed to have the welding done?

- Is aluminum welding that hard to get done, and if done correctly would it be strong?

- Dan, is your "bends like a bus" a really noticeable feeling?

- Vern, Would metal really move like that when it's bolted on in three places?

- My insurance company wants to write the bike off rather than try to help me fix it. Are they taking drugs?

Thanks everyone!
Doug Walker
Victoria, BC
Canada

I think the bendy bus feeling comes from this :

http://www.youtube.com/watch?v=JIo1lukQjcs

Will replace the telelever pivot these days and come back with news.

The bendy bus is not from the frame repair, that's for sure!

Dan.

 

[Pekkavee]

Yep. Me too. How did you fix it?

Welded the mounting first in order.

Pekka

 

[zarly]

I think the bendy bus feeling comes from this :

http://www.youtube.com/watch?v=JIo1lukQjcs

Will replace the telelever pivot these days and come back with news.

The bendy bus is not from the frame repair, that's for sure!

Dan.

Yeah that definitely looks a little odd Dan. I can see why the bendy bus feeling would come from that.

 

[biggles12]

Hi
One of our bikes broke the gearbox mount off and we thought about a fix like yours, but we were a little worried about the strength of the gearbox where the foot rest mounts. Have you been off road with panniers yet? I still have the old box here and was thinking of welding it but if your plate is strong I might just make a plate up.

Ta
Pete