R1150GS broken rear subframe

[JeffMunn]

Have scanned this forum, but can't find any other thread on this.

Thought I'd post this as a cautionary tale to other "adventurers". My 2001 R1150GS had it's rear subframe snap in two last week. Okay, it might have been before that, but I only found it last week. The frame break is on the right side, just below the rear brake reservoir.

I've seen it happen to others, and have long known of the advice to NEVER use a rear topcase, but thought I would avoid this issue. No, I never have used a topcase, and actually removed the rear seat to carry my gear more centered. But with over 132,000+ miles, 40+ countries and tens of thousands of miles of dirt/third world roads, I guess it was about time.

I've taken most of the morning to slowly disassemble the rear end, and remove the rear subframe. As of now my valiant GS sits brokeback and spineless in the shop.

I've got to admit, that with the Jesse bag frames, it is not a small or lightweight assembly. I'm really surprised that BMW has made the frame such a small diameter for a bike that is supposed to be an offroad monster. When I get the break fixed, I will be adding gussets on both sides for added strength at that location.

I've kept detailed notes on the disassembly. Would be happy to share the knowledge of others need it. Surprisingly, you can remove the entire sub assembly without major removal of other components.

Cheers,
Jeff

 

[DARKCLOUD]

Check with toura tech and see if they have braces to strengthen the frame. If an R1150RT rear frame is the same I have a spare. Jon

 

[PGlaves]

Two observations. First, notice that the Jesse case mounts stress this location as well as a passenger, and a rack or top case.

But, also notice that this location is in compression and not tension or shear when weight is on the subframe. This puzzles me because of several spots I might expect it to break this is not one of them.

BMW prescribes a specific order in which the mounting bolts are to be tightened. This break actually looks like a stress break due to stresses between the location of the two front bolts at the engine and the location of the two rear bolts at the transmission. I doubt the transmission was moving around, so it looks to me like the crack is from stresses imposed when the thing was last bolted on, or last tightened after a swing-up for a spline lube or clutch job, etc.

 

[podsobinski]

Another broken frame

Seems like I remember in the epic video/book/around the world ride, Long Way Round, one of those actors broke the frame on their Adventure also. They had it welded along the way and had no other trouble. 93,000 miles and 7 years of riding my GS 1150 with my bride and it never happened but I am a small 230 lbs. and my bride comes in at 140 and add our gear. . .wow those BMW's do pretty well.

06 K1200LT
07 DR650

 

[JeffMunn]

Two observations. First, notice that the Jesse case mounts stress this location as well as a passenger, and a rack or top case.

But, also notice that this location is in compression and not tension or shear when weight is on the subframe. This puzzles me because of several spots I might expect it to break this is not one of them.

Agree that the Jesse mounts are a major cause of the forces at that location. The entire rear subframe is a cantilever from the shock rearward, but the way the Jesse forward mount is, causes vertical stresses at that point. Loading it actually helped hold it together.

If you search Horizon's Unlimited forum, this actually happens fairly frequently to world travelers. There are several postings of solo riders and couples in SA or South America who have had this issue as well, and photos of the fixes.

BMW prescribes a specific order in which the mounting bolts are to be tightened. This break actually looks like a stress break due to stresses between the location of the two front bolts at the engine and the location of the two rear bolts at the transmission. I doubt the transmission was moving around, so it looks to me like the crack is from stresses imposed when the thing was last bolted on, or last tightened after a swing-up for a spline lube or clutch job, etc.

Paul, if you could share any specific re-mounting instructions that would be wonderful. Torques, order, etc. I understand what you are saying about this as a possibility, but am less than convinced that is the cause, but welcome any advice or tips on proper assembly . I'm smart enough to heed the experience of others and would be more than willing to take your advice on the re-assembly in order to limit future potential for issues.

The clutch was replaced at about 94,000 miles by a certified BMW shop, just prior to me leaving on my world trip. I did not find the break on return at 126,000 miles, but it has occured in the last 2,000 miles which were mainly on WV roads and twisties. Not much off-pavement at all.

All in all, this bike has done yeoman's work for a long time, in very rough conditions. I'm not surprised at all that something would eventually break. It is being repaired as we speak by a custom bike frame welder here. He has the table, jigs, and experience. He's also going to gusset each side, above the specific tube, and also below the one on the left side. $100 was the agreed price.

I'll post pictures when I get it back.

jeff

 

[JeffMunn]

She is good as new!

I'll apologize in advance for the lack of pics. I'm departing in about an hour for the Swamp Scooter Rally in Louisiana and am in a bit of a rush.

The rear subframe is slugged, welded, gusseted, and gooder than new. I do have pics, but will have to post them when I get back. Total cost was $100. Both sides were gusseted to reinforce the week points.

I'll have to say that putting her back together again was way harder than taking her apart. Most definitely a two person job. Disassembly was about 2 hours. Rebuild was closer to three, with a lot of swearing thrown in for good measure.

Took her out for a 350 mile shakedown ride in the mountains of eastern West Virginia last weekend. She is almost as good as new again.

I'll be at the rally near Lafayette, Louisiana this weekend if anyone wants to see the frame repairs. Just look for the silver 2001 GS with black Jesse bags, and the Chinese license plate.

I will post pics when I get back, I promise!

See you on the road,
Jeff