TerryM
Guest
HMarc said:
I think you are on the right track, but if the bars do not give in a prang the energy will be transmitted to the main structure. So I want them to bend and protect the bike from that eventuality. And I expect that the BM designer of the bars did those calculations, but who in the aftermarket could do so?
Eddy802
Guest
Some interesting points - and some questions this all raises for me:
1. Does anyone have a picture of the black H&B bars?
2. Should the H&B bars actually look symmetrical form the front?
3. With an order ready for H&B bars, should I ditch the BMW piston head covers that are on order?
I don't actually have my GS yet, but am finding these forums a fantastic resource.
Thanks guys.
Eddy
1. Does anyone have a picture of the black H&B bars?
2. Should the H&B bars actually look symmetrical form the front?
3. With an order ready for H&B bars, should I ditch the BMW piston head covers that are on order?
I don't actually have my GS yet, but am finding these forums a fantastic resource.
Thanks guys.
Eddy
Eddy802
Guest
Another question...
If I add bars that are so strong that in a crash the force is passed to my frame, to an extent that the bike is written off, is the insurance company going to have issue with this, any more than they would if had no bars and the damage was to the engine and other parts?
A mod to declare at insurance time I guess (he said, answering his own question - almost!!)
Eddy
If I add bars that are so strong that in a crash the force is passed to my frame, to an extent that the bike is written off, is the insurance company going to have issue with this, any more than they would if had no bars and the damage was to the engine and other parts?
A mod to declare at insurance time I guess (he said, answering his own question - almost!!)
Eddy
johnnybravo
Registered user
TerryM said:
I take your point about dispersal of energy but I have two questions.
1. Is the designer of the BM bars the same person who designed the "chocolate teapot" head protectors?
2. If you look at 1150 bars, they have bracing all round so where does the energy go then? I wonder whether the 1200 bars are as much of a styling exercise - to appeal to the crossover sports bike riders - as they are protective. I don't think that the engine's have changed that much structurally, so why the heavy bracing for one model and not the other?
TerryM
Guest
Being no expert on the detailed structural differences between 1150 and 1200 I cannot give a definitive answer, but the BM blurb for the 1200 shows the bike having a vestigial subframe attached to the power unit at the front and something a little more substantial at the rear. Which would dictate the load bearing path of any crash bars.
The BM bar mounting is triangulated on both sides of the bike, the two lower mountings(in a horizontal plane fore and aft) being very sustantial and the upper is rather like a compression strut at about 45 degrees but with a more flexible mounting than the lower two.
This seems designed to give relatively greater resistence to the topple and drag mode at the bottom but allowing the upper bar to bend in and back, to absorb shock without feeding loads into the top of the power unit.
The bars also have a double elastomer insulated(?)joint in each top horizontal side bar vertically in line with the cam/rocker box cover joint which is "pinned" by a rosette weld at top and bottom to an inner tube(?) on one side of the joint only. This seems to be designed to allow some give without breaking, and fits in with my understanding of the compression strut which needs such an arrangement to work.
It looks to be a sophisticated, well thought out and executed design. And demonstrates that clever design can eliminate the need for yards of tubing forming a ugly and heavy cage and still provide good protection.
But forgive my reluctance to chuck it down the road or take out my sledgehammer to prove it.
The cylinder protectors perhaps could be made stronger, but I suspect BM consider them sacrificial.
The BM bar mounting is triangulated on both sides of the bike, the two lower mountings(in a horizontal plane fore and aft) being very sustantial and the upper is rather like a compression strut at about 45 degrees but with a more flexible mounting than the lower two.
This seems designed to give relatively greater resistence to the topple and drag mode at the bottom but allowing the upper bar to bend in and back, to absorb shock without feeding loads into the top of the power unit.
The bars also have a double elastomer insulated(?)joint in each top horizontal side bar vertically in line with the cam/rocker box cover joint which is "pinned" by a rosette weld at top and bottom to an inner tube(?) on one side of the joint only. This seems to be designed to allow some give without breaking, and fits in with my understanding of the compression strut which needs such an arrangement to work.
It looks to be a sophisticated, well thought out and executed design. And demonstrates that clever design can eliminate the need for yards of tubing forming a ugly and heavy cage and still provide good protection.
But forgive my reluctance to chuck it down the road or take out my sledgehammer to prove it.
The cylinder protectors perhaps could be made stronger, but I suspect BM consider them sacrificial.
H & B
I've had them on the 1100, 1150 and now the 1200. They came on the 1100 and I fitted them instead of the BMW ones after seeng how the OEM ones didn't protect the heads in a satisfactory manner after a 1mph off for someone else on the Hardnose pass.
Seems to me that the opinion of most is that the OEM ones look the part they don't seem to provide as much protection as they promised. And that's with the thought that most "protection" is going to be no use above 30mph ish. It's only reducing the damage!
I've had them on the 1100, 1150 and now the 1200. They came on the 1100 and I fitted them instead of the BMW ones after seeng how the OEM ones didn't protect the heads in a satisfactory manner after a 1mph off for someone else on the Hardnose pass.
Seems to me that the opinion of most is that the OEM ones look the part they don't seem to provide as much protection as they promised. And that's with the thought that most "protection" is going to be no use above 30mph ish. It's only reducing the damage!
Read the reviews and seen plenty of pictures of the H+B bars, but none of BMW variety for the 1200... Can someone post a piccie or two of the BMW ones, please?
TerryM
Guest
GSmonkey said:
Right Monkey!!!!!!!!!!!!
As I said then when Andre posted the picture, they ARE the OE bars from BM. Is he still claiming that he and his fabricator invented them?
Of course it could just be that he designed the things in such a clever way that BM nicked his design and sells them for less than the after market do their stuff.
WHOOPS!!!!!!!!
Sorry guys, I just revisited the picture Andre posted, and they are a very poor cosmetic copy of the BM bars, the obvious difference being that they have only one weak looking lower mount, and not the double lower mounting on each side which is a key feature to enable the BM design to work. Consolation is that I goofed in the safe direction. Apologies. But does not change anything really.
The BM catalogue and on line stuff illustrates quite well . Sorry but I do not do photography. However if you spend ten minutes looking at and understanding what BM did here you will see what I am talking about.
TerryM
Guest
Re: H & B
Not much works above 30mph if you hit a solid object, usually you will be dead!!!!!
But controlled collapse of any structure delays demise very well, so I am interested in the detail of how the BM bars for your previous toys were designed and how they failed to impress you. Were they"identical"as near as you can tell to the present gs and what was the mounting arrangement?
John Armstrong said:
Not much works above 30mph if you hit a solid object, usually you will be dead!!!!!
But controlled collapse of any structure delays demise very well, so I am interested in the detail of how the BM bars for your previous toys were designed and how they failed to impress you. Were they"identical"as near as you can tell to the present gs and what was the mounting arrangement?
TerryM said:
Terry, I'm looking at the BM accessories catalogue now and the picture looks the same as Andre's i.e. one lower mounting point. If you look at an engine without the bars, you'll see an empty threaded hole which takes the bolt. This contrasts with the H&B design which spreads the load between this point and the more substantial engine mounting bolt immediately adjacent.
I stand to be corrected, as I haven't seen the BMW bars in the flesh, only in the catalogue.
TerryM
Guest
GSmonkey said:
Monkey,
I have the brochure here, and the bike in the garage with the OEM bars fitted on two lower mountings, one being the engine mounting. The picture in the brochure is very small and may not be representative of the actual bar mounting which is very substantial and clearly designed to take high loads. I looked at the H+B jobbies on the web and did not think the design as good. Also the tube to tube welding(out of round) and onto mountings(bracket to side of tube if I recall correctly) was badly designed and poorly executed.
I did think the OEM bars expensive at 130 quid, but did I not see the H+B's at 140?
All I suggest is that anyone seriously in the market should critically evaluate the OEM unit against the aftermarket. They look well and cleverly engineered to me and the details of welded joints(e.g. tig welds without dimples which indicates that the operator knew his trade) and attachments to the bike are to a very high standard and that is what I demand. After all I cannot do crash testing of competing types. So I do it on engineering, design and construction.
Terry
Looks like they must have changed the design in line with H&B, because if you look at the R1200GS catalogue (picture below) you can see that it only connects to the one point, which I assume is designed specifically for bars. Whereas the H&B also spans across to the engine mount. Maybe BMW cocked up the original design and realised it wasn't strong enough.
Attachments
TerryM said:
Try £195 for the OEM ones.
Rod
Registered user
Skimming through this thread, I can't see mention of the Touratech crash bars. On their web site they look well designed & good looking. Has anybody seen or bought these??
Eddy802
Guest
My questions got lost in the technical back and forth there....
1. Does anyone have a picture of the black H&B bars?
2. Should the H&B bars actually look symmetrical from the front?
3. With an order ready for H&B bars, should I ditch the BMW piston head covers that are on order?
Anyone?
Cheers
Eddy
1. Does anyone have a picture of the black H&B bars?
2. Should the H&B bars actually look symmetrical from the front?
3. With an order ready for H&B bars, should I ditch the BMW piston head covers that are on order?
Anyone?
Cheers
Eddy
See this piccy:Eddy802 said:
Well the bike isn't symmetrical, so why should the bars be??
Well both fit together see the piccy below, so I guess its up to you whether you want both, I will have when I've put the bars on:
TerryM
Guest
John Armstrong said:
Correct, misread the price list.
Terry
TerryM
Guest
GSmonkey said:
Certainly the OEM bars use the second mounting point which you indicate in the photo. I do not know if they ever sold the single point lower mount version or if it was a mock up for publicity pics?
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