Frame sliders/engine guards

[LikeAfox_imp]

I have crashed at 65 mph, while sporting SW Motech guards and they saved my crankcase. Left guard was twisted like a pretzel and was missing about 50% of metal, but it stopped the important parts from touching the road. Basically, get those if you want to survive. DO NOT buy the ebay copy guards, yes they cost less, but they are made from pot metal. Original part is solid steel.

Having said that, I'm currently rocking this set https://www.ruchkagaza.com/product-page/...crash-bars

They are hollow, but run the entire height of a frame. They are excellent for mounting foot pegs and other nonsense. I'm going to make plates to block wind to my lower body, come winter time. $200 shipped to my door from Russia.

[Bazbro_imp]

Yup! This is what happens in even a minor spill...



My favourite bars are the Hepco & Becker, very strong, subtle, but most importantly, they bolt straight onto the frame/engine mount, rather than onto a flat piece of metal that only then bolts to the frame. I see this as a weak point.



You're right, Likeafox - the Chinese copies are too insubstantial to be effective.

[max]

These look very nice Bazbro actually the least intrusive look, however we may differ in opinion slightly but i can see them breaking the aluminium cast engine mount on impact because the engine guard looks stronger than the cast mount.
This is what happened to my cb919 by the previous owner who probably mounted frame sliders directly onto the alu cast engine support and they had to aluweld the engine support back on after a crash, a bit of a job.
Just something to consider.

[Houtman_imp]

I still like my Over stainless steel engine protectors for the reason you mentioned.

[Bazbro_imp]

That's a good point, Max.

[2017EX_imp]

I have SW Motech on mine. I dont know if the H&B bars have purpose specific long engine bolts included included or not. SWM includes the two long engine bolts that are designed to fail instead of breaking an engine mount, or bending a frame, if an impact severe enough to damage those components takes place. Quite a while back I did a lot of research on bars before I bought. At the time some members were using the stock Honda long bolts instead of the included SWM long bolts. Here is the thread, what I discovered, and torque values. http://cb1100forum.com/forum/showthread.php?tid=8360

Among other pluses, the SWM have three points of contact with the bike. The supplied long bolts will absorb energy and fail if necessary. I have also seen pictures of these bars after a crash, whereby the flat pieces of steel that mount the front frame bolts and engine mount bolt, bent, but still protected the engine. Here again, energy absorbed and the flat steel bent before transferring enough energy to damage the frame and/or engine mount. Naturally we are talking worst case here, as much of the time the end result will probably be just a scraped up engine bar. I am certainly not throwing shade at any other bar brand or option, just explaining why I went with SWM.

Back in the day, I had case saver bars on my 1974 CB750 Four. The bike slid out from under me during a slow left turn from a stop at a stop light. The case savers were aftermarket, and bolted on at two points. The mount points were flat steel, and bent, but saved my engine case. Ever since then I have been a believer in engine guards.

[max]

Thanks for posting your explanation 2017EX, i have also followed the link provided and read the whole thread.
Most of it makes sense to me and is easy to understand with your posts and i can appreciate why you made the decision to choose these bars and how to mount them; again, they are the nicest ones to my taste.
The washers between the bars and the aluminium frame mount are a good way to spread the load when it comes to the point of stripping the threads of the provided softer bolts, bending them and thereby absorbing the force of the impact and maintaining support even if the bars come in contact with the engine cover, i understand that and agree with it.
Ironically it seems to me that the tighter the bolts are torqued the less force is left to absorb energy before stripping the threads.

Here is where i loose track of your statement;

" I have also seen pictures of these bars after a crash, whereby the flat pieces of steel that mount the front frame bolts and engine mount bolt, bent, but still protected the engine. Here again, energy absorbed and the flat steel bent before transferring enough energy to damage the frame and/or engine mount."

Whilst i agree with the statement i have trouble understanding which flat pieces got bent and how the cast engine mounts remained intact.
Could you enlighten the members and possibly provide the pictures you mentioned or point in a direction so we can find them?
Not trying to be picky but trying to understand what keeps the engine intact.

Very much appreciate the helpful and detailed information you provided, thanks.

[2017EX_imp]

No worries Max. The front most ( closest to the front wheel ) mount is a vertical piece of flat steel welded the the round bar stock. That piece of flat steel has two holes to bolt to the frame down tube. Moving toward the rear of the bike from there, the next mounting point is a vertical piece of flat steel welded to round bar stock. This piece has the mounting hole for the engine bolt. During my research I saw some pictures of SWM bars that had been in a crash. Those two flat steel mounting points showed some bending (twist ) toward the rear of the bike, but were not bent enough to hit the engine, or allow the engine to hit the ground.

[Bazbro_imp]

I am REALLY impressed with both SEMotech's thoroughness and your persistent research, 2017EX. So much so that I'm going to re-examine the H&B ones versus the SWM ones. If I discover anything significant, I'll post here

[Cqrlm911_imp]

Thanks for input....ordered the swm bars