: SW-motech crashbar modification
tsunamichop007 08-28-2008, 11:24 PM Bought a set of SW-motech crashbars...nice looks and well made....BUT it seemed to me the weak link in the design was the way the ends of the bars wrapped around the front of the radiator...my fear was that in a fall that part of the bars might fold in and hit the radiator...simple fix....tie both crash guards together at that point, effectively distributing the impact from one side to the other, locking the whole assembly together....how did i do it...SIMPLE....take a piece of 3/4 black iron gas pipe, cut to just over 12 inches in length, stick it in a vise....heat it with my propane plumbing torch, bend it in the middle, then took two pieces of 1/2 inch black iron gas pipe...make 2 slugs about 2 inches long each, tap them in the ends(some grinding may be required, loosen up one side of the bars slip it in and PRESTO!!... this makes a great place to mount driving lights, or a rock guard????? if you powdercoat it , it will look just like the rest of the guard....i'm thinking rattle can paint.......TELL ME WHAT YOU THINK....Peace
invader 08-29-2008, 02:47 AM Yeah that's perfect. It just needs a sanding and some paint.
I replaced my Hepco&Becker crashguard's crossmember with a twisted aluminum flat bar, to have an collector instead of a restrictor. It's also about a pound lighter...
Red Herring 08-29-2008, 09:04 AM That looks so much better for air flow. Did you make it?
Yeah that's perfect. It just needs a sanding and some paint.
I replaced my Hepco&Becker crashguard's crossmember with a twisted aluminum flat bar, to have an collector instead of a restrictor. It's also about a pound lighter...
invader 08-29-2008, 12:34 PM That looks so much better for air flow. Did you make it?
Yes I did, Red Herring... I twisted both ends in a vise with a large adjustable wrench, then drilled the mount holes.
Machog 08-29-2008, 01:10 PM Nice job invader.
Have to point out that when I 'tested' my H&B's a few months ago, what happens is the side you fall on, pushes the whole bar set up over.
The center bar didn't bend. In my case the right bar side bar ended up fouling the steering yoke, where it bolts to the cross bar, by the blinker.
Nearly fell straight off again, with the restricted lock. It was simple to push back. Lean bike on opposite side of crash, placing some pad or cushion under it and push down on high side gently.
http://i260.photobucket.com/albums/ii30/Macvalk/IMG_2007.jpg
Having said that, the H&B bars totally protected the bike, other than the bars (and my knee) there was zero damage to the bike.
Machog
atgatt 08-31-2008, 01:32 PM Very nice improvements, but it is sad when you pay all that money for a product that still has to be modified to work better.
Like my boss told me, only 10% of engineers are really worth anything. And it's true, a big majority fall short of fully thinking things through. In my job I see it so often and to me here's another example of not having it "right" the first time.
Stupid me for buying frame sliders that stuck out so far that no way could they take the leverage of a fall. I assume someone kicked one of mine off and I spent 4 hours in a hot parking lot trying to get the remaining stem out. Again, my fault for just not returning them as soon as I saw how far they stuck out. Frame sliders are only good if they attach with little protrusion for strong leverage. Just thoughtless engineering and that is what I get for buying the lowerst cost "engine guards".
miguelito 08-31-2008, 04:39 PM Very nice improvements, but it is sad when you pay all that money for a product that still has to be modified to work better.
I'm not an engineer, but the thought occurs to me that by connecting the two sides of the crashbars, and thus reducing the probability of bending them inward, you may also be increasing the probability of unwanted force/bends on the frame where the crashbars attach. Any engineers out there care to comment?
tsunamichop007 08-31-2008, 09:01 PM it's possible but i would think that the engine will act as a stressed member, supporting the frame that encases it, if i bent the frame in any of these areas, the bike will most likely be junk after that anyway, my main concern was not having the ends of the guards fold in and hit the radiator... i'm considering adding addtional tubing to go around the radiator itself...just my 2 cents
gti20vturbo 12-05-2008, 11:17 AM Very nice improvements, but it is sad when you pay all that money for a product that still has to be modified to work better.
But does it work better? It sure looks like to me that under hard braking the front tire/wheel/fender is going to hit that crossmember that was added. I talked to the guys at TwistedThrottle and that is exactly why the bars do not connect. I am still not convinced connecting them is a good idea otherwise SWMOTECH would have made a bar to do so.
Advanced Kawi 02-23-2009, 12:52 AM If you take an impact on one side, what's to stop the bar from simply folding in on the impact side, and bending out on the opposite side? It looks like you just have them mounted in the rear on both sides. I don't see any lateral support..? If this is the case, the only way it'd work is if you took equal amounts of force on both sides.
Maybe you do have some lateral support somewhere, that I'm not seeing..?
Then you have what looks like a travel-restriction on the front-end as well..? Looks like the front tire could hit it under severe braking/fork travel.
Nice first post eh..?
Sorry
tommylikesbeer 02-23-2009, 05:50 AM Not an engineer but crash bars are made to cut down on low impact falls. The stiffer/stronger the crash bars, the more force is transfered to the bike.
tsunamichop007 02-24-2009, 07:41 AM i've been running the crash bars with the suport i made for a few months now.....have not had any problems with the forks under hard braking or going over speed bumps in parking lots.....A few years ago a friend of mine went down on his bike...he had a set of engine guards that were not connected side to side....( harley) not a bad fall, but the guards just folded right back, breaking the mounting bolts right off, and damaging his floor board severely....the Motech bars are made sturdy but the front end of them will fold right end on the radiator, under a moderate drop, without any addtional suport added
joshmedley 02-24-2009, 08:57 AM Ahhhh....geez guys...why bash on the engineer????? We don't all suck!! Typically, most engineers do not have field experience, meaning they've never done anything but desk work...but there are a small minority that can pick up a set of tools and do some good designing. But as a P.E. I would bet, whoever designed the sw motech truely sucked!
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