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Alt-Rider Crash Bar Vibration Problem

15K views 32 replies 17 participants last post by  pond 
#1 ·
The Alt-Rider Upper and Lower crash bars are the best available for the Africa Twin (in my opinion). However, there is a very serious engineering flaw with the reinforcement bars (optional third piece that connects Upper bars to Lower bars on each side). Once connected, they cause a horrible high frequency vibration between 3800 and 4200 RPM. It is so bad, it will probably cause damage to the engine and frame welds over an extended period of time. The problem is that they turn the entire crash bar system into a huge tuning fork that adds harmonic vibrations at the RPM range previously mentioned. I'm going to try adding strips of weight to the reinforcement bars to act as a damper. I hope this works; Otherwise, avoid the reinforcing bars option.
 
#6 ·
I have not noticed this either.

Are you certain these are torqued down properly?

My only complaint about the brace bars is they damage the upper and lower powdercoating when you tighten these down or even fit them.

The cast pieces are super sharp and cut right into the paint. So if you make a mistake on placement you're pretty much boned.
 
#11 ·
They're definitely fit and torqued properly. The ride is smooth as silk without them and extremely noticeable vibrations (between 3800 and 4200 RPM) once they're added. Obviously, you need to be riding on a fairly smooth paved road or you may not notice it as much. Alt-Rider is looking into this and said they would try to get back to me within a week or so. I have the silver bars so there is no scratching issue.
 
#14 ·
Hey Sparky, if you have time you should let Bruce (bruce.n@altrider.com) at Alt-Rider know about it. I gave him a full description of the issue and they're very concerned and doing testing to find a solution. The more people they hear from may expedite their solution. I am personally trying to make a custom set of rubber mounts to isolate the harmonic vibrations and I may also try filling the tubes with lead shot to act as a dampener. I'm not thrilled about either of my ideas...I hope Alt-Rider comes up with something better.
 
#15 ·
Vibration Problem is ONLY With Reinforcement Bars

Since this thread is getting a little deep now, I just want to confirm that the vibration problem is ONLY with the "Reinforcement Bars" that connect the uppers to the lowers. This is a 3rd optional set of bars that can be added after the initial install of the uppers and lowers. I still highly recommend the uppers and lowers which can be purchased separately. There are no vibrations with the uppers and lowers...Only after installing the reinforcement bars which connect the uppers to the lowers.
 
#17 ·
Still waiting to hear back...Apparently, their Africa Twin is being used by their President on a Colorado journey so the testing is yet to come. I'm sure it's a problem with all Africa Twins using the reinforcement bars. I would suggest the 2 gentlemen that haven't noticed the problem do a more careful review at the RPM's I noted both with the bars and without. Extended exposure (hundreds of hours) to vibrations like these can cause very serious structural issues.
 
#22 ·
First of all I can give crash testimony that they work and they work well, they've saved the bike 3 times now and all three times have been in bad spots where an AT shouldn't be, just because it says CRF on the side doesn't mean that it's a trail bike. I've only seen photos of other crash bars and the Alt-Rider bars look as good as anyone else's.

About the vibration, I installed the upper and lower bars and rode the bike for about 500 miles, the reinforcement bars were back ordered, I have about 200 miles on the bike with the reinforcement bars installed and have not noticed any difference.
 
#23 ·
Glad to see I am not the only one that is finding himself areas and situations where AT is capable of taking me but I should have used better judgement. Thank goodness it is capable of getting me out too, and it is the bike not my riding skill that has saved my butt on several occasions now.

On and off road, no major vibrations with the full Alt Rider crash bars. They seem very strong but fortunately I have not tested them yet.
 
#25 ·
Yeah...I feel it very clearly (no sound)...It's nice and smooth and then suddenly at around 3800 I get a "stiff" vibration that comes on quickly in the handlebars. If I reach down and touch the reinforcement bars, I can really feel it. The right side seems to be a bit worse than the left. Everything is torqued and tight...It just seems to be the way the reinforcement bars are attached/designed...It's acting like a tuning fork.

Alt-Rider got back to me and said they were unable to recreate the problem so they didn't have any particular solution. They also noted that they have heard of certain Africa Twin production runs that have people feeling vibrations in the handlebars.

I'm just going to remove the reinforcement bars and eat the $120...I really like the uppers and lowers so they will be staying. I have no vibration problems without the reinforcement bars.

Thanks,
Scott
 
#27 ·
I've had the full system a while now and just returned from several 1000miles in Alaska with various terrain, and I didn't feel a difference at all. Since I've heard about this problem I've tried to replicate it. I've spent more time than I should since mine didn't do it to start with, but I was very curious about it and I can't replicate the issue. Obviously the bike vibrates more at the RPMs stated and I'm sure you understand that. This is right near the power and there will be more vibration. I took the support bars on and off a few times, to see it there was a difference.
Riding the bike and reving it in neutral, as far as I can tell there is slightly more in the upper crash bars with them on than off, but I think it's because it is resonating from the lower bars through he supports and into the uppers. I didn't notice a difference at all in the handlebars, or in my black dog foot pegs (no rubber on these pegs)
I'm sure AltRider is investigating this as well. They pay a lot of attention to detail and want to produce the best product for our bikes. Their customer service is top notch, but unfortunately , this may be a bike specific issue. I know Honda has had a few minor things different among these production bikes. I would be interested to know if you were to cut a few strips of a old front tube and put it in between the mounts of the support bars, if you erpierence a difference.
 
#28 ·
... there is a very serious engineering flaw with the reinforcement bars ... they cause a horrible high frequency vibration between 3800 and 4200 RPM. It is so bad, it will probably cause damage to the engine and frame welds over an extended period of time. ...
Pretty strong words and opinions.
No Professional Engineer would ever publicly critique or comment on another Engineers design without having first raised the issue with the design engineer, reviewed all design drawings and calculations, then allowed the design engineer an opportunity to respond to the review.

I hope you get it sorted out.

A while ago some were commenting on vibrations with SW Motech crash bars. Turns out they had installed the front cross brace on the wrong side of the sidebar tabs.
 
#30 ·
I have had mine for over a month and I have not noticed any vibration at all. I rode it to work yesterday & this morning and tried to pay close attention to see it i noticed anything but i felt nothing.
The majority of us with the full system cannot feel any more vibration than the bike naturally produces. The OP stated in another thread that he is selling the bike because of the vibration that exists even without the crash bars...
 
#31 ·
Yes, gentlemen they do vibrate when connected. I have had mine since 2017 and i made Altrider aware of this. They had many reports concerning this vibration problem and since i had the un-painted version they told me that the powdered coating would reduce the vibration. I switched and no apparent reduction in vibration. So I contacted Altrider and explained the situation and in addition explained my inclusion of thick rubber washers at all upper and lower crash bar points to no alleviation of the vibration. AltRider suggested that i disconnect the middle tie in bar ( defeats the purpose of the crash bar cage system) to reduce the vibration and it did diminish the vibration but was still there. So I only use the the mid-tie-in bar when riding other than gravel roads. Altride was adamant that they would not reimburse my money during that warranty year and not much else was out there at the time. Also, I have found that the upper crash bar's lower anchor tabs/points bend very easy with a mere tip over even with the Mid-tie-in bars install. so bending them back weakens them exponentially and soon will need replacement. I suggest that if you ride hard off-road to replace the Altriders with the Outback Motortek crash bars and skid plate system. Just my 2 cents!
 
#32 ·
Hey @strmboui - you appear to be an original Africa Twin Forum member??

Well, a long time comin' - Welcome to the Forum!

I reckon your Altrider issue is restricted to the upper bar system only since that is all you mention?

You must have some long running time AT experience? Feel free to introduce yourself at the New Member Introductions area of the Forum.
 
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