Separate names with a comma.
Discussion in 'Hacks' started by Melrone, Jul 19, 2010.
Picture of the complete bike. Thanks to Motoblag again. It doesn't seem to me at all that this hack is abused. I've seen worse.
It would still be interesting to see how this is connected to the sidecar frame:
For what it's worth I am going to guess that the eyenut with the broken bolt was sticking up vertical on the sidecar frame with the stut connected to it. The bolt probably became loose was unnoticed and eventually fatigue from 'working' got the best of it.
We use similar connections from time to time but with a larger base on the eyenut where it sits on the plate or whatever it is connected to. It is a different eyenut design than what we use on the struts.
I was thinking along what Claude suggested: one or more of the mounts may have worked loose and flex may have caused it to fail. Discolored metal at the break can be an indication it is an old fracture that has been working back and forth for some time. That is also why I hope you will take a hard look at the other mounts. They work together and often fail together, just as a broken spoke will cause other spokes to loosen and break.
Absent an obvious design flaw or material defect, one must at least wonder if the mounts had been allowed to loosen and work, leading to failure. In the photos these look very similar to what a number of manufacturers have been using and do not appear to be cheap or shoddy parts. Again, no way to tell over the internet and sometimes hard to tell up close. Take it to Claude and have him check the other mounts too.
Thats the thing. After i put my new final drive in I took off the lift and mounted the hack back on for the 3rd time I cheked every bolt I could find.Everything was tight.I'm splitting the rig agin for the 4th time this weekend and checking them all agin including the sub frame bolts.I'm about ready to put Ford sticker on it.(.Fix or repauir daily)As they say shit happens
it can be frustrating. we have been going through my brothers sidecar. It's a bitsa that we put together and he has been bouncing it off rocks. We can't blame the manufacturer although it was probably a Velorex strut that initially failed. But we replaced that with a stronger strut and the rig started folding up again the second day of the rally. None of the mounts had moved(we striped them with paint so we could see if they had shifted), Nothing looks broken or bent. We stripped the bike and the sidecar and found nothing wrong! So we put it back together with a little heavier bits and a new suspension. After seeing your thread I told Andy to pull the strut eyes off. I want to wire brush them and look again a little more closely!
Thats exactly what I'm going to do.Because afterThe tilt controlarm broke and fixed this rig was stiffer than its ever been.I'm not using this rig for a dirt bike.I wanted the power plant and big gas tank.This is my second GS so I know the bike.You'd think with all the work I did over the winter it would be bullit proof,but it looks like more dental floss is needed to fix my Pygmme Pony.Oh well its back to the lift and inspecting.
Listen up boys and girls I just talked my machinst.he said by the look of things the eyelet was definitly machined wrong.it was a one piece unit macined then thread to3/4x16 with a thread block which was done way wrong.I'll know more later he's playing with it right now..:dog
Here we go.I just went through every related part of the subframe and mounting areas of the on the sidecar.Nothing was loose or cracked. In my opion the subframe is tight and very well built.The opion of my machinist friend was a weak low grade material used in making the eyelet mount.He told me expected to eat a drill bit cutting into eyelet mount,but it was the other way around.The bit cut through like butter.He drilledout and tapped it for a 3/4x16 thead. So yet agin we modify these pieces to make them right.This pretty much wull be dine the way Claude makes his.I will run a grade 8 or 7 threade rod in Locktite Them add another locking bolton the top of the theaded unit.Jay did send me a new one but it was eaxctly like the old one.I can't afford to have another one break.My wife and Granddaughters ride in my tub.This is my presious cargo.i don't as a rule like to or enjoy bashing people or businesses,but when its a bad part and alot people are running these rigs.Its good thing to warn fellow hackers about the said problem.This way maybe it will prevent any bad accidents.This rig is suppose to be my retirement rig.I'm not going to giveup on my rig.But I will improve it to make it better.In 2012 we plan to make a run up to Neufoundland to visit her brother.I also plan to use this rig for major traveling,beause of my left knee replacementit makes it very hard to holdup a 2wheeler packed even solo.I had a snow plowing accident in 05 that has changed my life some.And this is one of them Short rides solo on 2wheels is fine.But long runs no good anymore.So I'm writing this to explain things.My love for hacks go way back to the first time I saw one.This is my 3rd hack in 10years out of 40years riding.I hope all you fans af Dauntless now understand my frustation about whats happening.I'd also like thank those who threw out some info to help me with these problems......
Is it that difficult to answer a question? It works both ways you know. Furthermore I would be very cautious with your conclusions ....
Well you got to try.As soon as I get it back together I'll shooy some pics.Won't be till Friday though..
This is friendly encouragement, not a requirement.
Put the rig back together on Friday.Went together really nice.Put about 200mi. on it over the weekend did escort for Ride For Kids on Sunday.No problems.The re-work we did this time looks like it works.I'll know later down the road.I plan to ride the shit out of it the next couple of weeks..Marked all the nuts with lines.No movement yet.if everything works out its on to The Falling Leaf Rally in Potosi Mo. in October.GREAT RALLY.Took pics of the work and remakes.Will post them later this week.
In my opinion as a mechanical engineer, eye to eye connections are a bad decision. Eye to eye connection puts the bolt in a single shear position. With eye to clevis connection the bolt is in a double shear position plus the connection has twice the clamping area of an eye to eye connection.
I'm not saying that all eye to eye connections will shear the bolts but the eye to clevis connection will take more than twice the shearing force before failing.
I do not disagree with you although we do use eye to eye as well as clevis to eye connewctions.
The clevis to eye connections that Richard NL posted pics of (upper pictures) are of our hardware. This double shear approach is also beneficial in that 'IF' a bolt were to come loose it will still tend to stay basically in place longer than with an eye to eye connection.
However, eye to eye connections do work, and work well, for the applications we, and others, are using them for even though possibly not the better choice from a technical standpoint.
A well designed eye nut will not break as a rule. A propperly tightened bolt and lock nut through thet eye nut will not come out either.
With that being said It is still important for any and all sidecarists to check all bolts and nuts for tightness on a regular basis.Fasteners clamping painted , powdercoted or even plated members together can become loose especially so on new connections. Loose connections can cause members to 'work' between themselves. 'Working between themselves' can lead to issues arising over time.
As mentioned before a failed strut of mouting point may or may not be the sole fault for the failure. A failed part is easy to blame but that particular part may have failed due to circumstances beyond it control. All mounting parts must share their portion of the responsibility to keep things in order. If one part does not or cannot do it's job well it may place more stress on another part than that part was designed to deal with.
Of course Design issues can also be at fault such as poor triagulation. mounts to close together and so on.
Take a look again...
It WASN'T the eye-to-eye connection which failed on THAT Dauntless Rig...
And it wasn't the bolt shearing on Melrone's rig, the eye link itself failed!
How would a clevis holding the broken off end of the eye have helped Melrone any better???
As another Mechanical Engineer (one who has spent time doing real-world failure analysis and redesigning to prevent future occurrences); you may be technically correct, but you are missing the larger picture...
Based on reports here and elsewhere, Dauntless built rigs/components seem to have a higher rate of failure than other professional custom sidecar shops.
Of course, Whether that is a function of the design, manufacturing, quality control, end user/usage, or reporting is open for debate.
iHOP; Can you describe this failure. Looks like you are mounted to a BMW. How long have you had the M 72D on it? How many miles? What kind of roads does it see (pavement, dirt)? Just trying to understand the background for this failure since I have an M 72D on a 2002 R 1150 GSA. I want to better understand the background for this failure and what to look for on my rig. Did you mount this rig yourself or did Jay and his crew do the mounting?