Rallye navigation bracket photo thread

I had a few attemps myself developing a roadbook holder and at the end I wrote to John who tailored one of his products for holding my Trailtech Vector on the top with the genium KTM speedo display at the bottom. If I had done it from the start I would have saved money and time. Already did Rally Dalmatia and Rally Albania with this set up and can't complain at all, only recomend.

Hi Muecke,

Apologies for the delay, Dakar is up so... quite busy following the race . Other than that a hectic week at work and everywhere else basically.

Have a look below.





Let's discuss the above design a little bit.

The above will fit a Touratech roadbook without leaving any space on top and bottom. I see that you have some zip ties beneath your roadbook but that is a no go in the above design. If you want I can add the button extention below the Touratech so you will in general have something like the top plate shown at the video at the end.

The IMO will go on the right. I changed the bend at the end of the tower plate to -90 deg, so now it is looking upwards, it provides some protection to the IMO. On the left, the space is open, as requested, do some measurements in order to make something that makes sense. On the top you have some space for Nav equipment. Let me know dimensions so I can edit that top space for you. If it is too big it just does not look right.

The four parts, shown next to the plate, fit below Touratech and they are used to ''grab'' the thing that you circled in red in a previous post. Bear in mind that I used bolts with a square shoulder so I dont have to take the touratech rb out when doing adjustments. You can find these in any bolt shop.

The other thing is that the above may need a stiffener at the bottom. (look at the video, on the rear side where the pivot/adjustment bolt is bolted) This should be welded, and it really depends on the design if you want to go for a middle one or two stffeners one at each side. Unfortunately, I was not being able to test my tower extensively, it was a solid rock for 100 racing kilometers and you could tow the bike from it. So, all in all I think you will be ok with just one stiffener in the middle.


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Till later,
D.

FInally got my brackets cut that I designed in Soiidworks.



Wiring is rough. Still have the entire cockpit to arrange and wire and tuck.

Hello everyone,

been following this thread for a while, as I will need a tower myself soon for my xt660.

I've seen a lot of nice 3d modelling etc, but I wonder if you guys did any FEA analysis to identify stress concentrations etc. or is it just trial and error approach, focusing on looks?

good thread, keep going

I did some Finite Element on my Tower. I had 4mm 'banana' plates and 3mm everywhere else.
Basically the tower will withstand a bog load if it was hit vertically, but that, as has been discussed before, it is not a good thing because the rider will sustain the damages. So, AntiPaul's excellent design will absorb the energy and break on impact.
You have seen in the previous messages that PE is a good material. If your run FEA with PE you will laugh your heart out . So, FEA is not of major help here, as the tower, under normal conditions will hold what? 2? 3 kg ? Something like that.

As far as the side blows is concerned, there is no design at the moment that will hold the dynamic impact from a crashing bike. I am quite busy designing a roadbook holder these days, but at the end I would like to create a tower what will protect the equipment from falling apart. A damaged roadbook is of no use even if the tower is straight ... You cannot make the equipment strong enough to withstand a direct hit, so you can make a tower which (1) will retract if it gets hit by the rider and (2) it will divert the forces somewhere else if it gets hit in order to protect the nav equipment. It can be done but it needs time designing which I do not have at the moment

Thoughts ? :huh
D.

hi, thanks for answer.

I am not as concerned about the crashes or constant static loads, as in my case I need a tower for travelling purposes.
I've seen in some ride reports people having troubles with their custom towers fatigue, from being bashed for thousands of km.
In this case I think harmonic oscillations plays the the greatest role in fatigue, as aluminium have finite life.

What about the thin walled steel tubes, as used in oem bikes, to hold all the instruments
have anyone tried using steel? more labour intensive for sure

@ 640 Armageddon.

Amazing work! I can't believe that. It looks so professional and I wondering what I have to pay.
I will take some exact measurements of my instruments and the bike, to make it detailed.

It looks great.

You wil hear from me. Maybe you can send me your emailaddress by PM?

This is indeed another matter. Vibrations can knock the hell out of everything, and as others will say even crash bars are destroyed on a 640A . A good practice is to put vibration absorbers in every joint so at least they absord the kinetic energy and the tower does not ''see'' the problem. You can even bolt absorbers in most places and they will absorb the vibration as the energy will flow through the easiest path. Steel is not good for a tower, imho, because it is heavier, (have you seen the weight of the front part of a 640A or an Africa ? :eek1 ) and then it needs to be painted etc. Now that PE came into play, it will absorb better than any metal the vibrations and if it contains carbon black will stay intact from UV attack so it will stay there forever... It is also lighter and cheaper. You have to keep trying different materials. May be it is better to use plastic parts somewhere so they break, may be not You get the idea ..

@ Muecke,

For the design you don't need to pay anything, I already had most of it so it was really a case of modifying my part. The question is do you have a local manufacturer there or you want me to do the search ? I could easily find a Laser cutter for Aluminium, and he makes an excellent job, I have not yet been able to source a good sheet metal bender here so I would not wont to try it in your parts. Well, you could try but I think you will be able to source somebody there.
These manufacturers usually want the part in 3D, so I can either send it to you or they want the sheet flattened, they cut it using laser equip., waterjet or whatever and then, they proceed with bending.
I will be waiting for the measurements and we take it from there...
Let me know if you need any lettering on the part so I put it in the drawings so you have a nice engraving there

D.

:) Armageddon: I will take the measurments and thinking about what I need to finish the model. Then I will write you a PM. Do you have detailed fotos of your T-BAR which is holding the plate? I think I also need the background holder behind the plate. Do you also make the T-Bar or you think doing that? Because your Tbar is combined with the background holder.
I also have a Tbar, but it is too small for my tower and I need to make some "spacers" to put it between the tower.

Hi muecke,

see below,



You are talking about the blue thing, right ? See below its thickness. No reason to be such a thick part, I made it last so had to adapt it in the other part's dimensions. I did not have enough time playing around. The bar is welded on the bottom part (to create the 'T' ) and it is, as you will see, 16mm in diameter. Most normal RB towers have 10mm. Again, no particular reason. It looks beefy though




Have to go and get some sleep,
Later
D.

This thread is absolutely fantastic ....

Really fun to watch ...

Paul Jr 8

Thanks for fotos. I will write you an PM in short time.

I posted this over in the XCW thread in Thumpers, but it probably belongs here more,

Plan is a bit of testing over the next few weeks, then a vendor thread.

Excellent design Paul,

The plastic shear bolt is a nice idea. good job that half the tower stays in place... It can be hard to do work while trying to keep the thing in one place before it fells apart taking some cables on its way down...

Looking forward to seeing the tests !!

D.

Looks great Paul, one question though, why go to the trouble and expense of a billet mould for a plastic fairing when they could easily be beautifully made in composite from an epoxy mould?

Thanks Dimitri and Mike.

There are pluses a minus's to any method, I find the composite route messy, dusty and toxic, way too much touch labor for each copy. With a plastic injection mold, they can shoot hundreds in a day, that are more consistent, durable and less prone to vibration or fatigue, easily and inexpensively replaceable.

Once a composite part is damaged the time and effort to repair it right is pretty high, as long as you don't crash a dirt bike, you're fine, but a plastic part will spring right back in the same impact a composite would be destroyed.

But by far the main reason is that I'm a toolmaker and that allows me to offer a decent part at a decent price.

I find the plastic a very good idea, especially in the fairing use. It is not like this part needs to be neither from composite nor from AL or SS or anything similar. I mean, don't get me wrong, I love CF and Kevlar as much as the next guy but for this use I think plastic is the way to go. The elasticity of these things is amazing...

Get ready for some roadbook parts in the near future

The cost of the plastic piece is all up front cost in making the mold. After that you can churn out hundreds of them on a plastic injection molding machine. the composite one is cheaper than an injection mold but the overall cost never goes down by much because each one produced is fairly labor intensive.

Look absolutetly awesome.

I'd love to have such posibilities in my shop

But one thing puzzles me.
Why would you want to put the Nav-Tower on your fork and not the frame?

It's just additional weight you have to steer with your arms.
Is this some kind of steering-damper ->more weight, less prone to wobble?
Personaly I'd hate to have that thing on my fork. Just put it on the frame....

Please enlight me
Martina

Frame mounted option......