Yamaha WR450F Amageza build

[alanB]

What do you estimate your nav tower with all its kit on, weighs?

I will tell you tomorrow, but weight was not the only motivation for this tower.  The incredible strength and flexibility of HDPE was very attractive to me.

Ja quite innovative, using something that will bend and not just break 

You did quite well and didn't suffer any sort of failure on the tower so clearly its a workable solution.

But the weight is always an issue for me, especially so high up and far forward, - did you notice any ill effects from all that weight on the front? 

If you can I would be interested in two figures:
1) The weight of all the instruments and switches, wire etc on their own
2) Total weight of the tower with all the supporting members.

The real issue here is how to get all the instruments out front where one can see them while riding.  How far that has to be is the big trade off - far forward and high up is ideal - but supporting that weight out there in such a hostile environment is the big engineering problem.

[N[]vA]

What do you estimate your nav tower with all its kit on, weighs?

I will tell you tomorrow, but weight was not the only motivation for this tower.  The incredible strength and flexibility of HDPE was very attractive to me.

Ja quite innovative, using something that will bend and not just break 

You did quite well and didn't suffer any sort of failure on the tower so clearly its a workable solution.

But the weight is always an issue for me, especially so high up and far forward, - did you notice any ill effects from all that weight on the front? 

If you can I would be interested in two figures:
1) The weight of all the instruments and switches, wire etc on their own
2) Total weight of the tower with all the supporting members.

The real issue here is how to get all the instruments out front where one can see them while riding.  How far that has to be is the big trade off - far forward and high up is ideal - but supporting that weight out there in such a hostile environment is the big engineering problem.

I can tell you that having all my nav gear (f2r roadbook, ico & screen + led spot lights) handle bar mounted didn't all that much of a weight difference that I wouldn't happily do it again. I also dont have a steering damper on the bike. It's not THAT heavy

Nice thing about the handle bar mount system is that it rotates on the bar in a crash rather than breaking.

I really enjoyed Rob's ideas on how he built his and am very keenly considering similar for my next build

[darthvader]

But the weight is always an issue for me, especially so high up and far forward, - did you notice any ill effects from all that weight on the front? 

Show me a own rolled rally bike that does not have this problem?  Good suspension setup in front and running the fuel from the front tank first makes this bike perfectly balanced for me.  It is actually very light, I cannot imagine it being more than 1.5kg for everything without the navigation equipment.  Aluminium or mild steel will be way heavier for the same strength.

If you can I would be interested in two figures:
1) The weight of all the instruments and switches, wire etc on their own
2) Total weight of the tower with all the supporting members.

It will take a while to get the measurements without the nav equipment, but I will have something ready in the next few days.  It took me 3 hours to clean up my garage after my frantic Amageza packing mission.

The real issue here is how to get all the instruments out front where one can see them while riding.  How far that has to be is the big trade off - far forward and high up is ideal - but supporting that weight out there in such a hostile environment is the big engineering problem.

I can tell you this : Day 2, Liason 1, we had moer big dongas to ramp.  Ask the guys I rode with if I had any problem Koos? Zarin? Donovan? ... we were flying and my bike was an absolute pleasure to ride.  I mentioned before that this was the first time I took a 450cc bike offroad, let alone a "top heavy" rally bike!  I had no time on this bike, I only road it on tar for maximum 3 hours and I still had no problem riding it flat taps with all the nav equipment.

What I am trying to get at, is that this bike, with the 1.5 to 2.5kg weight was very easy to ride.  The bike just felt right up until I had fuel tap problems and I had to run some fuel from my rear tanks first.  My tower is actually very snug up against the handle bars.  I don't think you can get it closer.

[alanB]

But the weight is always an issue for me, especially so high up and far forward, - did you notice any ill effects from all that weight on the front? 

Show me a own rolled rally bike that does not have this problem?  Good suspension setup in front and running the fuel from the front tank first makes this bike perfectly balanced for me.  It is actually very light, I cannot imagine it being more than 1.5kg for everything without the navigation equipment.  Aluminium or mild steel will be way heavier for the same strength.

If you can I would be interested in two figures:
1) The weight of all the instruments and switches, wire etc on their own
2) Total weight of the tower with all the supporting members.

It will take a while to get the measurements without the nav equipment, but I will have something ready in the next few days.  It took me 3 hours to clean up my garage after my frantic Amageza packing mission.

The real issue here is how to get all the instruments out front where one can see them while riding.  How far that has to be is the big trade off - far forward and high up is ideal - but supporting that weight out there in such a hostile environment is the big engineering problem.

I can tell you this : Day 2, Liason 1, we had moer big dongas to ramp.  Ask the guys I rode with if I had any problem Koos? Zarin? Donovan? ... we were flying and my bike was an absolute pleasure to ride.  I mentioned before that this was the first time I took a 450cc bike offroad, let alone a "top heavy" rally bike!  I had no time on this bike, I only road it on tar for maximum 3 hours and I still had no problem riding it flat taps with all the nav equipment.

What I am trying to get at, is that this bike, with the 1.5 to 2.5kg weight was very easy to ride.  The bike just felt right up until I had fuel tap problems and I had to run some fuel from my rear tanks first.  My tower is actually very snug up against the handle bars.  I don't think you can get it closer.

Thanks that basically answers my question.  The thick plastic looked quite heavy in your photo's but , 1 or 2 kg's isn't really an issue at all!

Still would be quite interested in the weight of all the instruments on their own, because those have to go any rally bike regardless of the nav tower solution.

I think you did fantastically well given the lack of time to get used to the bike 

I also think the balanced front/rear fuel tanks help a lot.

[husky]

Nice work; particularly the GPS.  Most impressive.

I know BB has seen it but the AdvRider Nav tower thread has at least one HDPE tower.

[darthvader]

I am running a bit behind on my build dissection, but I am currently doing tests on various thread locking products and viscosities & strengths. 

To my surprise, I found out that the "high strength" Loctite(TM) thread locking glue actually break down under extreme vibrations.  I used Würth-medium-strength on the last stage that I got from the KTM Cape Town mechanics and that seemed to work.  What other products do you suggest?

[Kenisis]

Awesome Build.

Whilst at speed did you have any problems with vibrations of the plastic head end?

Cheers

Al

[darthvader]

Visually, no.  Give me 10 minutes and I will go loosen up the main bolts and tell you if there was any wear and/or tear on any of the members of the tower.

[darthvader]

Visually, no.  Give me 10 minutes and I will go loosen up the main bolts and tell you if there was any wear and/or tear on any of the members of the tower.

I removed two main support bolts(refer to the construction), the top bolt of the bottom triangle and the bolt I added afterwards.  They had no visible wear on them.  I did test their torque just before I removed them and I could give each nut an extra full rotation!  

There are two and a half theories at this point.  The first would be that the nyloc was damaged and it vibrated loose.  Nylocs work best if used once, obviously(you damage the plastic insert each time you turn/rotate the nut).  The other part to this is that I did not torque it enough when I finally assembled the tower. For this very reason, I am going to use high tensile bolts for the tower as well, not just the base.  I can then torque it until it bleeds! B.T.W., I used stainless bolts?!!? vreemd!  The other reason for the "looseness" could be that the HDPE compressed enough although I doubt it.  

I have no mechanical or plastics engineering background, so please chip in.  If you did not read the whole thread, I used nylon for the spacers and HDPE for the sides.

[alanB]

I personally doubt if the nyloc nuts vibrated loose.  I re-use them all the time and never have issues with them loosening.

Possibilities are:

1) Maybe some sort of creep in the plastic (including the spacers) - meaning it sort of flowed away from the highly /stressed compressed areas (creep is a function of time and stress, exacerbated by vibration).  This is the most likely explanation IMO.   
2) I've had poor results with stainless bolts - often bend and loosen, especially when subject to heavy vibration and stress. 

Those would be my guesses anyway.

PS did a quick search for HDPE compressive creep and it seems that could indeed be the issue.  Although that's hardly conclusive.

[darthvader]

Creepy...    I checked the thread on the stainless bolts after the post and they are fine(no stretched threads)  There are zero signs of "creep" on the thickness, and if there are, we are talking micrometers, way less than one rotation.

I also noticed that the nylocs are way easier to loosen and tighten, so it is without a doubt  the nyloc nuts that loosened.  Again, stainless.  If I have used high tensile bolts, I would have torqued it much more.

[darthvader]

Creepy...    I checked the thread on the stainless bolts after the post and they are fine(no stretched threads)  There are zero signs of "creep" on the thickness, and if there are, we are talking micrometers, way less than one rotation.

I also noticed that the nylocs are way easier to loosen and tighten, so it is without a doubt  the nyloc nuts that loosened.  Again, stainless.  If I have used high tensile bolts, I would have torqued it much more.

O, and for final assembly, I would use new nylocs and some medium strength thread locking glue.

[alanB]

Creepy...    I checked the thread on the stainless bolts after the post and they are fine(no stretched threads)  There are zero signs of "creep" on the thickness, and if there are, we are talking micrometers, way less than one rotation.

I also noticed that the nylocs are way easier to loosen and tighten, so it is without a doubt  the nyloc nuts that loosened.  Again, stainless.  If I have used high tensile bolts, I would have torqued it much more.

If the plastic did creep then the bolts wouldn't still be be stretched and then the nuts would seem loose, and thus easy to loosen - just saying.

But I'm really guessing at creep being the culprit. 

But in any event, using stronger bolts, new nuts and loctite will at least eliminate those possibilities next time 

[darthvader]

I hear your, but, what I am saying, the nut can be turned by hand(removed from the rig completely)... before there was no way.

[BlueBull2007]

We should change this thread to engineering banter.

Keep it coming boys!

[Pleco]

Visually, no.  Give me 10 minutes and I will go loosen up the main bolts and tell you if there was any wear and/or tear on any of the members of the tower.

I removed two main support bolts(refer to the construction), the top bolt of the bottom triangle and the bolt I added afterwards.  They had no visible wear on them.  I did test their torque just before I removed them and I could give each nut an extra full rotation!  

There are two and a half theories at this point.  The first would be that the nyloc was damaged and it vibrated loose.  Nylocs work best if used once, obviously(you damage the plastic insert each time you turn/rotate the nut).  The other part to this is that I did not torque it enough when I finally assembled the tower. For this very reason, I am going to use high tensile bolts for the tower as well, not just the base.  I can then torque it until it bleeds! B.T.W., I used stainless bolts?!!? vreemd!  The other reason for the "looseness" could be that the HDPE compressed enough although I doubt it.  

I have no mechanical or plastics engineering background, so please chip in.  If you did not read the whole thread, I used nylon for the spacers and HDPE for the sides.

Check your torques and use a good torque wrench. The torque is supposed to stretch the bolt so that it acts like a spring. Too little and there is not enough pull to keep the nuts tight. Too much and the bolt looses its spring tension all together, then you might as well toss the bolt unless you weld the nut in.

A once torqued Nylok nut should not come loose. Ride it for the first day, back the nut off half a turn and retorque. Then everything would have settled nicely. You can always put some silicone onto the nut and exposed thread after the re torque. The nut wont come out, and you can get the silicone off easier than thread lock. Don't use stainless bolts, its too soft. Allen cap.

HT bolts and nuts with spring washers, torqued correctly with some silicone afterwards will work just as well. Otherwise you need to keep spare nyloks.

This worked well on my extreme 4x4 trips. 

[Kenisis]

I hear your, but, what I am saying, the nut can be turned by hand(removed from the rig completely)... before there was no way.

What about expansion and contraction? The SS bolts will expand differently to the plastic possibly less so than the plastic and then when warm it compresses it causing your looseness?

* Warning * I am no Plastics scientist!
 

[darthvader]

UPDATE : I have measured my spacers(vernier calliper) and the thickness of the sidewalls(eyeballed it in light and no dents or warps), they are all 100% the same thickness.  SO, Stainless and Nyloc damage was my problem.  I have to use HT bolts and galvanized Nyloc nuts(I am not sure you get HT Nyloc nuts) for my tower.

Silicone, yes, good plan, but I do think that a good design should not really need that much "glue" on the navigation tower.  Eventually any epoxy glue will fail if there is too much stress on the fix points.

I have studied the factory Honda and KTM Rallye bikes(photos and amageza, etc.)  Normal bolts should suffice... I also suspect Yamaha used the exact KTM tower and brackets, see the pic :


Look very closely... zoom in!  Then!  I have built my own bike, nice, cool, Darth, you are the best, blah, but! Check Cyril's bike, it is a 100% garage build.  I so want him to finish top 10 with this bike, because that would just prove you can build a low cost bike and win.

His tanks probably cost 1000ZAR in material   His exhaust is routed brilliantly ... and all the exhaust sections parts are sleeved, with springs! Super easy to fix at the bivouac.  If Yamalube pulls this off, it will reset history.

I am going to test my bike in the next 2 mounts with it full rally party dress.  Lets see if the girl holds up!

[darthvader]

I have fitted a new x-ring chain(it makes much more sense to me?), so lets see how it goes. 

Then, I have changed my front sprocket from a 13 to a 14; I just had way too much torque in 2nd and 3nd.  I have way more control in my wheelies    Atlantis will give me the final stamp of approval.

The new chain guide is a TM Designs UHDPE guide, so that should help a bit.

[darthvader]

I so want him to finish top 10 with this bike, because that would just prove you can build a low cost bike and win.

His tanks probably cost 1000ZAR in material   His exhaust is routed brilliantly ... and all the exhaust sections parts are sleeved, with springs! Super easy to fix at the bivouac.  If Yamalube pulls this off, it will reset history.

I am sure the suspension is worth 100K ZAR on Cyril's bike, but the rest of the parts are all within a frugal budget's reach.