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Old Oct 05, 2012, 07:14 PM
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3000 oil in the back damper. Still bobbly. I decided to do an old trick and put a cable tie around the lower leg to see how much travel I was using.

Holy Cow Batman! Full travel used on the 'smoothest part'!

I then realised that the front wheel was collecting the battery tray and probably causing many of the rear end flicks. Swapped to a leading front wheel setting and although a bit slower to respond to steering, appeared better. The longer wheel base seemed to upset the front to rear balance less. No oil in the front as yet, just air damped.

More to report soon.

(I'll scare them damn buggy drivers soon somehow!!!)

Current set up.

Standard steering springs at standard length.

New Savox 12kg digital steering servo.

Duct taped rider.

''Roller'' wheelie bar. ( to be replaced )

Gyro as standard.

15T Firebolt Brushed motor.

5000Mah 20C Hong Kong 2S Lipo

Mtroniks Viper ESC

Standard kit tyres.

Anderson 'Gold' forks. (Air damped),

3000 cst rear damper oil.

Damper assembly placed on hardest chassis setting.

Standard rear spring.
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Old Oct 08, 2012, 12:44 PM
RC Dirt Bike Action
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I thought the leading front wheel is how the anderson is setup already? Or did you change it like the dx450 here in states is setup?

So, when are we going to see some video of your bike???????
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Old Oct 08, 2012, 02:32 PM
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The Anderson from the box is the 'rear axle' setup. It's something Dez Chand kept rabbiting on about in the early parts of this thread. Change it to a 'leading axle' and get the benefits. I think he was claiming steering wise but unless he'd done something he never told about, the 'rear' axle setup is better in turns, both slow and fast from my experience. Only problem is when you start hitting bumps, the suspension compresses and catches the battery tray as you are aware.
That causes me some serious amount of time with the back wheel getting flicked into the air instead of getting as much power down as poss. By a curious quirk, having the rear wheel bouncing high in the air does have the advantage of the m-gyro spooling up more Can't bloody win sometimes!.
(years from now, there will be men stood at the rostrum getting whisty eyed and nostalgic for the 'good old days with m-gyros, when you really had to put some effort in to get around the track'). I wonder if we can keep a few of these generation of MX bikes around and have a 'historic' class in 20 years?!

Back on topic, for me on my track, 'leading axle' is my only serious way of coping with the bumps I'm trying to tame. Just need more gyro speed to keep me going through the section the attached picture is showing, though that arrives alongside a brushless combo, and that isn't a priority with Christmas looming ever closer.

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The cars are Hobao Hyper ST 1/8 truggys. The bumps have got worse since this photo was taken and much more compacted.

A video will arrive the day it's worth watching. No point watching an unfinished bike that's not quick enough. Wait until it's fast enough to worry the tail end of the 1/8 buggy brigade regularly. This lot I can get on the back of, when I (somehow) produce a good lap and they keep their engines running If they get good at that engine thing them I'm stuffed, they'll be able to work on car control and then I'm toast.
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Old Oct 08, 2012, 03:46 PM
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Ta for the replies lads.

I'll have a read of your thread JMc today. I can't face doing the main DX thread just yet Timmah's thread will be read before trawling that one! The M5 thread seems to be page after page of what brushless setup to use That's an easy one for me. 6000Kv and the biggest battery I can squeeze into the battery tray!

I'll give the 3000 oil a bash and see how it goes and maybe buy a Revo shock for a spare and as a comparison. Hopefully it shouldn't take too long to get some nice front to rear balance, something lacking at the moment. I'm either out of balance or the rear is spending too much time in the air rather than on the ground transmitting power.

The track I run at is not very smooth, especially at the worst places, the middle switchbacks where I'm losing gyro speed. The 1/8 nitro buggies have dug some nice solid bumps to try and tackle, which is easy for them, not so easy for me Hopefully, by getting the suspension right, I can stop the collywobbles developing because of the diminishing gyro speed. The M5 E-gyro is just too far out of price range at the moment and of course it wont produce the miracle cure when the suspension is wrong in the first place!

I'm on a bit of a mission you see, if I can scare them down the straights and make them worried everywhere else then I'll call that mission success! I wont beat them of course outright, but if I can get them worried...
Johathan
That would be the same Mablethorpe that holds the winter beach racing
Back to my question where I see mention of a commercial M5 E -gyro being available .
Like you and not wanting to expend vast amounts of but have been looking at a homemade version following on my grafting on of the disc brake and would be thankfull if you could provide a link so perhaps get an idea as to how they have done it
Have been following your recent threads and the change after moving to the oil front shock is a good one .Failing that just expanding the original air springs a bit gets rid of a bit of the pogo stick effect .I found that the change to the option harder rear spring and 3000 wt oil sorted out the rear
Thanks
Jim
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Old Oct 08, 2012, 10:03 PM
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Jim, the egyro is at a german website http://rc-motorradshop.de/produkte/p...bilder/?MHT-60
It uses an airplane type esc probably 15-30a range, with a servo tester controller to get the outrunner motor inside the wheel up to speed. Its not clear if it uses exhisting gyro flywheel or has a custom, but from the fricken price, I expect full custom flywheel inside. You dump that much into the bike and that egyro and your at least at the price of a 1/4 bike with egyro. lol
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Old Oct 08, 2012, 10:39 PM
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It uses an airplane type esc probably 15-30a range, with a servo tester controller to get the outrunner motor inside the wheel up to speed. Its not clear if it uses exhisting gyro flywheel or has a custom, but from the fricken price, I expect full custom flywheel inside.
It's been a while, but I tried using the stock flywheel to create an e-gyro. I installed magnets on the inside recess where the clutch shoes would ride. I have a ton of standard 22.7mm stators laying around so I used one of them. The problem was the bearings allowed the flywheel to move a little too much and the magnets dragged on the stator. My prototype Ricky e-gyro had a side plate on both sides so this was never a problem (wasn't as easy to get the wires out though.)

I should have tried to use a 20mm stator with maybe slightly thicker magnets. I can't remember now if that would have worked, and I don't have the bike to look at anymore... Seriously though, the stators are $0.65 and the wire can't be much more. A custom turned tube to mount the stator won't be much either.

Just paying for the labor to wind the stator - which gets easier the more you do it.

Dave
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Old Oct 09, 2012, 03:16 AM
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Jim, the egyro is at a german website http://rc-motorradshop.de/produkte/p...bilder/?MHT-60
It uses an airplane type esc probably 15-30a range, with a servo tester controller to get the outrunner motor inside the wheel up to speed. Its not clear if it uses exhisting gyro flywheel or has a custom, but from the fricken price, I expect full custom flywheel inside. You dump that much into the bike and that egyro and your at least at the price of a 1/4 bike with egyro. lol
JohnnyMc
Thanks for the link and agree the price is out of the ball park and even after translating into english it is not clear exactly what you get .
I notice the picture is careful to not highlight how they exit the cables from the casing .
Will continue to ponder and am like the other many thousands awaiting the arrival of the replacement E Gyro for the Venom to see if all the hype is correct .
Thanks again
Jim
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Old Oct 09, 2012, 05:46 AM
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Johathan
That would be the same Mablethorpe that holds the winter beach racing
Certainly is! I've done my own version of the beach race with the M5 but I got bored of full throttle speedway style slides after half a battery. If I was racing someone however...


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Originally Posted by Jimob23 View Post
Back to my question where I see mention of a commercial M5 E -gyro being available .
Like you and not wanting to expend vast amounts of but have been looking at a homemade version following on my grafting on of the disc brake and would be thankfull if you could provide a link so perhaps get an idea as to how they have done it
Perhaps Dave (Dmincin) can provide a link to any thread about the work he has done though he did a nice explaination earlier.

Here is Cesars' thread about his 1/4 custom MX bike and home brew E-gyro


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Originally Posted by Jimob23 View Post
Have been following your recent threads and the change after moving to the oil front shock is a good one .Failing that just expanding the original air springs a bit gets rid of a bit of the pogo stick effect .I found that the change to the option harder rear spring and 3000 wt oil sorted out the rear
Thanks
Jim
Now the tyre no longer clops the battery tray, all is hugely improved. The longer wheelbase is showing an effect (just like it did when I used to drive short/medium/long wheelbase Transit vans over the twistys of North Yorkshire, but that's another story) More stable over the bumps, the front tyre is not digging into any lips on the bumps, it appears much smoother riding on the front. The rear is settled for now. I will try thin shock oil at the front and see what effects occur. I just can't be using full travel on the least bumpy bit. I'll see what effect the oil has before looking at stiffer springs.
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Old Oct 09, 2012, 11:07 AM
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Certainly is! I've done my own version of the beach race with the M5 but I got bored of full throttle speedway style slides after half a battery. If I was racing someone however...


Before petrol became into the same league as gold it used to be a fairly regular ride up there to see the crazy guys on their 2 wheeled machines but need to turn the 1 coin over a few times before going that route frequently


Now the tyre no longer clops the battery tray, all is hugely improved. The longer wheelbase is showing an effect (just like it did when I used to drive short/medium/long wheelbase Transit vans over the twistys of North Yorkshire, but that's another story) More stable over the bumps, the front tyre is not digging into any lips on the bumps, it appears much smoother riding on the front. The rear is settled for now. I will try thin shock oil at the front and see what effects occur. I just can't be using full travel on the least bumpy bit. I'll see what effect the oil has before looking at stiffer springs.
[I have posed this comment before but did not get much response .
By moving around the front axle to in front of the forks it has increased the rake thus giving a change in turn ability .It does not appear as much but I suppose when scaling it back up to 1:1 it could be signifant
If you hold the battery box firmly and push the forks backwards you effectivly change the rake angle perhaps as much as moving the axle forwards .This is the main cause of the front wheel hitting on the battery box as if you just move the shock up and down there is sufficent clearance
I must do it one day( unless someone comes up and shoots my theory down in flames ) but the steering head is on a pivot point restricted by that large shock absorbing spring and my thought was to set up a simple bolt and adjustable nylock nut that would restrict its full travel forwards .This should change the rake but on the other hand the original set up was not just for show so is there for a specific reason .
Have yet to see a 1:1 bike with this moving rake set up .The Moto GP bikes have an adjustable rake angle but fixed not moving around
Regarding your front shocks I read it you had the original spring set up and not oil damped .I forget what the recomended oil is for the oil shocks but think 25wt and I did try a heaver wt but reverted back to recomended .
You could try expanding the standard rear spring a bit which is like changing the pre load but you dont get the spring coil binding effect
.If you try it just be careful as one can be tempted just to expand a tad more and you end up with a distorted spring .
Did read somewhere someone heating it up ,expanding and then re tempering again but no info if they cooled in oil ,salt water or plain water .
Bit of a black art and not enough time to search the web to find the answer
You will be fitting snow tyres up your way soon [/FONT
Cheers
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Old Oct 09, 2012, 11:48 AM
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One trick used for the pivoting headstock is a silicone tube that fits over the crashbar spring. A well used item by the on road crew. I have one to fit, so might give it a try. Stops the motion of the rocker arm but gives a little in a crash.

I can also discover which is better for myself, 'leading' or 'rear' set up. Now that I have tried the 'leading' axle, I can't see myself wanting to swap back. It just feels better and seems to cope with the rutty track better. There is a set of switchbacks that are flat and grass covered, I'll bob the silicone tube inside and give an objective appraisal of what happens. Then, I'll try some 25wt oil in the front and see what happens.

I've tweaked a few springs from Inferno paintball markers and know what a pain even them things are. I'll buy a spring, then know what lb rating is too.
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Old Oct 09, 2012, 01:46 PM
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One trick used for the pivoting headstock is a silicone tube that fits over the crashbar spring. A well used item by the on road crew. I have one to fit, so might give it a try. Stops the motion of the rocker arm but gives a little in a crash.

Idea there and the nitro tuned pipe connection is sometimes a silicone compared to the harder PTFE so would be interested to hear how you get on before I go a make mine solid .That movement cannot help the turn with the rake continually changing over bumps

I can also discover which is better for myself, 'leading' or 'rear' set up. Now that I have tried the 'leading' axle, I can't see myself wanting to swap back. It just feels better and seems to cope with the rutty track better.

That all falls into place as full size Harley etc have that extended rake which gives the 'cool dude' ride but not the best turning circle .Moto GP have a virtually straight rake but very touchy steering
'

I've tweaked a few springs from Inferno paintball markers and know what a pain even them things are. I'll buy a spring, then know what lb rating is too.
Anderson do offer a harder rear spring option and I purchased one .Not the best test but put them both between thumb and forefinger ,compressed but did not feel a signifant differance.Should have set up an arm and weight to measure the differance in rating but like most things another day !
I await the eventually arrival of the much hyped Venom E-Gyro upgrade to see if it makes the claimed change to the ride etc
It all makes sense with the mechanical gyro effect changing with speed and the Venom needs long runs to get up the gyro speed to stop it flopping around like a rag doll in tight turns
If it all went easy it would be no fun would it !!!!!!!!!!!!!!!!!
.
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Old Oct 10, 2012, 07:40 AM
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Ok, I wasn't going to, but as loss of gyro speed has cropped up, here is me, (much earlier this year) with a pretty standard bike, though I think it had the Mardave silvercan motor in it. I'm running the reverse course on the video as the buggies etc go the other way. Now modified of course. I've started running the other way too).

https://www.facebook.com/video/video...76175025780259

Quote:
Corners 1+ 2 I got the wrong line on, but out of two into three was good. Entry to four was spot on to avoid the bumps and the exit was good. Five and six, hit a bobble on entry to five, had to correct again mid corner with another bobble, then hit the big bobble on exit of 6. nailed the corkscrew flat. But other than that... Now I know it takes 29 seconds to do that much of a lap, I've some thing to aim for and improve on! The quickest 1/8 buggy laps are in the 23.5s
Anyway I digress. From 0.02 to 0.12 is the section where I'm bleeding gyro speed. Now I run the buggy way around, the first part is now the last part and that's where I'm needing the m-gyro speed to be up. In the video, it's a simple hit the brake and turn, then give it some welly down to the far hairpin and get some speed back in the gyro. In buggy way around, I'm hitting a few nice bumps and trying to corner smoothly and precisely, all the while balancing the throttle to keep the front end down, and that's with just a 15t firebolt brushed motor, and am at the lowest speed of the gyro (smallest violin playing in the distance)

E-gyro just looks tailor made for what I need. YMMV.

(Though I do enjoy the challenge of the m-gyro, makes your thumbs and instincts get it together).


Oh, and whilst we are on track performance, I'm ditching the roller wheelie bar before this weekend. They may be great for pulling long wheelies but when you just want to get the power down and distanced covered... It also helped the bike roll over easier 'can't explain to a conclusory satisfaction.' but the wheel bar induced the bike to sit up and carry on it's pirouettes. The drag bar caught hold of stuff and slowed the bike, getting the front end down again. I shan't test the wheelie bar concept any further. They (Wheeled bars) seem a hindrance to good performance.

Summary. Roller wheelie bars are useless.
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Old Oct 10, 2012, 12:47 PM
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You inspire me chaps, I'm a billy no mates on the Isle of Wight with my M5, such a shame as there are amazing places to "play".

Anyhow I'll com "oop North" one day for a race against you other bikers

I've been trying various set ups for a good all rounder and am still continuing that quest, I've 2 M5's, a Super Motard one and a Dirt one.

I'm currently considering a dual stage spring set up for the rear on the dirt bike to allow fast acting suspension for ripply stuff but also for to allow for hard hits, jumps etc. The best I've found so far for this was the standard shock/spring with the thickest spacer you can squeeze in and with very thick oil to provide more "packing" on the hard hits, however this does compromise the speed the shock can act at.
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Old Oct 10, 2012, 01:26 PM
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If the wheelie bar is too short and the wheel attached is nice and big enough, yeah the bike will either be nice for tricks or flip. Sounds like bar should be longer and "wheel" should be just a small roller just enough to not grind down the bar or drag/catch on anything. If you put a motor that is too fast thats not helping "put the power down" and from my limited time with my bike and a 4000kv motor I cant imagine a need for anything bigger than 4500-5000 tops for offroad.

As for that track, your doomed with all those switchback turns. Its inevitable that a m-gyro is going to suck in that section of 6 turns. Either grind down the knobbies so you get more wheel spinning (joking kind of) or for an actual bike race, consider bypassing/cutting out a few turns maybe with a ramp like they do at skipton. I figure you wont do that when running against buggies though
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Old Oct 10, 2012, 02:30 PM
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I cant imagine a need for anything bigger than 4500-5000 tops for offroad.
Need the speed!, those 1/8 rallycross buggies are quick! nearer 6000Kv and an experiment with that DXR slipper clutch (another tweak to the list).

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As for that track, your doomed with all those switchback turns. Its inevitable that an m-gyro is going to suck in that section of 6 turns. Either grind down the knobbies so you get more wheel spinning (joking kind of) or for an actual bike race, consider bypassing/cutting out a few turns maybe with a ramp like they do at skipton. I figure you wont do that when running against buggies though
When the going gets slippy, the bike comes alive! Side knobbles are over rated. That's why I've held off buying the Proline Badlands.

For a bike race, the full course stands!

Of course I don't cheat when up against buggies!() Well, like I said before, the less I can cheat and the closer I am to them, the more worry I can hand out
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