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Old Jul 21, 2012, 06:50 PM
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Australia, QLD, Burua
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Originally Posted by JohnnyMc
Those are nice pics, thanks for the link. Lots of lost feet lol.
Yes, the Feet are ripped off rather quickly, especially on the grass track. But that is just a cosmetical issue

Quote:
Originally Posted by JohnnyMc
So what is with the inconsistent laps on Manfred's bike? Gyro not strong enough, high center of gravity, or steering?
I'm still not sure if Manfreds Bike just had a specific setup, or if this is how the VMX generally behaves. At a certain leaning angle, the bike suddenly "fell" into the corner. Once you are used to that, this can be really fast. But you have no room for driver errors. If you hit the throttle just a fraction of a second too late, your bike crashes into the inner track marker. The tires and suspension of the VMX works really good, the bike "rolls" much better and quicker into and around the corners. But you just cannot push the Bike over it's Limits, it suddenly breaks away.

Manfred's Gyros are a piece of Art, they work perfect, and are highly tunable! The one on his Bike used a heavier weight than usual, since he borrowed that bike to another young driver for the weekend.
I think it is a mixture between the high Center of Gravity on the VMX, the rake of the fork, and the single pivot Steering that creates the handling issues.

Quote:
Originally Posted by JohnnyMc
Im curious what it is about the arx steering vs single pivot, that you think one is better over the other for dirt?
All Bikes that I have seen using a single pivot have serious headshake issues, and when pushed over the limits they suddenly "break" away.
The 4-link setup acts like a single pivot too, but the pivot point is far in front of the bike.
This adds a lot of Stability to your Bike which is definitely needed if you want to win a Race!

Getting a 4-Link Bike to turn quickly is just a matter of hard steering springs and a powerful servo. But adding Stability to a Single Pivot Bike just gives headache..

Next thing that makes the difference is the Center of gravity, and the rake of the fork.
Arx: Motor is level with the swingarm, Battery is as low as possible, Fork rake is relaxed.
VMX: Motor is above the swingarm, Battery is vertical and the Fork rake is very steep. This is good for SuperMoto Racing, but not for Offroad!

@Antonio: Great! This will be fun!

This is from Gartenzwerg from the Alpen Cup Forum.
One maybe the gyro isn't spinning fast enough or with enough force. Even with the mech gyro working well this bike is so stable at low speed but also turns on a dime when you want it to. Maybe a different driving style is required for these bike compared with the ARX. Personally I can't see the ARX being faster or more consistent on my track, especially on the stock tyres. Grass is more there domain. Now the MM is out watch out. Everyone can be consistent.
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Old Jul 21, 2012, 07:51 PM
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Originally Posted by chktm View Post
Kurtis I just took a few photos of the brake cable set up on the bike try the above link if you can. Deen can see them. Let me know if you need any others. oh I just realized you said pinion. Use blue locktite and a proper hard tipped driver to tighten as tight as you are game. I heat the grub screw area with a lighter for 30 second or so when removing to free the locktite being such a small size you have to be carefully. I replace the screw often if removing the pinion.
yup iv seen em pal, bike looks sick! and yeah the pinion haha, iv got a 13T pinion on order to! and if you was onna about the sprocket, iv got the pinned layshaft one mate,
and also chris just how have you got normal sized bike cable working with you brake,
i wanna try something as my brake isnt as i want it, i can spin the wheel whilst the brake is fully engaged iv tried mostly everything except from the pad, cable and a better servo
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Old Jul 21, 2012, 08:17 PM
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Originally Posted by Kurtis View Post
yup iv seen em pal, bike looks sick! and yeah the pinion haha, iv got a 13T pinion on order to! and if you was onna about the sprocket, iv got the pinned layshaft one mate,
and also chris just how have you got normal sized bike cable working with you brake,
i wanna try something as my brake isnt as i want it, i can spin the wheel whilst the brake is fully engaged iv tried mostly everything except from the pad, cable and a better servo
Thanks Kurtis, with the thirteen tooth pinion make sure it's a nice open area and the gyro isn't loading the motor 11 works good everywhere , maybe try it with the E Gyro am going to order one. I've got tonnes of the old sprockets and they work good with the bigger grub screw. The bike cable is stolen from brake or gear change cable on my push bike and threaded through an antena tube from a 1/10 truck cut to size. It fits perfectly through the tube, I drill the holes in the servo horn and caliper end slightly bigger thread through and use stoppers from brake mechanism from truck or buggy. Oh I also remove the threaded adjusters at each end and adjust with the stopper. Final adjustment can be done with the end point to adjust engagement point ( I use this to tune the rear brakes also. I set my brakes to work well but never fully lock. ) and brake mix percentage to adjust strength and feel of the brake. With this set up you can lock the front wheel on dirt and cause endos on grass. That's not fast though that's why I back it off to about 50 to 60 percent front mix and 99 percent rear end point. Once the front brakes work smoothly and consistently it helps the overall handling and settles the rear well under braking. Usually if the cable works well even with the stock servo and brake pads you should get adequate braking. If you really want those endos try 1/8 buggy pads.
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Old Jul 21, 2012, 08:37 PM
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JohnnyMc's Avatar
California central coast
Joined Feb 2010
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Originally Posted by chktm View Post
I use a drill bit or pin punch ground off. Will not bend got sick of bending them, and with the grub screw use drill and use a M4 0.7 tap to rethread and use a bigger grub screw. Use blue locktite. All my sprockets get drilled and tapped before use as I find not only does the std grub screw come loose but also it gets pushed out of its thread. You can get drill and tap from tool supply or hobby shop. You can use grub screw from newer models side bar mounts and replace with normal screw until you can get some grub screws.
Had same issue myself way back - stripped twice. Didnt even go that far, I just filed the flat area down again then took a drill and made an indention so original grub could set in more. That was enough to hold it. Of course, now I would just buy the new style front sprocket that uses the hole and pin and then give myself the excuse to buy that new micro drive from alleven. I wonder if I could find a trick gold link chain to match.

chktm, those stoppers you mentioned, are they something similar to this? http://www.rcplanet.com/Ofna_Stopper...p/ofn10322.htm
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Old Jul 21, 2012, 09:31 PM
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Yea that looks like them, they are even tricker. I like that spur gear cover and the chain adjusters. Will have to get some.



This one is high def

VMX450 (11 min 7 sec)


Some fun with my Son and a Dog. Lots of crashes wheelies and good times.
You can see my Son is a bit rusty and at times goes too slow for too long and the bike becomes unstable and wobbly and crashes. Also uses the bars a little too much. He is using one of my gyros probably needs a little more gap at times. Once he speeds up all is good. That gyro is set up to go fast.  Ill have to tell him to give it to it more often. He likes to go a bit slower and do more tight cornering. The MM450 should suit him really well. He hasn't had a go for about two months, he goes all right when he gets into it. Great dog exerciser.
His bike (. The red one ) has a 6000 pack and 11 tooth pinion and the yellow was running a 5200 and 12 tooth pinion. Both these bikes have the rear insert I made and Hot Bodies big bore shocks.
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Old Jul 22, 2012, 04:25 PM
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chris (chktm) this tube that you are onna bout, the aerial tube what size is it? as i can only find standard size?
i dont want to be drilling anything out if you get me.
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Old Jul 22, 2012, 04:32 PM
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chris (chktm) this tube that you are onna bout, the aerial tube what size is it? as i can only find standard size?
i dont want to be drilling anything out if you get me.
The tube is standard only the horn and the little red bit on the caliper need very slight drilling out. I have a piston hole drill set I do this with. Tiny drill. Try your fishing wire through the tube first, you won't have to drill anything.
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Old Jul 22, 2012, 04:34 PM
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Originally Posted by chktm View Post
The tube is standard only the horn and the little red bit on the caliper need very slight drilling out. I have a piston hole drill set I do this with. Tiny drill.
ah right, no way im doing that then it will end up wonky!
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Old Jul 22, 2012, 06:29 PM
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[QUOTE=chktm;22235537]The tube is standard only the horn and the little red bit on the caliper need very slight drilling out. I have a piston hole drill set I do this with. Tiny drill.

Kurtis try some fishing wire should work ok without drilling anything.
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Old Jul 22, 2012, 10:08 PM
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[QUOTE=chktm;22236333]
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Originally Posted by chktm View Post
The tube is standard only the horn and the little red bit on the caliper need very slight drilling out. I have a piston hole drill set I do this with. Tiny drill.

Kurtis try some fishing wire should work ok without drilling anything.
Already using it mate
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Old Jul 22, 2012, 11:16 PM
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[QUOTE=Kurtis;22238165]
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Already using it mate
Cool.
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Old Jul 23, 2012, 12:37 AM
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Here's my fun today. No hospital. Some backflips, crashed attempts and Vinnie thought he'd try a one handed 360. Didn't quite pull it off. The last one is the best. Sorry about delay between jumps. One day I'll sort out a movie app.

VMX450 (3 min 20 sec)
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Old Jul 23, 2012, 02:41 AM
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Originally Posted by chktm View Post
This is from Gartenzwerg from the Alpen Cup Forum.
One maybe the gyro isn't spinning fast enough or with enough force. Even with the mech gyro working well this bike is so stable at low speed but also turns on a dime when you want it to. Maybe a different driving style is required for these bike compared with the ARX. Personally I can't see the ARX being faster or more consistent on my track, especially on the stock tyres. Grass is more there domain. Now the MM is out watch out. Everyone can be consistent.
You are right - the VMX turns on a dime.
But you have to be very careful when opening the throttle out of the corners. And if you hit a bump in that stage, the Bike is gone.

The ARX may have disadvantages when turning into a corner. But the geometry of the Bike helps it a lot when you hit a bump "on Power".

Yes, the tires on the VMX are better. But they are also softer, which leads to a more inconsistent Handling. We've seen and experienced this on the road bikes over the last 2 years, and I don't see why this shouldn't be the same on the offroad-bikes.

Until now, no Venom Owner was brave enough to enter the Race in Fehring.
So maybe next year we know what bike is better on Dirt
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Old Jul 23, 2012, 02:54 AM
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You are right - the VMX turns on a dime.
But you have to be very careful when opening the throttle out of the corners. And if you hit a bump in that stage, the Bike is gone.

The ARX may have disadvantages when turning into a corner. But the geometry of the Bike helps it a lot when you hit a bump "on Power".

Yes, the tires on the VMX are better. But they are also softer, which leads to a more inconsistent Handling. We've seen and experienced this on the road bikes over the last 2 years, and I don't see why this shouldn't be the same on the offroad-bikes.

Until now, no Venom Owner was brave enough to enter the Race in Fehring.
So maybe next year we know what bike is better on Dirt
Sounds like the suspension needs some sorting more than anything or as I said Gyro speed. Once the Gyro is working well the bike is super stable cornering through bumps. Unfortunately I'm in Australia but from what I've seen I would love to race you guys. Oh this is off road, tyres need to squirm a little, I wouldn't say this leads to inconsistent handling. I use my tyres down to nothing on hard packed dry clay and they work like a dream. Awesome consistent slides. Once you've ridden a sorted Venom you will understand.
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Old Jul 23, 2012, 05:37 AM
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Originally Posted by chktm View Post
Sounds like the suspension needs some sorting more than anything or as I said Gyro speed. Once the Gyro is working well the bike is super stable cornering through bumps. Unfortunately I'm in Australia but from what I've seen I would love to race you guys. Oh this is off road, tyres need to squirm a little, I wouldn't say this leads to inconsistent handling. I use my tyres down to nothing on hard packed dry clay and they work like a dream. Awesome consistent slides. Once you've ridden a sorted Venom you will understand.
..thanks for the Advice.

I'm glad it's working for you, all I can talk about is what I have seen and driven in the last 2 full AlpenCup Seasons.

Regarding the tires: who says, that they need to squirm a little?
Common sense, Real MX guys or the stopwatch?
When you are racing, the third thing is what counts..

I would love to see more people racing Bikes (even here!), this way we would not have to rely on "What ifs..".

Did you ever drive a well-setup ARX?
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