TAV2 clone issue

O

OUTLAWD

Member
#1
#1
So I've had my bike together for a couple weeks, maybe has an hour on it, tops. 212 predator backed with a knock off TAV2 from OldMiniBikes. 12/54 gearing on a stretched DB30, 15x6-6 rear tire.

When I first got it together, the TAV would drag at idle and rotate the back tire slightly. Pulleys are aligned, and belt is in the correct direction. I ultimately attributed this to a new, tight belt. Upon inspection I noticed some amount of bronze dust, and assumed it was simply braking in. Looking at it today, as I was getting ready to order a new driven spring, the bronze bushing on the drive side is gone. I guess there was more bronze dust than I realized.

What would cause this? Belt too tight? I imagine it is a wear item, however I only have an hour on it, on pavement.
Is the bushing necessary? I see the 1" drive unit does not use a bushing.

Thanks
Dave
 
madtom421

madtom421

Member
#2
#2
I just had to buy a some these bushings. My buddy ate one up on his bike. I've bought a few tavs off ebay and the quality control is not the best. I would run it off the ground and really see how th tav is operating. My friends tav has a wobbly driver pulley which is eating his bushings and causing vibration.

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madtom421

madtom421

Member
#3
#3
These also never come with enough spacers, I use a straight edge to line up the pullies for the belt and always need to add extras.

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O

OUTLAWD

Member
#4
#4
Thanks. Pulleys are aligned. I will say there is some runout on the driver, and some vibration at idle. I have plenty of full scale toys but this is my first mini bike. I would expect some vibration from a rigid mounted single cylinder, but I don't have a good feeling for what is acceptable/excessive.
 
O

OUTLAWD

Member
#5
#5
I took some quick measurements before I left for work. Didn't have an ideal setup...but good enough for what I was looking for.

The outside of the inner pulley surface on the driver had 0.014" runout, while the "snout" had 0.002-0.003".

IMG_2701.JPG
IMG_2703.JPG

The Driven had 0.010" on the inner outside surface.

IMG_2702.JPG

I didn't get a chance to run it to quantify the "wobble"
 
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SAS289

SAS289

Well-Known Member
#6
#6
I think there are members who have said they run their TAV 30's without the bushing.

The way that appears to operate is that the bushing protects the belt at idle. Basically prevents unwanted partial engagement at idle. You would think that without the bushing in place there is more "breathing" room for the unengaged belt at idle. Something you can look at closely with the wheel off the ground.
 
ole4

ole4

#7
#7
You need to use dry lube on inside of bushing. Comet sells it or get dry molybdenum spray. Bushing is there so it does not drag at idle.
 
O

OUTLAWD

Member
#8
#8
I have new bushings on order...no one local had them in stock...once I get a Comet replacement, I will measure it and order more from an industrial supplier at $1/ea rather than $5/ea

That being said, I threw it back together sans bushing, and it worked fine, and didn't drag at idle. Maybe the chinese belt is too tight...I ordered some Bando kevlar belts.
 
T

Tre900

New Member
#9
#9
OUTLAWD said:
I have new bushings on order...no one local had them in stock...once I get a Comet replacement, I will measure it and order more from an industrial supplier at $1/ea rather than $5/ea

That being said, I threw it back together sans bushing, and it worked fine, and didn't drag at idle. Maybe the chinese belt is too tight...I ordered some Bando kevlar belts.
Click to expand...
any update on this one? What was the fix? are you just running with no bushing?
 
O

OUTLAWD

Member
#10
#10
I got some new bushings, polished the snub in the driven and applied dry lube. Now going on 5-6 hours on the same bushing, it's worn a little, but it's still there.
 
super nate

super nate

Member
#11
#11
the stock driver on the tav engages the belt at 1800 rpm which is too low for most engines. at idle its trying to engage the belt that's why it drags. the garter springs can be changed to fix that problem very easily. new springs are around 10 to 12 dollars,i would suggest the comet part numbers 011188a or 011190a. that will stop the drag problem. the bushing issue can be attributed to a few things. first the bushing is there to keep the belt from burning while at idle. if the pulleys are aglined correctly there are too things that I have found that ruin the bushing. first they are Chinese and are cheap the inside diameter can be off on these things and needs to be checked if they are too loose or too tight the will malfunction. I keep three or four all the time when drag racing they will wear. second the driver extension has a tapered end that rest against the inner pulley. if your belt is tight and not aligned correctly it will cause the belt to push the bushing to one side or another causeing it to wear. if it moves the bushing toward the extension it will mushroom and cause the driver to stink and not release the belt. I mill mine a little to give a flat surface for the bushing to ride against and has stopped that from happening. make sure your pulleys are aligned correctly and buy a real belt from beltpalace.com that's made from Kevlar and you should be good
 
O

OUTLAWD

Member
#12
#12
super nate said:
the stock driver on the tav engages the belt at 1800 rpm which is too low for most engines. at idle its trying to engage the belt that's why it drags. the garter springs can be changed to fix that problem very easily. new springs are around 10 to 12 dollars,i would suggest the comet part numbers 011188a or 011190a. that will stop the drag problem. the bushing issue can be attributed to a few things. first the bushing is there to keep the belt from burning while at idle. if the pulleys are aglined correctly there are too things that I have found that ruin the bushing. first they are Chinese and are cheap the inside diameter can be off on these things and needs to be checked if they are too loose or too tight the will malfunction. I keep three or four all the time when drag racing they will wear. second the driver extension has a tapered end that rest against the inner pulley. if your belt is tight and not aligned correctly it will cause the belt to push the bushing to one side or another causeing it to wear. if it moves the bushing toward the extension it will mushroom and cause the driver to stink and not release the belt. I mill mine a little to give a flat surface for the bushing to ride against and has stopped that from happening. make sure your pulleys are aligned correctly and buy a real belt from beltpalace.com that's made from Kevlar and you should be good
Click to expand...

Thanks for the response Nate.
I seem to have it straightened out. Alignment is good, no mushroom. Have new belts from belt palace and a few spare bushings.
 
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