manco thunderbird sprockets

#1
I just picked up this manco with brandnew predator 212 installed, has no clutch but the stock rear 72 tooth sprocket is there. What size is this. Do i get a normal clutch or do I go torque convertor either im not sure is this a 420 or 40/41 chain, its bigger than whats on my rupp, which I believe to be 35, Am I correct on this guys
 
#4
You have a number 40 chain on the 'Bird. Count the teeth on the rear sprocket, that should be 80 teeth. The stock clutch is a 10 tooth 3/4 bore. With Predator installed, you are going to have way too much bottom end and you'll not be able to keep the front wheel on the ground (which was hard even with the stock 3 1/2 hp Tecumseh). OldMiniBikes sells a 54 tooth #40 sprocket that will adapt nicely to the rear wheel hub. This will increase your top speed considerably but in exchange for more throttle control (and keeping the front wheel on the ground). The shorter gearing is more than offset by the torque of the predator, so you'll get up to speed quick enough.

I had a Honda GC160 on mine and until I switched to the smaller rear sprocket, the bike was scary to ride.
 
#7
As Doc said, with the big rear sprocket you will have a wheelie machine. And not a fun one at that.
On my T-Bird with a Predator, I dropped down to a 60 tooth driven/10 tooth drive, it's fast and still has enough power to pull the front wheel when you hammer the throttle, while cruising.
 
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#8
when the 14 tooth clutch arrives i'll test it out and report my liking or disliking. im only 130 pounds 5 foot 6 myself. so in the woods where I ride=e alot of hills i may spin tire not wheelie.
 
#9
My last T-Bird was really fun to ride with a 10 tooth clutch and a 54 rear sprocket with a 5hp Honda. I would also run a clutch brake, the rear one is almost useless if it gets wet.
 
#10
Just changed bearings in both wheels, flipped sprokets since dont have paint atm. Was still blackbon back. And is 72 tooth as i had read online. 20161220_141954.jpg 20161220_141954.jpg





Just reinstalled stock manco tank, what a hastle to bend back the mount but I got it after about 35 40 minutes.



Its looking like the front forks on this manco are bent not happy noticing this now.
 
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#11
HMMM any suggestions guys, I'd like to try to find another frontend to put on here. Maybe a pitbike forks like I seen on a rupp, maybe d do simislar to my rupp then put my rupp forks on this manco, or maybe buy another rupp set of forks to try to graft onto this manco. not sure the rupp can handle the Rake the manco has on its front forks though. ktm 65 forks would be sweet but I doubt I can get a pair cheap enough let alone mount it correctly.
 
#12
As Doc said, with the big rear sprocket you will have a wheelie machine. And not a fun one at that.
On my T-Bird with a Predator, I dropped down to a 60 tooth driven/10 tooth drive, it's fast and still has enough power to pull the front wheel when you hammer the throttle, while cruising.
According to the speed calculator that should be the equivalent to using a 12 tooth front and a 72 tooth rear, which is the gearing that I'll be running on my Thunderbird.
 
#15
The front forks are pretty easy to fix. Mine were high speed forks also (bent). When you go to repaint it, simply heat the forks up and they actually do spring back into place with little to no help. The heating relieves the stress on the metal.
 
#17
Im not happy. I recieved the clutch I ordered on xmas eve, and they send the 10tooth, now im playing the game to get the correct item and im not paying for extra shipping I told them so if they want this one back when they send me the proper 14 tooth I ordered i'll send thie 10 tooth back. was cheap but not the point I went out of my way to find a 40/41 420 clutch it says with 14tooth in the add. 20161225_224236.jpg
20161225_224313.jpg
 
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#18
Understand not being happy. Hopefully you didn't order from the sponsor of this site (OldMiniBikes). Not kosher to share frustration, if you did. Still encourage you to consider the small rear sprocket...the problem with the factory one is the sheer size: Take left turns at speed and the sprocket is in the dirt and you're most likely chasing the bike.
 
#19
wasnt purchased from OldMiniBikes, but you get what you pay for I guess. was 15$ clutch. Is all good I settled up with them but am still looking at another 14 tooth, this is still cheaper than a rear sprocket. Thanks for you advice though.
 
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