Smoother takeoff

#1
Just bought a Coleman CT 200U-EX for our 13-year-old daughter to learn on. Would like to alter/modify or replace clutch for lower RPM engagement so that she doesn’t have to experience half throttle take offs.
 

Lizardking

Well-Known Member
#2
Welcome aboard!

I went through the same thing with a ct200u for my son and I ended up just buying another bike then another then another until the right one came along. At least that's what I told the wife about finding the right one!!

I tried to adjust the rev limiter bolt to no avail. Something about those engines and the throttle setup maybe? Try putting a stiffer spring for the throttle witch is something I didn't try. Enjoy this great site!
 

SAS289

Well-Known Member
#4
Is this the thing where once the clutch engages the bike "takes off like a bat outta hell" as many have said over the years?

Lower engagement RPM should tame that down a bit but the challenge is finding the right spring or clutch assembly with lower engagement.

Because of the smoother engagement a torque converter is considered as a fix for this. Most people like the smooth engagement of the torque converter over a clutch. I like both and see the clutch engagement as part of the fun of riding.
 

Lizardking

Well-Known Member
#5
I left mine as is since I was able to tame the beast aka adjust my riding by leaning into the takeoff! I'm more into old school bikes so the Coleman sees very little riding.
 
#6
I have the same bike, and I have one word of advice : TAV
Change it over to a torque converter - I had to be convinced of this, and wasted time fooling with replacement clutches, etc.
Makes a night / day difference in the bike - An order of magnitude more controllable.
Do you have a part number, or a link to that torque converter? I’m mechanically inclined, but brand new to these little bikes.
 
#7
Is this the thing where once the clutch engages the bike "takes off like a bat outta hell" as many have said over the years?

Lower engagement RPM should tame that down a bit but the challenge is finding the right spring or clutch assembly with lower engagement.

Because of the smoother engagement a torque converter is considered as a fix for this. Most people like the smooth engagement of the torque converter over a clutch. I like both and see the clutch engagement as part of the fun of riding.
I purchased this as a learner/intro bike for younger kids. The throttle has to be halfway open for the clutch to stay engaged, which sometimes is a little faster than they need to be riding.
My goal is to have access to the lower RPM range for the initial training sessions.
 

2old2care

Active Member
#8
The thing about clutches, is that by their nature, they like to be either idling or fully engaged - They don't do well in between.
That's why they're preferred for racing - They transmit full power once locked up. And for racing, they're always locked up.
For low speed, or off road use, where you're constantly changing speed, the TC wins hands down - I'm a believer.

I just picked up another used CT200U for my wife - The bike was straight chained as found, no jack shaft, just the clutch (new) and rear sprocket.
My wife rode it briefly around the property, the way she does mine (with torque converter) - Up and down little hills, weaving around outbuildings, speeding up, slowing down, etc . She came back after less than 5 minutes, with the clutch literally smoking.

I have to believe the factories put clutches on these little bikes, for only one reason - They're cheap.
 
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2old2care

Active Member
#9
Here's the one that I bought, twice now :
https://www.amazon.com/Mophorn-Converter-2HP-7HP-Replacement-CVT/dp/B019SL0LUU/ref=sr_1_3?crid=1PCIL51BGGQAK&keywords=mophorn+torque+converter&qid=1659703771&sprefix=mophorn+torque,aps,849&sr=8-3&th=1

All these Chinese converters are about the same - So just pick any one for a 40-41 chain.
The one thing is, if your bike is newer than mid 2016, the engine has a 5/8" / 16mm crank shaft, and most of the converters are for a 3/4" shaft.
You either have to sleeve the shaft to 3/4", swap cranks (many folks do that), or buy a more expensive converter:
https://www.gopowersports.com/coleman-200-series-torque-converter-kit/

Lots of on-line info on installing one - Not a big deal to do it.
 
#10
The thing about clutches, is that by their nature, they like to be either idling or fully engaged - They don't do well in between.
That's why they're preferred for racing - They transmit full power once locked up. And for racing, they're always locked up.
For low speed, or off road use, where you're constantly changing speed, the TC wins hands down - I'm a believer.

I just picked up another used CT200U for my wife - The bike was straight chained as found, no jack shaft, just the clutch (new) and rear sprocket.
My wife rode it briefly around the property, the way she does mine (with torque converter) - Up and down little hills, weaving around outbuildings, speeding up, slowing down, etc . She came back after less than 5 minutes, with the clutch literally smoking.

I have to believe the factories put clutches on these little bikes, for only one reason - They're cheap.
are you aware if there are any lighter springs that can be installed for a lower RPM lock up?
 

SAS289

Well-Known Member
#11
I purchased this as a learner/intro bike for younger kids. The throttle has to be halfway open for the clutch to stay engaged, which sometimes is a little faster than they need to be riding.
My goal is to have access to the lower RPM range for the initial training sessions.
Here's another thing to consider. Is the time and effort of taming down the bike you have worth it compared to getting a less powerful bike to train kids with? The Coleman CT100 comes to mind.
 
#12
Here's another thing to consider. Is the time and effort of taming down the bike you have worth it compared to getting a less powerful bike to train kids with? The Coleman CT100 comes to mind.
Really not looking to tame it down, just want to be able to use the lower end of the RPM range and not smoke the clutches
 

2old2care

Active Member
#13
" just want to be able to use the lower end of the RPM range and not smoke the clutches "

I think you'll find that tough going with a clutch - I think you can get different springs for some racing clutches or maybe just the more high-end ones (Hilliard, etc), but they'll likely cost more than one of the Amazon TC's.
You could try keeping the clutch, and try a lower ratio rear sprocket (60T), but with a sudden lock up type clutch, I think that would just make the bike more prone to wheelie.
You know my opinion, so I'll say no more. Good luck.
 
#14
" just want to be able to use the lower end of the RPM range and not smoke the clutches "

I think you'll find that tough going with a clutch - I think you can get different springs for some racing clutches or maybe just the more high-end ones (Hilliard, etc), but they'll likely cost more than one of the Amazon TC's.
You could try keeping the clutch, and try a lower ratio rear sprocket (60T), but with a sudden lock up type clutch, I think that would just make the bike more prone to wheelie.
You know my opinion, so I'll say no more. Good luck.
Do you happen to know the part number for the Amazon TC?
 

2old2care

Active Member
#15
I gave you the link in post #9, as well as explaining about the 5/8" crank issue.
You can just go on Amazon, and search for "mini bike Torque converters", and you get pages of them.
 
#16
You'd be better off buying a bike like a CT100U for a kid that's learning to ride. They have about half the power, are smaller and a better choice overall.
 
#17
With the torque converter that 2old2care is telling you about the whole attitude of the bike will change. It will be as smooth and docile as a car with an automatic transmission. Easy part throttle take offs are the norm. You say you want low speed driving, get the torque converter. They are cheap, $65
to $70. They are also very dependable and don't need to be adjusted. I own
4 off road karts and one mini bike. Every one of them has a torque converter on it. As explained to you earlier centrifugal clutches either want to idle or be
fully engaged, not what you want for trying to teach your children how to ride.
 

2old2care

Active Member
#18
You'd be better off buying a bike like a CT100U for a kid that's learning to ride. They have about half the power, are smaller and a better choice overall.
I totally get this, but the OP said his daughter was 13, and so not a little kid - I think she'd be of a size to easily deal with the larger CT200, if only it was a bit more "user friendly". AND, she won't outgrow it right away.

OTOH, there are a lot of large, fully grown men on this site, that seem to have never outgrown some very small bikes ;~)
 

toomanytoys

Well-Known Member
#19
My ct200u with a tav even with an unmodified predator would wheelie out from under me if I gave it too much throttle….yeah it’s smoother engagement but too much throttle it smoothly engaged and the front wheel came up!
 

SAS289

Well-Known Member
#20
Another thing about this is that the clutch engagement behavior is something that the rider should learn to expect and get used to.

When my then 17 year old and his friend first rode it seemed that they noticed the behavior we are talking about here. What they started doing was slowly and carefully slipping their way to engagement. After a while I pretty much scolded them saying "quit babying the thing, throttle it and go". I was a bit annoyed with the clutch abuse and how it appeared that they were afraid of the bike.
 
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