Dual Chain Transmission Won't Fit

phil4989

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Joined
May 22, 2020
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6
We just got in a bikeberry dual chain transmission (link below) for my son's build. Now before you all tell me to return it and get a belt drive (which I may do), hear me out. My son is on a limited budget, thus the more inexpensive parts. We tried to install it on an engine that we got off amazon (link below) that I thought would be compatible. The engine said 142F and has a tapered shaft. When we installed the transmission, it wouldn't fit. The nut and bolt holding on the bell seems to stick out too far and touches the clutch, making the transmission not seat correctly on the engine.

Anyone else have this problem or know of a solution other that returning the transmission?

Transmission Link: https://www.bikeberry.com/4-stroke-transmission.html
Engine Link: https://www.amazon.com/gp/product/B06WRQRTH4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Due to Covid and shipping incompetence, the bikeberry transmission took a month to get here. So doing a return and ordering a belt drive is not our first choice.
 


phil4989

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May 22, 2020
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6
When we started, we had on a 44t rear sprocket. At the time we didn't realize it was not for hilly areas (NC), and he burned up several clutches. This also made the transmission a bit off balance and you could hear it rubbing inside. Sounds like the bell shaft me be slightly bent. We are currently putting the old one back on until we figure out what we are going to do with the new dual chain. I have read the one it came with is pretty bad and will fail quickly. He also wanted to upgrade, so the transmission seemed like an obvious choice.
 

Chainlube

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Jan 5, 2020
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1,146
Did you pull the transmission off the side of the engine, 4 little bolts and fit the BB trans on there?
 

5-7HEAVEN

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Jun 22, 2007
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1,051
With the information supplied, your final gear ratio seems too high. What's the transmission's gear ratio? You can tell by opening the cover and counting the sprockets' teeth.
How many teeth does the outer sprocket have? What type of rear sprocket do you have? #35?
 

phil4989

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May 22, 2020
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6
Chainlube: yes, we pulled the transmission off the side and put the BB one on there, but when the bolts are tightened down there is still another 1/8 inch to go before the transmission mates properly with the engine. All because of the center bolt in the BB transmission. I measured the depth of the bell on the new transmission, it is definitely more shallow.
 

phil4989

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May 22, 2020
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5-7Heaven: We were going for a low gear ratio. There are a lot hills around here, several have stop signs right in the middle. He would pedal assist from a stop, but it still wasn't enough. The clutch kept wouldn't fully engage due to the high torque and low RPM. The other benefit to a low gear ratio is his top speed is lowered at bit, which makes my wife feel better about him riding it. :)
 

Don_Parsons

Active Member
Joined
May 6, 2020
Messages
330
I try to avoid all clutch slippage as possible,,, and to make sure its properly adjusted on my unit...

I check it before every ride...

My Zdea 80cc kits came factory with the 10/44,,, got Four 56 tooth rear sprokets coming,,, and hope that i dont need to do the 60/ 61 rear drive...

Big loss in the top speed category,,, but its more about slow in my adventures,,, that and idling around slow...

But yes,,, I like too stay on top of those clutches,,, best bang for the buck if they last...

Don
 

Frogslayer

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Jan 20, 2019
Messages
1,455
@Don_Parsons He's talking about a centrifugal clutch inside of a "transmission" (reduction box) on a four stroke. Different yet somewhat similar to what is built into the 2 strokes. You can get centrifugal clutches for the 66cc if you don't want to have to use a clutch lever and make it auto engage but it would limit your bottom speed unlike the pressure plate and pads manual clutch that is in them stock. (I personally prefer the manual all day)
 

phil4989

New Member
Joined
May 22, 2020
Messages
6
Good catch Frogslayer. I forgot to mention that I was referring to a centrifugal clutch and that it was really a reduction box not a true transmission. I noticed everyone was calling it a transmission, so I jumped on the bandwagon.
 
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