Tsdz2 on strange bottom bracket

Joined
May 7, 2022
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Hello. I have a recumbent with a strange bottom bracket and im wondering if the tongsheng tsdz2 will fit. Check out the pictures. Thanks
 

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It looks like an Eccentric BB; these can be used to setup chain tension on single-speed stuff, etc.; I'm not sure if that's why they're using it on yours.

If the BB that's actually installed in the eccentric adapters to the shell is a standard one, then the middrives that fit that standard will thread in, etc.

But whether their casings will clear the shell and frame in the right way, I don't know--you would probably have to look at the dimensioned drawings for the drive and check if the clearances it shows will go around what you have to work with.

Also note that you may need to custom-design a retaining bracket to keep it from moving around, because whatever it comes with for a typical frame won't have anywhere to connect to on your boom, and wihtout something to secure it, it will "flip" up over the boom from underneath and smack into the top of the boom (unless you can simply mount it upside down on top to begin with), in reaction to the torque it creates on the crankspider/chainring.
 
So i did some research. The Bottom bracket that is on the trike is what is known as a "Niner eccentric bottom bracket" and it has an inner bore diameter of 55mm. So I think what I need to get is an adapter that would make the mid drive motor be able to fit through the bb with clearance for the outer casting on the motor. Something like this. https://www.levelninesports.com/niner-bikes-ebb-bio-centric-bottom-bracket/
 
Programinator said:
So i did some research. The Bottom bracket that is on the trike is what is known as a "Niner eccentric bottom bracket" and it has an inner bore diameter of 55mm. So I think what I need to get is an adapter that would make the mid drive motor be able to fit through the bb with clearance for the outer casting on the motor. Something like this. https://www.levelninesports.com/niner-bikes-ebb-bio-centric-bottom-bracket/

It looks to me like there is already that type of adapter installed with a standard Shimano type square taper bottom bracket (BB-UN26?) screwed into it. Have you considered using hub motors like the Grin All Axle designed for trikes like this?

411pNdNU9fL._AC_.jpg
 
It looks to me like there is already that type of adapter installed with a standard Shimano type square taper bottom bracket (BB-UN26?) screwed into it.

There is an eccentric bottom bracket in there already you are correct. But it does not provide enough clearace like the one in the link i posted. The one in the link has the thru bore closer to the 55mm bore.

Have you considered using hub motors like the Grin All Axle designed for trikes like this?

I seen those! Unfortunately over my budget and overkill for what i need. I only paid 350 for the trike! Thanks for suggesting though.
 
Programinator said:
It looks to me like there is already that type of adapter installed with a standard Shimano type square taper bottom bracket (BB-UN26?) screwed into it.

There is an eccentric bottom bracket in there already you are correct. But it does not provide enough clearace like the one in the link i posted. The one in the link has the thru bore closer to the 55mm bore.

Have you considered using hub motors like the Grin All Axle designed for trikes like this?

I seen those! Unfortunately over my budget and overkill for what i need. I only paid 350 for the trike! Thanks for suggesting though.

Maybe contact these folks. They sell a tsdz2 kit for trikes that includes a clamp for the boom. They do note that the thickness of the bottom bracket shell can't exceed 8mm (0.3"). This is the main problem you are going to have with that eccentric bottom bracket shell and the adapter. The thickness of the shell between the bottom bracket and the motor may change depending on the adjustment position of the adapter when you tension the chain with it.

"Compatibility: Designed to fit 99%+* of all Recumbents / Trikes (which tend to have standard JIS/BSA bottom brackets). This means a 68mm (2.68 in.) to 73mm (2.87 in.) wide bottom bracket shell with a 33.5mm to 35mm (1.37 in.) inside diameter. Other than that, note the wall thickness around the bottom bracket cannot be over 8mm (only an issue on some custom or carbon booms), and there must be no obstruction around the bottom bracket which would inhibit the use of a boom clamp."

https://www.eco-ebike.com/products/tsdz2ecoplusrecumbenttrikemodel
 
.note the wall thickness around the bottom bracket cannot be over 8mm (only an issue on some custom or carbon booms),...
From that statement, it looks like you would need a customised excentric sleeve, ( maximum offset, ) to get the Tsdz2 spindle as close as possible ..3mm or less.. to the bb shell.
That would mean you lose the chain tension adjustment though !
Note that “eco-bike “ do offer a full refund if it does not fit.
I agree that you should talk to them,...they may have done this before .
 
Note that “eco-bike “ do offer a full refund if it does not fit.
I agree that you should talk to them,...they may have done this before .

I have talked to David from Eco and he said the same thing about the adapter. Yeah he said it could be returned if it does not work out. Just as long as in gets returned in new condition. So i have to be super careful handling it on the test fit.

this is the adapter i ordered. https://lunacycle.com/luna-threaded-bb-adapter-for-niner-eccentric-bottom-brackets/
 
So I got it to fit. Had to modify the eccentric adapter bit it worked out. :D. Barely fit though. I was left with absolutely no clearance between the motor housing and the bb shell. I had to remove housing cover and replace after install. Glad I don't gave to send it back.
 

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Hillhater said:
Good news !
How are you dealing with chain play now, without thr excentric adjustment !

Thanks. First i had to add a few links. Then I just fabricated a tensioner with some pvc tubing. Works good.
 
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