dahon folder conversion - fast and light

[Woosh]

so what's the smallest lightest crank drive kit?

I would fit the Tonsheng TSDZ2 CD kit.
There is only one cable going from the motor to the LCD that is exposed.
The kit is also cheaper and lighter than Bafang BBS01B.

 

[sandyman44]

hi whoosh
I dont see that kit on your site, only on other peoples (At the same price as the BBS01)? and its a torque sensor right versus BBS cadence?
With torque sensor am I right that I am going to get better shifting (versus your BBS without gear sensor)? adding gear-shift sensor to BBS would give equivalent good behaviour?
torque sensor would be nice in some aspects -I assume that if I am just coming up to a junction, tapping lightly on pedals - no push from motor, and then stamp on pedals to pull away in low gear - big heave from motor delivered quickly, versus the 1-2 sec delay from the cadence types? But on the other hand at cruising speed I want the motor to give its all , and I supply what I feel like (up to the non-sweaty barrier), rather than motor dropping back to match me... is that going to work with a torque? do I need cruise control (throttle) for this?

the LCD on that tonsheng is a bit massive as well can see me needing a bar extension to mount it.

they can all be rotated when fitted so the motor sits in front of the BB not under it right? (under it is a needed space on a folder so it doesn't ground when you fold it or interfere with seat post drop)

 

[Woosh]

I dont see that kit on your site, only on other peoples (At the same price as the BBS01)? and its a torque sensor right versus BBS cadence?
With torque sensor am I right that I am going to get better shifting (versus your BBS without gear sensor)? adding gear-shift sensor to BBS would give equivalent good behaviour?

We don't sell the TSDZ2 yet, we are just evaluating it at the moment. It looks good on paper though. The buy price for us is about 10% less than BBS01B and Bafang just put their prices up by 2%-3%.
You don't have the same problem with shifting gear under load that the BBSes have. Also, there is no need to fit hydraulic brake sensors if you use it with a bike fitted with combined shifter/brake levers or dropbars, so it should be the preferred choice in those cases.

I assume that if I am just coming up to a junction, tapping lightly on pedals - no push from motor, and then stamp on pedals to pull away in low gear - big heave from motor delivered quickly, versus the 1-2 sec delay from the cadence types?

that's correct, although you could achieve the same instant power with the BBSes using the supplied throttle.

they can all be rotated when fitted so the motor sits in front of the BB not under it right?

You are restricted here, with either BBS01B or TSDZ2. You have to install the motor exactly like it is shown on the pictures.

 

[sandyman44]

We don't sell the TSDZ2 yet, we are just evaluating it at the moment. It looks good on paper though. The buy price for us is about 10% less than BBS01B and Bafang just put their prices up by 2%-3%.
You don't have the same problem with shifting gear under load that the BBSes have. Also, there is no need to fit hydraulic brake sensors if you use it with a bike fitted with combined shifter/brake levers or dropbars, so it should be the preferred choice in those cases.

ok if you get to the point of having a built bike with one I'd be interested to take a look.

that's correct, although you could achieve the same instant power with the BBSes using the supplied throttle.

thats not what I was aiming at - wouldn't want to press a throttle from a standing start. More about using a throttle to force the motor to stay at full power when I reduce pedal torque at higher speed for "cruising". I believe the TSDZ2 can have a throttle as an option though right?

You are restricted here, with either BBS01B or TSDZ2. You have to install the motor exactly like it is shown on the pictures.

not quite what I meant again. having studied a number of pictures of people's installs. the axle is the fixed point. but the whole unit is rotated around the axle by varying angles depending on geometry of where the tubes are to fit the motor part right? in some bbs01 installs the motor is sat horizontally in front of the axle, in some its sat down at 45 degrees below and in front, and in your scirocco its horizontally behind?
so do you have the same freedom with the TDZ2?

 

[Woosh]

I believe the TSDZ2 can have a throttle as an option though right?

I don't think you can fit a throttle to the TSDZ2.

but the whole unit is rotated around the axle by varying angles depending on geometry of where the tubes are to fit the motor part right? in some bbs01 installs the motor is sat horizontally in front of the axle, in some its sat down at 45 degrees below and in front, and in your scirocco its horizontally behind?
so do you have the same freedom with the TDZ2?

No, the TSDZ2 has a pedal torque sensor which needs the motor to stay horizontal for the software to work correctly. It also relies on a bracket, acting like a kind of torque arm, bolted to where the chainstays are welded to the bottom bracket shell.

 

[Woosh]

and in your scirocco its horizontally behind?
so do you have the same freedom with the TDZ2?

It may be possible but I don't know, the software needs to know the angle of the motor to the horizontal. I have not talked to people at CAF in the last 3 years.

 

[sandyman44]

It may be possible but I don't know, the software needs to know the angle of the motor to the horizontal. I have not talked to people at CAF in the last 3 years.

I think that will be the key. On a folder, directly underneath the axle is a no go area - the bottom of the seat tube will come out there (seat post usually will come out through it down to the ground to act as a stand ) and/or there is often a stand there welded into the frame to keep the chainring off the ground when folded. If installed with motor under there, the motor will either foul the stand, foul the seat post, or be the first thing to hit the ground when folded :-(.
I've seen a number of pics of installs of BBS01 on various dahons they all have it rotated so the motor is horizontally in front of the axle leaving the frame area under the axle clear.

as for the throttle for the TZD, there is one available if you google it on aliexpress but the only feedback that looks genuine says it probably doesn't work. if it won't fit its a moot point anyway.

 

[Woosh]

I've seen a number of pics of installs of BBS01 on various dahons they all have it rotated so the motor is horizontally in front of the axle leaving the frame area under the axle clear.

you are correct, the BBSes don't care about the angle, you mount it at any angle you like.
I think the TSDZ2 will probably still work if mounted at an angle but I haven't tried this myself. It was my assumption that torque sensors need to know where the cranks are, If I have caused doubt, please ignore my earlier comments.

 

[sandyman44]

you are correct, the BBSes don't care about the angle, you mount it at any angle you like.
I think the TSDZ2 will probably still work if mounted at an angle but I haven't tried this myself. It was my assumption that torque sensors need to know where the cranks are, If I have caused doubt, please ignore my earlier comments.

you have caused doubt but I think its a valid doubt... studying the TZD2 install diagram that bracket looks like it clearly attaches to the horizontal between the chainstays. meaning the motor can't be anywhere other than under the axle - thus invalidating it for a folder where the seat post drops down out of the tube.

is BBS01 where this going to end up or are there any others to think about?

 

[harrys]

I see that PSWpower.com sells a TDS mid drive with a throttle. While I am a pedal assist enthusiast, I find throttles very useful. I don't need another folding bike, but it looks like fun to build one.

 

[DouglasXK]

Regarding the angle that a TSDZ2 is set, i often have the bike upside down running the motor through the throttle or pedals. The orientation doesn’t matter. And a throttle requires a VLDC5 display (larger one), the bus wire HIGO connector from the motor has to have 2 pins more (for the throttle) and it has to be programmed. You’re much safer buying the unit with the throttle included; retrofitting one is probably impossible.

The problem with the seat tube having to go right through the frame really only applies if you are folding it to get it inside a carrying bag. My seat tube didn’t like being removed - it started to slip badly.

Such a motor weighs about 3kg and the battery about 2kgs. Will you mount the battery on the rear pannier?

 

[Nealh]

Doug is correct the tsdz2 can't be retrofitted with a throttle you have to buy the kit supplied with one and they only work with VLCD.

 

[Elmundopalladio]

I have done similar with my Moulton - although it’s not really a folder. Installed Magura brakes - a really decent upgrade, but quite fiddly to adjust at first.
I went with a Tonsheng mid motor to complement a nexus 8 rear hub. In all honesty it’s not a perfect setup as you described to keep a constant cadence. It does require a break in peddling to allow a change and you need to time it to allow the motor to stop as well as there is lag. I went for this due to urban commuting start stop which allows me to chang gear when stationary at the lights. I really prefer the torque assist and it doesn’t require the cut-out switches.
Motor is quiet and no more than other mid drive bikes I’ve tried.
Speeds on my commute are fine for a similar distance. I find a 10ah bottle battery does a full commute with a little left (I’m big and the commute is hilly here in Edinburgh) battery life can get a bit touch and go if I’m cycling back into a headwind! Generally I’m on the near max power to keep speed up.
This setup isn’t light. The bike started off about 14kg and is now 22kg fully set-up.
Without battery power the motor has significant drag when peddling. You can cycle, but it’s like having the brake partially on. I think this is due to there not being a direct drive from the crank.
It’s not quite as refined as a purpose built ebike, but it is a full suspension commuting bike at a fraction of the cost and kept a spare bike on the road.

 

[DouglasXK]

I had to work quite hard with my TSDZ2 motors to silence them. Success made it easier to drive especially without power. I suspected the torque anchor could distort the BB and also they require “running in” ie several hundred miles! So I disagree with your assertion of significant drag. I can support that because I can get 250 miles out of a 12,000 mAhr pack which you’ll only get if the motor is off for extended periods and I’m not alone in getting huge mileage from these motors.

 

[sandyman44]

Regarding the angle that a TSDZ2 is set, i often have the bike upside down running the motor through the throttle or pedals. The orientation doesn’t matter. And a throttle requires a VLDC5 display (larger one), the bus wire HIGO connector from the motor has to have 2 pins more (for the throttle) and it has to be programmed. You’re much safer buying the unit with the throttle included; retrofitting one is probably impossible.

The problem with the seat tube having to go right through the frame really only applies if you are folding it to get it inside a carrying bag. My seat tube didn’t like being removed - it started to slip badly.

Such a motor weighs about 3kg and the battery about 2kgs. Will you mount the battery on the rear pannier?

ta for the help on the TSDZ2 orientation and throttle. On the dahon folders, the seat tube pushing all the way down is part of its stability when floor standing. as it will be in a train carriage for me. so a motor design that stops the seat post going out the bottom isn't going to work for me.

the bike is on order from Fudges of london (who I can really recommend as having a good range of differnet shape and size folders) they will be putting Magura's on the front for me.

Battery wise, once I have got the bike, I will try riding it with 3kg weight in different positions - Rack, top tube bottle mount, front luggage truss (which is quite low down) before deciding. bear in mind I will usually have a pannier of some sort on the back as well so i dont want to overweight the back

I'm still pondering on how to electrify. BBS01 seems like main option from a "making it fit" and "the power/usage profile that I want" but heavy. so not sure...

just came across the "bimoz" system online, its a startup on indiegogo, they claim to be shipping in january, much lighter crank drive system but unproven and crowdfunding risk..

 

[sandyman44]

well now I am thinking of going front hub for simplicity. what do people know/think of these ?
http://shop.crystalyte-europe.com/product.php?productid=16694&cat=327&page=1

- 74mm so fits right in without messing with the fork dropout
- can be run at 36v or 48v for more oomph

48v and 36v controllers available from the same site. Belgium based.
nice performance calculator at
http://www.ebikes.ca/tools/simulator.html?bopen=false&motor=MSAW2013&batt=B4812_MH&wheel=20i&axis=mph&cont=C20