Scrap made into e-Bike with vintage spare parts - base giant bolder 1999

[Tonvo]

Giant bolder 1999, deraileur gsx shimano front deraileur 200gs shilfters a200 gs

 

[Greg Watts]

187757

@Tonvo - welcome to the forum!

Your thread title mentions a scrap-built vintage e-bike and white spare parts - that's an intriguing project. The number 187757 in your post doesn't give me much to go on though. Is that a part number you're trying to identify, or maybe a reference from somewhere?

If you can tell us a bit more about the build - what motor you're running, what era the frame is from, and what parts you're hunting for - the community here will have a much better shot at helping you track something down. Home-built e-bikes tend to attract some very creative problem-solvers on here, so you're in the right place.

 

[Moderator]

Moved to here from Ask Greg as no information provided and no answers to Greg's questions.

 

[skizzian]

View attachment 187757

is the motor at the Bottom Bracket?
I was expecting a lump in front of the BB

 

[Tonvo]

BaView attachment 187757

View attachment 187805

View attachment 187806

View attachment 187807

Wheels compout made in Japan 1975

 

[skizzian]

Biopace chain ring - not sure how that will integrate
does the Chain ring free wheel backwards like other emtbs?
although from memory Shimano got it backwards on the Biopace kinematics

 

[Zimmerframe]

Biopace chain ring - not sure how that will integrate
does the Chain ring free wheel backwards like other emtbs?
although from memory Shimano got it backwards on the Biopace kinematics

Biopace chainring was one of the early ovoid attempts in 1983 (for anyone else reading) :

Like you say, not sure how well that will work with a motor system with cranks in varying positions as the leverage will be constantly and randomly changing .

Can't work out what the motor is.

Is that hydraulic rim brakes ??

 

[skizzian]

Biopace chainring was one of the early ovoid attempts in 1983 (for anyone else reading) :

View attachment 187808

Like you say, not sure how well that will work with a motor system with cranks in varying positions as the leverage will be constantly and randomly changing .

Can't work out what the motor is.

Is that hydraulic rim brakes ??

Seems to be a bolt on Mid motor - but I can't see where the actual motor is
yes looks like hydraulic rim brakes - maybe magnesium wheels?

 

[Zimmerframe]

Seems to be a bolt on Mid motor - but I can't see where the actual motor is
yes looks like hydraulic rim brakes - maybe magnesium wheels?

I think the wheels are nylon/thermoplastic : looks like these but can't find any more info :

The rings seem to be directly mounted to the motor, which presumably squeezes through the BB for mounting, but sits externally parallel to the chainring. I think there's a motor blob hanging out the front which we can't see in the pictures, so a Bafang bbsXX or Tongsheng TSDZ2 or similar (toseven/viribus and so on)

 

[skizzian]

I think the wheels are nylon/thermoplastic : looks like these but can't find any more info :

View attachment 187809

The rings seem to be directly mounted to the motor, which presumably squeezes through the BB for mounting, but sits externally parallel to the chainring.

Yeah you're probably correct - Mag's would have bare metal at the rim
I think maybe we can see a teeny bit of the motor poking out in front/behind of the 48T ring
the motor is probably summat like this