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Lower bracket with extension

My question comes in two related parts: firstly, what is the piece of folded, drilled metal projecting rearwards from the lower bracket in the photo above?

Secondly, does this piece of metal have any significant implications for the suitability of this bicycle to have a mid-drive e-bike conversion kit installed?

EDIT

wider view

This is a wider view of the bike. In order to address matters brought up in current answers, I should point out that I am this machine's first and only owner and rider, and it has spent most of its existence gathering dust in storage. It is around ten years old, and I doubt that I have ridden it more than around ten kilometers. It was very cheap, less than $200 Australian brand new from Big W.

I was considering installing a Bafang BBS or similar mid-drive kit.

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The piece you refer to is a kickstand mounting. As to whether it can be utilized in, or get in the way of, a conversion depends on the 'kit' use. Can it be cut off? Yes.

The frame looks like a high mount single pivot style rear suspension - with the shock mounting almost horizontally between the top front point of the swing arm frame and the downtube. This might have chain length issues you would have to be mindful of - the chain 'length' changes depending on the rear axle's position along the arc of suspension travel. A trickier conversion. The bike doesn't look like it has been used a lot chainrings, wheels etc show few signs of wear - though it maybe an older style, older build. a picture of the whole bike would help further.

  • +1 for correctly picking the suspension design correctly, before the whole bike photo was added. Welcome to Stackexchange! – Criggie Aug 31 at 13:05
  • You're absolutely right that it's a kickstand mount. I'd just like to roll my eyes at the idea of a kickstand on a full-suspension mountain bike. – David Richerby Aug 31 at 19:27
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Agreed that the folded metal bit is for mounting a kickstand, I do not believe this would would get in the way of mounting a motor. There are two other potential issues I see though.

  1. The down tube on your bike is very wide. This won't keep you from mounting the motor altogether but it will force the motor to hang down a bit lower. I'll try to demonstrate what I mean with some pictures. You can see in the two following pictures that there is a bolt for the mounting bracket that, on a frame like the one in the photos (smaller diameter steel frame) sits beside the down tube. On your frame, the bolt would have to be rotated down to below the tube, effectively lowering the motor. This should not be a deal breaker, just something to be aware of.

bafang motor

bafang motorbafang motorbafang motor

  1. Probably the bigger issue, where would you carry the battery? There are not cage mounting points for a water bottle mount battery. There is probably not enough room inside frame for a triangle mount battery. You cannot mount a sturdy enough rack on this bike to carry a battery there. The only type of rack you could mount on this bike would be a seat post mounted rack, which would not be sufficient. That seems to only leave carrying the battery in a backpack, which I've heard some people do, but it would not be my preference. You may be fine with this though. enter image description here

So in my opinion, you COULD mount a Bafang motor to this frame, but there are other limitations that keep this from being a viable ebike conversion candidate.

I'd suggest you sell this one for what ever you can get for it & buy a cheap, preferabley steel framed, non-rear suspension bike for your conversion.

Good luck!

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Given there's a hinge / pivot just forward of the front derailleur, I'd guess you have a MTB frame with rear suspension, and that someone has removed the rear shock and linkages?

A full photo of your bike might help confirm that, but as it stands that bike is probably really saggy in the middle, with a low BB and inclined to pedal scrape on the ground/road.

I also see flat pedals with pins that are worn or abraded, so this bike has done a few miles. The bottom bracket appears to be a traditional 68mm English cup and cone BB with a visible lockring, so this is not a high end MTB. The welds also suggest a heavy steel lower-end MTB from the 2000's.

That flange has no bearing on a motor, and it should have the bottom mounting stud of the shock through the holes.


As for whether this frame would suit a mid drive motor, you'll have to read the requirements of the motor kit you're intending to buy/install.

I'd worry that the lack of chain stays in the frame would cause increased wear and strange handling. The lack of a shock means your frame is also running on the end of all arcs of motion, and there's no absorption of vibration.

OPINION: I would not motorise that frame in its current state.


EDIT: answer was based on the first image only, showing the BB and immediate area.

  • could be the flange is for a kick stand and shock out of shot. Single pivot usually have a horizontal shock connection to top tube or down tube. – mattnz Aug 31 at 8:54
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    Uh... other than the dust of years in storage, this bike is practically brand new. Certainly neither front nor rear suspension is sagging, and the few miles that this bike has done can probably be counted on one hand. – Monty Wild Aug 31 at 11:20
  • @MontyWild OK thank you for the extra photo. That confirms this answer is way off base. Mattnz' idea is probably correct. – Criggie Aug 31 at 13:03
  • Would you care to comment on the suitability of this frame for a mid-drive e-bike conversion then, in light of a more complete picture? – Monty Wild Aug 31 at 13:10
  • Your answer wasn't all that far off base... you did pick that it's a cheap-ass bike dating to last decade, even if you did suspect that the suspension had been removed and it had done way more miles than is actually the case. – Monty Wild Aug 31 at 13:15

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