Fatbike BB torque sensors and weird sizing.

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SayWatt   1 µW

1 µW
Posts: 2
Joined: Nov 16 2018 6:20am

Fatbike BB torque sensors and weird sizing.

Post by SayWatt » Nov 16 2018 6:43am

Hello all,
I'm new here and brand new to ebiking. I've only been reading up on the subject for the last couple of months waiting for my motorbike to sell so I can build an ebike. Every build I plan out ends up getting stuck somewhere usually due to the donor bike's weird sizing. I'm looking at bikes from BD and some cheap mongoose bikes as donors. I have searched the forum here but I can't find anything relevant.

My first choice was the 2019 Gravity Bullseye Monster and I am trying to find out if the Sempu 175 bb torque sensor would fit. The bike's bb is 100mm/144mm. The torque sensor is 100mm/175mm. I emailed their customer support and asked if it would fit and they said no, so I started looking for other donor bikes just to realize I can't find a single bike with the 100mm/175mm sizing. I emailed the customer support asking them the size of the part without the end of the spindles, the sensor housing itself that would have to fit in the BB. The reply was the data/spec sheet that still doesn't answer my question, and no reply since. The mongoose are even worse with a 110-112mm BB according to various forums. Can't find a spec sheet for any of the cheap models. Also asked the customer support for an example of a bike that fits the Sempu 175 and got ignored for a few days now. This will be for a fatbike hub motor with a big batt and PAS only for flat road riding and I want a quality torque sensor.

Bonus question, will a 175mm hub drop into a 170mm dropout without modification?

SayWatt   1 µW

1 µW
Posts: 2
Joined: Nov 16 2018 6:20am

Re: Fatbike BB torque sensors and weird sizing.

Post by SayWatt » Nov 18 2018 8:09am

I solved my build issues.
This post can be ignored/deleted.
Thanks.

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