Starter Questions and Gear shifting problem bbs02

maxitwist

Finding my (electric) wheels
Feb 24, 2022
10
1
Hello ebike forum,

Ive installed a bbs02 mid drive on my trek 7x, heres some bits im not sure about that have popped up.

1) I needed to fit the chainring what looks like its is back to front, as there wasnt enough clearing on the frame to fit it the other way, is that ok? It has been running fine so far.

2) Some of my gears are unusable as the chain is not long enough to fit over them anymore with the bigger chainring, should i get a new longer chain?

3) NB - I am unable to change gears while the motor is engaged, just nothing happens when i try shifting gears. Do I need to buy the gear sensors to enable shifting through gears or is something wrong here? Are the gear sensors worth buying?

4) Because of being unable to change gears while riding, I set the bike to always be in the highest gear. Will this drain the battery faster?
b) How long should a 13ah battery last?
c) Will a larger battery increase the top speed as well as distance?

5) I live in a wet country, what should i be waterproofing ?
b) If im leaving the bike outside should i always cover the whole thing with a bike bag, should i disconnect the battery and take it with me.. etc

6) Is the programming cable worth getting?

7) The 6v headlight which came with the set doesnt seem to work, is that worth investigating or should i just get a proper one that doesnt need to connect to the motor.
 
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sjpt

Esteemed Pedelecer
Jun 8, 2018
3,814
2,745
Winchester
2) You certainly need a longer chain.

3) That may help shifting under load as well. I don't know about gear sensors. Just stopping pedalling briefly for gear change should help, as long as the PAS responds quickly enough. Are both the down and up changes bad?

4a) Always riding in too high a gear will drain the battery faster; the motor will be revving too slowly and run at lower efficiency.

4b) Do you mean range on a single charge or how many years? Range depends hugely on how and where you ride. Look at https://www.bosch-ebike.com/en/service/range-assistant/ to get an idea of variation. (for Bosch but gives very good idea of variation for other bikes, and a fair idea of absolute range). You will see setting up perfect conditions on the 400wh battery in eco mode could go up to 100 miles, but plug in more realistic conditions and it will drop to 30, and use full assistance to not much over 20 miles). Your battery will fall between the 300wh and 400wh, range is linear with capacity.

4c) Bigger battery won't make much difference to speed. Might help a tiny bit on hills as there will be less voltage sag.

5) Should be ok for riding as is in normal rain, but definitely cover if at all possible when standing. It's often the display that suffers most from rain.
 
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wheeliepete

Esteemed Pedelecer
Feb 28, 2016
2,047
757
61
Devon
1) You may still have problems using the lower gears with the chainring on back to front, even with a longer chain, due to bad chainline.
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
20,882
8,517
61
West Sx RH
4. Start off in high gear will eventually cause controller failure, one needs to spin in a low gear so the strain is less from standing start.
5. Cwah left a battery on his bike all night during rain with no bike cover, it failed afterwards as it was water logged.
 
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guerney

Esteemed Pedelecer
Sep 7, 2021
11,251
3,195
1) I needed to fit the chainring what looks like its is back to front, as there wasnt enough clearing on the frame to fit it the other way, is that ok? It has been running fine so far.
Chainline problems could arise when you sort out the gear shifting issue?


3) NB - I am unable to change gears while the motor is engaged, just nothing happens when i try shifting gears. Do I need to buy the gear sensors to enable shifting through gears or is something wrong here? Are the gear sensors worth buying?
The gear sensor is well worth buying IMHO (waterproof the ends of that too, also keeps dust out of the sensor), when your chain and gear shifting problems have been sorted out - as others have mentioned, your chain may now be too short (if your original chainring was larger).


5) I live in a wet country, what should i be waterproofing ?
b) If im leaving the bike outside should i always cover the whole thing with a bike bag, should i disconnect the battery and take it with me.. etc
After a bike and complete motor immersion incident following a heavy thunderstorm, I waterproofed all connections and connectors using 4:1 self-adhesive marine heatshrink and self amalgamating tape. I'd never leave the battery out in rain. I've covered the battery with two watererproof rucksack covers, secured with velcro.


6) Is the programming cable worth getting?
Absolutely! Sorts out many niggles about how the bike behaves, if you have niggles which need sorting out.



7) The 6v headlight which came with the set doesnt seem to work, is that worth investigating or should i just get a proper one that doesnt need to connect to the motor.
The 6V headlight is low light activated by the display on the handlebar, so it won't automatically switch on in daylight or under bright artificial light. If you long press the headlight button on the handlebar and the light doesn't activate (long press overrides the low light sensor activation function), check those wires using a multimeter to determine if you have been sold a duff headlight. If you have been sold a duff headlight, hunt down the seller like The Terminator (or request a partial refund, or replacement),
 
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maxitwist

Finding my (electric) wheels
Feb 24, 2022
10
1
Thanks everyone for your help here. I solved most of the problems with your help.