Help! Novice fitting Bafang BBS02B 48V 750W to Trek Hybrid

Encantador

Pedelecer
Jul 18, 2008
48
0
Hi,

For those that might remember, I started the below thread just before the first 2020 lockdown. hence nothing much has happened since.

A brief summary is that I purchased two Trek Hybrids from Cytronex in Winchester in 2008, the batteries are now both defunct. At the end of the last thread I had decided to go with another hub motor kit, that of course never happened.

Having started the whole decision making process again now, I have decided on fitting the above to my Trek due to my weight which is now over 19 Stones (hence the need to cycle more)( I am aware of the legalities surrounding this choice) and then if all goes well fitting the same but lower powered kit to my wifes Trek as she is about half my weight.

Having watched numerous videos and waded through mountains of jargon, I am still confused by a few things that hopefully someone here can answer for me. I will be starting from scratch as a complete novice buying a stand, tools etc. Hopefully learning a lot along the way.

Similar kits are on Amazon and AliExpress but with different choices to be made. I would prefer to go with Amazon in case of any problems, although AIiexpress can deliver a few weeks quicker.

Save me waffling on I will just ask the questions if that's OK and am sure more will come from the answers.

1. The motors are advertised as 48v 750W, does this mean I should stick with 48v battery or would a 52v be OK?

2. The dropdown list on Amazon lists a mountain of battery options, some mention 44T 48T etc and 17.5Wh etc, some including 48 or 52V as well. The Aliexpress kit appears to offer a few battery choices and it says just 44T. So it appears that Amazon has a lot more options but I have no idea which is a good or bad combinatiion?

3. The bottom bracket seems to cause some issues on some videos and I have no idea how to find out what mine is without stripping it down first and taking a chance the motor fits easily. Are there any easy ways to check beforehand?

Thanks

Steve
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
8,982
3,563
Basildon
1.Stick with 48v for cheaper batteries that are more widely available and give fewer problems.
2. If you're a big bloke, a smaller chain ring will be better.
3. No. You should always dismantle and check before ordering to avoid wasting your money.
 
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Encantador

Pedelecer
Jul 18, 2008
48
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Thanks for the replies. I will take some photos.

The Cytronex control box is attached below the bottom bracket which I assume will be easy to remove.

If I order the kit from Amazon and start the job just before it is due to arrive, I can at least return it if it does not fit.

I have been told that in the drop down battery list on Amazon, if there is no voltage shown, it will be 48v.

Assuming the above is true and they are 48v the difference between......
44T & 13Ah Down Tube Battery and
44T & 17.5Ah Down Tube Battery is about £100 more. Does that sound about right and is it worth the extra??

Thanks again.

SteveIMG_0796.jpegIMG_0799.jpegIMG_0798.jpegIMG_0797.jpeg
 
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wheeliepete

Esteemed Pedelecer
Feb 28, 2016
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As you said, the control box on the BB will need to be removed and you will need to remove a section of the trucking on the down tube to fit the motor. Otherwise as long as the BB is between 67-73mm wide you look good to go.
 
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Encantador

Pedelecer
Jul 18, 2008
48
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The best I can measure it the BB is about 68mm, so hopefully OK.

Just the battery to decide on, is the extra 4.5Ah worth £100?

Do the photos help with knowing which tool I will need to dismantle it?

Thanks
 

peter.c

Esteemed Pedelecer
Apr 24, 2018
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thurrock essex
Unless you intend to do longer trips the smaller capacity is lighter:) helps if you have to lift the bike i get 30+ miles with the £199.00 yose power battery
 

wheeliepete

Esteemed Pedelecer
Feb 28, 2016
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592
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The best I can measure it the BB is about 68mm, so hopefully OK.

Just the battery to decide on, is the extra 4.5Ah worth £100?

Do the photos help with knowing which tool I will need to dismantle it?

Thanks
Your BB is fine at 68mm. Decide how far you want to ride when choosing a battery. The one peter.c mentions is 12.5ah.
These tools will get your old BB removed.
 
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