Fitting BBS02/BBSHD to a belt drive, the Priority Eight?

J

jdash

100 µW
Joined
Sep 8, 2015
Messages
7
Hi,

I'm seriously considering to buy a Priority Eight (http://www.prioritybicycles.com/theeight) and install BBS02/BBSHD to it. But this is a fairly new bike, and I cannot find any information whether it is feasible or not.

The potential problem may occur from its belt drive. I don't want to change it with chain.

Anybody have similar experience? Could you tell me whether this will work or not? What kind of problems may I have? Then, how can I solve them? If any custom parts are needed, where can I make or order them?

Thanks!
 
I am not so familiar with this, but my 2ct are:
if you want t o keep the belt drive you need to fit the existing beltring from the bike to the BBSHD motor.
this you only know, when you have the beltring (chainring) in your hands take good pictures and measurement and ask somebody with a CNC machine to fit it to the BBSHD.

there are other ways, which I don´t know, but I am also curious about the outcome here.


uwe
 
Thanks for the reply. Is it easy to measure the exact size of chainline? How much does it cost roughly to make a custom adapter at a CNC shop? Any recommended CNC shop?
 
If the belt lining can be done just by adding some sort of spacers, it may be easier. But is is possible whether it would be required to shave off the bottom bracket?
 
Gentle reminder: if you put too much power, specifically too much torque, through the Nexus 8 hub, you'll break it. Then it won't matter whether you have a belt or a chain.

In my opinion, that bike is OK in its own right, but it's a poor candidate for any electric assist system other than a front hub motor or a compact friction drive.

If the bike turns you on such that you don't want to change any of its details, why don't you just pedal it as the designers intended? Then no worries about the belt drive or the hub's integrity.
 
Biggest issue I see will most likely be the belt line.. doubt you can get the belt sprocket close enough to the seat tube to line up with the cog .. any Bafang adapter (104 110 130) will space the sprocket further away from the seat tube than the stock BBS02 chain ring.. I mocked up a BBS02 on a production Moulton belt drive bike and then moved on to a different frame..
 
brucemetras said:
any Bafang adapter (104 110 130) will space the sprocket further away from the seat tube than the stock BBS02 chain ring.
Click to expand...

Then, it's highly likely that grinding away some portion of bottom bracket will be needed (using an angle grinder?). Is it ok to do that? Threads inside bottom bracket go deep enough so that shaving off doesn't cause any problem?

Modifying the frame sounds difficult for me. Where can I ask such modifications?
 
I found that there are cheap angle grinders. Cheap ones will work fine on (aluminum) bike frames? Maybe I can buy one. But, still, I wonder whether it is ok to grind off some part bottom backet for Bafang installation.
 
Modifying the bottom bracket shell should only be attempted if you research first and are absolutely certain that the mods you plan will work. There is the possibility that the final reduction of a BBSxx series kit might push against the front of the right-side chainstay, preventing it from properly seating.
 
spinningmagnets said:
Modifying the bottom bracket shell should only be attempted if you research first and are absolutely certain that the mods you plan will work. There is the possibility that the final reduction of a BBSxx series kit might push against the front of the right-side chainstay, preventing it from properly seating.
Click to expand...

Chainstay clearances at the final reduction housing on my three BBS02 builds range from the thickness of business card to about 5mm .. if one was absolutely sure they wanted a BBSxx series kit, buy it .. buy the Priority 8 .. mock it up in the frame like I did with the Moulton.. you'll clearly see what's possible and what is not if you wish to maintain the belt drive .. once you find it isn't going to happen, move the new BBSxx to a more suitable frame .. and if the Priority 8 needs e-assistance, go the front hub motor or friction drive route as previously suggested..
 
You must log in or register to reply here.

Similar threads

marka-ee
Going from hub motor to 3000 watt belt drive. A good idea or not?
Replies
12
Views
560
marka-ee
marka-ee
K
BBS02 vs BBSHD - how much can you alter programming also
Replies
16
Views
1,832
uhmwpolyethylene
U
R
    • Like
Really good article comparing Bafang vs. Tongsheng vs. CYC
Replies
12
Views
10,579
999zip999
999zip999
M
determining the over/under voltage capability of motors?
Replies
0
Views
136
mindgames11
M
Cybernetica
2 Power mode switching for semi-legal EU option. BBS02 / 850C
Replies
4
Views
933
Cybernetica
Cybernetica
Back
Top