scfoster
10 W
Used to hacking away at aircraft (that's what parachutes and ejection seats are for :lol: ) and for some reason I can't stand not having all the gears available. After giving a quick ride it appears that only the largest rear gear sprocket is unavailable.
According to the BBS02 manual (here's the manual online) page 8 shows the center of the drive gear sprocket is 16mm from the side of the bottom bracket. Not a bike gear expert. What would be the "optimal" distance from the side of the bottom bracket to the center of the drive sproket?
I took some measurements from my road bike. The distance from the center of the frame to the largest front sprocket is 50mm. Did the same measurement for the BBS02 and the distance is 55mm, for an increase of 5mm. Doesn't sound like much but it definitely prevents the use of the largest rear sprocket.
Looks like 5 mm can be shaved off the right side bottom bracket to achieve the "correct" alignment.
With what appears to be most of the production bikes now having 73mm bottom brackets, the BBS02 housing should account for this and provide shims to center the unit for narrower bottom brackets.
Another annoying "feature" is the difference in distance between each crank arm from the center of the frame. The it's a 20 mm difference! This is borne out in the schematic on page 8 (see doc referenced above). The distance to the end of the spindle on the drive sprocket side is 76.5 mm and the other side is 87.5 mm (159 mm total width - 87.5 mm). Don't know why this wasn't designed correctly in the first place.
That said, the quick "test" ride in the dark at 11pm last night was great!! I didn't configure the system correctly so I have no idea how fast I was going but it sure felt fast. I have a very steep hill right outside the house and the bike just zipped up it at a higher rate of speed than I would have expected. So overall I'm pretty happy with the experiment so far.
According to the BBS02 manual (here's the manual online) page 8 shows the center of the drive gear sprocket is 16mm from the side of the bottom bracket. Not a bike gear expert. What would be the "optimal" distance from the side of the bottom bracket to the center of the drive sproket?
I took some measurements from my road bike. The distance from the center of the frame to the largest front sprocket is 50mm. Did the same measurement for the BBS02 and the distance is 55mm, for an increase of 5mm. Doesn't sound like much but it definitely prevents the use of the largest rear sprocket.
Looks like 5 mm can be shaved off the right side bottom bracket to achieve the "correct" alignment.
With what appears to be most of the production bikes now having 73mm bottom brackets, the BBS02 housing should account for this and provide shims to center the unit for narrower bottom brackets.
Another annoying "feature" is the difference in distance between each crank arm from the center of the frame. The it's a 20 mm difference! This is borne out in the schematic on page 8 (see doc referenced above). The distance to the end of the spindle on the drive sprocket side is 76.5 mm and the other side is 87.5 mm (159 mm total width - 87.5 mm). Don't know why this wasn't designed correctly in the first place.
That said, the quick "test" ride in the dark at 11pm last night was great!! I didn't configure the system correctly so I have no idea how fast I was going but it sure felt fast. I have a very steep hill right outside the house and the bike just zipped up it at a higher rate of speed than I would have expected. So overall I'm pretty happy with the experiment so far.