2017 Breezer Downtown 8 ST and BBS01

[Dewey]

BBS01 motor kit from California ebike, 36v battery and 42t chainring from Luna. I discovered the BB was 73mm so I bought some 5mm longer M6 screws and washers from a hardware store to mount the fixing plate and had to omit the second M33 locking nut. I needed to replace the Breezer chainguard so bought an Hebie chainglider from Bike24, 700c Schwalbe Marathon tires, gearsensor, 21t rear sprocket, KMC ebike chain, Ergon grips, VP flat pedals for my big feet, Busch and Muller battery lights, Wald basket, u-lock holster, Brooks B66S saddle required a replacement seatpost.

[ncrkd]

Very nice and practical bike - thanks for posting about it. I'd like to get one of those Hebie chaingliders for at least my step-thru build - any post-install issues?

Hopefully the Breezer wheels are better built than my Priority 8 (and some others seen here) had. It's probably best to keep an eye out for loose/broken rear spokes.

[Dewey]

Only installed the chainglider this morning but it was quiet on the test ride. Thanks for the heads up on the spokes, I have a spare Nexus 8 IGH 700c wheel I can use if it comes to that.

[ncrkd]

I forgot to ask - looks like you used a Luna 104 chain ring adapter with a raceface (42, 44?) ring, and you have a 73mm BB - do you know offhand what the front chain line ended up being? Did you go with the dished rear cogs?

Unfortunately, there's not a lot of chain line data on the BBS01/02 and the respective adapters.

[Dewey]

Sorry I didn't measure the front chainline before I installed the chainglider, if it would help I can get out a ruler and measure the distance from the center of the downtube to the middle of the chainglider to give you a rough measurement?

Originally I had a Lekkie 42t ring fitted to the BBS01 on my old bike, that pushed the front ring chainline in by 9mm, but Lekkie offset rings are too wide for a chainglider so I went with the Luna 104 4-bolt adapter and Luna's own narrow-wide 42t chainring. My local bike shop fitted a 21t rear cog to replace the 18t Breezer had fitted, to get the 2:1 ratio Shimano recommend for Nexus IGH. Sheldon Brown's site says Nexus and Alfine both require a 3mm dished sprocket.

[ncrkd]

If you get a chance to measure / document it, it would be good to have. The Nexus/Alfine tight chain lines are hard to hit with the BBS01/02 motors, chainline-wise.

You added, "Lekkie offset rings are too wide for a chainglider" - crap - I was afraid of such an issue.

I've got a pretty good handle on the chainline with the BBSHD motor (easy with the Eclipse chainring).

There's a lot to do between the chain line, gear ratios and individual unit weaknesses, to build a reliable IGH/BBS setup. But, I think an IGH makes more sense under motor power that an open, twisted chain 9-10-11 gear derailleur setup.

[Dewey]

The center of the seat tube to the center of the chainglider is 50mm, measured from behind the seat tube.

[ncrkd]

Thanks! I was guessing at least high forties.

[Dewey]

Just measured the center of the Nexus 8 IGH to the center of the rear section of the chainglider and it is also 50mm

[ncrkd]

I'm guessing that your LBS set that 21 tooth sprocket dish-out, and it's actually 48mm (per Sheldon Brown's 42-45-48 specs.