Chainring selection

[tomjasz]

I installed a Luna Cycle 30 tooth mighty mini chain ring on my BBSHD Kit.

Any BBSHD chainring under 42T will significantly mess up the chainline on most builds.
Exception being the Lekkie 40T BBSHD kit. $180.

 

[slayer1962]

Ok I am going to start thinking about cassettes. First I need to ride it with the 42tooth and see how it is

 

[voidedwarranty]

I'd like to jump in here with some related questions. I've had my ebike for about 2 months now. Biktrix Juggernaut with BBSHD 10speed Shimano 11-42. I'm a fat boy and this bike struggles to get to and maintain 30mph in my top 3 gears. I've seen 6th gear hit 30 on the flats so would dropping my chain ring give me a better chance of hitting those low/mid 30mph? I'm not sure what chainring came with the bike. I want to say 44 but it could be 46.

Also @tomjasz I saw you mention the BBSHD doesn't like 52v. My bike has dual 52v batteries and when I plugged in the programming cable my low voltage cutoff was set to 41v and the nominal voltage on the right hand window was 48v. Max Amp was set to 28 and the programming software won't allow me to bump it up to 30a or change my low voltage cutoff higher. What's the deal with this? Is my setup neutered?

 

[tomjasz]

See the BBSHD firmware thread on endless_sphere.com some users claim a firmware flash can change settings to 30A.

 

[Alaskan]

Modifying your bike will void your warrenty.
Biggest US internet supplies I've found are modernbike.com and thebikeshopstore.com. Davidbrown in UK is highly competent but stuff might get stolen in customs like my recent Newark order.
Competitioncycling is competent but carries only high end racing gear. I bought my helmet there since only racers prevent breaking their chin with a chin guard.
No US supplier provides any dimensions on anything they sell. The tooth count might be right. Whether the mount holes will line up is totally up to chance, and your estimation of the picture. Shimano & sun websites are worthless on dimensions, pretty good on sales blather. I bought 4 rear sprockets and none of them fit.
A LBS might be able to send things back and get an actual support person on the phone. You'll pay a decent markup. Both my LBS have sold me garbage for accessories, and one dumped me on the street with improper assembly of a MBT, so I don't buy anything there but tires anymore. If you're not buying a top end racing cycle or getting it maintained don't expect much competence at a small city (2 million) LBS.
Count your teeth and estimate how much slower you want to go. You'll also need a chain splitter and master link to shorten the chain. Chains come in different widths, count the number of sprockets on the back axle to get the right one. The schwinn chain splitter doesn't work. The dodge small industrial splitter only works on single speed or 5 sprocket chain. Industrial 1/2" master links fit single speed & 5 sprocket (15 speed) chain.

This post reminds me of the Yogi Berra quote, "Half the lies people tell about me aren't true." Changing chainrings does not void most bike warranties. Most on line US bike parts seller, like Jenson USA or Modern Bike, include BCD (Bolt Circle Diameter) info as well as tooth count in their chainring info. Many of us have had excellent service and care from our local bike shops. I could go on but...