I was pretty depressed yesterday when a surprise package came in the mail from Eric at Lunacycles. Inside of a box filled with candies and cookies was a brand new Mighty Mini 7075 t6 heat treated alloy chain ring for the BBS02 available here for $56. I was so astounded by the sheer beauty of this chainring that I actually sat and stared at it for about 5 minutes. I carefully looked over the machining to see if I could find a single flaw. I couldn’t.
I started to tear up a little bit, and then I hung it on the wall like a piece of art. I was going to call the machinist and tell him what an amazing job he had done, but I didn’t want to have him hear me be all emotional and weepy on the phone, so I didn’t. The next day I took down this work of art, threw it on my Dark Matter build and took it for a spin. It did not disappoint.
First I did a speed test with my old 34T Race Face chainring and my Biktrix chainring adapter on the Biktrix BBS02. On the flats with a fresh battery and pretty low tire pressure, I got up to about 27mph GPS verified. At that speed, there was a good pedaling cadence with an 11T cog engaged in the rear. With the 30T Mighty Mini my top speed was about 26mph GPS verified with a very fast pedaling cadence on the 11T cog. That means that if you switch from a 34T to a 30T chainring you lose about 1mph of top speed. You should also expect that with this chain ring you will have a fast pedaling cadence at anything over about 20mph or so. Even though I suffer through my wife’s Brazilian Buttlift video weekly I still weigh in at a hefty 200lbs so your builds will probably go faster because you’re not fat. Or ugly either.
The Mighty Mini was able to creep up insanely steep slopes using the 32T granny. I could not even find anything steep enough to need the 36T granny, but it’s nice to know that it’s always there. This is one area the BBS02 really excels at, crawling up really steep slopes in a very low gear. Under high loads, the BBS02 likes to spin fast, not slow. It’s much easier on everything in the drive unit and it generates much less heat. You’ll have to trust me on that one.
As I expected, I had no chain issues with a 10-speed chain and most of the time I was able to ride in the middle of my cassette, which is always the best place to ride. If you are always in your granny gear then your front chain ring is too big and if you’re always on your smallest cog then your front chain ring is too small. Like Goldilocks, for single track this chain ring is just right.
The weight is simply astounding, nothing else I’ve found even comes close. The Biktrix adapter and 34T Raceface chainring that this replaced weighed in at a hefty 138g, more than twice what the Mighy Mini 30T BBS02 chain ring did.
The torque that you get with the smaller ring is not as noticeable as the 30T mighty mini was with the BBSHD, mostly because the BBS02 is just not as powerful of a drive unit. If you have a BBS02 cargo bike, a tandem with a BBS02 or a singletrack trail machine with a BBS02 then the 30T Mighty Mini is an excellent choice for a front chainring. If you want maximum top speed then you should go for a larger chainring like the Lekkie 42T Bling Ring or even a crap-ass 52T steel factory chainring for the highest top speeds.
As a side note I do NOT recommend the BBS02 for a cargo bike or a tandem. If you can afford it, then spring for a BBSHD drive unit instead. You won’t regret it.