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Kat’s Bridgestone BB-1 Part 4

The original concept for this bike was a wide range 2x. The 1x we put on was borrowed from my old bike just to see if this Bridgestone would work for Kat. Her 1992 Trek has a wide range 2x with drop bars and friction shifters. She decided to put ENE Wing shifters and a wider range 2x on the Trek and move her Trek’s ENE Thumb shifters to the BB-1. So we took a bunch of parts off the Trek.

The bottom bracket and rusty purple chainstay of a 1992 Trek. A chain is hanging over the bottom bracket shell without a crank on.

Getting all the parts ready.

A bin containing a crankset, rear derailleur, old pedals, old front derailleur, cassette box, and chain box.

Thanks, Multitrack. We appreciate it. We also love function specific design. Also known as design. Also get a load of that 0mm Discord stem with some beautiful thin rust under the clear cerakote.

The purple top tube of a 1992 Trek. It reads 'Function Specific Design' MULTITRACK'

And here it is! 11-42t with a 24/40 and shifts great.

A blue bike with gold accents propped up with a stick on a dirt trail in a forest.
Kat riding a blue bike with gold accents on a road during golden hour.

BUT! — and we didn’t see this coming because she’s a die-hard 2x fan — Kat ended up going back to a 1x for a couple of reasons:

  1. Preferred the experience of a 1x on trails once it had a friction thumb shifter instead of the SRAM trigger shifter she didn’t vibe with. She likes the simplicity and the ability to dump a lot of gears at once on trails (for changing your gear more than a front shift would do).1
  2. The clearance between the tire and chain in the easiest gear was really tight. Even with a 127.5mm spindle bottom bracket.

So, this is the second strike on rear tire width (see part 1). Kat decided to axe the rear Ultradynamico 2.2" MARS for a Panaracer GravelKing SK 2.1". Clearance issues solved with the chain and chainstay! Knobby in the front for traction and knobby in the rear for uhhhh, maximum utility.

1x back on, this time with an 11-51t Deore M5100 cassette and a bronze crank extractor cap instead of the old purple ones. The 11-42t with 24/40 had a gear range of 15.1–96.1 gear inches. The 11-51t with 28t chainring gives a range of 14.5–67.2 gear inches. And the same with a 32t chainring gives a range of 16.6–76.9 gear inches. There’s a 32t on order. That’s a top speed of 20.6mph when pedalling at 90 RPM. Totally sufficient (in general but definitely for this bike). The same cadence on the 24/40 gets you 25.7mph.

She kept the RD-M8000-SGS rear derailleur from the 2x and it worked just fine on on the 1x with the 51t cassette despite its low sprocket max of 46t. In fact, the B-screw and cage position in the biggest cog aren’t even that extreme.

A blue and gold bicycle propped up with a stick in a misty forest. The bike has a dark tanwall rear tire and a medium tanwall front tire. There are silver cranks and a silver front rack with a burgundy bag.

And, of course, the Fabio’s Fanny on a Nitto Mark’s Rack! The bag just doesn’t work without the rack because of the backsweep and forward extension on these bars.

An IQ-X front dynamo light mounted to a dull silver rack.

Almost done!

Kat riding her BB-1 on some sligtly winding single track in a misty forest.

  1. Kat says even the range of an 11-42t cassette is fine but it’s where you put that range that makes the difference. So if she shifts through her whole cassette at once on a 2x then it’s not enough high-end on the 24t and not enough low-end on the 40t. But on a 28t or 32t moving across the entire cassette in one shift movement gets you low or high enough for your sudden need. She says a 3x might also accomplish this since she could stay in the middle to simulate this but then still have more range even on top of that. But ultimately this bike has enough low-end and high-end for its purpose. ↩︎