September 11, 2008

Big Dummy Spec Report

The last few evenings I've spent rebuilding my back wheel and fine tuning the rest of the bike.  For my own benefit, and for anyone who may be interested, I thought I'd list all the components I used and a little info about them.  Perhaps someone out there is contemplating a similar project and this my help them.  Maybe in the future I'll talk about some of the unique problems I had to deal with in building a somewhat unconventional bike.

Anyway, here's the list.

Frame:  22" Surly Big Dummy frame and fork, 4130 CroMoly steel.

Wheels:  Front:  Chris King ISO disc hub (red anodized), DT Swiss Competition spokes (2.0/1.8 double butted), Mavic EX 729 disc rim.  Rear:  Rohloff speed hub 500/14 CC OEM2 (red anodized) with tandem length cables, DT Swiss Competition spokes (2.0/1.8 double butted, 238 mm), Mavic EX 729 rim.  Both wheels "custom built" by yours truly.

Cranks:  Deore XT hollowtech II triple, 175 mm.  Converted to single by removing two inner chain rings.  44t outer chain ring.  Spacers set up for a chainline of 54mm.

Bottom bracket:  Shimano external bearing.

Pedals:  Crank Brothers Mallet 2 (red anodized).

Headset:  Chris King 1 1/8" threadless (red anodized).

Handlebars:  On-one Mary.

Stem:  130 mm.  (Simon at Wheelsport gave it to me for free with the idea that I'd order a different one from him once I figure out if this length and angle work for me.  It is aluminum, don't know who makes it)

Grips:  Specialized BG Comfort locking grip.

Brakes:  Avid Juicy 5 Disc (185mm front rotor, 160 mm rear rotor--proprietary Rohloff rotor with only 4 bolts).  Tandem length rear hose.

Seat:  Brooks B17 Standard, black.

Seatpost:  Thomson double butted aluminum, 27.2 mm diameter by 410 mm long.

Tires:  Schwalbe Big Apple, 2.35".

Chain:  SRAM 9 speed, 86".

Other:  Rohloff chain guide and chain tensioner.  Xtracycle freeloader.

Any questions?  Pictures tomorrow (or later today, depending on when I wake up after working the graveyard shift--yes that means I'm posting while at work, the ER is a little slow at the moment).


  1. great build. fancy stuff. Picture?
    I'm new to discs, so this may be a dumb question, but how can you have two different sized rotors on the same bike? Isn't the rotor size ultimately dictated by where the rotor tabs are welded on?

  2. Did you buy/order most of your components through Wheelsport South? I've had good luck getting some wheel related take-off deals there, but I haven't purchased any new stuff there yet.

  3. John, I'm not an expert with disc brakes, but the standard is to have a larger front rotor for more stopping power. There are a lot of iterations of mounts for disc brakes. The big dummy has "international standard" mounts. That said, there are several different mounting brackets the calipers fit on and the calipers come with a rotor and a mounting bracket presumably specific for the rotor size. The rohloff required its own special rotor because there are only 4 larger bolts on the hub whereas there are usually six (IS?).
    Jason, I tried to use wheelsport as much as possible. There were some things that their distributor didn't have so I did use the internet from time to time and got a few things 2 wheel transit had in stock (trying to spread the LBS love). I actually ordered the frame from North Division mistakenly thinking that they were the only shop I could order a Surly frame from. Simon at Wheelsport south gave me a few good deals, but only on old stock on hand, which is understandable. He also offered mechanical advice and a little labor. I was bent on doing all the work myself but did have them face and tap the BB and head tube since the price of cutting tools is prohibitive.
    Pictures later today.

  4. Hey,
    This is Jeremy from Xtracycle. I currently ride a Big Dummy, built up with SRAM bits (i9 hub, iLight dyno hub) and other parts from the SRAM/Avid/Truvativ pile including Code 5 downhill brakes.
    For people considering a Dummy, I'm partial to freeride disk brakes over cross-country brakes for heavy load hauling in hilly areas. The bike can be a bit of a freight train, and having the big stoppers is really nice.