1994 KHS ZH²B Aero Turbo
Part Diary, Part Technical Manual, Part Tips & Tricks

This is one of those bikes that I've always liked because of the unique curved seat tube. For a relatively common and inexpensive bike, they are surprisingly hard to find for sale. These bikes were made in various models from 1993 to 1999. The ZH²B stands for Zinn Hed Boone, an all-star team of aerodynamic industry leaders, Lennard Zinn (Zinn Cycles, author, technical writer for VeloNews), Steve Hed (HED Cycling, aero wheels), and Boone Lennon (inventor of aero bars). The frame was only offered in three sizes - 52 , 55, and 59 cm, as a conscious effort to reduce dealer inventory.

So I find this ad for a 56cm Turbo in Alameda. The size was right and the frame looked like it was in pretty good condition. Since I was planning on building up a fixie, I asked the seller if he would be willing to sell the bike without the wheelset - he agreed. So while I was heading over to Alameda to check out the bike at 3:00, I received a text message regarding a NIB Origin8 wheelset in San Francisco. I told him that I could be in SF by 4:00. So I see the KHS, looked ok, I take my ruler to the top tube and it was 54 cm - just a tad smaller than I had hoped. But the price was right, so I bought it and put it in the car. Then I headed off to SF to check out the wheelset. The wheels were literally still in a sealed box, the seller opened it up and showed me the wheels, a beautiful gray color with black bladed spokes - sweet! So on November 26, 2010, I brought home a KHS and a new set of track wheels.

11/28/2010 - So I spent a couple hours last night and a couple hours this morning and got the bike setup as a fixie. A major oversight on my part is that this frame has vertical dropouts, I somehow optimistically assumed that with the right gearing combination that the chain tension would be ok. I was actually more preoccupied with chainline and what bottom bracket/crankset combo to use. So after trying a few different combinations and the use of a half-link, I was able to get the chain tension acceptable. I rode it around the block and since the chain tension wasn't perfect, there will always be a little play between forward and backwards. Now that I own two track bikes, this slop in the drivetrain is not acceptable anymore. So it seems like this frameset will be built up as a geared bike in the near future. But for now I'll ride it as is, just to dial in the stem height and reach, to make sure I like the fit of the frame.

4/6/2011 - This has been a very long project, but it is finally complete. Inspired by the brown and pink color of my daughter's clothes, it began as a beat up bike with no wheels, to a fixie conversion, then purchasing a Vitus 979 for its Shimano 600 parts, then changing my mind and buying a Vitus 992 for its with Dura Ace parts, then stripping and powder-coating the frame, a few bits from eBay, and finally bringing everything together. Problems along the way included rusted bottom bracket, grinding the front derailer braze-on, filing the forks to accept the hub axle, and countless handlebar/stem combinations. But I'm pretty pleased with the results, I just came back from a short ride and everything performed flawlessly.

5/11/2011 - I finally got the Dura-Ace hubs laced up to some new Velocity rims, so now I have the entire gruppo together and I dropped 8 oz. in the wheelset alone. I also installed a nice pink Selle San Marco saddle, which was pretty light as well. So the overall, the bike went from 22lbs 5oz to 21lbs 11oz, a drop of 10 oz! Not bad.

11/21/2012 - I decided the frameset was too small for me, so I stripped out the bike and transferred most of the DA gruppo to the Time Helix Equipe. Then I took all the parts I could use in the garage and rebuilt the bike up to sell. There were only a few things I had to buy, such as a rear wheel, brakes, tires, and bar wrap. The bike actually looks very nice, instead of the brown and pink color scheme, I went with a more conservative brown and white combo. When all was done, the bike weighed 22lbs 8oz..

1/9/2014 - After procrastinating for a long time, I finally sold the frameset on eBay to a person in Philadelphia.

Here are the specs:

Frame: KHS ZH²B Aero Turbo, 55cm, 130mm spacing. True Temper AVR double-butted tubing, TIG-welded. Serial Number: K50 U40904291 (U=factory 4=1994 09=Sept). Powder coated RAL 8016 "Mahogany Brown".
Fork: Soma straight blade fork, 1" threaded, 41mm rake. Tange Infinity tubing, chrome.
Front Wheel: Shimano Sante HB-5000 hub on Wolber TX Profil hard anodized aero rim, 32h. Bought on eBay a long time ago.
Rear Wheel: Felt hub on Mavic CXP 22 rim, 32h. Bought on craigslist.
Tires: Forte Pro Lite, folding bead, 700x23c.
Cassette: Shimano CS-HG50 7sp, 13-23T. Bought on eBay.
Cranks: Shimano Dura-Ace FC-6400, 52x42, 170mm, 130 BCD. From the black Vitus 979.
Bottom Bracket: Shimano BB-UN54, 110mm spindle, square taper.
Front Derailer: Shimano 105SC FD-1056, braze-on. From the Cannondale R700.
Rear Derailer: Shimano 600 RD-6400, 7sp. From the black Vitus 979.
Shifters: Shimano Sante SL-5000. Bought on eBay a long time ago.
Headset: Shimano Sante HP-5000. From the Schwinn Circuit.
Chain: Shimano 600 CN-6400, narrow. From the black Vitus 979.
Stem: Nitto 1" quill with 25.4mm clamp diameter, 95mm reach. From CyclePath's old parts bin.
Handlebar: SR Sakae Custom, Modolo anatomic bend, 25.4mm. Came with bike.
Brakes: Shimano 105 BR-5501, dual pivot. Bought on eBay.
Brake Levers: Shimano 600 BL-6401. From the black Vitus 979.
Pedals: Shimano 600, PD-6400. From the black Vitus 979.
Seatpost: Aluminum, 26.8mm diameter, 35mm setback. Came with bike.
Saddle: Selle San Marco, white. From the Kestrel 4000.

The bike currently weighs 22lbs 8oz as shown. The frame weighs 4lbs 7oz (2,012g), the fork weighs 1lb 9oz (708g).

The following are parts that I am currently not using:

Front Derailer: Shimano RX100, FD-A551, braze-on.
Shifters: Shimano RX100, ST-A550. Shifter mechanism broken.
Headset: Shimano Dura-Ace HP-7410, from eBay.
Stem: Forte 1" threadless with 26.0mm clamp diameter, 120mm reach, silver.
Seatpost: Shimano Dura-Ace SP-7410, 26.8mm. NOS from eBay.
Saddle: Selle San Marco Caymano, pink.