So one of the caveats of this build was that I wanted it to be fast ---- as fast as possible. Retro wasnt really a "design theme" it just kind of happened that way. Partially because of the aero-revolution that occurred back in the late 80's/early 90s and the parts are cheap.
Cheap was the design theme. And fast. And neon.
So I had this 56cm Schwinn Varsity and I remembered that Gerard Vroomen from Cervelo once said in a newsgroup that the Schwinn fork was the fastest fork Cervelo ever tested in the windtunnel.
So that's cool.
So I went to my local Craigslist and picked up this Schwinn Varsity for like $25. And began building it up.
One of the reasons I decided to build up the Varsity was the fork and the known aero attributes, the other "advantage" is that the tubes are super small. This bike is not standard. The headset is special, the rear wheel spacing and front wheel spacing, the seat tube is narrow. It takes a special 13/16" seat tube which was basically just used on old Schwinns and some old BMX bikes.
So you can see that slack seat tube angle above and how far back that saddle is compared to the BB. This was going to be a problem ---- I like riding super aggressive seat tube angles. I was imagining that I was going to have to either build or have built a customer seatpost that looked something like this:
And I still might do this, but while browsing eBay one night I came upon this:
It's a BMX layback seatpost that is 13/16" ------ turn it around and its a forward TT seatpost! Because the post is so narrow ---- 20.6mm ---- the gusset helps so that the seatpost wont bend/break.
So then, I was like this is cool but what this frame needs is a fairing behind the headtube. I did a similar thing on my Cervelo P3 a few years ago.
I did some searches for Schwinn Varsity Time Trial and found this result from Slowtwitch. The guy shaved the cable stops off the tubes and ran the cables through the frame. I liked the idea and appreciated the effort, but didn't want to drill my frame and wanted to make the tubes more aero anyway.
What also fueled my motivations was a Specialized Win Tunnel video that a modern Shiv was "only" 73 seconds faster over a 40k than a steel round tube bike. link
The thing was, my red/white/blue Schwinn was too damn pretty to grind off the cable stops. Hmmm what to do..............I just bought another Varsity off Craigslist for $40.
Sweet. So I grinded off all of the random cable stops. Sanded the frame down to get some of the rust off, then primed it white.
Then I got to work running my tubes that will house the shift cable housing. One tube ----- I epoxied it onto the downtube ---- zip ties are holding the tubing down while it dries.
Second tube epoxied on
So when I built the P3, I built up the shapes using Bondo. This worked, but I wanted to try something else. So I decided to build up the profile using spray foam. My idea was that it'd be easier to shape.
If I did it over, I wouldnt do this again. I'm a little concerned about how "stable" the foam is going to be as a base foundation. It seems to work so far. But we'll see. And it didnt make anything easier to shape ---- I still needed to Bondo over the foam, so that took a ton of hours. The only real advantage I can think of with the foam is that its lighter. But I don't care about weight with this build. It's a Schwinn Varsity!
Here are some more in development photos:
I considered fairing the seat tube too ---- but I wanted this project to be over sooner than later. Maybe on the next iteration.
Then I put a layer of fiberglass over the downtube in an attempt to "hold in" the bondo from cracking/popping out etc.
Priming it white again helps to identify surface imperfections
Sand, fill small holes, sand again, repeat, repeat. Then I painted it my retro neon colors
Clearcoated over the neon. Let dry 5 hours or until I couldnt stand it any longer ---- and begin building.
I just took off all the parts I hung on the red/white/blue Varsity. And put them on this one.
Build list:
| Aerobars | Scott 100k |
| Aerobar pads | Scott |
| Bottle cage | Batwing |
| Bottom Bracket: | Schwinn |
| Brake Levers | 24mm CX levers |
| Front brake | Weinmann Delta |
| Rear brake | Caliper - long reach |
| rear brake dropbolt | homemade drop bolt |
| Cassette | Shimano 7 speed 12x25 |
| Chain: | KMC X8 |
| Chain link | KMC |
| Chainring | Schwinn 52/39 |
| Cranks | Schwinn one piece |
| Fork: | Schwinn Varsity |
| Frame: | Schwinn Varsity |
| Handlebar tape: | Black foam |
| Handlebar: | Scott 100k |
| Headset: | Schwinn steel |
| Pedals: | Schwinn |
| Shifters | Shimano 8 speed friction barcons |
| Saddle: | Adamo |
| Seatpost | 13/16" layback post turned forward |
| Seatpost clamp | 1" black |
| stem adapter | 21.1 stem adapter |
| stem adapter adapter | 25.4 to 21.1 adapter |
| Stem: | Dimension 26.0 silver stem |
| Tire (Front) | panaracer paperlite 700 x 23 |
| Tire (Rear): | Specialized Mondo tire |
| Tubes | 700x 23 |
| Wheelset | Rigida Dp18 |
| Derailleur Rear | Exage 400EX short cage |
| Derailleur Front | Schwinn |
| Derailleur hanger | bolt on |
And got something that looked like this:
So I originally kept that downtube round (not airfoil) because I wanted to put a front derailleur on there. Then I read this thread on Slowtwitch and got to thinking: this bike is heavy, it wont go up hills, it's meant for flat time trials ----- so why do I need to a small ring? I dont.
So I airfoiled the seat tube. I would have liked to get the wheel closer to it, but because this bike has forward facing dropouts, it needs space to get the wheel out.
I know from cyclocross experience that a double guard is one of the best ways to protect a chain from falling off. But I'm using the stock Schwinn 1 piece cranks which are special size -- like most things on this bike. I was planning on making an aero cover/fairing for the outer chainring anyway, so I figured that I just make two -- one inner and one outer.
I'll spare you the details, but it took some serious noodling on how to get these guards mounted just right. Each is four layers of fiberglass.
You can see the RD cable exit there as well
So here she is:
Some notes on the build:
Pedals - my A race is this run/bike/kayak triathlon which is more like a duathlon so I'll be racing in my running flats the whole race ---- the bike is short (12.5 miles)
Front brake -- Weinmann Delta --- from my parts box --- hard to find an aero brake that has a long enough reach. Had to trim the pads with a razor blade so they didnt rub the wheel.
Aerobars --- Scott 100k --- found these cheap on eBay ---- like $30 shipped. Figured they were the perfect bar for this bike ---- you can see from the first few pics I originally was going to use VisionTechs, my guess is that these are more aero. Also, since I only have a rear derailleur, I figured I might as well have two front brake levers ----- the vision lever (also from my parts box) is mounted on the end, and then runs to the cyclocross 24mm lever on the inside of the 100k bar.
BTA bottle mount --- this is actually from Target for $7 --- including cage! Velcros onto the top tube ----- which helps corral the cables.
Rear disk ---- homemade from two sheets of ABS plastic ---- instructions on Slowtwitch
I'm thinking I might have to replace the stem with something that has some more drop to it ---- this is a 140mm with 15 degree drop. We'll see if this lets me get as low as I want.
Airfoil ratios:
Headtube: 37mm wide x 153mm deep = 4.13
Seat tube: 25.4mm wide x 55.5mm deep = 2.18
Fork: 9.3mm wide x 23.7mm deep = 2.55
Airfoil ratios:
Headtube: 37mm wide x 153mm deep = 4.13
Seat tube: 25.4mm wide x 55.5mm deep = 2.18
Fork: 9.3mm wide x 23.7mm deep = 2.55
That's pretty much it! Thanks for reading!
