Introduction
This bike was born out of the desire to own and ride a 1992 Cannondale Track without having to pay the cult-status premium. I also didn’t want to take the risk riding 30+ year old aluminum. I figured if I was going to reproduce the frameset, I wanted to make some changes while preserving the integrity of the iconic track bike. I decided that I wanted to make it out of titanium.
Planning
The first task was to figure out the geometry of the original bike. Consulting online forums, I was able to source this geometry sheet from a 1992 Cannondale magazine:
I typically ride a 52cm frame (520 top tube), but the C-Track 52cm is slightly longer. I figured I would try and go in-between a 50cm and 52cm.
The next step was to source tube diameters. I was able to ask around on Instagram from those who owned a C-Track, and I collected the following:
- Toptube: 38.1mm
- Downtube: 50.8mm
- Seattube: 31.8mm
- Seatstay: 16mm
- Chainstay: 22mm ovalized to 18mm by 26mm, then tapered to 16mm
- Head tube: 38.1(?) ← unsure about this measurement, was hard to accurately gauge
With these numbers, I was able to start planning in CAD:
I quickly identified two issues:
- A 1” threaded fork is out of date by modern standards, should I change it?
- How would the tubing work for the downtube/headtube junction? Can titanium be welded with oversized tubes?
The first question was rather easy. I knew I wanted the front end to be less flexy than the original C-Track but to preserve the look, I knew it had to stay straight. That meant a 1-1/8” fork with the skinniest possible head tube around it. I also knew I wanted to use a Chris King headset, and in order to achieve this goal I picked the DropSet 4 which uses an IS42/IS42 top/bottom bearing, effectively giving the headtube a diameter of 46mm.
In terms of which fork I would use, I wanted something readily available and settled on an Alpina Track Fork. With a rake of 35mm, it’s a little more relaxed than the original 28mm steel fork on the C-Track, but I figured it should be close enough. (I later found a first-generation Alpina fork with 28mm rake).
The second question was harder. Steel and aluminum can be welded and then have additional smoothing performed, but for titanium that wasn’t possible. I decided that in order for the downtube to work, it needed to be slightly smaller than the headtube. The diameter I settled on was 44.5mm. Although not as large as the 50.8mm original, it was as close as feasibly possible.
It was now time to draw up the actual dimensions.
Fabricating
I went with Waltly, a Chinese-based OEM titanium frame manufacturer. They have a pretty good reputation and have been around since 2009.
Waltly Communication:
Iteration 1
- 90% of the measurements dialed in immediately, main issues were regarding chain stay dimples and tire clearance. The logo on the head badge was the beginning of my “brand”, A-Frame Cycles.
- They included water bottle mounting points by default which I later told them to remove
Iteration 2
- I still wanted to attempt to make the downtube 50.8mm, but would require ovalizing at both ends and I didn’t want that since it would change the aesthetic, although it would increase torsional strength. No22’s track bike, the Little Wing does this.
- Changed headtube logo to an updated one
Iteration 3
- Reverted back to 44.5mm tubing
- Somehow the headtube angle got slightly tighter? Not too sure what happened here.
- Missed a detail with the seat-tube being a smidge too long (ideally 520mm instead of 530mm), could chop it (around 29mm extends above the top tube), but probably won’t be necessary since the BB is much higher off the ground even by track bike standards (28mm drop)
- Chain stay detail
- Headtube
With all the details confirmed, I sent in my order in late December 2021. Four months later, I received pictures of the the complete frame and the frame itself the following week.
Review
Build Quality
The frame has a brushed finish with very clean welds. There is no pitting or raised welds and the spacing of the welds is very consistent. However, when compared to an American-built titanium frame (No22 Little Wing) the different between the welds becomes obvious (Waltly left, No22 right) :
Final Assembly
Parts List
- A-Frame Track Titanium Frame
- Wound-up Road Fork, 40mm rake
- Chris King DropSet 4
- Thomson X2 120mm stem
- Thomson Carbon Road bars
- Thomson Elite 27.2 seatpost
- S-Works Power saddle 143mm
- Light Bicycle 25mm carbon rims + Mack hubs with Panaracer Pasela 25mm tires
- Sugino 75 DD cranks + AARN 49t chainring + Soma 19t cog
Total Weight: 6.8kg (15lbs)
The Fork
Like I said previously, I had designed this with a 35mm Alpina in mind, but using the original geometry meant that it was actually designed around a 28mm rake fork. I managed to source one of the earlier generation Alpina with a 28mm rake, but riding that felt way too twitchy and caused massive toe overlap. I didn’t want to use my BMC’s 35mm rake fork, so I opted for a Wound-Up road fork with a 43mm rake. It handles much better now and I no longer hit my toes during turns or trackstands.
Final Thoughts
I planned for this to be a one-off project without much of a future, but after showing the frameset to multiple people in the Fixed-Gear community, I plan to bring this prototype to production. I’m not sure when or how many, and sizing is also a huge issue I’ll need to sort through, but I will start looking into it. This has been an incredibly enriching experience and I hope to deliver more interesting projects like this in the future.
Thanks for reading,
Anthony
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March 2022 Update:
Since writing this original post on my personal blog, I have decided to upload it here to the official A-Frame site. Please check out the subsequent article and the final production frame!