I thought I’d share some of the details of an interesting bike I just had the pleasure to build. It’s for a tall guy, tall enough that I was getting up to the some of the limits of available tubing and approaching the top of the range of some of my frame fixture adjustments. Seven feet is a lot of rider. That’s a lot of leverage and power to put into the bike, so in designing the bike we scaled things up. We used an Enve Gravel Road Disc brake fork, as it has a long steerer with larger diameter than a standard road fork. It also has room for larger tires for a larger rider. Thru axles are a more robust connection of wheel and chassis and the disc brakes give more stopping power and modulation.
Here are the tubes partially prepped.
The seatstays are up top. I put a custom S bend in them, as with almost all the bikes, to manage tire clearance and add some subtle curves to the bike to look sexy. These are a larger diameter stay with more wall thickness than I normally use on road bikes. Later they get mitered and I used pretty much the full length.
Below that is the top tube, a larger diameter (34.9mm OD). I was fortunate to find this one in my stash. It’s made from a True Temper OX Platinum/S3 alloy but in a little greater wall thickness than the lightweight material, it would normally be used as a down tube. It has a subtle bi-oval shaping, which works out well for mating to the large head tube and the smaller diameter seat tube.
The seat tube is the next tube down from the top. It’s one of the few remaining specialty seat tubes from True Temper. I used every bit of the length. It’s a great one for this bike as the diameter is larger than the seat tubes I normally use, it has a little more wall thickness and is triple butted with a nice external butt up top to reinforce the area that sees joining of seat tube, top tube and seat stays, as well as reaming and slotting to take the seat post. The down tube is a large 42mm diameter, and has a nice aero, tear-drop shape that I ovalized in the opposing direction at the bottom bracket to better resist pedaling loads there. You can see some of the shaping in the lower pictures. Below that are the chainstays, a tandem chainstay, that I dimpled for tire clearance and joined to stainless steel Paragon Thru axle dropouts and a flat mount disc brake mount.
Whoa, that’s a lot of head tube. File for reference. I machined the outside center section down a little bit to shave some weight of this big tube.
Here you can get another view of the tubes and a sense of the shaping of the down tube.
After mitering, cleaning, tacking, checking alignment, welding and more alignment checks, we have the front triangle and chainstays done.
Seat tube/top tube junction
Down tube/ Head tube junction. With the photo so close up you can see the change in thickness of the head tube from where it is full thickness at the end, then the tool marks of the machining operation. I posted a quick video clip on Instagram (@caletticycles) of machining down a head tube recently, so you can take a look to see that process in action.
The completed frame after the seatstays, bridges, cable guides and bottle bosses go on.
You can see how long the seatstays are – there is plenty of room for a 32mm + tire, but it doesn’t look that wide due to the proportion. The amount of space above the seatstay bridge gives a bit of perspective of the length.
It was a fun project to design and build, and I think Jon will really enjoy the ride of this bike. Keep an eye out on Instagram (@caletticycles) and the blog here for pictures of the bike after it get’s back from paint and is built up.
Thanks for reading!