The seven p’s. It’s good to keep them in mind as you do anything.
I almost got caught off guard. I was getting ready to put a new bike together with a frame I designed and made. Once a finished frame goes to paint and with enough time to get a QBP order placed and received before the weekend, I like to go over the parts, clean them up and make sure everything is as planned. There’s nothing like good preparation to ensure that everything goes as planned. This time, I had the time to make things right.
I designed a very short 85mm head tube for my new flow bike. Having a very short head tube was an issue in the past as tapered steerers had taper lengths (105mm) that essentially limited head tube length to around 100mm. That’s crazy long by modern standards. Most new tapered forks now come with far shorter taper length (85mm) for more flexibility (design wise). This is incredibly important as most 29er frames need sub 100mm head tubes.
The problem with this bike is that it’s 26″ and I have a perfectly good long taper fork (RS Revelation) that I was taking off of my old flow bike. It’s a good fork and there’s no reason to get another. I found out about the issue in time to do something about it before the initial build. An extended upper headset solves the problem. Good for me, the added length can be corrected with the stem. I’m glad to make this fix as the X-fusion fork I have in the corner of my basement is just gross.
This is very similar to the old PVD PlusTwentyFive cups, although for the opposite side of the head tube. Those were used for correcting geometry. This new part is simply to adapt.
Life is funny.
I refined the side detail and inner detail to be a little nicer after I made the part. If I have to do another it will look nicer. I was working quickly today, thinking more about solutions than design. I had in mind maximum plunge depth in the space available rather than best looks and relieving the inside. Nothing like rushing to ensure a crap product. I like to have designs sit with me overnight for them to gel. This initial design got made within the hour. Not good practice.
I really like the look of the revised part. Like a band of Doric columns.