Rob’s plus bikepacker
I took my first bikepacking trip three years ago, riding from Sedona to Phoenix, including the 67 miles of singletrack of the black canyon trail. I rode my folding 29er (for ease of flying there and back), with borrowed bags. It was a great trip, and really informed me about what worked and what needed improvement; I started designing the ‘perfect’ bike in my head, but as ever with personal projects, it took a long time to actually realize.
The things I wanted to address were: Bigger tires for more comfort and control. Bags that didn’t sway or bounce – the seatpack swaying and the bar-roll bouncing made riding technical singletrack much more difficult. More storage so I wouldn’t have to wear a hydration pack. But to retain the ability to pack the bike for travel.
I settled on 650B+ 3” tires. This would enable the deflated tires to fit in a travel case, plus enable me to keep my bar height low (as opposed to 29+) which I need for my fit. I had been intrigued by the idea of a truss fork – it seemed to make good sense here as having to make the fork so wide could be done with much skinnier tubing, and the triangulation would likely make for a lighter structure with the same strength/stiffness. Plus, once I started looking at it, I realised I could incorporate a space for the front roll within the shape of the truss, thus having the bag completely retained and independent of straps to the handlebars.
Boost spacing is helpful for better chainring/tire clearance. Once I looked at chainlines, I realised (similarly to Cannondale), that actually going out an additional 3mm at the back would give the best chainline. But I didn’t want to use a 148mm hub owing to the wider hub being harder to pack. So the rear end is offset to the right by 6mm, using a 142mm hub.
I wanted the chainstays to be really short for traction and handling (my position is quite low-forward, so I need the rear wheel tucked under for weight balance). Using an elevated chainstay allowed for more tire/chainring clearance, along with a curved seattube. Then for packability I harkened back to the old Nishiki Alien, and made the rear end bolt to the front triangle. This allows the two sides of the rear end to be removed for ease of packing. Shaping the stays for all the clearances and being anti-symmetric was somewhat challenging….. Chainstay length is 406mm.
The truss fork gave plenty of room for bottle cages, so four there, plus one under the downtube. Leaving the mainframe free for a full-size framebag. The bag incorporates straps for the cables, enabling quick release of the cables to aid packing. I worked with Brian at Kaibab Customs for the bags – he came up with a front roll with a sleeve that locks onto the rack built into the fork, which also prevents the bag from contacting the headtube. Then for the seatbag, I built a lightweight anti-sway bar, and Brian created a mini-harness for the saddle rails. This enables the bag to be slid on and off easily, without wrestling with buckles through rails, and keeps it solidly in place.
I rode the bike a bunch last summer without paint, to test it out – it rides great, it will be hard to go back to smaller tires! Then because I would be taking it to NAHBS, Eric at Colorworks came up with an awesome topo paint design, which Brian was able to mirror with stitching on the bags. Almost too pretty to get dirty. Almost……
25.9lbs complete with bags as shown.
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- Rob’s prototype gravel bike | English Cycles - […] been working on. The first is the lightweight truss fork. I previously built a truss fork for my mountain…
This is just awesome beautiful – i have a new dreambike
Thanks a lot
Friggin GENIUS Rob!
Should alert the folks at Bikepacking.com
Did you feel any movement at the bolted chainstay connection??
Hi Eric – no discernible flex. The bolted connections are all socketed so that the frame structure takes the load and there is no shear force on the bolts. With the bolts tight it is as stiff as a one-piece structure.
thanks, Rob.
pfff… impressive & beautiful!
please, what chain line for the ring?
thank you!
best regards,
Mircea
Boost spaced chainring, then the rear end is offset to the right so that the non-boost rear hub has the cassette correctly aligned.
thank you!
have a good 2022, wish ya all the best!
M