The ‘super commuter’ appears to be very much with us now. Some people like to adapt a cyclocross frame, others find inspiration in an old tourer and some people…
Rich, AKA turboferret over on the Singletrackworld Forum had a dream; to create the ultimate commuter. His needs were complex, and his shopping list long, so he decided to turn to crowd-sourcing to get some feedback on what he had in mind.
This lead to one of the most interesting and longest running forum threads for a while, I checked with Rich and he was happy for me to put together a condensed version over here on the blog.
The bike is going to be my ultimate commuting machine, consisting of the following:
- Ti frame
- Eccentric bottom bracket
- Di2 Alfine
- Belt drive
- Dynamo hub lights
- 700cc 28mm tyres
- Full mudguards
- Hydraulic disc brakes
- Drop bars
- All internal wires and cables
It was that last point that gave the first hot point of discussion – just how much work can you do to conceal cables and wires? Rich’s first idea was to put extra gussets and tunnels around the bottom bracket to route things through.
Brant Richards (On-One, Ragley, you know, that Brant) set things straight by pointing out that it would be almost impossible to fabricate and risk weakening the whole area by subjecting it to so much extra welding heat.
So it was back to the drawing board for ideas on how the cables and wires were going to thread their way through the bottom bracket area. Taking them along the top tubes was considered too, but the issue there would be how to run them through the seat tube area. Running extended seat stays that ended up as a double top tube would have been another option, although it would have changed the look of the bike quite a bit! Rich also didn’t want to compromise the ‘clean’ look of the frame by using sliding dropouts and felt the eccentric bottom bracket option would be more stealth.
Eventually Rich came up with a system of ports that would allow for the cables to be run around the bottom bracket without escaping too far:
Although that did mean putting lots of little holes at the end of frame tubes where they’re at their most stressed, was he lining himself up for future stress fractures? Brant certainly thought so, although Ben Cooper, frame builder at Kinetics, thought he’d probably get away with it. Ben had some other creative ideas too, including running sliding dropouts with an extended downtube that dropped below the bottom bracket shell to create a straight path for cables to exit out of.
There was some talk of how to route the cables through the shell itself, around the internals of the eccentric bottom bracket. Which then lead to a discussion about the different types of eccentric bottom bracket! Niner’s BioCentric won that battle. It’s a very elegant design that just clamps together with thru bolts into a plain bottom bracket tube, no need to worry about self expanding wedges or clamping the bottom bracket shell itself.
Rich also had to wait for a larger belt drive chainring to be released. The Di2 shifting mech means that the smallest sprocket you can run on the back is a 28 tooth, he wanted to pair it with a 55 tooth chainring to give a similar spread of gears to his other road bikes.
Decisions, decisions and Rich hadn’t even begun to think about where the wires for the dynamo hub and lights would run!
Ordered my frame from Titan Products who have been very happy to comply with all of my bizarre requests.
I wanted it to have the same riding position as my Chinarello and factored in the longer CX fork to give the same geometry with extra clearance for tyres and guards. With, of course, all the holes for internal Di2 and dynamo cable plus rear hydraulic hose routing!
As the Di2 Alfine has a rather narrow chain line, which is made even narrower when you add the belt drive. When you want clearance for decent sized tyres and guards it necessitated a scalloped drive-side chainstay for clearance up front.
The Biocentric is a very elegant EBB solution, but it changes a 68mm shell to a 73mm after fitting. This is a bit of a no-go with the chainline issue, however with some subtle machining on the internals of the EBB, and a 63mm shell, I’ll be back to 68mm.
In case I can’t run some of the cables through the bottom bracket shell I’ve made extra provisions with routing through the chainstays.
Wow, certainly not your usual frame there! Rich wasn’t wrong about the chainline issues coming from the Di2 Alfine hub, he’s ended up with one of the most worked chainstays I’ve ever seen. The issue is compounded further by the holes necessary for running shifting and dynamo cables internally, I’m not surprised that he went with maximum 1.6mm wall thickness tubing for them!
Fancy seeing how it all turned out? Stay tuned for part 2 next week…
In the meantime, have you had a frame made that you’d like to showcase? Drop me a line via the contacts page and you might well be able to see it here too!