I know, Happy New Year, right? It’s been a while and I shouldn’t have left you without some fine titanium machinery to err, step to, so let’s see if we can take care of that right now…
David’s story is a very common one, he contacted Spanner Bike to see if I could help him replace his trusty Genesis Longitude Adventure bike. He was struggling to find something which quite hit the mark, not surprising considering that his shopping list was pretty unique:
The Shopping List
- At 6’2″ riding a ‘large’ frame he had to work hard to make the Genesis fit, even with its unusually long reach. The first priority was accommodating his long legs while keeping the bar height comfortable. His current setup involved many spacers, a tall stem and some super rise bars!
The design also had to accomodate:
- Rohloff hub gears (but be able to run a normal derailleur too if needed)
- 29 x 3″ tyres at the front and 29 x 2.6″ rear tyres
- Custom Spanner Bike Quadpuss rigid fork to match
- Clearance to run full mudguards
- Double top tubes
- Plenty of room for frame bags and luggage mounts
A ‘tall’ order indeed! (Thank you, thank you, I’m here all week, try the beef…).
Thinking Cap On
I spent the majority of the design time on David’s bike getting the front end height he was looking for. It helped that he was having a custom fork made at the same time. As David confirmed he wouldn’t be running a suspension fork on the frame I was free to use a custom length, this would restrict future upgrades slightly but would give us the best chance of keeping things looking balanced.
Length was added to the headtube and fork to ensure we wouldn’t be seeing that huge stack of stem spacers again! The balance there is to make sure the bike doesn’t look like a chopper, or end up with a weirdly long head tube. The longer headtube also has the advantage of giving us a larger front triangle, perfect for frame bag mounting!
With David’s long legs standover height wasn’t too much of a consideration but we went with a nicely sloping top tube anyway. This balanced the look of the frame and avoided it getting too ‘gatey’, which can be an issue on larger sizes.
Turn On, Tune In…
Having taken care of the fit it was time to look at the transmission. David was already running a Rohloff gear hub which had been bodged into the Genesis frame. He wanted to do things properly this time around but also have the option of running different hubs and gears if needed. Rohloff hubs run a 135mm back end which can make upgrading difficult.
Our cunning solution was to splash out on some Paragon Polydrops. These have plates that you can swap out to run different hub standards: 135mm Rohloff fitting? 142mm thru axle with mech hanger? Even an old school quick release? We’ve got an adapter for that! The other interesting feature is that the frame plates aren’t joined together, when you take the dropout plate off there’s a gap which makes running a Gates belt drive possible too!
I needed to ship the Paragon Polydrops from the US to China for the factory to use them but the effort should be worth it in terms of extending the life of the frame.
Great Eccentrics
Running the Rohloff we also needed some way of tensioning the chain as it’s effectively setup as a single speed. Sliding Rohloff compatible dropouts might be too much of an ask so we looked to the other side of the drivetrain instead. Bushnell eccentric bottom brackets are used in tandems to tension the synchronising chain between the captain and the stoker, they’re simple, reliable and generally creak free – a great choice for our project. The larger bottom bracket shell doesn’t rely on super fine tolerances too which makes them easier to manufacture.
Four Claw
Cables were the next thing on the menu; we needed the flexibility to run two push/pull gear cables for the Rohloff hub, plus a rear brake and a dropper hose, but how to carry four cables on the downtube? Also, what was the easiest way to switch back to three cables if David decided to run a standard derailleur at some point?
Unique problems deserve unique solutions, I like using bolt on guides as you can match the guide to the number of cables that you need to run. But no-one makes bolt on guides for four cables, where would we find some of those?
Using all my wit and cunning I finally tracked down some 3D printed cable guides via additive manufacturing specialists Shapeways, they even came in a shade of steel to match the titanium frame!
The rest of the frame used standard zip tie mounts for the cables, simple and unobtrusive they wouldn’t be noticed so much if they weren’t in use.
What’s the rush?
For the finishing touches David decided on a reverse band ‘Spanner’ branding on the down tube but wasn’t sure about the rest of the frame. His name on the top tube? A project name somewhere else on the frame? He decided that motivational messages weren’t quite his thing but perhaps a little half hidden ‘Easter egg’ for those in the know to point out?
Et Viola!
With so many unusual features and critical fit calculations, it was a nail biting wait to see how it all turned out.
I held my breath and opened up the box from the factory, thankfully I needn’t have worried, I could see they’d done me proud again! The critical dimensions, special order parts and even the graphics were spot on. The question was, would David be happy with the results of all our hard work?
It took me a while to get all the parts together, but I’ve got a cracking looking bike sat In front of me now! I think we’ve proper nailed the look I was after. It’s a stunner…..
And that was before he was able to take it for a spin:
Unsurprising it fits like a glove and the ride felt spot on. Weight reduction compared to the genesis is very noticeable and it definitely felt smoother to ride, it’s not as harsh…
Winning words all round! I’m really pleased with the way the bike turned out too. Balancing the fit that David needed with the unique features he wanted was a huge challenge, there was much midnight oil burnt working everything out and getting it to all fit together.
It was a pleasure to work with David who had a clear direction that he wanted to take the project and he ended up with a truly unique machine as a result!
Do you have a particular project in mind? A set of requirements impossible to find off the peg? Do you live in the UK? If so Spanner Bike may be able to help you too – drop me a line via https://spanner.bike/
