Posted: March 28, 2012 Filed under: Uncategorized
At the UK Handmade Bike Show, Bespoked, I won the Best New Builder award for my “Wilkinson Mixed Gear” bike:
Photo by Kayti Peschke.
Here are some more pictures I took of my bike:
Polished stainless front mech band – protects paint and looks cleaner when removed for singlespeed mode.
My “Wilkinson Mixed Gear” dropouts.
Mudguard extension tube allows for a more rearward wheel in tour mode.
The Wilkinson Wheel Carrier – compatible with lawyer tabs!
Removable shifter bosses pass through a stainless tube brazed inside the downtube.
Here’s an article listing the winning bikes in all the categories: http://road.cc/content/news/55706-bespoked-bristol-robin-mather-wins-best-show-plus-prizes-feathers-rapha-collab
My girlfriend Saga for all her help, without which I’d have had a nervous breakdown.
Dan Hamilton – for the CAD drawings for my dropouts.
John Discombe – for all the help with the jigs so I could make my dropouts.
Peter Flynn – for doing a great job with the paint.
Ryan McCaig – for letting me borrow the odd tool and sharing the acetylene.
Dan Fennings – for doing the CAD for the wheel carriers.
Tamsin – for commissioning Wilko 3 and coming up to the Bristol show.
My mum – for lending me the car.
Mike Salmon – for putting us up in Bristol and making us feel at home.
Sarah and James at Brixton Cycles – for letting me use the headset tools.
Peter at Ceeway for sponsoring the prize of a frame tube set.
Columbus for sponsoring the other prize of a carbon fork.
And everyone who came up and chatted, prodded the bike or squeezed the tyres. It was a great show.
Bye for now.
Posted: March 10, 2012 Filed under: Uncategorized
So I have to get this bike frame built and to the painters asap to be ready to build up and photographed before Bespoked. There’s no time to lose..
..Better whip out my Herbie Helm lug vice. Stainless, of course.
Checking my hand-filed mitres. Hmm.
New lug and filed lug. Pointy. These can hurt you if you're not careful. Ask Ryan at Oak Cycles.
I wheeled out the Wilkinson "Abominator" jig. I made this in my kitchen a couple of years ago. The swivel vice has a V-groove and I got it from Axminster. I must upgrade soon. Donations welcome.
Silver brazed headtube/downtube. I used Cycle Design's "Stainless Light" flux. It comes off easily with water.
The story so far..
Internal cable routing. How hard can it be?
Some eight hours later, after making sure the internal brass guide didn't touch the tube wall, rattle or kink, I got it all brazed up.
It was rewarding when I got it done.
Lining up everything with the drawing.
Ok, I own up. I made a mistake. When I was planning the cable run I looked at an American bike in the workshop and a German road bike at my house. Brake levers on wrong side. Whoops. What a wally. I had offset the internal cable entry and exit to suit a right hand rear brake lever. Remember that the cables should cross in front of the head tube to give a decent run. So… in keeping with the concept of this bike, and in order to partially conceal the cable entry point, I put it underneath the top tube at the front. This gave me a better cable run and a side-exit to the rear caliper on the correct side. A serendipitous event, no less. Hoorah!
The top head lug needed to be blacksmithed to conform to the tube. I tapped it with a small brass drift made from a bathroom door sliding bolt lock, after squeezing it in a tubing block.
And I also had to file the point shorter on the lug, as it was overlapping the first lug's point. A peril of short head tubes.
Now it fits.
Checking the fit in the lug.
Testing the fit on the tube.
Grinding out the chainstay sockets in the BB shell.
My belt and braces approach to dropout alignment.
Cleaning out a chainstay so the brass will take to it.
Fluxed and brazed with brass. Lots of cleaning up to do here.
Time to silver braze a gear cable stop onto the chainstay too.
After soaking the flux off under the tap.
I decided to put the chainstays in on Ryan's frame jig. The stainless band on the seat tube will stay unpainted for a 31.8mm front band-on mech that won't leave damaged paint to be visible in fixed gear mode.
I ran a cord from the dummy axle to the BB to double-check the seat tube/chainstay angle with a protractor.
Using my angle-finder.
I brazed the tops in the jig, then finished in the Park stand.
Next I drilled holes for the bottle bosses. I had to enlarge them slightly with a round file.
I had to improvise a way to hold the diamond reinforcement while I increased the hole diameter.
I tried to resist the temptation to add that little bit more silver just to "make sure", but it gets me every time.
Let's check the rear spacing..
And the left alignment.
..Matches the right alignment according to the Park FAG-2 tool.
Rear wheel looks fairly centred. I built and dished the wheel myself so I know the rim is centred.
Same goes for the fixed rear wheel.
The H-Tools say yes!
Time to use the piece of extruded aluminium I tapped and put an M5 threaded probe through. Use it like the FAG-2 tool but touch the 3rd contact on the wheel rim, not the dropout. This shows that the dropouts are level, and one is not higher than the other.
After pulling the stays around, the other side matches. A perfectly dished wheel is essential for this. This is used before the seatstays are attached. I checked the resulting angle of the chainstays against my drawing to make sure my geometry would stay as expected.
Getting the brake bridge right. A mudguard has to fit in there too. I have only tacked it in here. I got it in the perfect position eventually, and almost straight.
Note to self: procure something more fireproof to shield the drawing whilst tacking. Although we have a cast iron surface plate in the workshop, I tacked the frame tubes on shimmed V-blocks on top of my drawing, which was on top of a sheet of 12mm toughened glass.
I’ve now taken the frame and fork to the painter. Tamsin my customer has chosen a very vibrant green. You have been warned..
See you soon.
Posted: March 4, 2012 Filed under: Uncategorized
I’ve made some progress with my 3rd frame build. Here are the pictures:
These are my fork ends. I'm going to cut the rack mounts off them but keep the mudguard mounts. One is done already in this picture.
Filing them smooth after cutting.
Bending my fork blades in the bender I made. Not 100% happy with the curve I get, but it's not too bad.
Checking the fork rake against my home-made gauge. I want 43mm of rake. There are lines to centre the blade so it's straight.
Cutting the blades to length.
Finding the straightest side of the seat tube. The worst side will be used in the fore and aft plane of the frame to minimise lateral misalignment.
My seat tube is brazed into the bottom bracket shell after tacking and checking alignment.
Oh yeah, and they let me try out brazing a bottom bracket assembly at work a few weeks back - here it is (it was rejected)... Come off it, it was my first one!
Here's my fork held in the Wilk-O-Matic SPX-3000 De-luxe laminate construction steel-reinforced fork jig that I made in my kitchen 3 years ago. My workshop mate Ryan's just bought a proper fork jig so perhaps if I ask nicely next time I can use that..
The bits 'n' bobs so far.. The top tube will have internal cable routing.
After brazing in the fork legs. The flux got a little tired and began to darken after I chased around the shorlelines with the flame, but I'm confident that I didn't overheat the joints as the steel didn't go red. It cleaned up nicely.
I’ve done quite a bit more on the frame at the time I upload this, so there are more pictures to come when I take my camera to the workshop.