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Levy Bike Works

Fanatically hand made steel bikes, components and tools

Phils fast road bike build part 12 – paint match

Right a custom bike needs a custom paint job. Le Sportif has a lovely livery of a light green and pastel pink pallets with white font. So the frame as per the design needs to be Green. or specifically Hex 65BBA3 which has not RAL colour and the nearest Pantone is 3258C. But the bottom line is there is not off the shelf paint that works. I have tried ordering premixed paint for the UK but they were about £60 and now the post wont ship them because of the solvent. Nice.

Inspire airbrush paint for custom bike frames

So I have bought some Green, Blue, and red and will mix it by hand. I am using Inspire air bush paints as the pigment is strong they are easy to paint and cure quickly. I will use a 2k epoxy base to make sure they are well protected on the frame.

Its always good to do a test piece. So I have a test joint that I have white primed and done a single coat of test paint. I use a 3hp compressor with a lightweight tough up paint gun withe a moisture trap running at 60psi. It’s gone on well and looks a tad dry but they sometimes come out lighter when dry.
test paint for bike frame
Nope so this needs a smidge more white in then wetting out read for painting.

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Phil’s fast road bike build part 11- Mudguards

So the frame and forks are set up for mudguards. but we though it would be nice to have some alloy flat sheet mudguards and colour match them to the frame. like these:
mudguards
Alloy is hard to file as it clogs the file or grinder. So the best way is to get a hole saw and a block of wood.Clamp the mudguard to the block with some clamps and then cut using the whole saw and then file the remaining shape.Then sand to key, ready for etch priming.

Phil’s fast road bike build part 10

Right so the frame built. now it’s time to finish it. a few bits of handy kit required:
frame finishing tools

Useful tools include a adjustable reamer (set to 27.2) and a old seat post to check. A motorbike cylinder hone and drill. some rotary wire brushes. some strips of emery cloth, sand ceramic plumber tape. some Dremmel sanding wheels and a bottom bracket tap and a headtube reamer. so time to ream the head tube and bottom bracket:
Bottom bracket ream

Now it time to ream the seat tube until the seat post fits, then I run the cylinder hone down to make sure it wont scratch the new post.

Bottom bracket ream

Seat tube hone

Then check with the old post

Seat post fit

Now for the paint staking hours of sanding and finishing. all signs of flux must be gone. all the joint must be smoothed and sanded. Using the emery cloth like dental floss on the join gets and nice finish:

Fillet brazed frame head tube

hand made steel frame

Paint is on the way, carbon fork ordered and matching alloy mud guards are here.

Phils fast road bike build part 9

Right time to put the brake bridges in. Measuring from a frame with the correct brake height. Lots of filing and faffing to get this in. A quick check then braze it in.

Brake bridge

The put the dummy wheel in to check. Great. It’s too low! Right start over. I decided to use a light weight bridge. Same all over again but a little higher. Small fillets just to fit the look of the frame.

light weight brake bridge

pop a brake on to double check. I am trying to run it a little high up so there is room for the alloy mud guards. Job done.

brake bridge check

Now on to Braze-on’s. I should have mentioned that is did the bottle braze on earlier as you have to drill the tubes before you assemble otherwise you can fit a drill in easily. So the next braze on are the STI stops. These you can put a long 5m bolt in and then use a welding magnet to hold them straight. Silver solder on these as the butts are short and the tubes are thin.

sti boss braze on

Cable stops, I use a welding wire clamps to hold them in place and a flat blade screwdriver to make sure they are straight. The bottom bracket cable runs. These you can use a plastic clip on. But I wanted to do some nice guides that we can then use plastic tube to keep the inner cables clean. These i bent to shape and filleted in with brass.

fillet brazed bb cable runs

I have also made some tide bottle bosses into mudguard bosses by putting them at the bottom of the seat stay out the way.

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Nest is clean up detail, sanding the fillets by hand & reaming, honing and paint prep.

Phil’s fast road bike build part 8

Chains stays are in so it time to hand mitre the seat stays. Seat stay mitre

Then is time to fit them and one last check with the dummy wheel. We then pop the dummy wheel out and drop a dummy axle which is a normal axle set to a 132mm so that it will come back to 130mm when it done.

rear stays

flux and braze in both ends:

frame2

before i clean it up it best to check the dropouts with a tool:

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you can add filler at the Bottom bracket to move the stays but since this is very close a qucik cold set. pullign on the handles to set it straight.

frame alignments

Perfect. loads of cleaning up to do then the brake bridge and brazons.

Phil’s fast road bike build part 7

Checking the other full scale frame drawing for the chain stays. I can measure the chain stay angle (8.5*).

full size frame view
frame chain stay view.

Because the are Columbus Spirit chain stays they are flared and ovalised i can’t use a tube mitre program so the tube notcher is out again.

tube nothcer

When both are are done it time to fit up on the jig to check they are the same length.
Chain stay on jig

It’s best to do one side at a time with a couple of small tacks to see if it’s square.
Chain stay vertical to plan

On the plan its square in the plan view but not on its side. Dam. that’s why you tack and check. So brake those tacks and adjust the jig by 4 mm and do it all again.

Chain stay on plan

The quickest way to get the other chain stay on is to use a dummy axle set to 132 (+2 mm of the final axle width as the bridge will pull it together). tacked and time to check with a real wheel.

frame rear end alignment with dummy wheel.
frame rear end alignment with dummy wheel.

Bang on sorted. Seat stays next.

Phil’s fast road bike build part 6

Right its time to put in the top tube. It’s all been mitered and is set up with resting on the tube clamps as per the drawing. then its time to tack it and check it:

fillet brazed front end

The oval top tube looks good even though the joint is not finished yet.

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Then its checked against the drawing. then i put it in the jig so i can set up the rear end.

steel frame on bike jig

Phil’s fast road bike build part 5

Right BB joint time. The Mite has been checked:

Bottom Bracket down tube mitre

The preparation it sand the outside and inside of the frame. The wipe down with Propanol. The bottom bracket needs a 15mm vent hole. then its time to set it up on the bench to get it square slide it all half off the bench so there is room the weld and tack it and check it. Then get the whole joint warm then wet it in outside to inside, then check it.

Bottom Bracket

All square. The seat tube needs re-enforcing 0.8mm tube silver soldered to the seat tube.So the total thickness is 1.8mm which should do but not be to much extra weight.it can be cut to lenght after.

brazed bike re enforced seat tube

The top tube can now be mitred ready to tack next time.
Custom bike frame front end

Phil’s fast road bike build part 4

Right now it’s time to do the most important joint, head tube down tube. The angle has been check on both the angle and on the drawing. Then you need to set up the joint and weight it and flux it.
Fillet brazed head tube bike.

Then 4 tacks at 12,3,6,9 o’clock.
tacked head joint

Then check the angle again:
head angle

then warm the whole joint to stop warping then wet the joint and check the angle again. Then finish the joint from 8-4o’clock and 10 to 2 o’clock, then 8 to 10 o’clock and 4 to 2 o’clock. you can add a little more filletto the joitn to pull it slightly in that directon until you can see its spot on angle. Then stick in hot water for 30 mins scrub the flux off and tidy up.
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Still square and a pretty tidy joint :¬)

The next joint is the bottom bracket down tube. This is a 2 way mitre one longitudinally across the bottom bracket shell. The other is where to the down tube meets the seat tube.
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Time to take a brake. line up and tacking next time.

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