Search

Levy Bike Works

Fanatically hand made steel bikes, components and tools

Category

Uncategorized

Phils fast road build part 3

Head tube down tube joint is pretty much the most important on the bike. If it’s not straight your bike will veer to one side. If it’s not set and the right angle the handling will be poor. If it’s week or poorly welded you may need dental surgery. So it always a best to pay special attention to this joint in this case a Columbus 36mm head tube with reinforced top and bottom brazed on and 34.9mm Columbus Spirit down tube.

First job is to cut the head tube to length then braze on the reinforcements and tidy up. With the reinforcement they are 3mm longer but that fine as I will ream them down when I ream the headstock. Then Drill and breathing hole, I have gone for a 13mm to save a bit of weight.

Head tube

Next to mitre the head tube. You could use a tube notcher for this but a 36mm bit seem to be rare or over £100 to buy. So I am going to old school it with a paper template and a hand file.

tube mitre

Cut the template out and tape it to the tube draw round it. Then cut the bulk out with a hack saw and a bench grinder. Then its time to get the 8* half round second cut file out.

tube mitreing

Take your time to get this right. Check the angle with a digital t angle finder. I am looking for 60.2 degrees +/- 0.2.

angle check

mitre good fit

the fit has to be near perfect. ideally if you put a piece of paper between the tubes and pressed you should get a mark the whole way round. if you are TIG welding you can be a little less fussy but with brazing you want it spot on even if you are using stronger braze (sif no.2 5% nickle) its still good practice and alloys you to use a smaller fillet (4x tube thickness so a 4mm radius in this case. I will probably go a little thicker to give  margin of error.

Then you need to get it on the full size drawing to double check. it all looks good, but note even with a good brazing technique you will change the angle as you braze. More about that next time. Its late now so I am not going to start brazing so that will have to wait until next time.

Check against bike frame drawing

Phil’s sportif build part 2

Right time to crack on with this build. Firstly time to check the butting to see where best to cut. I have left the seat tube butt relatively long so the frame can take some power and not flex laterally to much.

columbus tube butting
columbus tube butting

Then drill the bb for venting and removes a bit of weight. then to stamp the bottom bracket: 7-pip-13 (number 7 frame – customers name/initial – year:

levy bikes bottom bracker
levy bikes bottom bracket

then its time to make a notch cut:

tube notching

hand finish the joint. then check the angle is square:

20131011_202034[1]

check the set up:

20131011_205800[1]

Flux and weigh down before tacking:

20131011_210357[1]

Check the angle then wet in the joint then pit down a small fillet.

20131011_213309[1]

Then clean up with boiling water and wire brush to re check the join and that its square:

fillet brazed bike bottom bracket weld
bottom bracket joint

I love using good quality tube sets like Columbus spirit in the this case or Reynolds 853 and clean up is easy and there is no rust flashing. back to the bench to make sure it 100% straight. While I have the tour torch out i though i would fit a small eyelet to the brake bridge on the rear of the bike so we wont need any ugly mudguard mounts. tidy.

bike bridge integrated mudguard

 

Phils Fast Sportif bike

My latest project is a fast road bike with fitted guards for weekly wet sportifs. Going for Columbus Spirit Tubing so the tube set is around 1400-1500g. The design is close to Phil’s current design just tweaked for mudguards. The design is up in the design section and you can track the build here if you want.

Phil Adkins Sportif custom fillet brazed frame

20130923_194326

why

Oms-aston-v1It turns out that I have an incurable affliction to all things bike. I have been to see a Clinical Psychologist about my bike problem and he said I should buy a new groupset. I expected this kind of prescription as he is also an avid bike fan as well! So I guess it looks like I am adicted for life.

It all started when I was 10 and all my mates had BMX’s and I had a 20″ wheel racer. So i put mx bars on it and changed the brakes. hey presto a kind of hybrid. after that all things in my life were bike building.

Since then I have raced on and off since 1988, including early MTB racing through to the Mega Avalanche last year. I have also owned an made an huge range of bikes over the years. Thats when it dawned on me that I should really be making the lot, from the frame up. So this is where it all starts.

Blog at WordPress.com.

Up ↑