Sunday, January 31, 2010

29er is getting started...

Well I am finally getting started on the 29er, I am using 29er specific tubing as well as a fork tube set specifically for 29er wheel size...

Here are the tubes of the trade, talk about beefy... a 35mm diameter down tube is huge!
Oh and I bet you noticed the "420mm seat tube" yeah I admit it was kind of on purpose... and no it's not a stoner thing... it is my birthday.

I have been dreaming about these Paragon sliding drop outs for months, they are absolutely beautiful and I got the no hanger single speed drop out as well for future conversion.

Check out those beefy fork legs, they are huge with 19.5mm tips for drop outs... thankfully Henry James had just the drop outs for them.

Can't get much tighter miters than this... did I just say "tighter miters"? I guess I am a poet and didn't know it :0)
Fits like a glove!

More "tight miters"


Not a lick of light peaking through this miter... if you are wondering what the heck I am talking about... well the miter needs to be as perfect a fit as possible. Basically I shouldn't be able to see any spaces or light showing through where the seat tube meets the Bottom Bracket... and these suckers are so tight I could basically super glue this frame together!


More to come through out the week.
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3 comments:

Unknown said...

Mark,
Nice work you have going on. Keep posting plenty on this one for me. I am going to dabble in the MTB realm here soon. I see you are using BikeCAD. Do you like it? Could you shoot me your email so I can discuss things with you as things progress? Thanks, Wil

February 5, 2010 at 3:55 AM
Unknown said...

what are you using for jigging to braze and are you cutting and mitering by hand or do you have a notcher? Thanks, Wil

February 7, 2010 at 5:51 PM
Mark said...

I am using temporary Jigs to align and also I will tack straight from the drawing/ V-blocks. All the miters are done by hand and I use the miter template from Bicad.

February 9, 2010 at 8:58 AM

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The lessons I am learning are amazing and really fun to work out...

The pictures below are the work I did last night, finished grinding the bottom bracket sockets.
Notched out the seat stays to fit the drop outs...
And the big big moment... doing my 1st miter on the seat tube (Tim calls this one the most forgiving miter and he is right)

I think that many of the lessons and techniques I have learned from wood working are carrying over into metal working very nicely.

bottom bracket, right side done (before finshing sanding)

bottom bracket, right side done (before finshing sanding)
the left socket is just starting to get ground, notice how thin the walls of the right socket have gotten. there is a lesson there and you will see in following pics!

grinding with a stone

grinding with a stone
it took a while with this stone but with the tight corners I had to use it because I only have one small sand paper bit left

ooh ahhh... a little sparks flyin

ooh ahhh... a little sparks flyin
That lesson I spoke of earlier is happening in this pic...

Ahhh... oh DOH!

Ahhh... oh DOH!
is that blueing? Yup that is the lesson that I learned on this socket. the grinding stone heats the metal very fast and as that wall gt thinner it started blueing. Bad, bad, bad! so I will have to sand and reshape that wall a little because I even got some chipping around the blue.

Chain stays with the drop outs notched in...

Chain stays with the drop outs notched in...
So this one was a little scary because I wasn't sure if I would get them straight and true... it ended up ok but I can do better.

Notching wasn't to hard but keeping everything even was hard

Notching wasn't to hard but keeping everything even was hard
I decided to try the bevel sides on the notch, I think I can do better so I may do the stays again?

The big moment... my first miter!

The big moment... my first miter!
I should have taken some before during and after shots but this went pretty fast actually. this is the ruff cut, I rounded it out better and got rid of that hump on the back wall

A little different angle... check out my home made tube holder... works like a charm!

A little different angle... check out my home made tube holder... works like a charm!
I am so proud of the wood block tube holder... now I just have to make the other sizes

A quick fit test...

A quick fit test...
Not bad forthe 1st miter and fit check... I only need to file the inside edges to match the bevel of the inside of the BB

Nother fit check after some finishing

Nother fit check after some finishing
still need to angle the inside of the edges then it is done and ready for finihsing before brazing. I also still need to finish the socket wall to clean up any uneven edges or tooling marks