Kalten's Dirt Road/XC machine

Kalten had a plan...use his experience from hanging around the shop and some guidance from me to build a do-it-all bike for use at college.  He plans to run everything from 700x35c to 29x2.5" tires, with room for a front and rear rack and fenders.  Not an easy design to accomplish, as the geometry has to be set to balance the line between road handling and not too steep for the trail.

With some numbers in place, we began by setting up the fixture under the watchful eye of Cubby...

With the fixture set, we began with the spine of the bike, the seat tube.  Kalten turned down a piece of 4130; creating a shoulder to press into the main seat tube, boring out the inside to the diameter needed for the seat post, and creating the pinch bolt interface...

The parts made up, Kalten practiced working the TIG torch to tack on the seatpost binder...

The days pass...and each opportunity to work on the frame is put to the side to take care of other needs prior to leaving for school.  Soon my role of advisor/teacher transitioned into "lets get it done" and doing more than originally planned.  The frame mostly put together, we dropped back into the instruction role and allowed Kalten to begin learning to braze on the rack mounts, water bottle bosses, and other fiddly bits...

One of the most difficult decisions any customer has is how to paint the bike...it has to reflect their personality.  Given the options, there are sooo many choices.  Kalten found a pic of a vintage race car that he liked.  Blue, scratched, hand painted artwork and racing stripes with the common discoloration of dirt and rust.  And Cookie Monster, had to have Cookie Monster  :)

I created a paint scheme based on his picture.  I began with a bright blue powder coat, sanded it down with 80 grit to give it some texture, began going over it with the Dotco belt sander to bring it down to bare metal in spots, then grabbed some Scotchbrite pad and brown, black, and grey paints to begin to create the weathered look.  The racing stripes and graphics were painted on with a horse hair brush, heavy bristles so that it does not leave a solid paint line, then brought down with a bit of sand paper.  A matte clear and bake in the box helped to yellow out the decals to show some age.

The build took place the morning we were leaving for Ohio University, a race to the end.  A nice mix of functional parts that should be solid for him as he fends for himself.

This bulletin board outside his dorm room was a good indicator that he was in the right place.

cheers,

rody

It's FORK week...ti and steel flavor!

Worked on forks this week for a few projects, first was a Ti fork to go with Andy's bar/stem combo. I'm cutting in on the action, as I've already got the steerer tube, race seat, and fork legs bent and mitered.  Focusing just on the sticking it all together part right now...

The fork is in the fixture, which holds the pieces in alignment, sets the fork offset (distance the axel is placed relative to the centerline of the steerer tube, and dropouts parallel to each other.

The Ti fork is purged with argon from the top down, allowing the oxygen to be displaced out the top as it is a lighter gas.  This prevents contamination of the welded joint from the interior of the tubing.  Once fullyt purged, the fork is tacked together.

Once welded up, I mitered the steerer tube at the base to provide just a bit more tire and mud clearance.

Fresh off the mill...

The main body of the fork is complete, so now to add the disc tab.  The tab is first machined to fit the fork, providing the correct standoff of the mounting holes relative to the center of the axle position in the dropout.

The tab is then machined with a hole saw to match the round shape of the fork leg so that it maximizes the contact surface area.

The tab is a nice fit, time for welding it in place...

All sewn up on both sides...

With the fork all completed in fabrication, I then cut out two Groovy masks for the media blasting...

The fork is then media blasted with an 80 grit glass bead to give a uniform finish in the cabinet.

 

Onto the steel forks...I built a rigid fork for Todd's Bomber bike and a unicrown fork for Kalten's monster cross project.  Both utilized the same set of blades and dropouts, I just modified the axle to crown distance for the differing frame geometries...

Once the fork is fully fixtured, the fork is tacked together.  the blades are about 1.2mm thick at the top of the unicrown, so it creates a heck of an edge to blend in to the steerer tube.  With the thickness of the tubes, it takes a lot of amperage and filler to get it to create a smooth bead transistion.  In this case, I ran a small pass around the "ears" of the fork blades first, then ran a full pass around the whole fork.  This allowed me to build up this area for both good penetration and stress reduction.

The finished weld around the crown...

I used a different disc tab for the steel forks.  It has a long tab for attachment so that it spreads the stress of the braking forces along a long section of the tapered fork blade.

Todds fork will be coated in graphite black ceramic, Kalten's will be finished in whatever paint scheme he comes up with.

2013 Groovy Jersey Order

Groovy Jersey part deux...

Due to popular demand, we are re- producing our Groovy Cycleworks jersey. To ensure we have just the right size for you, we are taking pre-orders, beginning today.

We are making custom Groovy short sleeved jerseys, raglan sleeve, full length zipper, available in a men's club cut, men's race cut, or women's cut. These feature CS Tech moisture management fabric for superior comfort and wicking.

These will be $65 USD each. Shipping in the US is $5 for the first jersey, $2 per additional jersey. $15 international for the first jersey, $2 per additional jersey.

To pre-order, check out the chart to figure out what size you need.

Then send payment via PayPal to rody@groovycycleworks.com. Please note in the comments section the cut & size you prefer. We will only be taking pre-orders for this run until Friday, August 9th.  

Christi

Ti bar/stem combo fabrication pic-a-palooza

I had the opportunity to fab up a ti bar/stem combo for Andy, so took some pics along the way to share with y'all...

I started out by taking a piece of 1.25" x .065" tubing and boring it out to fit our titanium forks steerer tube outer diameter of 1.125".  After boring, the piece is parted off and faced on both edges.

A double bolt clamp is mitered and then welded to the steerer clamp.  I use a double stacked slitting saw to make the cut in the clamp section, which gives me enough width to insure that when the ti section shrinks during welding, then stretches during clamping, that a moderate spacing still exists for adjustment.

I then mitered a section of tubing for the mating surface of the clamp section.  I normally miter this using an auto-feed on the quill of the milling machine so that the miter is well paced and deliberate.  Folks often ask what type of hole saws I use and how long they last...well here is a 1.25" Starret bi-metal hole saw that has probably a thousand miters on it, over 4 years old, and just now broke a tooth.  Not bad for a $12.00 consumable item.

As each bar stem combo is unique, it makes it tough to devise a fixture that is fully adjustable for each one, so I often fabricate each in a progressive build.  As the entire piece is built off of the steerer tube, I will use a steel piece clamped in place and indicated off of to insure each step of the following processes is accurate.  Here, because the Luv Handle uses a 1.00" center section and the body of the stem is 1.25", I need to swage down the handlebar end to fit.  I measure with a dial height guage as well as a level to insure the stem is squre in the swaging dies before applying pressure.  This insures I have an oval section that is at a perfect right angle to the steerer.

With the piece successfully swaged, I then move it to the miter set up.  As the oval section is now taller than the round portion of the stem, I slip a piece of paper under the miter and watch carefully, my hand on the quill feed release.  When the cutter touches and moves the paper, I disengage the feed.  This insures that I do not move the cutter into the vise table.  It is literally a hairs distance, so it pays to have small tips like this to preserve your tools.

The miter made, checking the alignment and fit...

Everything is cleaned up and then purged for welding with argon...

The finished product...