Thursday, January 28, 2010

Shimano Direct Mount FD...fabrication

Yep, I know it's been too long since the last can hold my eyebrows in protest if ya like ;) 

I've been working away at finishing some final work before I can start on customer projects for the show.  Most of it has been fairly mundane work, hardly worthy of presenting and capturing your attention with, but I did snap a sequence of shots for one special project.

Today, I thought I'd share with you the Shimano Direct Mount Front Derailleur and what it takes to fabricate the necessary mount for the frame to utilize it.

The redesigned front derailleur is a boon for folks who like to run big wheels with short chainstays, odd shaped seat tube configurations, or desire the ability to creatively place a derailleur regardless of seat tube size or shape.  It can be used in a bottom or top pull configuration, mounts directly to a fabricated plate the framebuilder creates, and reduces the clamp and much of the garbage that extends towards the rear of the piece that reduces tire clearance and collects mud.

The interface on the rear of the derailleur is comprised of a flat plate with a projected ridge and a M6 slotted hole to allow up to 5mm of vertical adjustment.  The projected ridge allows the derailleur a secure interface to prevent from rotating on the frame mount.

To machine a mount, Shimano provides a tech document with most of the desired dimensions, though I found that I needed to modify a few for better performance and aesthetics.

To get started, I cut down a piece of stock 1/2" x 4" steel into two pieces that will eventually become four mounts.  I then face milled all the pieces to insure clean, square dimensions to begin working from.  Once machined to my desired starting dimensions, I grabbed the edge finder to establish a known reference point.

Next up, I positioned the mill to cut the support slot for the derailleur over the vertical length of the mount.

Multiple passes and a little patience helped me achieve the final depth necessary...nice and clean with a .01" tolerance.

After cutting the slot, I cut the two pieces into four and milled to the final dimensions. 

I then repositioned the pieces in the mill, reestablished my origin point, and found the center of the M6 bolt hole.  Creating the hole is a three step process; using a center drill to start, an undersized hardened drill bit follows, then machine tap the hole for the anchor bolt.

Tapping in the mill is a nice process and can be done easily with some care and due attention.
Once the holes were all created, some quick math helped me determine the center of bottom bracket to outside face dimension necessary for the bottom bracket witdth I was using.  I then determined where on the seat tube the mount would need to sit for proper alignment.  Armed with this knowledge, I was able to mill the back side to the appropriate depth and position.

The finished piece...

Holding it in place on the derailleur, you can see how the two pieces fit and the vertical adjustment that is possible.

Should make for a clean, custom touch on geary bikes.  A bit more time on this end to do it right, but well worth it for the benefits.



Wednesday, January 20, 2010

Black and white Bonty Dart for James

Here ya go James, your black to white Dart stem for the dropbar Bonty...

I moved a bunch of pieces through paint today...still have one final coat of clear to shoot, will let it sit over the weekend, then shipping them all off on Monday.

Glad to be off the throne and in the paint booth ;)


Tuesday, January 19, 2010

Been battling it out, and losing...

Yup, the last couple of days I've been fighting the seasonal stomach flu and have spent the majority of my time close to here...

I did have an opportunity this weekend to get started on some paint work though, spraying a bunch of custom color bars and James's stem in two coats of sanded primer.  Had to run (literally) out of the shop though to pay tribute to the porceline god when this all began.

Been surviving on frozen Italian ice the last two days...easy to eat and doesn't upset the stomach.  Feeling a bit better today, hoping to actually be productive in the shop tomorrow.

Don't forget to wash your hands folks ;)


Friday, January 15, 2010

BOI for sale...

Hey folks,

The tough economy has hit a customer hard and he is not able to follow through with his commitment to purchase his Big One Inch fork, so it's up for grabs.

Here's the details:

Groovy BOI replica fork
1.125" steerer, uncut
430mm axel to crown length, Old school 80mm suspension corrected
1.56" standard offset
canti bosses
currently in primer...pick your color!
$315.00 plus shipping

Interest will be taken in the order received, so drop me a line at



Thursday, January 14, 2010

James's Drop bar stem...

James has been patiently awaiting a high rise stem for his Bonty drop bar project so I thought I'd share a few pics of the process from yesterday.

Laying out the dimensions on the table...

The stem will use a removable face plate for a 31.8 clamp diameter, an 1.125 steerer tube and an ovalized/offset stem body for better rigidity and support.

Once the tubing is pulled out of the stock, it's time to cut it up to rough lengths, into the cold saw it goes...

With the rough lengths completed, it's time to turn down to final length, true the edges, debur, and chamfer

Now we'll miter the ovalized center section to fit the handlebar clamp...I'll offset the center of the cut just a bit to allow more material to wrap under the clamp for a bit more support.

Clean them up by sanding off the mill scale, run them through the degreaser tank, and then into the ultrasonic cleaner for final weld prep.   Let's tack them together, shall we?

and weld it all up...

Now to do the steep miter for the steerer section.  A 53 degree miter is required, so I split the difference by setting the stem into the vice with a 30 degree angle plate and tilting the milling head to 23...the cutter is advanced with the quill feed nice and slow so that it doesn't skate across the surface.

Wanna know a little trick to help set this kind of stuff up?  The angle plate the stem is gauged off of is much thinner than the width of the stem body, so it is tough to keep it in place and from falling over while you get the final position dialed.  I use two of those little foam pieces that come in the Thomson Elite stems (to keep the clamp inserts from falling out) on either side of the plate; it snugs everything up and you can still tighten/loosen the vice without changing it's position.  There are a few parallel holders available through MSC and such, but I'm too cheap, I mean innovative ;)

Once everything is mitered and cleaned, it's time to weld it all up... fits the table layout perfectly :)

Next, I tacked on the binders, silvered them in place with 45%, split the binders and plate with the cold saw, and ran it through the media blaster.  Final pics once she's all painted up.



Monday, January 11, 2010

End of the year numbers...

Not that anyone really cares, but I've been spending the last couple of days getting ready for Tax time and have compiled some numbers that are an interesting look into the work/life of running a frame shop.  Some of the catagories surprised me, and others are just a little interesting.

So, without further ado, the 2009 end of year numbers of no significant importance  :)

Total number of customers served....   265 (frames, bars, stems, forks, restos, etc...)

Number of failed products ... 1 (1 bent Luv bar from jumping a creek and hitting a tree, sponsored rider)

Number of maroon Scotchbright pads used ... 25

Number in feet of 80 grit shop roll used ... 75

Number of times I cleaned the paint gun ... phhht, I don't even want to think of this!

Number of wheels built ...  11

Number of countries Groovy products are now found in ... 26

Number of customer inquiries/emails / comments received... 4982

Number of email responses sent ... 3919

Number of magazine appearances of Groovy products ... 2 (thanks to Dirt Rag and MBA)

Number of Blog posts ... 146

Number of folks who stopped by the spring open house ... 25

Number of races sponsored/attended ... 7

Total product donations for races, charity fund raisers ... $6607.00

Number of days I got out to ride ... 32

Number of pounds gained due to my miserable number of days ridden ... 25

Number of out of state rides ... 9 (6 in AZ, 2 in Pa, 1 in WV)

Number of flat tires changed at races as neutral support ... 8

Number of times Christi threatened to quit and came back ... 3

Number of hours dontated for local trail work ... 28

Number of hours worked at the shop (not inclusive of email/blog/races) ... 1664

Number of hours worked at the Fire Department and teaching/medical instruction ... 4313

As we head into the new year, I'm looking forward to sharing another 365 days with y'all   ;)



Wednesday, January 6, 2010

Raw finishes and a seasons worth of racing...

Da "RAW" finish...

Customers desire it as it shows all the fabrication in an unadulterated perspective, naked and visible for all to see...the colored HAZ from welding, the disparate hues of the brazing material and the base metal, and the industrial beauty that is the fabrication process.

Though desired and popular, the concept of a "raw" finish on frames is seldom embraced by builders for a variety of reasons, but the most typical is the short term durability of the finish.  Unlike Titanium and Aluminum, where oxidation forms on the surface and creates a protective layer over the substructure, oxidation of the steel bike is not at all desirable, manifesting in slow corrosion of the material in the form of the "R" word ('s RUST).

To protect the steel frame, the liquid paint process uses three different layers; the primer layer which is chemically designed to stabilize and seal the material, the color layer for all the purtyness you desire, and the clear layers to protect the colors and provide depth of vision.  Liquid finishes are designed to chip or fail under stress/impact, releasing from the primer layer leaving the protective sheath in place.  Without the primer layer, oxidation will ensue.

Powdercoats, which are becoming more popular with builders, protect the steel frame in a different fashion. Using an plasticized dust that electrostatically binds to the frame and then melts around it much like saran wrap, it is a very different process than liquid paint.  Powdered finishes may use a single to multiple layers.  When a powdered primer is used as the first layer, it will protect and seal much like the liquid primer, keeping oxidation physically and chemically at bay.  Color and clear layers can then be built upon it.  However, if pigmented layers are used without the primer, it merely acts as that proverbial saran wrap, allowing moisture to creep between the base material and the powder coat.

To achieve a raw finish, a liquid or powder clear is applied to a carefully prepared frame without a primer layer.  This transleucent coat allows for the underlying characteristics to shine through.  However, what you are sacrificing is the durability of the finish.  In time, oxidation will creep between the finish coat and the base material, showing through in ugly spider rust and discoloration.

Early last year, I painted up one of my sponsored riders bikes in a hybrid finish; powdered clear with liquid colored panels on top.  My goal was two allow folks to see the level of craftsmanship that goes into a handbuilt frame and to have a visual object lesson at the end of the season to share with y'all on the durability of such finishes.  This bike was raced in all weather conditions, long off road 100's, short dirt criteriums and everything in between.  The consistent factor was that it was generally abused, neglected, and put away wet in our humid Ohio climate.  Anywhere that moisture can get in, it will.  Most often the entry points are around the headtube after facing off the paint, areas with high wear due to cable rub or other friction, and places where the finish has been breached due to stone impacts or other damage.  The pics above showed the frame right after it was completed, now here are the pics one year later. 

Caution, not for the faint of heart :)

From a distance, she still looks good, maybe not as shiny and new as early in the year but still hanging in there.

Close up, you can begin to see the progression of the corrosion under the clear powder coat, slowly moving from the entry points at the faced surfaces of the head tube and the headbadge holes.
In areas like the seat post (where I delaminated a bit of the powder to show you it's thickness), where there is mechanical force from tools, friction from taking the post in and out, or sharp edges that the powder does not like to cling to, there also tends to be moisture penetration...

       Sharp wear zones due to cables and chips from stones allow the little rust spiders to grow unabated :(

Pretty yucky, eh?

Please remember, this activity is going on under your powder coat finish if your builder is not using a special primer...I restore a lot of frames and this type of corrosion is common place.  Just cause you can't see it does not mean it's not there.

So, as much as I like to check out the raw finish too, if not properly prepped and cared for, the beauty can quickly turn beastly.

Jeffs frame got stripped and blasted, and is ready for it's new liquid colors for the 2010 season.  Though I'm sure it will be just as beat on by the end of next year, I can assure you that the frame will be preserved and protected from this type of damage when next ready for more love.



Tuesday, January 5, 2010

Some booty shots...

Hey folks, catching up on some older pics for ya so I can get to the current crop of work.

I thought I'd share a couple shots of Steven's frame coming together. 

Fitting up the chainstay to the dropout, I first mitered the end of the .75" tube off center with a hole saw and then slotted the piece to take the flate plate dropout.  The gently mitered round cut will receive a matching scallopped plate to ease the transition into the dropout once finished.

As I'm using larger round stays to match the style of the older frames, but trying to insert a larger 29er rear tire into it, I needed to create a bit more clearance between the stays for mud room.  I achieved this by crimping the stays at the apex of the tire line.  Notice that the crimp is centered on the stay and is parallel.  I like to use these linear placements vs. a vertical crimp, as it allows the depression to be placed along the length of the tube, increasing the surface area to distribute the stress and relieving the potential for stress related failure.

Mocking up the fit in the fixture...

And a shot of how she'll look once all put together...lots of gentle bends in this rear end, should be sexy once in the dirt ;)

Things will be heating up in the shop the next two months as I prepare customer bikes for NAHBS.  Jim and Chad, I'll be dropping you some emails this week to discuss your road bikes...thanks for your patience.