Removing a broken stud...

Picked up a new to me Diacro bender that had a stud broken off in the fixturing portion of the table.  Here's a quick video showing one method of removing it so that the table will be fully functional again....

cheers,

rody

One of these is not like the other...

You've likely heard the instant ripples coming across the internet; yes, there is another bottom bracket spec coming down the line.  This time, however, it is not driven by a big corporation wishing to redevelop a standard to sell more of their branded components, it's origins lie among a small frame builder, a family owned component company, and the man who has been responsible for the explosion in frame building today by developing more high quality fiddly bits and offering them for sale, than any other.

It began one year ago, at the Philly Expo, when a conversation between a customer and a builder blossomed into a discussion on what needed to improve upon the bicycle as we know it. At the crux of the conversation, the inadequacy of most frame builders to accurately create a high tolerance, well machined interface for the press fit 30 bearings, and therefore, the erosion of consumer confidence in the standard.

Once you've been in this industry long enough, you begin to see "trends" come around a time or two.  The complaints about the press fit 30 bottom bracket ring through the air; the bearings must be pressed in with a special tool, after use they can creak and make noise, bearings fail more rapidly, they are hard for consumers to work on, etc...  Anyone remember Klien, Fat Chance, and a few others?  Pressed in bearings that gave people fits and subsequently went back to threaded interfaces...here we go again.

Let me introduce the T47 bottom bracket; a piece that begins with the same inner diameter as the press fit 30 and then adds threads.  Isn't this just a bigger standard English bottom bracket?  Nope, let me explain why...

The T47 has the following positive attributes:

- uses a larger shell to allow oversized diameter tubing to match without swaging
- the shell is thick enough to allow welding of both steel and titanium without distortion
- the threads are properly sized to facilitate hand tapping post fabrication and for maintenance
- the bb shell will allow cups to fit all current crank spindle sizes
- existing frames with press fit 30 metallic shells can now be reamed and tapped with threads, prolonging their lifespans of use
- at least three bottom bracket manufacturers are already producing parts for this spec, so parts will be available

The T47 has the following negatives characteristics:

- weighs slightly more than a standard English bottom bracket shell of the same width
- builders will have to purchase new taps and make tooling accommodations
- people who like to grumble have another opportunity to do so

I've been fortunate to have known of this for quite some time and I'm in favor of it.  I like the fact that if I include it in a build, it allows the customer to have options in the future.  I like the fact that it will save some frames already equipped with noisy pf30 shells.  I like the fact that a certain headset maker whose product I love will be making their first bottom bracket to match this spec.  I like the fact that I have a shell in my hand to build one of the first bikes...off to the shop to start making plans.

What does it mean to race?

“So are you riding in Dr. Knob’s Malevolent Team Challenge on October 10th?”

It’s a question I’ve asked a lot of folks as the date draws near.  Some respond with an enthusiastic “YES, can’t wait!”, but many give me an automatic response… “No, I’m not a racer, I just enjoy riding for fun.”

That’s disappointing, let me share why.

Whether the trails you enjoy riding are privately held or on public land, the monetary burden of maintaining these trails often falls to local volunteer groups who have embraced the effort of maintaining and improving the trail systems to the benefit of all.  Though their time is given freely, tools, materials, insurance, and requisite permits/fees are not.  That money has to come from somewhere.  With government budgets under the scrutiny of the public eye, that money must often be generated by private groups who care enough to see the trails thrive. 

Here in Ohio, revenue is commonly the result of participation in our local races.  331 Racing and the OMBC both host races on private/public trail systems with proceeds from the race fees returning to the venues to be used by the local advocates.  Your race dollars are going back into the trails you are gliding across, administered by the folks who care the most about them. 

In the case of Vulture’s Knob, we toe a very tight financial line.  Unlike public lands that have the ability to include rider liability into their overall insurance policies, funded by a large tax base, this property must stand alone and pay for its participants each season.  We generate income through two primary revenue streams; donations and race participation.  Donations yield about $1500.00 a year, leaving a gap of approximately $8500.00 annually to cover insurance, utilities, maintenance, and any improvements we wish to make to the trail system.  That’s no small potatoes.

I implore you, re-define your perspective on what it means to participate in your local races. 

Some race to set performance goals, push physical limits, and compete; it’s about going fast and we welcome that.

There is, however, another relevant perspective; racing is an element of community participation and support.  It’s part of a movement to support your trail systems, creating a sense of advocacy, ownership, and contribution to a larger goal.  Race participants are the financial backbone of many of our trails, creating recreational opportunities for all to enjoy, from cradle to grave.  Regardless of whether you stand upon the podium or just finish with a smile, race participants are stewards of our trails. 

For us, it’s about giving back to something you believe in.  Vulture’s Knob allows us to share our love of mountain biking with others in a way that is unique, special, and is held tightly in our hearts.

“So are you riding in Dr. Knob’s Malevolent Team Challenge on October 10th?”

I hope you will join us?

Broken seatpost removal...

Have not had anything too informative that has not been covered in this blog in the past, but had Paul's Space Bike come in with a broken seatpost, the end stuck fast in the frame.  That makes riding difficult if not down right uncomfortable.

You need two distinct forces to remove a stuck stub of post; mechanical and temperature.

I've never met a stuck post I could not remove yet, so though I don't relish these fixes, they are strangely alluring in their challenge.

Here was a walk down memory lane for a stuck Thomson...

Stuck Thomson post...

This ti post gave up the fight pretty easy though.

First thing I did was look to gaining some mechanical force.  Trying to grab the stub with a pipe wrench or other "crimping" style tool will only ovalize the tube and create pressure on the inside of the seat tube, increasing the difficulty of removal.  So I drilled a through hole in the remaining material that allowed the passage of a 5mm allen tool that I would then use as a lever to turn and lift with.

Next, I applied heat to the inside of the post in it's full diameter; enough to create some expansion of the seat tube and loosen the potential corrosion, but not enough to affect the paint.

Then it was a simple twist and pull with a few choice words when I cut my finger on the ragged edge of the broken post.

Wah-lah...

Inspection of the post showed that there was a distinct discoloration inside the wall of the tube about 1/8" long, possibly a defect during the drawing of the material.  Who knows, just glad that Paul is Okie Dokie and that the bike will now be on the trail again soon.

cheers,

rody

Three Phase Power, a work around

Every once in a while when a builder decides that they want to add a machine or two to offer fabrication options in their shop, I get an email about how to power these large machines. You see, most mills, lathes, etc that you find available are surplus or outdated industrial equipment equipped with 3 phase motors, whereas most home shops/garages are single phase power only.

So, how do we power this new toy?

What most folks first consider is "simply" replacing the motor with a single phase unit.  While possible, this is seldom a good option due to the necessity of fabricating custom motor shafts, pulley adapters, or mounting brackets; all timely and frustrating hurdles to get your machine up and running.

A popular option is a static phase converter, an in-line piece of equipment that is only activated when the machine is started.  Priced from 100 - 500 dollars dependent on motor size requirements, this will get your machine up and running, although at a reduced/loss of power around 2/3rd of it's rated horse power.  While effective, the disadvantage is that you must purchase a static phase converter for each piece of equipment you wish to power.

The option I want to share today is using a idler motor as a integrated piece of electrical equipment to provide the requisite power requirements for your new machine.

A single three phase motor can be wired into your system as a rotary phase converter.  This is accomplished because a three phase motor can be run off two poles, allowing the third pole generated from the idler motor to be fed back into the machine circuit.  This will provide an unbalanced three phase power that will allow your machine's motor to run at full capacity.  When wired into your machine circuit, this single converter can be used to power all your machines simultaneously.  The disadvantage...you have to provide some type of mechanical force to start the idler motor turning (pull start) and your energy consumption will be higher as you will be essentially running two motors during machine operation.

I like to have an idler motor that is 20- 30% larger than that of the highest rated HP motor in your machines if you want to run multiple pieces of equipment. For example, if you have a machine with a 5 hp motor, look for at least a 7 hp idler.

Use a good quality motor.  I like Baldor motors for their smooth bearings and quality build.  The motor will have an information plate which tells not only it's specifications, but also the appropriate wiring configuration...

I typically turn down a piece of aluminum round stock to fit over the motor spindle, machine in a keyway, and then glue a piece of automotive rubber hose over the whole shebang.  This allows me to wrap a flat piece of webbing tightly around the spindle to give it a smooth pull and get the motor running...

In this case, we are using low voltage connections.  There are a total of three wires leaving our panel , going to the idler motor (red, black, green).  Our two power leads (red and black) will power the motor once it is spinning.  So using this chart, our Red lead will attach to wires 7/1, our black lead will attach to wires 2/8, wires 4/5/6 are bundled together, and our green ground to the motor ground.  The White wire, left out from our initial run, will then leave from the motor after attaching to wires 3/9 and go out to the breaker in the panel for our machines.  Coupled with the other two power leads,  the idler motor generates the third pole that our machines will use.

To use, I simply wrap and pull the motor spindle in the correct direction of travel, turn on the breaker or disconnect switch to keep it running, and then the machines already wired in the shop circuit have the capacity to work all day on generated three phase power.

Note, there are comprehensive guides available online to help you set up an electrical system to meet your 3 phase needs.  This is intended only as an awareness piece, not a "how to" guide.  If in doubt, contact a licensed electrician to help discern your shop needs.

The business of small batch building

A recent thread on VS has encouraged me to write down some notes on my experience with small batch manufacturing as a business model and how it differs from one off custom building.  The question distilled down: ...is it a viable business plan to build factory spec frames in batches and how can one best market/partner with shops to create a streamlined product line without the intensive time involved in one-off building.

I learned in what I would consider a small batch production facility that also did custom work in limited numbers. The basic structure I will share is what provided a successful business that supported 4-5 families for many years. The key, like any successful business, is having a well thought out plan with known COGS, production capability, and defined marketing plan.

In short, here are the key elements:

Your production frames need to have defined geometries and sizing that land solidly into the physiologic standards accepted by the industry but have your personal vision/interpretation of performance characteristics. Your perspective on how a bike should "feel" and handle should transfer through the experience to the rider. We found a 4 product size range to meet 95% of our needs...beyond that, it became time intensive helping define the fit for the customer.

The frame design and the tubing/components used need to be readily available or stocked in ample supply to maintain a consistent work pace. Using component design, such as dropouts, gussets, etc..., that allow for use across the entire size range is imperative as it eases fabrication and increases efficiency in both manufacturing and cost. These items should also speak to your identity, creating an aesthetic that differentiates you from other brands on the floor.

The majority of your capital investment will be in creating dedicated fixtures for each model to expedite the fabrication process. Time spent fiddlefucking around with machine set up is money lost. Invest in being prepared for efficient/repeatable work flow.

Standard finishes that are distinctive and easily created need to be determined. If you will not be doing your own finish work, you MUST identify multiple vendors who can work with your timelines to create repeatable finishes so that there is no differentiation in final product. Define expectations and keep custom finishes for custom bikes...you need known qualities and costs for this endeavour.

Set a finished price for each frame that positions your product competitively AND meets your business plan profit goals. These can afford to be cheaper than custom one off work as you are batch building, but that does not mean you are self depreciating the value or quality. Set a defined profit that allows prosperity. If you are looking to undercut existing product lines, you are doing this for the wrong reasons. Predictable margins and productivity are your goals, this should be a daily bread product.

Network with shops that wish to represent or carry your brand and have dealer agreements ready to be signed that clearly communicate minimum orders, cost, terms, and parameters of product representation through the build. Folks have stated various opinions on if you should provide a discount/wholesale pricing model. We operated on a 20% margin, offering shops the frame at our set price based on the previously mentioned business plan targets. If a frame was sold direct, it was at that same retail number, preserving equity in the retail market. This gave the shop an easy bump for stocking a frame, but allowed them the opportunity for greater profit if they built a complete bike.

It has been mentioned that you should only sell complete bikes as it maximizes your profit potential. For a small manufacturer, it is not as easy as it sounds. It does take an inordinate amount of time to spec and order OEM complete builds, assemble, and then pack for delivery. We found that although we could make more money on the build, it did not offset the time required for so few hands...the time was better spent making OUR product. I would suggest creating component spec standards for each model that maintains consistency for your bikes. Upgrades are encouraged, but diluting your vision can not be accepted. Allow the shop to build the bikes, the margin on the components and labor is another share of the pie that benefits them and puts some skin into the relationship. Their advantage is that customers cans see/feel/compare the bike at hand and have it NOW vs. ordering directly from you and waiting for shipping. Prices should be equitable, so that does not factor into the decision making process for the customer.

If you can sell a complete bike direct, do it. However, as a small manufacturer, understand that you can quickly turn inventory over in frame only sales. Your business is maximized by inventory rotation and recouping investment dollars so that you have greater liquid assets on hand. Many customers enjoy the process of completing the build own their own, don't negate your product from consideration by only selling complete in this small production plan.

Ensure warranty standards are clearly defined and begin at the point of sale. Handle them swiftly and accommodate a line item into your COGS for future warranty work. Not every product will require it, but every product sold should share the potential cost.

Support the customer's desire to rep your brand with accessory soft goods...have tees, stickers, hats etc available for stocking shops and direct ordering. You are creating a brand and want to encourage loyalty. Happy customers will be your best salesmen.

Remember, this is a totally different plan than being a "custom" builder and should be approached differently. Although the two can operate synchronously, they are exclusive in operation.

$90 for a replacement QR?

One of the worst attributes of some companies is making "standards" that don't fit anybody else's products. One particular fork company has a 15 mm through axle that uses a different size male thread than everybody else on the market. I can hypothesize that the desire to have a "proprietary" design allows them to charge customers a whopping 90 bucks to replace it if lost or damaged.   So, reason #122 to own a lathe; make a custom insert to fit the more common 15 mm standard through axle.

The original female 15mm receiver that requires you to rotate the piece to find the perfect lever tightness and position. On the right is the new 15mm insert that stays in position and works with a standard 15mm through axle, allowing you to tighten down and go. 

The new insert in place...it's a perfect fit.

A happy DT Swiss skewer with adjustable lever, a quarter of the price of the original and so much more functional. Common sense FTW!

MUST you have machine tools to fabricate a bicycle frame? No, you can do much with hand files, patience, and skill. However, when a level of repeatable accuracy is required, the use of machines and fixtures arguably becomes necessary. In the video below, I walk you through one part of the process of machining the Hot Rod Cranks to visually demonstrate the need to move beyond the simple tools of the trade.

cheers,

Rody

2015 Groovy Tees

The new Groovy Tees are in. The good news is that Eric at Illusions Screen Printing said that things are slow right now and he would have time to do another run before the show, so we are going to open up the availability for everyone NOW. Em is going to spearhead the orders and shipping, so here is what we need from you.

Unisex Colors - Blue, Green, Red, Orange, Teal

Women's Colors - Blue and Berry

These are Canvas/Bella shirts and are a "modern" fit, meaning the soft tri-blend material tends to fit a little tighter, go up one size if you are all angsty about your luv handles showing smile emoticon

Cost: $20.00 per shirt, $5.75 shipping in the US via USPS Priority Mail.

International shipping will be determined by destination, please email me for details Prior to ordering.

If you would like to pick up a shirt locally, please note that in the comments area and disregard adding shipping.

Please make sure your shipping address is updated.

Send the money by Paypal to rody@groovycycleworks.com and include the color and size you would like.

Tapping titanium...what's the secret to success?

A month or so ago I posted a vid showing power tapping steel parts on the mill.  Seemed fairly straight forward and did not require a bunch of explanation if you are aware of the fundamentals of machining.

When moving to titanium, it is a whole separate ball of wax, full of missteps and broken tools if you are not keenly aware of the changes necessary.  As I'm just finishing up some titanium hot rod parts, I thought I'd share a few of the lessons that are worth knowing.

Know your material:

When speaking of Titanium, we might as well talk about the grand daddy of toughness, 6/4 ELI in a non-annealed state.  Machining titanium is much more difficult than steel, as the material does not like to dissipate heat, instead keeping it fairly localized. This means that you need to be aware of your tool speeds, feed rates, and coolant application to prevent tool failure and work hardening.  If you push the material too hard, you will find your tools quickly dulling or becoming burnished at the cutting edge, the material pushing and forming instead of cutting cleanly, and an inordinate amount of smoke coming from your work space...not good in any combination.

Ti also has an inherent springiness, a by product of it's elasticity.  This makes it want to close in on your tool, so having a proper lubricant that reduces the cutting edge friction is paramount.

Know your process:

Tapping titanium is not difficult, per se, it just requires a different approach.

Preparing the hole for tapping will require a stepped approach, using more incremental sizes and a higher peck rate to insure that the heat build up is reduced.  In the case of the spider interface below, I begin with a center drill to create a focal point, then use two drill bits to step up the through hole size, finishing with a third drill bit designed to work specifically with the tap I'll be using.  Due to the hardness of the material, the final bit is one size larger than you will typically find on the suggested drill charts, as the 6/4 Ti does not need near the depth of thread steel or aluminum would require to for the threads to have sufficient pull retention properties.

The extra steps and measured pace in creating the through hole is worth the time as it increases the longevity of the tap.

Know your tool:

I mentioned that titanium does not dissipate heat well, keeping it localized during the machining process.  This manifests in a binding action on the cutting edges of the tap, creating a circumstance where the force required to continue to advance will quickly yield to the torsional forces, breaking the tool off in your work.  We need to select a tap profile that will limit that potential.

The best choice for machine tapping titanium through holes is to use a two flute spiral point tap with a relieved back edge and tooth chamfer.  This allows maximum space behind the cutting edge for chips to be pushed out the bottom of the hole while reducing friction and heat build up on the cutting surface.  Several manufacture's make taps for exotic/hard metals, but I like OSG (EXO TI) and Emuge (Rekord C Ti) the best as they are material specific for titanium, have a nice tooth rake, and are designed for rigid tapping.  Below is an example of some new bits and taps from OSG...I always start with fresh tools when I begin a run of Ti parts so that it is a pleasant experience.

These taps are designed to be machine fed in one push...no back and forth hand work here, don't even try.  The parts MUST be rigidly fixtured as vibration is one of the forces of evil to tap longevity.  Make sure that you consult the manufacturers guidelines for speeds as they will differ.  I run these taps at between 10-13 sfpm,  That equates to an rpm around 240...seems pretty damn fast for how hard a material 6/4 is but that is what is required for proper thread shape and chip evacuation.

You'll see that I am still power tapping with the mill,  I don't use a tapping head.  The key to doing this successfully is to only tighten the chuck enough that the tap will self feed but if it binds, will slip in the chuck before breaking.  It takes a bit to get the right feel, but it is a process that allows you to start with light pressure and work your way up.

Know your friends:

One of the best friends you have in tapping titanium is a little bottle of Moly Dee CF Tapping Fluid.  Heavier and more clingy than your typical "Tap Magic" or equivalent, this lubricant will make life a LOT easier for you.  Good friends do come with a price...expect to pay around 50 bucks for a bottle.

Using these processes on my manual mill, I am able to get about 30-40 holes out of a tap before it is no longer sharp enough to cut efficiently, that's 10 crank arms.  At a cost of $50 per tap, you can begin to see why working with ti can be such an expensive proposition.


Know what to do when things go wrong:

Unfortunately, if you are going to be tapping a lot of holes in titanium, you will break a tap off in the work piece.  When that happens, those buggers are STUCK.  No amount of trying to turn it out using the brittle shards left above the work piece or breaking the tap with a punch will get them out.  So what do you do?

Drop the piece in a small container of Ferric Acid and walk away for a few days.  This can commonly be found at Radio Shack labeled as a PCB Board etcher.

 The acid will eat away at the cutting edges and thinner portions of the tap, leaving the titanium alone.  After a few days, rinse it good and give it a tiny little tap with the punch, out it comes with little more effort than the patience to wait.

If you are going to make custom Ti bikes, you need to know how to work with all the variables of the material.  I hope this gives a little insight and saves you a bit of time and money in the process.

cheers,


rody