Bullwhip

Matt’s 29er

February 25th, 2013

Allow me to introduce Matt’s 29er. We are big fans of repeat customers – among other things, they are our most reliable test-beds to see how our bikes hold up, what fitting or handling tweaks me might consider, etc. I built a cross bike for Matt back in September 2010, but now he was ready for some more serious off-road action. Here it is:

           

Those are Black Cat Rocker dropouts, and some fun paint (three color logo!) that was Matt’s idea. Here are some pics in progress, including making sure that the fork cleared the down tube:

     

I also painted a new Mostowy, an old Bottecchia, a suspension fork, and am building a 20″ fork for a folding bike. All well and good, but some of us can’t wait for spring:

Next: Alfredo’s coupled road bike, and Mark’s belt-drive internal-geared commuter!

Jeff’s Rando Fixie

December 19th, 2012

The Rando explosion continues, this time in fixed-gear flavor. Truly a return to tradition, seeing that well into the 1930’s most bikes were fixies. 650B wheels, Henry James lugs, Pacenti PBP crown, SON generator hub, Paul and Phil components… this is a nicely trimmed light tourer. New for us was the SON SL hub from Peter White – no pesky connectors at the hub, a special dropout conducts the juice to the lights. More on that in a sec, first some pictures. I left the rear fender struts long to handle chain stretch, gear ratio changes, and the fact that Jeff will also occasionally be running the 42c Hetre tires from Compass (show here are 38c Lierres). It can be a bear getting a good fender line with horizontal dropouts.

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Other things to note: Supernova E3 lights, Campy Cross brakes, and a painted-to-match Lezyne pump. So about those dropouts: one is specially machined to accommodate in insulating washer and a contact that runs up a wire thru the fork blade. Similarly, the drive side of the generator axle is isolated and provides juice for the lights. Here it is going together:

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Now, this means that this wheel will only work as a generator in this fork. But come on, if you have that many 650B bikes around you have bigger problems than that… the advantage is quick and easy removal and installation of the wheel, which is especially great if it gets packed or put on a roof rack a lot. And it just looks smoove.

I also installed a frame break to adapt this Soma for belt drive use:

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And finally, I’ve been doing a dropout replacement on Bobby’s Wojcik. He’s going to use it as a single speed, with Black Cat Rocker dropouts. They’re pretty cool:

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Next: Bobby’s finished, Tim’s Bottecchia repaint, and it’s 29er o’clock!

Road Elegance, and, Destructive Testing

November 12th, 2012

I have the pleasure to introduce to you one of my favorite builds in recent memory, a road bike for Patricia:

  

 

Let us first note that some Conti Classic tires are destined for those white Velocity rims, fear not! This is just what was on hand.

So the most refreshing thing about this is all the lovely silver, am I right? This is Campy Veloce 10, great for anyone who thinks that 10 is the proper maximum number of cogs on a cassette, and just easy on the eyes as well as working flawlessly. The rims are Velocity Aeroheads in white, and a Thomson seatpost and stem and Ritchey Classic bars round it out.

Before I talk about the challenges of this geometry, some more pics of the frame:

  

  

     

Ok, so Patricia came to us with a Davidson custom frame that fit well, but she wanted some tweaking and more to the point, she wanted lugs. Conventional lugs are cast with a conventional geometry in mind – 73 degree seat and head tubes, 60 degrees between the DT/ST & DT/HT. Well. Not so much here. We were shooting for a traditional look, so didn’t want to go past a 2 degree slop on the top tube; and we wanted to do a slack head tube and plenty of rake in fork for toe clearance. All of that helps to use off the shelf lugs, but it left us with an untenable 57 degrees between the down tube and seat tube, which effectively ruled out any available lugged BB shell. So, we chose to weld all the BB joints, and I just promised to keep it soft so it won’t look too out of place.

Patricia chose the colors and layout, and all I can say is I approve.

Now, that was the start of a small frame – let’s look at one from back in the archives…

DESTRUCTIVE TESTING

We don’t have the budget to do a lot of destructive testing, which is why we tend to stick with what we know. Fortunately, we have friends who are badass racer-types and every once in a while, one of these friends gets in a scrape. Liane was in the middle of a pileup on her nearly ten-year-old Cirlce A (pre-stainless head badge!) and this was the result:

  

Most important to note, not only did she walk away, she attempted to ride away. Then her front wheel hit the down tube… well. At first blush, you might think this is a terrible thing for a builder to see. But actually, it’s a great study in frame building, stress risers, and why we love steel.

First, let’s note that this was a serious, catastrophic impact. Clearly the front triangle has buckled in several places, but perhaps not clear from the pictures is that the fork is bent as well; the blades are bent slightly back, and the steerer is bent a touch at the crown. But what’s really interesting is what happened to the frame.

For the builder, the best thing is that Liane walked away. The second best thing is that it didn’t break at a joint. In other words, the forces applied to the frame were transferred from the wheel, through the fork and into the front triangle of the frame – which is what happens every time you get on a bike – and in this extreme situation, when those forces achieved a moment that was beyond what the frame could handle. it sort of broke all over.

It’s a study in stress risers; see how the top tube buckled at the cable stop, and the down tube at the shifter boss and the BB lug. Then you have the buckling in the down tube – exactly in the middle of the tube. In other words, it was trying to bend, but eventually the center could not hold.

This is what happens with well made, lightweight bikes. They can break. But they will usually not break at a lug (even a minimalist, bikini lug as seen here), at a fillet or at a weld. And, unlike aluminum or carbon, we can fix it. As I do here.

With a silver brazed frame, relatively little heat is used to join the lugs and tubes. So, you generally have the option of heating the joint and pulling the tube out, or cutting and grinding it out. In the case of a full front triangle, I generally will pull the top tube out of the seat lug, but I like to grind out the dt from the bb. This is mostly because there is so much mass at the BB, it takes a lot of heat on all four joints there. In general we like to keep the heat cycles down, but this is more important in a high stress area like the bb as opposed to the seat collar. When was the last time you saw a bike break at the seat lug? Ok, so here’s work on the BB shell:

  

For the seat lug, I cut the center of the tube out and use a bungee cord to pull it straight out. This helps keep the seat lug in shape; pulling by hand or trying to twist it out can distort the hot metal.

 

Note the shadow of silver on the top tube in the shape of the lug. This is what we in the frame building industry refer to as full penetration. In other industries this might mean something else.

Anyway, here’s the (re) finished product:

  

  

  

So, we hope this sort of thing never happens to you. But if it does, we can help.

Next: Jeff’s fixie rando! I know, what? And 29er fever takes hold!

Dirt-O-Rama

September 18th, 2012

OK, so the off-road fest continues, with Dan’s old-school mtb and Charlie’s S3 cross bike:

 

I’ll start with Charlie, keeping it chronological. It’s the brother bike (or sister ship) to Cindy’s from last time, a superlight cross racer made from a mix of True Temper S3 and Deda Zero and Zerouno tubing. Again, the S3 is challenging to work with, but the results are pretty spectacular.

       

It was also another couple weeks of welding, which regular readers will know is a bit rare around here. Here are some shots of Dan’s mountain bike in process. To note: 26″ wheels. Rigid fork. Canti brakes. Single speed. WHAT? No full suspension, hydraulic brakes, 29er 30 speed? Not here. Light, simple, fun.

  

And the finished product. Dan wanted to be surprised by the paint; he did specify earth tones and general subtlety, but we had to push a bit, right? So here you go, just in time for foliage season.

            

Dan picked up his bike while working – it’s always fun to see a bike ride away, I just wish he had a brake on that fixie…

  

Next: finally, Bert! Patricia! Also some repairs and other stuff!

Cindy’s Featherweight Cross Bike

August 27th, 2012

Cindy is one of the luminaries on the Bikes Not Bombs-Circle A Cycles ‘cross team, and for this season she wanted something with a better fit and lighter weight. Something to win on. She’s not tall, and was eager to engineer in some toe/tire clearance. This is what we came out with.



The frame consists of a True Temper S3 front triangle, with Dedacciai rear triangle featuring Zero chainstays and Zerouno s-bend seat stays, and weighs in just a tick over 3 lbs. The fork is by Enve. I’ll be building a steel rando fork for her as well, so I’ve included rack and fender mounts. Putting the “light” in light touring.

        

The S3 tubeset is a bit tricky to work with; only the seat tube is round, and the extremely thin walls (.5 mm at the butts!) make it easy for it to tear in the mill, so every miter is done by hand. And they have to be tight if I’m not going to burn through while welding. Also the small size of the frame demanded a funky compound miter at the head.

     

Next: Dan’s single speed MTB, Charlie’s ‘cross machine, Bert’s rando rolls!

Rohloff Rising

August 13th, 2012

Allow me to introduce Bryan’s 14 speed Rohloff-equipped tourer. He just completed an 8 day tour of the Great Divide on his Tout Terrain Silkroad (also a Rohloff rig), and we’ve spent the last several months coming up with a custom bike that will be similarly suited for adventure touring, but more nimble and lightweight – as well as providing toe/fender clearance, which bedeviled Bryan on the TT.

  

  

  

  

Here are some frame details. It’s a TIG welded frame of True Temper and Dedacciai tubing, with clearance for 40c tires and fenders. The Rohloff-specific dropouts are from Paragon; one of the advantages of the Rohloff compared to other internal-gearing systems is that’s very easy to disconnect in order to remove the wheel to fix a flat – you simply pop off the black box that holds the shifting mechanism, and you can drop the wheel out (with the sliding dropouts, you don’t even have to worry about re-adjusting the chain tension).

Bryan is running a Schmidt SON 28 Dynohub, with Busch & Müller lights. Because the twin Rohloff gear cables were running to the back of the bike anyway, I ran the wire to the rear light bundled with them; but it does run inside the fork and the rear rack. There are disconnects so that Bryan can remove the racks, fenders or fork easily for service or shipping.

  

  

  

I also did a disc tab installation on Mike’s IF, and am finishing a superlight cross bike for Cindy, just in time for the D2R2! Here are some pics, but more on that next week! Then, Dan’s mountain bike, Bert’s Rando, and Charlie’s cross bike!

  

Russell’s Rando, & Repair-O-Rama

May 23rd, 2012

Yes it’s been a while, but wow have we been busy. It’s that time of year in New England, everyone wants to get rolling, and we’re doing what we can to oblige. Soon to make it’s way to him in British Columbia, here’s Russell’s rando bike:

I’ll be building it up next week with some choice parts: Nitto racks, Paul Racer brakes, a SON generator hub with Supernova lights, Ultegra drivetrain, Honjo fenders… Russell created the knot graphic, and yes, those are Space Invaders. The colors are inspired by the palette he saw in Morocco. Stay tuned for pictures of the built-up bike.

  

  

  

  

  

I also did a raft of repaints, some of which turned into unanticipated repairs. Bill’s vintage Raleigh ended up having a cracked chainstay (I blame his 56 tooth big ring and tree-trunk legs!); I replaced the stay and painted it up, with lug lining by Josie. Here’s the finished product, followed by some process shots. Note that the chrome was too far gone to save, this is a good example where paint can cover it and keep the original feel of the bike’s look.

  

  

At the same time I also repainted Sarah’s Raleigh:

  

Ted’s Nishiki MTB came in for a dropout replacement and repaint, but while stripping the paint we found this crack in the seat collar:

I made an internal sleeve that I brazed inside, and reamed out so he can use a standard 27.2 seatpost, not the odd early 90’s size he had been stuck with. Crisis averted!

  

In a collaborative effort, I did some braze-on updating on Bob’s Specialized Sequoia; Jay did the paint and Josie, of course, did the custom lining! The inspiration was a locomotive designed by Raymond Loewy, who also created the Studebaker Avanti.

  

 

It was a month of smashed rear ends, one of which was Richard’s vintage Abel Borne; after straightening the frame, there was a small crack above both dropouts; I brazed a sleeve around the area and then shaped it to mimic the original profile:

  

I also added a disc brake mount and brace to Avi’s IF:

 

And last but not least, and to cement that fact that it’s been Giant Bike Month, I replaced a broken seat stay on Tony’s Paramount, straightened the other stay, and repainted:

 

I cut out the old stay, heated it to pull off the brake bridge and seat lug, and created a cap to match the old one.

  

  

Next up: more pics of Russell’s rando, and then Bert and Bryan are up!

A 15 lb bike. And an 8 lb one. For an 18 month old.

April 2nd, 2012

Consider this my entry for most sickly sweet blog post ever: for your consideration, my new bike, and my son Oscar’s first:

And to up the ante:

So, me first. For the 250th Circle A (!) I wanted to do something special, and when Bobby came to me a few months back asking about an S3 club racer (see last post), I thought to myself, “Self,” I thought, “what’s the lightest steel bike I could reasonably come up with? Why, a belt drive fixed gear made from True Temper S3 tubing, is what.” This is that, without the belt drive, yet (watch this space). In the mean time, I moved the parts over from my fixie commuter – Circle A #1. But here are more pix. To note: monostay, for no other reason than I love how it looks; Paul dropouts with integrated tensioners (ready for the belt drive); Enve carbon fork; and a custom frame break for the belt. I was aiming for subtle in a sort of Liberace vein – silver logos, white panels on pearl white.

         

As for Oscar’s: granted it’s a bit early, but he’s bike-obsessed (likely due to lots of time in the trailer), and we had all this old tubing lying around… we tend to joke that it’s no big deal to screw up the miter on a tube, because there will always be a smaller bike. Well, this would be the smallest, and I raided our rejects pile for a Dedacciai Zero tapered down tube and a pair of OX Platinum seat stays. I cut the dropouts off an old project bike, and decorated the fork blades with a little actual bling, so Oz doesn’t have to wait til he loses a tooth to get some coin – and of course 2001 was when I founded the shop.

    

I also rebuilt the rear end on a Rhygin; and not just rebuilt, but redesigned to accommodate disc brakes, single speed or derailleur setup, and 2.5″ tires:

     

Here are some shots of that project:

           

And last but not least, I repainted Beth’s Circle A, one of the first bikes I built in Providence – circa early 2002. We’ve come a long way!

 

Next: it’s a vintage Raleigh repaint rally! and Russell’s rando!

We Build Bikes, All Kinds

March 7th, 2012

It’s been an exciting few weeks – just out the door are two bikes that, apart from both being 700c road bikes, could not be more different. Take a look:

 

On your left, Bobby’s welded S3 Club Racer in mind-bending black and white; on your right, Mike’s fully loaded randonneur, lugged, with integrated generator lighting. Folks, if you’re riding on pavement it doesn’t get much different than this. First, Bobby. Yes, it’s one bike! I know! My head hurts too.

 

  

  

  

  

  

  

  

  

Bobby wanted a light but durable racer and training bike; he’s had some bad experiences with carbon forks so wanted to stick with steel. To keep the weight down we used True Temper S3 tubing, one of the lightest steel tube sets available. The 54cm frame comes in just under 3 lbs, and the complete bike with the custom steel fork is under 18. I also made him a custom steel stem whose angle matches the 5 degree slope of the top tube.

As for the paint: Bobby is a fan of French new wave cinema; “L’OBSCURITE” & “LUMIERE” (dark and light) are painted in the font that Jean Luc Godard used for his credits. The scheme was his inspiration, I just made it happen.

Ok, now Mike:

  

  

  

  

  

  

Mike’s frame is a mix of True Temper OX Platinum and Verus HT tubing; the lugs are from Richard Sachs, and the crown is a Pacenti PBP. He’s running a SON generator hub with Supernova E3 lights. As with Tom Walker’s bike I called on Benno to do the wiring; he installed disconnects under the fork crown and behind the BB, so that fork and fender removal are easy. Mike also has a Kimura battery light mounted under his chainstay just in case. The eagle-eyed may have notices that he’s running Campy 10 speed ergo shifters with an Ultegra 9 speed drivetrain. I know! This is made possible by a Jtek Shiftmate. These are available in all sorts of combinations to allow all manner of mismatching of shifters and drivetrains.

Coming up next: a Rhygin gets a new rear end, a Nishiki gets a new lease on life, and it’s a Raleigh restoration marathon!

BELT DRIVE SINGLE SPEED MTB

January 29th, 2012

This may seem like deja vu all over again, but belt drive fever continues with this single speed MTB for Dawson. It all started with a lovely Phil hub with belt-drive single speed cog – the challenge was to build a bike around it. And here it is:

He’s running a SID fork, Avid Elixir brakes, and a 39/24 ratio.

  

  

The tricky thing about single speed belt drives, as discussed before, is that you have to be pretty certain about what gear ratio you want. I have to calculate the precise chainstay length based on the front sprocket, rear cog, and belt length – unlike a chain, you can’t just add or subtract a link; there are a finite number of belt lengths available. Fortunately Dawson is an experienced single-speeder so he knew what he was looking for. As with Matt’s Alfine belt drive, we used the Paragon sliding dropouts with the frame-break option. This makes assembly very straightforward, and provides an integrated tensioner which makes setup a snap. Here are some pictures of the frame in progress. The tubing is True Temper OX Platinum, with Columbus Zona seat stays.

    

Next up: Bobby’s S3 club racer, Mike’s rando ride, and another Bobby’s re-imagined Rhygin!

Circle A Cycles   |   523 Charles Street   |   Providence, RI   |   401.831.5221
background: keira in the garden with her new circle a tourer. (reveal)

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