Singlespeed & Fixed Gear - Bianchi Pista Concept w/ front break

All,

There was a discussion a while back about whether the track fork of a Bianchi Pista Concept could be drilled to accept a front brake. Check out the pics. I started with very small titanium drill bits and worked my way to the correct diameter for the cane creek sl brake. I then did the back side of the fork to accept the nut that holds the brake. It took about an hour or so. The most difficult part was removing what looked like a bolt inside the fork that had been "bonded" inside the fork where the brake would mount. Note where the drilling occured is not actually carbon, but aluminum. The carbon of the fork doesn't begin for about an inch below the brake pads.

Note I called Bianchi USA to ask if it could be done - they said "no, buy a new fork". Of course I'm sure it voids the warrenty, but..."

was the spelling of brake as "break" meant as a pun or some sort of premonition?

What the hell did you do that for?!

PS - Sweet ride, it puts to shame my black Concept...

was the spelling of brake as "break" meant as a pun or some sort of premonition?


it could be a look into the future for the fork breaking because of the brake. nice catch.

i almost missed it!

guh guh guh and i agree with raygunner. what the hell did you do that for?

What the hell did you do that for?!

PS - Sweet ride, it puts to shame my black Concept...


I saw your post of your black concept. I thought it looked pretty good, especially with the bullhorns. Did you fix your seat clamp?

I would assume you would do it simply to see if it could be done....and presumably are not too concerned about the fork?

Hey Chase, what lever is that?

Beautiful bike!

Nice one!

I was going to have my steel concepts' fork drilled. Mr Brown said not a great idea...I lucked out finding an aluminum drilled fork with the same rake, celeste color matched too. Pic's some day.

why didnt you just get a different bike?

thats nuts

Sweet bike (that will probably be my next frameset though I don't like the integrated headset), but I would agree with others. That setup looks risky. That fork is not designed to take braking forces.

Per Sheldon Brown's admonishment, I've been running a front brake on my Calfee fixed for the last couple weeks. This after years of riding brakeless. I find that I'm getting places about 5-10% faster. I got a ticket from the style and asthetics patrol, though. I've put almost 150 miles on it since Monday and it is just so much easier on me, both physically and mentally. I almost T-boned two Monster Trucks that pulled u-turns from parking places right in front of me and I was glad to have the thing there in case I needed it. For most manuvering in the city, backpedalling still works because the input is quicker than a brake, and obviously in the rain skidding can be more effective, but for 95% of stuff, I'm a converted brake guy. So there are good reasons to ride with a brake.

As to whether it is a good idea to have drilled out that fork, I don't think you'll find unanimous agreement either way. Furthermore, it is a CANE CREEK SL brake on that bike, not exactly a v-brake, so I think it will be fine, although I probably would have just tried to trade forks with somebody instead, but you know how some forks are, want to do things their way. Looks and sounds like a responsible installation. I'd want to hear it from Bianchi what fork that is. It may be the same fork as used on their road bikes, unless you know for certain that it is track specific.

Hey Chase, what lever is that?

It's a Cane Creek Crosstop cyclocross lever.


As for the fork, my LBS master mechanic and I were both convinced when looking at the fork - ie. the flat section both front and back (indicative of where a break would go), the screw inside the fork which was probably inserted and then bonded to the fork to create a smooth surface for painting, and aluminum upper portion of the fork - we figured it was probably a road fork originally in the manufacturing process that had the brake holes filled in to become a track fork. When we called Bianchi USA, the rep really couldn't tell us anything about the fork besides "it can't be done".

Seems pretty obvious that you have a road fork with track rake and as you say a bolt used to fill the hole. The fact is is that you were not drilling into an all carbon fork. You now have the best of both worlds. A usable brake installed on a kick a$$ looking fork. Makes showing up at the track that much easier when all you have to do is remove the brake and still ride with the correct rake fork.

I say hats off.

As for the fork, my LBS master mechanic and I were both convinced when looking at the fork - ie. the flat section both front and back (indicative of where a break would go), the screw inside the fork which was probably inserted and then bonded to the fork to create a smooth surface for painting, and aluminum upper portion of the fork - we figured it was probably a road fork originally in the manufacturing process that had the brake holes filled in to become a track fork. When we called Bianchi USA, the rep really couldn't tell us anything about the fork besides "it can't be done".

Aha, makes sense to me now-good deal. The rep probably can't recommend any alterations of anything for liability reasons.

what the hell did you do that fffoooorrrr?!

I was asking about this a number of months ago. Im really excited to see how well it went! When I hear "Not built for braking forces" coming from people I am quick to think they dont know what theyre talking about. The torque exerted on the fork from the brake is operating on a lever arm of about 1" maybe? It seems trivial. Reading "The Bicycle Wheel" by Jobst Brandt he says that braking forces exerted on the wheel are trivial compared to the static load of the rider, and I suggest that the force on the fork is equal and opposite that force on the wheel.

Of course I havnt taken physics in 6 years, either. ;)

Alex

hella badass!

I just won a Pista Concept in a raffle and was wondering about how to do this. I don't have the bike yet, though....maybe Tuesday.

luuuucccccccccckkkkyyy!

>torque exerted on the fork from the brake is operating on a lever arm of about 1" maybe?

The real force on the fork is coming from the contact patch on the tire. That contact patch is what is actually slowing you down, and it's exerting leverage on the fork both at the dropout and at the brake.

Traditional round steel track forks are not build to withstand this leverage, which is why they have a tendency to "chatter" under hard braking- the fork blades are flexing backwards from force exerted at the dropouts by the wheel.

However, as you said, this fork probably has legs from a road fork design, so this shouldn't be a problem.

fatbat.

are those Mavic rims (ellipse?) really made for braking? Seems iffy on a radially laced, track specific wheel...

I dont see the break on the front anywhere?!!? :p

The Ellipse is really nothing more than a rebadged and unmachined Cosmic. Don't give Mavic too much credit as being ground-breakers.

I wish I had a resident physics/mechanics angel. I would like to know more about this stuff.

Oh. also. The front wheel on my road bike is laced radially so again Im pretty sure thats not an issue. Ill look in that same wheel book again tonight. -a