Pista Chain Line
 

In anticipation of rain tomorrow morning, I put my new Pista up on my garage work stand while I installed my SKS Race Blade fenders.
Two easy minutes.

As I spun the crank to check for clearance, in the quiet of my garage, I realized I could hear the chain and chain ring interacting.
Watching very carefully, I could see the chain did not line up perfectly with the chain ring and as each tooth of the chain ring engaged the chain it did so at a small angle and made a noise.
Just eyeballing the whole drive train, the chain looks straight and I can't hear it while riding.
However, watching and listening in the peace and quiet of my garage the misalignment seems ENORMOUS. :)

What kind of adjustment options do I have; and, should I just live with it?
A trusted helicopter mechanic friend sometimes tells me to not let perfection keep me from enjoying good enough.
If I can't see the misalignment with a stationary chain, and if I can't hear it over ambient street noise (suburban Oregon street noise/quiet), perhaps I already have a case of good enough.

Comments or advice?

Heh, I wonder how helicopter owners would feel about their mechanic saying that? =)

My chain line is bugging the hell out of me too (although I don't own a pista). I'm buying a new bottom bracket as a result. I'd suggest taking your ride to a good bike mechanic (or the place you bought it from) and asking them what they can do to fix it. If you're lucky the solution will be quite simple/cheap.

Is it possible that the back wheel is not completely straight.. so is at the slightest angle which would cause it to make that noise?

Geekylucas wrote, regarding perfection and good enough:

"Heh, I wonder how helicopter owners would feel about their mechanic saying that?"

We have five mechanics here, and they take care of three turboprop airplanes and one helicopter.
One of our mechanics does pursue perfection, relentlessly.
I can't say that in the long run he does a better job than anyone else, but he doesn't seem as happy.
At some point it just gets silly and counter-productive.
So, I think the original perfection and good enough statement had something to do with mental health and not with the quality of the machine or the work.

Anyway, I have taken a harder look at my Pista.
The top of the tire does not center between the seat stays (off center to the right) but it does center between the chainstays.
I could have a misaligned frame from the factory, or maybe I need to move the hub to the left a little.

Assuming you're talking about an '05 Pista: those Sugino RD cranks have a 44mm chainline (reference: Harris Cylery) when installed on a 107mm spindle (which is what I assume they're on), while the track hubs probably have a 42mm chainline (that's the standard anyway). I hypothesize that this is the source of your maladjustment. If I'm right, I think you should just convince yourself that 2mm off is good enough, that or buy a 108mm Wood BB whose cups will allow you to dial in that chainline as accurately as you're able...at the expense of the symmetry of the cranks with the BB shell.

if it doesn't bother you while you're riding then why care?
the only difference it'll make is in chain/cog life time, and if you only notice it when it's totally silent in your garage then i think the damage will be negligible...

...on second thought, maybe a BB with a 103mm spendle?

The Pista comes installed with a 103mm BB. The chainline, with the stock Sugino RD crankset with the chainring on the inside seemed maybe 1mm off to me. I upgraded to SUgino 75, a true track crankset and replaced the BB with a 110 (though I should have gotten a 107 - it doesn't matter since it's the non drive side that's too far out). The chainline seems spot on now.

I had the same problem to an extent. My issue was only with the alignment of the rear wheel in the dropoffs, as the frame was straight, as was the wheel and hub/cog. You'll also have to remember that the sound of the chain engaging with the cogs will make noise, and there's no surefire cure to that. I've also noticed that throughout winter and along with wear, my fixy has become signifigantly louder. Keep an eye on that chain if you ride a whole lot!

Hope this helps.

Absntr wrote:

"The Pista comes installed with a 103mm BB. The chainline, with the stock Sugino RD crankset with the chainring on the inside seemed maybe 1mm off to me. I upgraded to SUgino 75, a true track crankset and replaced the BB with a 110 (though I should have gotten a 107 - it doesn't matter since it's the non drive side that's too far out). The chainline seems spot on now."

How absolutely cool.
I love this forum.

Devious Golden wrote:

"I had the same problem to an extent. My issue was only with the alignment of the rear wheel in the dropoffs, as the frame was straight, as was the wheel and hub/cog."

I've only had this bike two and a half days, and I haven't played with it, mechanically.
Given the off-center nature of the tire in the seatstays, it has occurred to me I might loosen the axle nuts and see if I have any wiggle room that will center the tire between the seatstays.
This could correct some or all of the problem - but - if it doesn't, do I understand from absntr that a 107mm bottom bracket alone will give me better chain alignment?

I write this from work and I can't wait to get home and loosen the axle nuts.
Oh, I get to ride the bike, too.
It doesn't get any better.

I am just flabberghastedly blown-away with how beautiful that statement is.

While not a cure- chain lube may be a quick 'fix.'

I have the same problem with my '04 pista, only I can tell when I'm riding on the street. I had it with the stock cranks and still have it with the record pistas I recently installed. Also, my wheel doesn't line up between the seat stays either. Maybe the frames are just really sloppy...

Ken - that would be my first adjustment. A wheel not aligned in the dropouts will throw off your chainline. A few things you can do to remedy this (if this is the problem, which it sounds like) is to (as you've guessed) is to loosen up the track nuts re-align the wheel and crank those track nuts down. Due to the high gearing (48x16), the amount of torque you're applying, especially on uneven terrain will lead to rear wheel slippage if the nuts aren't sufficiently tightened. To make alignment and chain tensioning easier, you may want to invest in some chain tensioners. I picked up some MKS tensioners this weekend, small, beautifully made and NJS certified. They look like this: http://businesscycles.com/trtool_chaintugs.htm

A 107 mm bottom bracket will not solve your problems. I had to get one to mate it with the Sugino 75 crankset I upgraded. Chainline is dependent on a few things: BB, crankset, rear hub. This is a handy reference (though track specific): http://businesscycles.com/tr-refspec.htm#b/b

This all depends on the thickness of the crankarm and the length of the BB that's needed to either draw it closer or further away from the frame to achieve the proper chainline.

As the poster above noted - the chain engaging the chainring will indeed make noise. If you don't hear it on the street, then you're pretty a-ok.

We have the identical saying in software engineering. The problem is that good enough for us is quite frequently not good enough for everyone else.

EDIT: I meant to add that heavier lube is generally quieter.

A chain without enough slack will tend to be noisy too. The problem is that in order to run a sufficiently slack chain, your chainline must be spot on or you risk derailment.

In my industry, we live by that concept.

A little side note: I find it odd that this problem actually exists with the Pistas? I am thinking twice about saving up for one now.

Surely a straight chain line is one of the first things Bianchi would've accounted for when designing the bike? A brand new track bike with a dodge chain line seems kind've lame to me.

Is anyone able to report if the Pista Concepts have this problem too?

The stock pista is a cheap bike and no-one makes cheap track cranks period. Really wish truvative would or someone, but right now zip AFAIK, so Bianchi did the best I assume their margins would allow. 1-2mm is not too bad and is better than probably a lot of the bikes riden by folks on this forum. Granted considering how well they've taken off you'd think someone could retool to produce good quality cranks with a 42mm chainline for the bottom end of the market.

The Concepts either come as a frame or a complete bike with track cranks cause for 1,300 USD you better believe that things are a little more dialled in.

It's not the frame as much as it is the crank and BB you end up using. Because the Pista has used road cranks (and MTB cranks in the past), you're not getting real a real track chainline but the next best thing. 1mm is to me, a neglible amount.

This is not so much a matter of the frame but a matter of the BB and the cranks you're using.

Actually that's even worse - the Concept complete comes with that Mavic Ellipse wheelset - a 44mm chainline! And that's Mavic's fault. Do a search and read the horrors...

I got home from work this morning, put the Pista in the workstand, loosened the axle nuts and got the wheel perfectly square in all axes.
That felt good.

I still had a little noise.

So I rode to my physical therapist appointment and demonstrated the Pista for him in his parking lot.
It amazes me how such an agile bike behaves itself so well at slow speeds.
I have never felt this confident on a bike.
Anyway, he wants one now.
Can't live without it.

Then on to my lbs, where he put the Pista in a workstand and looked and listened.
He said it doesn't get any better than this, and in 500 miles I won't hear a thing.
I already don't hear anything.

I asked him about bottom brackets, and specifically a Phil Wood bb, and whether that would give me the silly millimeter or two I wanted to make it perfect.
He said he'd sell me one and install it for me, but he considered it an unnecessary extravagance (he said it nicer than that) and it would move both my pedals to the right.
I think he used the phrase "Q factor."

OK.
As I rode home, though, I thought about what absntr had written earlier.
Wouldn't a wider bottom bracket move both pedals away from each other?
In other words, instead of drifting the entire bottom bracket to the right, with a Phil Wood, couldn't I move the right pedal to the right and the left pedal to the left with a much less expensive, but wider, bottom bracket?

I have probably revealed my naked dangling ignorance here, for all to see, but I've done the naked dangling ignorance thing before and survived.

Anyway, do I have a correct basic understanding of the bottom bracket width?
Can I move both pedals further apart, and, in the process, move my chain ring to the right, with a wider bottom bracket?

For geekylucas:

I love my Pista.
In fact, I have an unwholesome relationship with it.
Despite the silly millimeter issue, I have never enjoyed anything (except you know what) as much as this bike.
It literally flies, and I feel like an F-16 pilot on this little steel pony.
Hm.
A little steel pony that flies: Pegasus.
Pegacito!
Cheap?
Maybe.
Thanks, Bianchi, for making it cheap.
It works, looks cool, and I can afford it.
A good design will overcome a lot of cheap.

So, I got home, put the Pista in the workstand, spun up the wheel and eyeballed the chain line from the rear.
No doubt about it: it wouldn't hurt for the chain ring to move over to the right just a teeny widdle bit.
For that matter, it wouldn't hurt for it stay right where Bianchi put it.
Fascinating.

If I could improve the chain line for a few bucks, I'd like to do it.

Ken -

With a Phil BB at 68x105 symmetrical, you damn well could get that pesky 1mm!

forget phill wood, try a .50c freewheel spacer
1mm under the drive side cup will put that ring 1mm to the right!

my Pista '04 stock cranks (Truvativ) and Miche hubs is OK.

Take it to the shop and have them check the chainline with this http://www.parktool.com/tools/CLG_2BIG.shtml.

If its really only 1mm, it could be your eyes playing tricks on you.