Scrodzilla

I'm pretty sure I said "al dente".

scoho

Even better, the seller lists them as--wait for it--Record Pista Strada cranks.

As for the flexiness discussion, it's my (totally unsubstantiated) contention that almost no one is ever identifying actual differential flex in cranks or frames. They're either misattributing to flex in the crank/frame some genuine mechanical phenomenon that's occurring elsewhere, or else it's entirely psychological in the first place (e.g., I expect something to feel a certain way, so it does).

seau grateau

Pretty much.

SquidPuppet

What would cause this perception when someone changes cranks and feels a change? Nothing else on the bike was changed.

scoho

Hope/expectation/desire to fit in: I just paid a lot of money for these fancy new cranks, and, oh, yeah, they're so much stiffer! Or: Everyone says these cranks are stiffer than those other ones, and, oh, yeah, I can feel it too!

Or, less cynically: The crank itself is rarely the only thing to change. There's also usually a clean bb installation, new chainring, etc., plus just a general tune-up of the whole drivetrain. So all of that can cause a real and noticeable mechanical difference that people might misattribute to the most salient change that was made--i.e., the installation of the expensive new crank that drove all of that other maintenance--but finally that difference isn't down to the stiffness of the crank.

seau grateau

Placebo, confirmation bias, etc.

scoho

^^

SquidPuppet

I can assure you that the opposite was true in my case.

Nothing else on the bike changed. No tune up. Same chain. No new lube. Nothing. I "Upgraded" cranks once. The old one was a cheapo with lots of ugly wear and tear. I installed the new one. There was a big difference. It was not a placebo effect. Know how I know? The expensive new crank introduced a lot of flex that wasn't previously there with the cheap one. The frame tubes, bottom bracket, tire pressure, spoke tension, pedals all stayed the same during the brief time it took to swap out the crank.

I neither expected to be, nor wanted to be, disappointed. But I was. So for me, the change wasn't because I desperately wanted to believe that my new crank was a piece of junk.

scoho

Don't worry, I have plenty of speculation left in my quiver. You weren't totally happy with your initial bike setup for whatever reason, and you wanted to believe that it was something that could be fixed, in this case by ditching the old, cheap, grotty crank for a new, expensive, "better" one. So your expectations were high, and, since the new crank didn't provide any objective improvement, its performance fell below your (high) expectations, which you interpreted as objective diminishment.

Anyway, I'm not claiming that no one can ever notice a difference in crank stiffness:

So maybe your cranks were different and you were able to notice it. But I strongly suspect that all the folks talking about whether Omnoms or 75's feel stiffer are full of it. Heck, I doubt most people could tell the difference in a blind test between RD2's and 75's. (Chainrings and so forth are another story.) Anyone up for a little social experimentation?

SquidPuppet

IAmSam

I just installed a new square taper BB on my sw8 phiksie - gonna throw the crankset on after I get back from an afternoon ride on my "beach cruiser"...

Anyone care to revisit/comment on whether it's better to put crankarms dry, or grease the taper?

TenSpeedV2

I swapped out the cranks and BB on my TK2. The only thing I noticed was that it was a bit smoother? I cleaned the drivetrain at the same time so who knows. It was not like there was instant powah and max wattz.

TMonk

I tend to be pretty insensitive towards bike equipment changes as well. After all, it's just a bike - the ride/rider is what makes it go!

scoho

Install one side wet and one side dry, and see which one blows up first.

bonsai171

Personally I would suggest a little bit of lube on the tapers. Any time there is metal contacting metal, lubrication can only help, if you would like to be able to take it apart again A friend of ours had a hitch mount on his car, and left the bike carrier in it. Over time, the metals bonded together, and no amount of persuasion would get the bike carrier off.

Dave

scoho

This is one of those cases where both sides of the argument make perfect sense to me. The other side here being that lubrication can lead to bolt over-tightening and consequent deformation of the spindle and crank (because the lubrication encourages the crank arm to slide farther onto the taper than it should at a given torque).

Personally, I split the difference: Apply a super thin film of grease to the spindle, just enough (I hope) to provide a barrier but not so much (I hope) as to promote slipperiness. I have no idea if this works.

bonsai171

That sounds good. I don't go crazy with the lube either. If you're worried about over-tightening, use a torque wrench.

Dave

bonsai171

What determines bb width on a fixie? Got a 118mm now. If I buy a Wabi frame which uses 103mm obviously my current bb is no good. Would my current wheels be ok as far as chainline on the wabi?

Dave

scoho

That's precisely the problem with lube on the spindle though. The lube makes the crank slide farther onto the spindle at a given torque. So, holding torque equal, the crank will slide farther down a lubed spindle than an unlubed one, possibly leading to deformation of the contact surfaces.

Think about the different mechanics involved in bolting on a crank versus all the other bolts you tighten on your bike. Typically, you're just squeezing the broad surface of one part directly against the broad surface of another. (Think, stem and handlebars, or seat post and seat tube.) But, with the crank, you're sliding it farther and farther onto the taper of the spindle. Totally different mechanics involved.

scoho

All modern frames use a 68mm bb shell. Spindle length is then determined solely by your crankset., i.e., you need to choose a spindle length that will give your cranks the right chainline and keep them from hitting the chainstays.

seau grateau

Kinda depends on the manufacturer. Phil recommends lightly greasing their bottom bracket spindles, for example. If the BB wasn't designed with greased installation in mind, then I guess you might risk pushing it too far onto the spindle.

Phil Wood & Co.

SquidPuppet

There are some people who believe that with lube, the same amount of torque will press the crank on further, potentially causing damage. Over the years I've read everything I can possibly find on the subject and I'm still not sure which camp I belong in.

scoho

but if you do it wrong your bike will explode

edit: TIL that bikeforums automatically downcases the entire comment if you overuse all-caps.

hairnet

Sounds weird to me because JIS and ISO tapers are the same, 2 degrees off the centerline. However, they use different length and section of the total taper. Maybe they mean they recommend it for their cranks, which I'm sure they want you pairing to their bottom brackets.

bonsai171

So are you saying the rear wheel will be ok as is?

Dave