Author Topic: Elementary

sam

Elementary
« on: November 05, 2021 »

What's lovely about finding a chewed up chainstay, you ask?



It solves a longstanding mystery, which is something I don't get to do very often.

As detailed passim, my Litespeed


Once upon a time I used to just turn my bikes over when I wanted to work on them. Then I discovered workstands.

has been causing me grief on and off for years because it wouldn't shut up with its ticks and creaks. I've tried a long list of remedies, and been through countless cycles of short-lived success.

Its story begins in 2000, when I bought it from the States on mates' rates for being a cycling journo, or close enough. Our first years together were trouble free. We shared a lot of happy miles. It had gears then, gripshifers on straight bars. Later I switched to caressable Dura Ace downtube shifters.

12 certificate required
The aftermath:



The holes I had drilled later sprouted cracks, which as you might expect caused their own screech. This scar is a reminder of my stupidity.
[close]

When it was around seven I converted it to single speed, seduced by the visual and mechanical appeal of a simpler drivetrain. Initially clunky,


CLUNKY

it then offered up a magic gear (three cheers for 44x17!). Later it dawned on me that this is when our troubles began.

Clearly a chainring arm has been rubbing against the chainstay. How on earth could I have missed that? Because the surfaces only met when the bike was under significant strain when it was being coaxed uphill, that's how. NACF HQ is nestled in the the High Weald rather than the Fens, so here we are.

Until yesterday's denouement, a word I now feel committed to using after dropping in passim, suspicion has most frequently fallen on the bottom bracket. I removed it so often it became a running joke.



Indeed, the bracket has been trying to tell me something all along. (First the headset/forks had something to say, but that's a different solved case.) It's too short.

Paging a metallurgist: on those occasions when the chorus* of complaint didn't start until after I'd been riding awhile, is it possible this was because the frame also got a tiny bit bendier as it warmed up?

*not a pun, as it has a Record crank

I'm also guessing that with every BB reinstallation I don't tighten the crank the same exact amount, leaving it a very slightly varying distance up the spindle – which could help explain why there were quiet periods.

Judging by the horrible picture near the top of this post you'd think I'd have noticed the scrapes a long time ago. Perhaps I did, but it never occurred to me there could be so much flex. Hiding behind the chainring it's easy to ignore then forget about. I only got a good look at it because I finally decided to minutely inspect



that part of the bike in search of cracks, which thanks to my love affair with titanium are now something I have a good deal of experience with.

Fortunately I had another bottom bracket in stock, 103mm instead of 102mm. Don't remember how 102mm was settled on in the first place; possibly someone at a shop told me way back when and that was that. The chainline obviously worked.

Anyway, I put the 103mm in, hoping the extra millimeter would make a difference. It made a LOT of difference.


This would be the after pic

Then it struck me: the new bracket is JIS, meant for the Sugino in my life. The Campagnolo crank is ISO. According to Sheldon Brown, on the same size spindle this should have the crank about 4.5mm farther out! No wonder.

It works, and surprisingly isn't way out of kilter. I'm kicking myself retroactively, but otherwise very very happy.


sam

Uncle
« Reply #1 on: November 06, 2021 »
Yep, I was feeling pretty good when I posted that. Like House, wrong wrong wrong before he's right. Turns out I've just added another wrong to the tally. Maybe I was right about the cause of one of the noises, a tick with each revolution of the cranks, but the creak is back with a vengeance. It turns out that neither this fix nor changing the headset/forks (the one with the loose crown race, the previous likely suspect) sorted it. Plus there's now also a slightly different creak, possibly hiding in the new used headset. Who the hell knows.

Quote from: Sherlock Holmes
When you have eliminated the impossible, whatever remains, however improbable, must be the truth.

Holmes didn't have to deal with a bike seemingly possessed by a legion.

I've tried everything. I'm done.

sam

Misery loves company
« Reply #2 on: November 07, 2021 »
That was my way of saying if I lived near Beachy Head, the bike would now be at the bottom of it. (Alone – I'm neither Thelma nor Louise. Neither of whom were especially concerned about littering, either.) Instead I went looking for other members of the creaky titanium club.

Quote from: MerckxMad
I own frames made of every material (or combination) known to man (and tolerated by my banker), including Unobtanium, as well as several ti frames made by two manufacturers, and the unavoidable truth is that ti creaks and Sidi squeaks. I use two top-notch shops to service whatever I don't on my bikes, and have found that eventually you will hear the creak.

You (and your ti riding buddies) will stare at the bottom bracket, push on a crank, twist the bars, push on the hoods, and grease or anti-sieze every junction of two dissimilar metals to no avail only to to learn, that it's the dreaded OP creak, or so you thought. Then, as your riding along in bliss with the drivetrain humming, it will strike again. This time, you'll start twisting your Sidis in the cleats convinced that this is the source of all on-bike noise, but it will not stop no matter how loose or tight you adjust the pedals.

You'll bring your bike to the shop where the good natured wrnech will pat you on the back and tell you to go to Dunkin' Donuts and everything will be fixed when your return. He will then lube and tighten every fastener on the bike, and assure you that you do not need teflon tape on the BB threads. You will be happy for a week or two, but it will come back.

At this point, you will smile self-assuredly knowing that the creak is emanating from the aluminum seatpost head and the titanium rails of the saddle, and out will come the tube of lube or anti-sieze...

Here's the universal truth that no one who appreciates the ride quality of ti and who has dumped $5K or more into a bike will tell you (except for LBS BS), they creak. No one knows why... ti creaks. Ignore it. Buy the bike that fits and excites you.

Rant over.

My only consolation is creaking is better than cracking.


A little reminder of En*gma quality

Three Time Loser meets Mr Creak

"You lookin' at me?"

At 1 a.m. this morning I was slathering anti-seize around (on the bike, not me, though as the years roll on it may become necessary). There is no expectation that doing so will be my ticket out of the club. Call it, rather, an anointing. Maybe even acceptance.

la la la
« Reply #3 on: December 05, 2021 »

is one way of dealing with creaks. Another, it seems, is anti-seize. Or just doing a better job cleaning the threads.

I'm not going to say the creak is gone. It's just taking a break. 4 weeks so far. We'll see.



Indeed we did. This saga continued here then across the road here. Persistence finally paid off.