I picked up a cheap conversion on CL awhile back for a beater, but I was puzzled by this part:
https://www.imgur.com/34OaR.jpg
It seems to just be some kind of extra security just in case the wheel slipped in the dropouts? I googled around a bit and looked at sheldon brown, but I couldn't find any info on what it is and whether or not I need it. Thanks in advance.

It's a chain tensioner or "chain tug". Whether or not you need it is entirely up to you.

Hm, my idea of a chain tensioner was this: pricepoint.com/images/styleImages/D_075%20YESBT8.jpg but I guess there are different kinds. Is is basically like I said in terms of just adding a little extra peace of mind?

It helps in keeping your wheel from slipping forward in the event of your axle nuts not being tight enough and also helps dial your chain tension in when installing your wheel. I've never found them necessary.

Scrod, do you think I should be worried about this pea sized paint chip, that has an ever so slightly vertical dent that runs the length of it on the inside of the chain stay. It's an aluminum frame (725tr mid). No idea how I got it, thanks.

I wouldn't worry about it.

Hey Dave, I was tightening my friends headset just a while ago and no matter how I tight I tighten the top cap, the entire fork still moves freely. Like I'm missing something completely. Which I'm almost certain I'm not. What gives?

See Post #1703 in the "Dear Carleton" thread.

/notscrod

Scrod,

I'm squandering my annual bonus into a second bike. I'm really digging the Pista Via Condotti. But is all that sexy worthless on daily street riding? Seems like the stock angle on the bars is track geometry, right? So that means to be functional you'd have to swap bars and raise the stem?

You're asking Scrod's opinion on a Bianchi Pista ?

any thoughts on Soma Hellyer Track Crankset?

I'm trying to get a silver crankset for myself on the cheap and it seems really hard to get a quality one (also need the BB) for a better value than Omniums. I was thinking about andels, but finding them in my size is an issue. can you think of anything that can compare to omniums in that price range, that come in silver?

what does scrod think about the affinity crankset? https://affinitycycles.com/2011/11/af...s-chain-rings/


175 for cranks, ring, and bb sounds like a deal to me.

The Hellyer is an older Andel crankset with a different chainring (like the current Leader cranks). If you want a decent silver crankset without using Omniums or springing for 75s, it's pretty much either the Hellyer or IRD Definant (which are excellent IMO).

I've never seen them in person but they seem pretty nice and yeah, that's a good deal.

hamfoh - looks like another option has just presented itself.

You could always just flip the stem to give it 17° of rise.

TT is right, I'm not very fond of steel Pistas and think they are wildly overrated/overpriced. But hey...it's your money.

ty sir!

I might be our guinea pig for those. That chain ring looks a lot like the velo solo one too

It does look similar but I doubt they're made in the same place. I really like the look of the beveled edges on those crank arms.

those things are really pretty but i am worried they might not be terribly stiff. it doesnt say that they are forged then machined anywhere in the blog or storefront, just CNC

good point. I guess when they use terms like 'high end' and 'for track racers' that you just assume they're going to be stiff. I should definitely find out

Stiffness is only dependent on the thickness and cross-section of the chainring. Solid rings like ZEN are stiffer than those with a lot of cutouts simply because there's more material. All aluminum alloys and treatments have the same modulus of elasticity, and therefore the same material stiffness.

but cold working should make the peak of the stress strain graph go up further? to make an overall tougher material right? its been a while since materials lab :/

I pulled the trigger either way and emailed them asking about the process. I think they're closed for the week too (along with coghouse) - I just think Scrod is the only one who actually told some of his customers they weren't shipping stuff until next week.

Harder and stronger, yes. Stiffer, no. Harder chainrings will last longer, because the teeth will not wear down as quickly and become "shark's teeth." As to strength, you will never get close to breaking a track chainring, regardless of the alloy used or heat treatment. More important is that real track cranks are 144mm bcd, such that the radial distance from the bolt circle to the chainring teeth is smaller, making them stiffer. If you want the stiffest setup, then go with a smaller chainring and cog. For example, I used to race with a 50 x 15 combination, but now use 47 x 14 for racing, which is the same gearing.

yeah I guess my main concern was the flex in the arms. I had some couriers that bothered me just ever so slightly mentally that I couldn't get over it.