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eSporks
Jun 10, 2011



I've always been curious about that myth.

In the BMX world, everyone knows it's the opposite. Chrome rims provide far superior stopping power than anodized.

I've definitely experienced garbage performance on cheap beach cruisers with chrome rims though.

Does anyone know what's actually going on there? Because it's not as a simple as chrome/not-chrome.

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eSporks
Jun 10, 2011



CopperHound posted:

Judging by the few BMX bikes I've worked on, stopping power is not a concern that designers give much thought to. Have you tried a side by side comparison of different wheels on same bike?
Scuse me?

That pic is actually me, I have lots of experience with chrome and ano rims on identical set ups. Its common knowledge in the BMX world.

quote:

The stopping power difference becomes much more noticeable in wet conditions. You need the iron oxide based brake pads to get wet steel rims to do anything more than just sorta slow you down a little.

Some steel rims are textured for increased brake performance:

I am really curious if the rim being steel is a factor here. I can definitely confirm that every chrome steel rim I have encountered has poor brake performance.
Mid to high end BMX rims are aluminum that is first coated in a primer, usually copper or zinc, and then chrome plated. I am not sure why or if that makes a difference in braking power, but I am certain a high end BMX chrome rim performs better than a high end ano rim.

I've always been bothered by this myth about chrome rims. It does have merit, and is certainly true about low end chrome rims, but its not true across the board. Something else has to be at work.

Flatland Crusoe posted:

Back in the cyclocross dark ages when we used cantilever brakes we would sometimes score our rims with a box cutter perpendicular to the wheel rotation to get better stopping......
Brakes in picture are canti's. FWIW

eSporks
Jun 10, 2011



CopperHound posted:

It could be that I mostly deal with BMX shaped objects, but between stamped steal cailpers, u-brakes, a gyro, and the front brake cable making a u-turn, they seem mostly vestigial.

I want to see more close up pics of your bike that actually has functional brakes.
It was an old bike from years ago and pretty custom, but I've had good brake performance on normal u-brake set ups too.


Housing stop in topcap, cable runs through the steerer and out a hole in the crown.


Center pull cantilevers, with a spoke yolk for maximum stiffness.

kimbo305 posted:

I submitted a q to Lennard Zinn's Q&A column in VeloNews; just need to remember to keep checking.
Sweet!, I'd love to hear what he says.

eSporks
Jun 10, 2011



e.pilot posted:

mech discs should be immediately replaced with TRP HY/RDs
I think you mean trp spyke/spyre.

eSporks
Jun 10, 2011



What is a hy/rd getting you? Other than a more complicated brake. The main advantage of hydro is the lack of housing compression followed by self centering pads. Hy/rd does nothing for the former, and spyre does just fine for the latter.

Hy/rd is solar powered flashlight.

eSporks
Jun 10, 2011



Peel off the sticker and look for cracks. If there are no cracks, its totally fine.

eSporks
Jun 10, 2011



Agreed. Looks fine. Check on it periodically for cracks, but I wouldn't worry.

EDIT: VVV Oh yeah good eye. Keep an eye on that.

eSporks fucked around with this message at 21:35 on Sep 13, 2020

eSporks
Jun 10, 2011



Looks like your chain is rubbing as well. Check to make sure you don't have an unnecessary spacer behind the cassette.

eSporks
Jun 10, 2011



kimbo305 posted:

Facing it means to file/smooth
I want to make clear that you should not try and file your brake tabs.
That's an accurate description, but getting them flat and even will require a jig or expensive tool. Attempting to anything with a hand file will destroy your bike. Just making sure no one gets the wrong take away from this.

eSporks
Jun 10, 2011



CopperHound posted:

I made a tutorial to share with aspiring wheel builders for calculating spoke lengths.
https://docs.google.com/presentation/d/1ULyPizAvmtR_SJlOeXDUb4XNIsOIiFklmvbsKRrEAMQ/edit?usp=sharing

I did not make a tutorial on how to physically measure a hub and rim. Figure that out yourself.
This is really awesome and well made, thank you!
I've seen formulas tossed around, but nothing that in depth really.

eSporks
Jun 10, 2011



EvilJoven posted:

Sometimes I make double butted or bladed pokey spokes just so I can look down my nose at plebs using straight gauge pokey spokes.

Edit: another incredibly useful spoke based tool is to curl the spoke around tight to make a handle and affix the magnet from a speed sensor on the two ends, using the j bend for additional security. Use that thing to fish bearings out of hubs and stuff.
A bladed spoke is easier to control than round one. The j-bend can be a super useful hook for fishing cables through internal routed stuff, you can also exaggerate the j-bend a bit to help.
Pro-pro-tip. You can also slide some housing over your homemade spoke tool for a bit of a better grip and to make it magnetic so you can stick it to your toolbox or truing stand or whatever.
I also used to cut down nipples and thread them onto the spoke backwards leaving a few threads exposed. Its super useful to hold a new nipple in place when you need to insert it into a rim. I got the EVT nipple holder and never looked back though.

eSporks
Jun 10, 2011



BeastPussy posted:


Terminology may be different where you live so ymmv.

Here's the real diagram though.
Its good they got the whiskey on there. With enough of that you won't care about the rest.

eSporks
Jun 10, 2011



tylertfb posted:

I don't mess with that rotary broaching dark magic I would if we had the tools in the shop
Coward. Make your own.

This is the black magic for those that are curious.
https://www.youtube.com/watch?v=GWyHJVOxKK4#t=444s

To flat tire guy. That sure is weird, I don't see anything in the rim to cause that. Are you positive its on the "bottom" of the tube and isn't on the side and possibly caused by pinching?
Are you using tire levers to install the tire?
Have you switched tube brands? Possible its a bad batch.

eSporks
Jun 10, 2011



Oldsrocket_27 posted:

LBS had some velox tape, and the 5min test spin I had time for didn't blow a tube, so maybe that's really what it was. I'll know for sure when I try for a longer ride. It amazes me that the difference between tape brands could be that significant, but there you are.
Velox is stiff, electrical tape is stretchy and can sink in to the spoke holes after inflation.
Electrical tape usually works though, hopefully the velox fixes your issue.

eSporks
Jun 10, 2011



Is the fork steerer carbon? What's the frame material?

I'd pull the fork and check the steer tube to be safe. Get the bike on a stand and check the frame for cracks or stress in the paint.

If you see a questionable chip on any carbon part, tap it with a quarter or screw driver. A crack in the carbon will sound deader than the area around it.

eSporks
Jun 10, 2011



kimbo305 posted:

cross top levers
Have these always been part of the equation? Cross tops themselves are always going to disrupt the lever feel and introduce some mushiness and play into the system. They also put a ton of stress of cable housing.
The other tips here are all good ways to minimize things, but a system will never feel as good with cross tops installed.

eSporks
Jun 10, 2011



Newer shimano FD has a built in tension adjuster too.
Also follow the directions, it's different than ever other FD shimano has made.

eSporks
Jun 10, 2011



Is it holding now?

I can't think of anything in the wheel build process that would cause that, unless the wheel was SEVERELY out of true or round.

I'd suspect faulty gauge and too much PSI, or a defective tire/rim bead.

The gauge would have to be off by a lot though, like 50% or more. Inspect the rim/tire bead for any deformation, surprised it didn't deform just from blowing off.

eSporks
Jun 10, 2011



kgibson posted:

Hey all, still no luck with this issue. I did end up swapping out pulleys and retrying b-screw and cable tension adjustments to no avail. I also tried adjusting the tension on the chain by moving the wheels around in the dropouts, but that didn't make much difference at all. I grabbed a quick vid of the noise I'm trying to address:

https://imgur.com/UwrgWLA


(Sorry for the shakiness and portrait orientation.)

The clicking in the third to smallest cog is the issue. The same noise is present to a lesser extent in the fourth largest. They seem worse in the small ring but are present in both.
It sounds like the chain is trying to climb gears. Does the sound go away if you turn the barrel adjuster clockwise 2-5 clicks? If yes, cool. Does it still run smooth in the larger cogs? If yes, cool. If no, check the der. hanger.

eSporks
Jun 10, 2011



kgibson posted:

So this is what gets me wondering about the hanger: adjusting the barrel counter clockwise seems to help the shifting and the noise on the small cogs but then in turn worsens it on the larger ones. My understanding is that that's typical of a bent/misaligned hanger...?
It's definitely where I would start.

eSporks
Jun 10, 2011



The abbey one is an absolute dream to use, and the price difference is worth it over the park if you use it regularly.

From home use, anything that gauges against the rim will be fine though.

eSporks
Jun 10, 2011



What's your favorite tubeless tape?

I have some hplus son hydra's that have always been a head ache.

Gorilla tape seems too tall, the bead snaps into place aggressively and if PSI drops below 35 the tire slides off into the rim channel. Also burps a lot.

Stans is always trash. The channel is really deep and stans is too stiff to get into it.

I tried some kapton tape, and it was ok for a bit, but it didn't have enough stick and peeled up.

eSporks
Jun 10, 2011



Ordered some of that powder coat stuff.

Looks similar to the kapton, but I think the stuff I have is just cheap. It barely sticks and it snaps if you stretch it.

eSporks
Jun 10, 2011



The powdercoat tape won't stick to the rim in the slightest. Worse than stans.

Edit: spray adhesive. Seems to be working.

eSporks fucked around with this message at 19:23 on Jan 5, 2021

eSporks
Jun 10, 2011



I couldn't get it to stick enough to even stretch. Rim was clean with alcohol, roughed up with sandpaper. A touch of spray adhesive on the start of the strip gave it enough tack to get started.

Held up for an aggressive ride.

eSporks
Jun 10, 2011



TobinHatesYou posted:

When I start taping a rim, I run a Pedro's lever over the tape at the edges, over the bead-lock, and in the center channel. It generally stays in place after 2-feet of tape is laid down, though sometimes it'll lift slightly. That's not really a big deal though.
I'll try that, sounds like a good idea.

bicievino posted:

Yeah, I stick the wheel in the truing stand so I can use both hands - one thumb holding the tape down, the other stretching more down.
Then slide my thumb along as I go to force out any air bubbles.
Thats my standard method. I'm not sure if its the profile on these rims or what, but nothing ever sticks to them.

eSporks
Jun 10, 2011



Dangerllama posted:

Okay so one more dumb question. Is there a trick to getting the front derailleur properly tensioned without two people? I got the rear tensioned up well, I think. But the front is giving me fits.
1) Use the low limit screw to push the derailleur outboard.
2) Then pull the cable tight and clamp tight enough to hold, but not loose enough to crimp.
3) Re-adjust the low limit screw.
4) Check tension BEFORE shifting. If you can't get the low limit to back off enough, release some tension carefully. If it feels slack with the low limit correctly adjusted, re-peat 1-4
5) Fully tighten the cable clamp and check shifting.

eSporks
Jun 10, 2011



Are they flat mount?

I'm going to defend the shop here and call out SRAM. Their flat mount t25 bolts are made out of the softest stainless I have ever encountered. They also have a terribly loose fit on every t25 wrench I've tried including Silca, PB swiss, and wera. On top of that, the caliper was designed without proper tool clearance and the body interferes with the wrench, cocking it off to the side.

I've told every SRAM rep I've encountered about it and they just shrug their shoulders and say "we know." If it were up to me, every equipped bike would include a $25 labor credit to fix the problem.

The shop should still take care of it for you, but unfortunately it's SRAM's mistake and SRAM will make the shop eat the cost.

eSporks
Jun 10, 2011



sweat poteto posted:

Front caliper bolt clearance is indeed crap, at least with 160mm rotors.



Please send this picture to SRAM as a customer and complain about it. It's unacceptable that they have a design so poorly thought out and just expect everyone to be cool with it.

eSporks
Jun 10, 2011



EvilJoven posted:


And don't get me started on that lovely hybrid system Giant had on some bikes for a few years. That's 100% remove throw in garbage install compressionless housing and Spyres right there.
We had a sale that our salesman made contingent on putting aero extensions on one of those. No matter how many times we told him it wouldn't work. We ended up having to eat the cost on spyres to make it work, but then the customer got mad a month later because they realized the brakes weren't hydro. We ended up taking the whole bike back and selling it at a loss. The kicker is that the service department got blamed for it because the sales guy was the golden child and that shop was run horribly.

Going to throw in support for spyres though. If they can stop my fully loaded touring bike, they can stop your road bike too.

eSporks
Jun 10, 2011



Frame is bad enough that it would need repair. An experienced carbon repair could fix it, but the cracks mean you definitely can't just put new rivets in and call it good.

eSporks
Jun 10, 2011



evil_bunnY posted:

I'm gonna be the party pooper here and say that you can't know how much damage you've done to the seat tube without NDT, and additional riding can totally propagate cracks as they're stress concentrations once they start.
Agreed.
You can see cracks in the pic. Those alone will spread, and there is really no telling whats underneath.
*might* be cool on a trainer, but riding this thing in the wild is a death wish without a professional looking at it.

eSporks
Jun 10, 2011



Interesting, I've never heard of the cloth tape trick. I usually go with grease or carbon paste on the rails.

eSporks
Jun 10, 2011



Park Tool BSH-4
Big honkin' plastic dog bone with 4 sides.
Gets the job the done, cheap.

DT-swiss
Expensive, but it's the best one I know of.
Fits a tool box easily. If paired with the DT swiss nipple wrench, it's holds the spoke as close possible to the nipple to prevent twisting.
Size specific.

eSporks
Jun 10, 2011



Should have told him to take it to the dump. That guy is just going to waste the shops time and money and then leave a bad yelp review.

eSporks
Jun 10, 2011



ExecuDork posted:

blasting the internals of the shifters with INOX (WD-40's better Australian competitor).
Quick Google shows INOX is a PTFE lubricant, so it should be OK for general bike use, but there are better lubricants.

Friendly reminder to anyone else reading that WD-40 is NOT a lubricant and it has no business being anywhere near your bike.

eSporks
Jun 10, 2011



You could probably get creative with a Greenfield (?those are the big standard kickstands, right) by drilling out the threads on the kickstands and using a bolt with thick washer.

Also. You don't need a kickstand, especially on a kids bike. They are just going to throw it on the ground anyways, and if the kickstand drops when they go off a jump it might make them crash.

eSporks
Jun 10, 2011



I want to add that a proper hybrid tire will give you *more grip* than an a knobby MTB tire when used on pavement.

It seems counter intituitive, but the knobs are designed to hook up in loose soil, and/or to cut through the layer of dust on hard pack.

On pavement, you have neither of those issues, so you just want surface area. A smooth tire has more surface touching the ground than a knobby one.

VVVV whoops, I missed that.

eSporks fucked around with this message at 13:55 on Apr 15, 2021

eSporks
Jun 10, 2011



Some of the teeth are intentionally shaped funky to aid with shifting, so some the wear you see is just that profile.

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eSporks
Jun 10, 2011



Ovoid chainrings come and go as a fad. There has been contradictory evidence as to whether they actually work or not, and personal anecdotes vary.

If you want it, go for it, if you don't, don't let anyone talk you into it.

My personal experience is that they are good for a single speed. Out if the saddles mashing at a low RPM feels smoother. I don't notice it in any other scenario.

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