mack_turtle

Four years later.

I'm experimenting with flat bar gravel again. Anyone have a flat 31.8mm clamp bar in the 680-700mm range? I checked Yellow Bike and they have a handful of really nice wide bars that I would not feel good about chopping down, and the rest are itty bitty bars that have already been chopped down to useless width by hipsters (says the guy trying to convert a drop-bar bike to a flat bar!).

Look what I found at Yellow Bike!

I have no idea who did this, but it appears to be a 170–150 mm conversion. I found what I believe to be the appropriate Octalink v2 BB. Can't wait to try it!

17 hours ago, RedRider3141 said:

...but then I came across this over the weekend, I didn't realize the depth of proprietary parts that are being created for e-Bikes. Hopefully as the technology matures you'll see no more than a few different standards come up for charges, motors, batteries, etc. 

this is the kind of thing that makes me want to go full old man shaking fist at cloud rant. all these companies know exactly what they are doing, and they don't care. they will trot out a yearly sustainability report full of greenwashed nonsense. most of those batteries will end up in a landfill. a few of them will get tossed in municipal recycling bins, where they will start fires that injure workers and damage facilities (yes, this happens all time). I'd be curious to know how many of them are properly recycled. recycling is one of the least impactful ways to reduce waste, but for things like this, the damage has already been done and it's the best way.

this is especially disappointing considering they were awarded 1/4 of a million bucks for the development of Revved carbon. https://companyweek.sustainment.tech/article/guerrilla-gravity, assuming I read that correctly.

Anyone have an idea as to how we can educate people who do this shit?

https://youtu.be/Lu-CvZQGsyo?si=L91wWrEfJMitt2bb

I had hella fun last year, but I have other plans. Sorry if the photo of me above made everyone expect to see me there.

9 hours ago, AntonioGG said:

Are the spindle and new hole location on the same plane or do the cranks flare out.

That's a great question! I'll take a flat edge to the arm and see how much flat, parallel space I have. Trying to make a pedal thread in to a crank arm that curves in would be horrible.

13 hours ago, AntonioGG said:

Seems like 9/16" regular and reverse thread tap set are a normal bike shop thing, the best thing may be to drill the holes and take them to a bike shop for threading.  Old BSS was reasonable for machining type work (facing, reaming, chasing).

I have access to the taps at Yellow Bike. The question is, how do I drill the holes straight? I would need access to a drill press and some sort of rig to hold the spindle parallel to the axis of the pedal. Freehanding it would certainly lead to the cranks ending up in the trash.

Does anyone around here have the tools or feel confident drilling and tapping a cranks to make them shorter? Trying to make some old 170mm SRAM cranks more like 155 or a short rider. Yes, I can start calling machine shops, but I want to see if anyone here has a specific recommendation of where to get it done. The cranks are cheap and old, so I'll just replace them if it's cost-prohibitive.

On that note, why in the hell have so many bicycle companies held out for so long from making proportional cranks? A grown woman who is 5' 1/2" should not be turning over 170mm cranks on her gravel bike.

50 gear inches. That should be fine if you're on the strong side, but I shoot for something a little lower. 32/19? One tooth makes more of a difference than you might expect.

What frame is that? What's the longest and shortest possible chainstay adjustment on it? Salsa Timberjack has a 420-437 range. I like to balance my desire for a rear-length bias with the gear combo. 34/21 and 32/19 would be the shortest chainstay settings possible, close to "slammed," but that's really short. 32/20 would push the acle rearward about 10mm, which I find is very noticeable.

Stand and mash!

What front/rear combo, and tire size, are you riding? It's likely that the combo that works best in the long run is lower than you expect. Most mortals @ 32/20 with 29" tires. The ratio might be slightly different if you're riding 27.5" tires. Because math—gear inches. Some of the ridiculously strong riders I know use a lower gear than that.

If the bike is dropping chains, I'd consider getting a different ring, or maybe the cog. Beefy cogs help a lot when flimsy ones might allow enough flex to drop the chain under torque. Hardtails flex under load, so if the loose spot on your chain becomes looser, it could drop it.

Quick link: there must be some that fit this chain perfectly. You might need to measure the width of an inner link to see how many "speeds" is the appropriate one. Most likely, 8-speed links will do it, if not a "narrow" master link.

edit: found one!

Looking for a SRAM 9-speed rear derailer, medium or long cage would work. Before I dive into the bins at Yellow bike, does anyone have one lying around?

2 hours ago, AustinBike said:

One of the things you'll find about a singlespeed is that if you have sliding dropouts, the dropouts will move over time and you will need to crank them back occasionally. I keep an eye on my chain tension and when it can move up or down more than ~1/2" I tighten it up a little more.

I need to move the EBB on my gravel bike or the sliders on my mtb, and I always wonder if it's the chain wearing out, or the adjustment slipping. Those Paragon sliders are beefy!

tension: tight enough that it does not drop the chain is all that really matters. I like to get it just tight enough that I can't feel the chain bouncing around annoyingly. anything tighter than that will cause additional wear on your whole system that doesn't occur with a derailer.

I've always found AB rings to have pretty consistent tension all the way around the ring. The owner posted a video some time back claiming that there's no reason you can't use singlespeed with their oval rings. It's really annoying that he used a bike with a bolt-on tensioner to demonstrate, though.

if you have an oval ring that has significant tight/loose spots, there's something wrong with the way it was made IMO. no chainring is perfectly round, even so-called round ones. oval chainrings should be ... is cocentric the right word?. they all have tight spots. find the tight spot and make the chain the tightest at that point, but not excessively tight.

long-time singlespeeder here to help!

put as many spacers on your hub as you need to take out the slack when you crank down that lock ring. I've never measured, but I measure the chainline on the chainring and space the rear cog so it's within 2mm of the front. (1/2 of your seat tube diameter + distance from side of seat tube = your chainline. 1/2 of your axle OLD – chainline = distance your cog teeth should be from the end of the axle. adjust the orientation of the spacers accordingly.) 

I've used oval and round rings with a singlespeed setup using some sort of sliding dropouts, track ends, and EBBs. all of those work fine because and oval ring that's made right does not experience any more chain tension change than a decent round ring to drop a chain. with a springy chain tensioner, though, that might work differently—I have not tried it with an external tensioner.

I had this Rotor crankset and oval ring on my bike recently, and the Rotor ovality is very aggressive. no problems. if your oval ring changes tension enough to drop the chain, I'd consider replacing it with one that's not defective.

I don't bother with oval rings any more. I just don't feel the difference.  

Almost all of the mountain shoes are now gone. That made a lot of space for storing other stuff. We still have a lot of road shoes though so if anyone needs those let me know.

They said it could not happen here, but this video has millions of views. The e-bike zealots have declared holy war and they are armed, ready to make you swear allegiance to lithium-ion batteries with their machetes! Hug your children, kiss you spouse, grease your hub pawls—lest they hear you—and hope that they reach the end of their assisted range before they catch you.

https://www.bikemag.com/news/machete-fork-fitment

Too many breweries! I'm not beer-sensitive enough to tell the difference among juicy IPAs and saisons, so if I'm going to visit a taproom, I go for ambiance and food. Currently, I enjoy:

Beerburg out on Fitzhugh great for a post-ride meal and drinks after riding Pedernales, Reimers, etc.

Fast Friends on the south side next to I-35. Giant pizzas and a huge space for gatherings. It's also close to the far-east segments of SATN, so it could become a hub for rides there.

Koko's Bavarian on the east side. They have been "Temporarily closed" for quite a while, which has me concerned. I hope they reopen. Central Machine Works is right next door and also a great spot.

I've been wrenching on bikes since I was 12 and just now learned how to ACTUALLY use Vernier calipers.

https://youtu.be/vkPlzmalvN4?si=7bVuu4sb9hg39pdn

Yay, rain! Go ride some bike paths. It's wet but warm.

I admit, those Yamaha bikes look like a blast. Two wheel drive? Yes.

Behold! the form of your destroyer!

https://global.yamaha-motor.com/showroom/event/japan-mobilityshow-2023/ypj/

Where can I refill water in between routes? I am pedaling from home and I guzzle a TON of water when I ride—more than I can carry from the start.

the group of people who ride EB and the people who ride SATN Social is most likely a Venn diagram with very little overlap.