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bicievino posted:A shimano BB-UN300 is like... $15 and will last forever. This was true with the un55 but the un300 is poo poo. I've seen some get completely destroyed in a year of riding. Granted it's still very cheap and I don't know if there's anything much better available that don't cost ten times as much.
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Jun 9, 2023 05:11
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Havana Affair posted:This was true with the un55 but the un300 is poo poo. I've seen some get completely destroyed in a year of riding. Granted it's still very cheap and I don't know if there's anything much better available that don't cost ten times as much. Well dang. That's a bummer. I'd still go that route over anything but a *very nice* loose ball bb. Bad ones of those are real bad.
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Jun 9, 2023 05:47
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bicievino posted:I just put square taper cranks with cup and loose bearings on my race bike. I had that too! 
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Jun 9, 2023 06:19
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I think the bugs are worn out in my bottom bracket any idea where I can get replacements?  
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Jun 14, 2023 02:10
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Mauser posted:I think the bugs are worn out in my bottom bracket any idea where I can get replacements? Nope. NBD.
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Jun 14, 2023 07:20
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Sometimes if you just give the bugs a good cleaning and some fresh grease you can reuse them as long as they've still got most of their legs
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Jun 14, 2023 09:26
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"Bike shop seeks mechanic. Must have entomology degree."
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Jun 14, 2023 13:12
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Bicycle Maintenance and repair megathread:Dog Case posted:if you give the bugs a good cleaning and fresh grease you can reuse them
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Jun 14, 2023 13:46
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so I discarded the bugs because they looked to be in pretty bad shape. This is from a '70s French bike and the BB did have reverse threads on one side, so it's not a French BB. I'll see if I can count the threads a little later to check what standard it's using. Someone mentioned that you could keep the other parts, and replace the cottered crank spindle with one that is square taper. Is there a sizing consideration beyond the overall width? Diameter, for instance?
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Jun 14, 2023 14:13
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Mauser posted:so I discarded the bugs because they looked to be in pretty bad shape. Yeah. First off there's something like three different square taper profiles, JIS for a lot of the Japanese ones and ISO for a bunch of the Euro ones, and the other thing you have to worry about is maintaining the right chainline distances. Sheldon Brown has some articles on it https://www.sheldonbrown.com/bbtaper.html https://www.sheldonbrown.com/chainline.html
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Jun 14, 2023 14:30
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Mauser posted:so I discarded the bugs because they looked to be in pretty bad shape. The cups aren't universal, either - they need to match to the spindle. I don't think you'll do yourself any favors trying to re-use half a BB. Since you're replacing the cranks and bb together, you just need to get the right bb for the new cranks.
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Jun 14, 2023 14:51
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Mederlock posted:Yeah. First off there's something like three different square taper profiles, JIS for a lot of the Japanese ones and ISO for a bunch of the Euro ones, and the other thing you have to worry about is maintaining the right chainline distances. Sheldon Brown has some articles on it I've got a replacement set of square taper cranks from the parts bin which are euro manufactured, so likely ISO, but I'll bring them back to the coop with me to see if I can find a replacement spindle. I watched a video on getting the chain line correct going from cottered to square taper, so I'll read through the link and have another look at spindle now that I can measure the thing more accurately outside the bike.
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Jun 14, 2023 14:52
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Mauser posted:I've got a replacement set of square taper cranks from the parts bin which are euro manufactured, so likely ISO, Assuming things like this will get you only frustration with bike parts
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Jun 14, 2023 15:29
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A digital caliper is well worth it once you get this far in the weeds with parts and standards.
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Jun 14, 2023 17:33
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kimbo305 posted:A digital caliper is well worth it once you get this far in the weeds with parts and standards. The local coop here has a nice mitutoyo caliper and oh my god I've never used anything so perfect before
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Jun 14, 2023 18:13
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I'm trying to use the original BB and grabbed a new spindle that looked about right for the square taper chainring and forgot to hold this last one up against the original spindle to see if the ridges that fit against the bearings were in the same space and they're not. The others all were and I just forgot to check the last one.Now I gotta wait until the coop is open on Sunday to grab a replacement and try again  Not sure if they actually have one that's the right length though because I think I need one that's 115/118mm
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Jun 16, 2023 02:06
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Mauser posted:I'm trying to use the original BB and grabbed a new spindle that looked about right for the square taper chainring and forgot to hold this last one up against the original spindle to see if the ridges that fit against the bearings were in the same space and they're not. The others all were and I just forgot to check the last one.Now I gotta wait until the coop is open on Sunday to grab a replacement and try again Yeah it's a crapshoot. I went through a few dozen spindles in the bins last night before I found one at 115mm that gave me a serviceable chainline, and even that one would've been better at 113. The only one that was 113 was too short between the bearing races. The original cottered crank was actually even further than the new one I found so it's still an improvement. My bike overhaul is going great.. other than the 3 small chips I put in the new paint because I banged it up against some metal while the paint was still curing
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Jun 16, 2023 15:06
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Friend reported his single speed was making a horrible clicking noise when pedaling and had snapped a link in the chain. Upon inspection the entire (cartridge) bottom bracket had migrated about an inch to the right - drive side unscrewing, NDS disappearing into the BB shell. Never seen that happen before. Then, with the bottom bracket correctly seated and a new chain, there was still clicking while pedaling under load. Turned out that when the old chain broke due to the hosed up chainline, it slightly bent one tooth of the freewheel! What a mess.
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Jun 16, 2023 17:31
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Last year I got an old 80's Peugeot Carbolite road bike to just putz around on and see how I enjoyed cycling. Well, it turns out that I really liked it, but this thing is in need to some repairs to get to a point where I feel comfortable taking it more than 5-6 miles from home. A few things that I want to tackle are replacing the whole brake system. It currently has suicide levers that I want gone, and it has single-pivot brakes that barely stop the bike. I've been looking at brakes online, and I have no idea if the new levers, cables, and calipers I'm seeing will fit. Is there any way to check on this before I buy? I also read that you can get dual pivot brakes that have a single mounting bolt that works much better than the single pivot brakes that I have now, any recommendations? I also saw that I'm missing a tooth on my read derailleur. I searched the number that is on the item and see a lot of Chinese replicas but also a lot of Shimano or other name-brand derailleurs. Can I use one of the better quality or am I stuck trying to replace this one for one with a knockoff?    
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Jun 17, 2023 20:36
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How attached are you to that specific bike, and how much would to be willing to spend before you thought it wasn’t worth it?
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Jun 17, 2023 22:26
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Follow up question, do you have a co-op with tons of used parts bins that you can fish around in for replacement parts that cost 1-6 dollars?
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Jun 17, 2023 22:48
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Mauser posted:Follow up question, do you have a co-op with tons of used parts bins that you can fish around in for replacement parts that cost 1-6 dollars? This is the Way
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Jun 18, 2023 01:15
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No coop that I'm aware of and not too attached. I picked it up for $100 and I wouldn't want to put more than 60 or 70 into it.
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Jun 18, 2023 01:31
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Aero737 posted:No coop that I'm aware of and not too attached. I picked it up for $100 and I wouldn't want to put more than 60 or 70 into it. I'd be surprised if you could even do the brake changes you want for under 100. I don't think the derailleur jockey wheel missing tooth really matters. Throw a new set of brake pads on it and see if it stops to your liking. Clean the braking surface too. Kool-stop salmon pads are well regarded I believe.
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Jun 18, 2023 03:47
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You can maybe get some generic jockey wheels for the derailleur, just match the number of the teeth. The bolt might be some weird size though but that's hard to say before. For the brakes the important thing is to have the correct reach for the calipers - that's the distance between the bolt and the brake surface. They should be non-recessed nut type too. All drop bar levers should fit your handlebars. Just the parts can be 150 dollars new though.
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Jun 18, 2023 05:45
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So, I found a pretty decent Sugino 2x square taper crank, all aluminum or some kind of alloy, at the local bike co-op, but there's a problem. It's got a 52T/42T pair of chainrings, and I'd definitely like to adjust the gearing down to 48/38 or something of that nature. I did find a pair of chainrings with the proper BCD and sufficient life in them, a pair of weird Sugino Cycloid oblong rings that should be a better gearing choice. I can't for the life of me get these drat original chainrings off. It's got the crappy rear nut that has like 1mm of metal to engage against the tool, which obviously sheared right off into a ramp when I tried removing it with one of the proper chainring wrench's and a large Allen key. Have used penetrating oil and love taps from a hammer, but I can't get these last two bolts off. Any tips on getting these out? Or am I best off just drilling the whole thing out and getting replacement nuts, properly anti-seized up for the future? E: Got them out, included some sideways drilling into the edge of the chainring nut, and then tapping out with a punch around the perimeter while the bolt was anchored by an Allen key on a vise. The other two stuck ones I was able to get out with this method https://www.youtube.com/watch?v=E6SCwijgdyQ Mederlock fucked around with this message at 23:53 on Jun 18, 2023 |
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Jun 18, 2023 07:29
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Building my final set of wheels using some vintage record hubs and lightweight tubular rims and was trying to figure out if there's any reason to go 2x vs 3x for the front wheel. It seems like 3x is standard lacing pattern for 36 hole hubs, so I was just going to go with that because calculating the difference in weight between shorter and longer spokes didn't seem to have any meaningful difference and what I've read online says the more crosses is better
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Jun 23, 2023 21:32
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Mauser posted:Building my final set of wheels using some vintage record hubs and lightweight tubular rims and was trying to figure out if there's any reason to go 2x vs 3x for the front wheel. It seems like 3x is standard lacing pattern for 36 hole hubs, so I was just going to go with that because calculating the difference in weight between shorter and longer spokes didn't seem to have any meaningful difference and what I've read online says the more crosses is better It's not more crosses equals better but rather you want the spokes to be as close to tangent to the flange as possible without going to a negative angle for the strongest wheel. For a 36-hole hub on a 700C wheel that's basically always 3-cross. A hub like the Rohloff with huge flanges requires 2-cross, as might a 28-spoke hub, depending. E: some good reading here from noted Bike rear end in a top hat Jobst, and the guy's dead so feel free to find it on  https://en.m.wikipedia.org/wiki/The_Bicycle_Wheel
SimonSays fucked around with this message at 21:41 on Jun 23, 2023 |
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Jun 23, 2023 21:36
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Thanks. That's what I meant, i just didn't have the right vocabulary to repeat back what I've been reading. The more crosses you can do according to spoke count the stronger it'll be without too great of an angle. I was looking for that book at my local bookshop and they didn't have it on backorder so I'll consider alternative means of getting it. Once it stops raining and I have a chance to get out somewhere fun I'll post a pic of my completed wheels. I didn't like the look of the rims because they clashed with the vintage look of the bike, so I leaned into it and found some supremely discounted ugly looking gravel tires to throw on there and now it's pretty fun. These eventual tubular rims will be fit with the '80s aesthetic for road riding
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Jun 23, 2023 22:32
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Follow up to my crank issues: I took the bike to a shop where the dude confirmed the other shop had greased everything up and also hadn't tightened the bolt on the other side much. He cleaned everything up a bit and tightened the bolts with a real wrench and my crank arms are no longer backing themselves off. Hooray!
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Jun 24, 2023 03:27
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The Musson e-book is worth  
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Jun 24, 2023 04:54
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How normal is it for disc brakes to be totally silent and perfect for 5 miles, then rub once per rotation for 5 miles, and then go back to being silent? Its just a very light brushing that makes a noise, but I would LOVE to get rid of the noise. I think the minivelo just flexes because I can lean forward over the bars and get rid of the noise every time. The extreme length of the seat post plus the very large rotors I think are amplifying the effect of the flex. It seems like the brake caliper has way less room between the rotor and pads than on my mechanical discs. I can get a single piece of paper in-between them on both sides, so I've got probably a quarter millimeter total wiggle room. I almost think once the pads wear down its going to go away. Still curious if anything could help. I made it better by closing the quick-release while holding the brake AND sitting on the seat post, which adds to my flex theory.
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Jun 25, 2023 21:31
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sweat poteto posted:The Musson e-book is worth
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Jun 25, 2023 21:41
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What would cause this? I assume this is the culprit on these lovely loud brakes: 
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Jun 26, 2023 23:21
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Possibly a burr on one of the cutouts on that side of the rotor. Feel for it and sand it down with a small file. Possibly also the pad springs are a hair weak and the pad is kinda resonating and jittering along against the rotor. Spread em out a hair to see if they keep the pad away from the caliper better. Seen that before as well. EvilJoven fucked around with this message at 04:50 on Jun 27, 2023 |
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Jun 27, 2023 04:46
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EvilJoven posted:Possibly a burr on one of the cutouts on that side of the rotor. Feel for it and sand it down with a small file. But a burr on the rotor would gouge the pad along a constant radius, not some kind of expanding, repeating pattern.
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Jun 27, 2023 05:51
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Is the pad hitting the disc at the correct height?
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Jun 27, 2023 06:49
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I've never seen anything like that, maybe some weird harmonic frequency is happening from the way the rotor is spaced in the caliper? I have no idea.
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Jun 27, 2023 06:58
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Could you swap the pads side to side to see if the hatching starts forming the other way?
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Jun 27, 2023 12:05
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TobinHatesYou posted:But a burr on the rotor would gouge the pad along a constant radius, not some kind of expanding, repeating pattern. Not if it was at just the right point to snag and cause the pad to basically bounce along the rotor, it could very possibly be that, and only triggered when the frame flexes a certain way. It's worth spending the few minutes and no cost to check. SRAM brakes are such a pain in the rear end. Much smaller clearance to work with. DOT, and then there's the chronically failing level and guide levers I'm not sure they ever actually fixed.
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Jun 27, 2023 13:12
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