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Hello thread - I discovered a weird problem with my bike, and I was hoping for some pointers. The bike is an aluminium frame, rear hub motor ebike. When I bought it, it had rim brakes and it became apparent immediately that the bike was too heavy for those - local bike shop suggested installing hydraulic disk brakes, which I agreed to. They're great! Fast forward several months later, and I get my first flat. I discover that the addition of the brake rotor means that the rear wheel doesn't really fit between the rear forks anymore, and getting it off and back on was extremely difficult (and nerve wracking given the aluminium frame). I'd like to be able to change a flat by the side of the road, and I'd need to fix this for that to be feasible. A friend (who's a much better mechanic than I) suggested swapping from my current 1x7 gears to 1x6, and then adjusting the spokes of the wheel to recentre it. This should give me enough room to get the rear wheel in and out without any issues. Here's where I'd like some advice - the current drivetrain is a shimano altus 7 speed. I don't think there is a 6 speed altus shifter, so I'd need to go to a shimano tourney one? I'll also, obviously, need a new set of rear gears, with 6 rather than 7. Is there a way to determine if I've got a cassette or freewheel without removing the wheel? As I mentioned, getting it on and off is a big challenge currently, so I'd like to avoid that if I can. An alternative idea, is can I just remove one of my gears from my current set, or do they need to be evenly spaced to shift properly? Finally - will I need a new derailleur, or will the current 7 speed altus be compatible with the new gears and shifter (as the shifter does the shifting)? Is there somewhere easy to find all this compatibility information? I'm also open to other ideas or warnings if this whole approach is a stupid idea. Splode fucked around with this message at 14:04 on Apr 13, 2024 |
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Apr 13, 2024 13:52
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| # ¿ May 21, 2024 00:02 |
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Excellent thanks for the advice everyone! Sorry, another absolute monster of a post follows: it sounds like I can keep the derailleur, but will need to replace the shifter as expected - to confirm, can I be really dodgy and just remove one of the gears, or do I need a new full set? As its an ebike, my need for gears is odd: when it has battery, it basically lives in the high gear to go as fast as possible, but in the event I run out of battery, it becomes a very heavy bike, and the very lowest gears tend to get used instead - so the middle gears really don't see much use at all. Given the ability to remove a gear of my choice, I'd probably remove the 3rd gear, but if I have to keep a straight sequence, I'd lose 1st gear, as the little high gear is absolutely indispensable, and tbh if I could get an even smaller one, I would (unlikely, its already very small, and I wouldn't want to make the front gear much bigger as its already quite close to the ground). I took some photos: (caption for each photo is under the photo)  This is the bike itself. Specific model is an Independent Torquay from a local company around here (I'm in Australia), but lets face it its likely some branded standard chinese frame with standard off the shelf parts. Annoyingly, and in a way that's making me question my hold on reality, it now appears that this model is sold with disks standard. Fundamentally this issue could have always been present, and the rear forks were just made too close together - I have heard that bike frames can have pretty wide variations from their nominal dimensions.  Rear view, left side of the rear wheel. These spacers were all necessary to ensure that the disk rotor aligns with the caliper. Notably, the caliper cannot move any more to the left: it is already all the way up against its slot holes. Filing those holes out would give me a at best a mm before the rotor was interfering with the frame itself. In theory I could grind that down too but I don't have a grinder and that's all seeming like a very sketchy option I don't really want to try.  A shot of the rear brake caliper, for a bit more context.  Rear view, right side of the rear wheel. There's only the inside, location-locking washer as a spacer here. It is necessary before the gears/chain catch on the frame.  view looking down on left side of rear wheel.  Close up of left side spacers  Straight on view of the right side of the rear wheel View looking down on right side of rear wheel. I am hoping those show everything necessary? So my next steps are to determine what I need to get for the gears - can I bodge my existing set, or do I need to order a whole new set, and if so, is it a cassette or freewheel. As before, all comments are welcomed! -- Answering some specific comments: kimbo305 posted:Yeah, it would be strange but I suppose not inconceivable if the shop decided to shove in a wider hub motor wheel just because it had a rotor mount. But also strange that the frame would come with disc brake mounts but not be sourced with disc brake out of the factory. The shop who did the break upgrade was not the same shop I bought it from (the guy I bought it from extremely gave off the vibe he didn't want to do any bike repair/service work, only sell bikes - in hindsight, a red flag, but I was extremely new to bikes when I bought it). There's almost no way the shop who installed the hydraulic brakes replaced the wheel or motor. This bike appears to be sold with disks standard now, which is annoying. I presume the original intent was for the guy selling the bikes to save some money, but clearly, I wasn't the only one who discovered that the rim brakes were completely inadequate. Hindsight is 2020 and all, but if I had my time again, I'd have gone back to him and asked for disks. He really wasn't nice to deal with however, and the shop I did use for this install have been a lot more approachable and helpful. Unfortunately, it's a just enough mm that it is beyond my personal strength to jam the wheel in without using a push clamp to hold the frame for me while I get it in. Being an e-bike, my current solution is to just have a push clamp in my pannier all the time, but this is a bit poo poo, and I'd really like to be able to just pop the wheels on and off easily, as you would any other bike. I am a little bit concerned about the extra stress on the frame, and I also will be the one servicing the bike going forward, as I've been volunteering at a local bike coop, so I can do it myself with their tools and save a fair amount of cash. Havana Affair posted:You should post some pictures about what's going on. How have they mounted the disc brake to your bike? Is the hub somehow wider than before? You probably have a freewheel on your bike and I don't see how swapping to a 6 speed is gonna help if you don't space the hub differently on the axle and that might not be possible to do because of the motor. I hope these photos help. From what I can tell, I think they just slid the disk rotor onto the axle: this means, while the axle, of course, isn't wider in total, the total amount of poo poo that needs to be between the rear forks has increased: all the original components, + the new rotor. Its also possible that they added spacers to ensure that the rotor lines up with the calipers, unfortunately I didn't take any photos before I had this done, so I don't have a point of comparison. I did know that derailleurs must have the right ratio between how much the cable can move vs how much they move, and that for sizes above 9(?), chains and gear spacing gets narrower and thus derailleurs need to follow suit. As I am going from 7 to 6, and sticking with shimano, it sounds like I'll be fine with my current derailleur, but yes I was unsure, which is why I asked. Thanks for giving the specific details about where it could be an issue. I am also aware that all manufacturers have use different ratios, so you can't mix and match brands - that was another reason I wanted to check, as I wasn't 100% sure if shimano maintained the same ratio between families, but it sounds like they do, and the tourney shifter will be ok with the altus derailleur. Thankyou Shimano for not doing something dumb. Splode fucked around with this message at 01:00 on Apr 14, 2024 |
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Apr 14, 2024 00:49
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PolishPandaBear posted:Are you sure the upgrade wasn't from mechanical disk to hydraulic disk? It does look like Independent has some product photos on their website with mechanical disks. It's entirely possible - I can find no mention of rim brakes anywhere online either. And I don't think there's a hole in the frame to mount the rim brake caliper. I knew almost nothing about bikes when I bought it and had this upgrade done. I'm beginning to seriously doubt my memory. This changes the story - the bike had this issue from birth and the local shop did nothing wrong. However, it doesn't change the problem, or the solution, does it? If I knew then what I know now, I likely would've bought a different bike entirely (I do not really need the folding frame after all), but this one is serving me well, so I'd like to get it perfect.
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Apr 14, 2024 05:04
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Havana Affair posted:Ok, I'm guessing they added the extra spacers so the disk will clear the frame. So you would remove spacers from the other side to return the width to what it was but you have to first get the freewheel off to see if there's anything to remove. There might not be any. Getting a freewheel with less gears might help if the current one doesn't clear the frame after moving the spacers but might not be needed. You can't remove any gears from the one you have. Then you also would have to redish the wheel and working on that wheel is gonna be awful - though with the extra spacers it's already off center so it might be good enough. Yeah, there's no spacers left to remove on the gear side. Good to know that I do indeed have to buy a new set of gears - I'd assumed as much. Redishing the wheel will be necessary but I'm ok with that. Why do you think this wheel will be awful to work on? I trued my first (very normal) wheel recently so I'm not familiar with what makes some wheels easy and others hard. I really appreciate warnings like this. I think you're all correct, and they just swapped from one kind of disk brake to another. My current theory is that the bike had this issue new. I never removed the wheels until I got this flat, long after I'd bought it and the brake had been modified, so it absolutely could've always been like this and the bike shop just didn't bother telling me about it. In fact they may have told me and I just didn't care, and then forgot, as at the time I wasn't confident in my ability to do a roadside flat repair on any bike, let alone this one, and figured if I got a flat, I'd fold it up and call a cab, or walk it home. Thanks again everyone for providing so much expertise and advice. Splode fucked around with this message at 05:15 on Apr 14, 2024 |
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Apr 14, 2024 05:11
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Havana Affair posted:There might be spacers under the freewheel on the axle but you have to remove the freewheel first to see them. If you aren't touching those a new freewheel won't change anything. surely a freewheel with 6 gears would reduce the stack up of stuff between the rear forks by the thickness of one gear? Noted about high spoke tension and thick spokes. This is all partially an exercise to help me learn more about bikes generally. There is a strong case for me to just live with it. I did go ~1200km without a flat, and when I did get a flat, it was a slow puncture (I made it home and discovered the flat the next morning), and on the inside of the tube: a spoke had done it, I believe when I didn't avoid a big pothole in time while I was pulling a trailer of cargo. The tires were fine, and are puncture resistant. I still very much have the option to do nothing at all, or to find and install some tougher rim tape. I would like the peace of mind of knowing I can do a roadside flat repair should I ever need to, but also this whole adventure has helped me to learn a lot about different drive train compatibility issues, and is motivating me to learn a lot more about wheel design, maintenance, and modifications. Also next time I buy a bike I am going to make them take the rear wheel off in front of me to prove it hasn't been jammed in with a hydraulic press.
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Apr 14, 2024 05:53
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Havana Affair posted:The freewheel sits on the hub, not between the hub and the frame. If you were to remove the freewheel altogether the hub still wouldn't fit to the frame any better than right now. Oh I see, if I went to 6 gears, the extra space would be between the last gear and the spokes, and the total width would be the same. Bugger.
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Apr 14, 2024 06:11
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Wow thanks that really helps. I think I'm going to have to give up and live with it. I could try and pick a fight with the company that sold me the bike, but given I already messed with the brake system, I doubt I'd get very far. I believe that aluminium frames are heat treated, so modifying the frame to widen the distance between the forks is not feasible. It appears that messing with the gear side of the wheel is also not really feasible. Replacing the rear wheel entirely is not worth it - I'd just get a new bike and sell this one instead. It does seem like loving with the brake side is a somewhat feasible. So the best I could do would be to file the brake mount position, allowing me to remove some of the spacers on that side. Next weekend I might brave removing the wheel and having another look at exactly how much material I could safely remove from the brake mount, and if that's going to be enough to take it from "drat near impossible, and also, is this frame about to crack" to "annoying but doable with enough swearing". I'm not entirely sure how many mm I actually need, so something else I'll probably do is actually try and measure everything. I agree: it's far more likely that the axle width is some standard (135mm or otherwise) and the frame ends up being out of spec. If its super obvious, I might have a case to go back to the manufacturer and go "hey man what the hell" Thanks again, everyone in this thread who's helped me. You've given me some really great advice, and you've now saved me from going down a difficult and ultimately doomed path. I'll be sure to update the thread if I make any progress or discoveries because I am sure at least a few of you are morbidly curious now. edit:  Using an image I uploaded earlier, I've taken the width of that larger spacer (green box) and moved it to the brake mount. obviously there's some perspective stuff I am ignoring here, its not exact: but for this to work I might have to remove quite a lot of material: not just slot out the brake caliper bolt holes more (that's fine) but also grind off a few mm of the mounts themselves. That seems... risky. I think my plan is going to be to take out the rear wheel, measure the distance between the forks, take a photo of the measurement and then call up the original manufacturer and make them find a solution. Because if the frame is out of spec then its there problem. Splode fucked around with this message at 07:33 on Apr 14, 2024 |
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Apr 14, 2024 07:19
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jammyozzy posted:I'm jumping in late but, are you able to remove that rack and see if it makes the rear wheel any easier to fit? Not late, I haven't fixed poo poo yet. This is a great idea and I'll give it a try!
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Apr 15, 2024 22:06
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HamburgerTownUSA posted:Really depends on what you plan on doing with it. Personally, if I were to have a bike that I would take around to do stuff where I would even have to lock it up and let it leave my sight, I would just get a beater bike and make sure to lock it up next to a bike that's locked worse, and still operate under the assumption that someone is going to try to steal it or parts off of it at some point. Turns out my rear fork issue is actually a clever anti theft feature
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Apr 16, 2024 13:57
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KKKLIP ART posted:Is there a definitive bike maintenance guide? I know Park Tools has a ton of good youtube content but I'd like something that I can read as well. Park tools has the big blue book of bicycle repair. They also have a bunch of tool kits depending on how deep you want to go into bike mechanic world
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Apr 21, 2024 22:04
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Kazzah posted:I hosed up my ankle and need to stop running, at least for a while. Was doing like 8km per day, before. Anyway, what's a reasonable amount of money to spend on a bike, if I'm mostly sticking to roads and paths? My town is fairly flat and has some nice lakes to cycle around, also a good number of hill tracks. I also live a few k's from work, and would be up for some commuter cycling. There's a bit of a gulf between the disassembled bikes they sell for like $150 (Australian) at the department stores and the ones that go for $800 in the specialty shops. I can afford one of the expensive ones, I just don't want to waste money on something wildly out of my requirements. It sounds like what you you're looking for is a very normal bike. You should be able to get something worth owning for under $500 AUD in my opinion. There are some great bargains to be had getting something second hand, but that can be a bit of a gamble - worth the gamble at a bike shop, or bike coop, but not worth trying your luck on facebook marketplace or gumtree.
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Apr 26, 2024 09:00
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verbal enema posted:I told the bike shop guy I don't know poo poo about gently caress and he was like ok well you don't need a 1400 dollar bike here is a model on sale that does what you want. Gets you to work and back easy to ride fits you and won't disintegrate under you while you ride so I picked up a roll A:1 Adventure Looks like a good bike!
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May 11, 2024 03:50
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