18

The way you asked the question, it sounds like you think the following is happening: first, the derailleur hanger wears out/weakens, then it snaps, and this causes the derailleur to go into the spokes. It is much more likely that the chain of events is the following: the derailleur is mis-adjusted, when you shift to the largest cog on the rear, the ...


18

If you carry a multi-tool which happens to include a chain tool, you could also convert your bike to a single speed. If you do so, you would have to replace the chain afterwards as well (since you shorten it) but in some situations it could get you out of a rural area. If you do so, carefully select the gear you would put it in, as you won't be able to ...


16

You can see in the video how the teeth on the cassette rotate quickly at the moment it slips(at :05 seconds), while the spokes of the wheel actually stay slow, then jolt forwards to catch up. This means that the freewheel mechanism in the rear hub is failing to engage. It's actually quite dangerous because as it gets worse it could cause you to lose ...


13

If the teeth on the jockey wheels appear to be in good shape then you probably have nothing to worry about. Many jockey wheels use bushings instead of bearings, and either way they are not going to spin for very long just because there's not much weight to them and therefore they don't carry much inertia. If there is noticeable resistance when you try to ...


13

If you want to change your cassette to something with more gears, then you will need to replace the rear shifter and possibly the rear derailleur. A cheaper option would be to get a wider range cassette which still has 8 gears. You'll have bigger jumps between the gears, but you'll have a bigger range of gears. With a wider range cassette, you may need a ...


13

Another suggestion: Scooter it. The bike is functional but the drive train cannot transmit power. So one solution is to scooter along with one foot on the opposite pedal, and your other foot pushing directly on the ground. This can be uncomfortable, so rotating your saddle ~30 degrees to the opposite side from where you're standing can give your hip ...


12

The derailleur needs to guide the chain into the sprocket - which means it goes on the bottom. The tension pulley needs to go on the slack side of the chain - which again means it goes on the bottom (the top side of the chain loop has the drive tension). If the drive train was reversed, you could do it. Put the drive wheel in front and steer with your butt ...


12

Simple answer would be that it's heavier, which is very important in road-bikes. Regarding the cable friction and smoother shifting, road shifters are going towards electronics


12

Derailleurs will last almost indefinitely. The jockey wheels will wear out in time (tens of thousands of km) but the rest of the mechanism shouldn't see significant wear.


12

The pawls in your freehub are most likely getting stuck, causing them not to lock and transfer the force from the cassette to the wheel. In your case as the bike is new it is probably due to it being assembled with grease rather than a lighter oil, but the problem can also come with ageing. You will need to rebuild the freehub. This is not the easiest ...


12

It doesn't matter how it's set when you first begin the installation. If it were out so far that it prevented the guide pulley from clearing the large cog at all, that would be a problem, but you'll see that pretty quickly. The ideal time to set it is after the wheel, derailer, and chain are all in place, after the limit screws have been set, and after the ...


12

TL;DNR A Shimano 'Shadow Plus' or SRAM Type 2 dérailleur (aka clutch dérailleur) means you can change the chain tension by flicking a lever. For completeness - back in the late 2000's, Shimano introduced the 'Shadow' dérailleur (refer OP's link) which brings the deraileur in behind the cassette, providing it more protection from knocks and damage. A ...


12

I've got a 2nd hand Hercules too and I've done this exact thing. Get a quality chain tool and look up some videos on Youtube about how to remove and re-link a bike chain. I pretty much winged it as I had no clue what I was doing. It took a bit of work and a lot of frustration to get the chain length right. I probably did it wrong, but it works. EDIT: ...


12

The derailleur wheels are small and light weight, so have very small moment of angular inertia. The bearings they run on need to withstand a significant force due to the action of the chain, not just the weight of the wheel. So the bearings are fairly robust and lubricated. As a result there is a little "greasy sliding resistance friction" (for want of a ...


11

The picture is a RD-M780-SGS long cage. Shimano have three codes for rear derailleur length: Short - SS Medium - GS Long - SGS I'm not aware of where this is printed on the RD though so not so helpful. However Shimano only have one non-clutched XT Dyna-Sys (10 speed) RD the RD-M780-SGS (long cage 43t capacity). The clutched (shadow+) RDs come in GS (...


11

Gasoline aka petrol, is a volatile fluid that will dissolve grease and oils. It will penetrate, soften, and loosen impacted and congealed dirt and dust. Petrol / Gasoline will NOT fix your rust, nor remove your rust. It will not restore chrome. Petrol is not terrible for rubber parts, but I wouldn't leave them soaking in the fluid. The best use for ...


11

You need to tighten the cable. Also, check that you're not missing a limiter screw, because that looks plain dodgy. Once the limiters are set up, follow these steps: 1)Set the gear shifter in the highest number (6/7/8 whatever your maximum is). 2)Undo the bolt pinching the cable, the bolt with the spanner on it. This will allow the cable to move freely (if ...


10

From your photo, the left pulley (beefier, with metal bushing) is the top one, which goes closer to the cassette. I know that because that's how things were in every shimano derailer I had over the years, and I think that makes pretty much sense, since the beefier pulley (the upper one) actually shifts the gears, while the bottom, thinner one is only an ...


10

It's much better to open the chain. Derailleurs are not really designed to be opened repeatedly, and doing so inexpertly can potentially ruin the derailleur. Chains might have either a lock link or a master link of some kind, find that open the chain and then thread the chain through the derailleur. If the chain does not have one of these links, you will ...


10

This would never work due to fact that no force would be transmitted to the rear wheel until the derailleur cage was at maximum extension. The derailleur has to be below the chainstay to allow it to take up the slack in the chain. I suppose you could split the derailleur into to parts, one to keep the chain tension and the other to change gears, but that ...


10

That is a Direct Mount derailleur. The hanger there is a separate part that is part of the frame. When companies call them Hanger Mount or hanger style, the hanger is built into the derailleur and not removable. To replace it, order the Direct Mount one.


10

Confirming @Swifty's diagnosis. It's the freewheel mechanism. Take it back to where you purchased it and demand full refund or at least a complete new rear wheel. Don't let them try to repair the freewheel or the hub. Accept replacement only. The store has already demonstrated incompetence and a disregard for customer satisfaction by being unable or ...


10

The inner plate seems to be on upside down. Not sure why but if it's second hand, maybe someone dismantled it to clean it the put it back the wrong way round. If you need to swap it around you just need to undo the screws holding the jockey wheels in and flip it, then reinstall them. Its a bit tricky with the chain tension, but if you can do it without ...


10

If the low limiter screw on the rear derailleur was very badly adjusted, it would be possible to move the derailleur far too far past the end of the cassette by shifting into the lowest gear (i.e. shifting onto the largest cog on the cassette). This would move the chain off the top of the biggest cog and could force the derailleur into the spokes which, in ...


9

There are several suppliers of universal derailleur hangers. The intended use is to mount a modern derailleur to vintage bikes. At one time the derailleur hanger was part of the derailleur and mounted under the axle nut. Cambria Bike.com Harris Cyclery both have several models that start at $1.00. You could also try to find one of the older derailleurs like ...


9

Yes, all 9-speed Shimano rear derailers share the same actuation ratio as all Shimano 7-speed ones, except for pre-7700 Dura Ace. I've never seen a 7-speed chain rub inside a 9-speed RD cage. If somehow that were an issue, an 8-speed chain would work fine.


9

Rode downtube friction shifters bikes for a while. I can see two possible causes : either the shifter was too lubricated, or the screw isn't tightened enough. Try to tighten it more, but pay attention not to tear the screw. Usually the lever is pretty rigid when moving. If it's easy to move it to the point it moves alone, it's probably because it wasn't ...


9

There are two aspects to the derailer that come into play here. One is total capacity, which is the total amount of variance in chain slack the derailer can accommodate while keeping the chain taut. Single ring setups such as yours with any kind of "traditional" range cassette (say 12-32 as opposed to whats on some modern 1x bikes, like 10-50) come nowhere ...


9

https://bike.shimano.com/en-EU/product/component/alivio-m4000/RD-M4000.html says that derailleur will handle Low sprocket_Max. 36T Low sprocket_Min. 32T ANSWER: You cannot run a 50 tooth cog with that derailleur. You might be able to use a hanger extension, but that will make the small gears even worse. Wolf's Roadlink allows up to 40 tooth, and ...


9

If your bike has slotted dropouts and a rear wheel secured with axle nuts (which Poster's answer implies you have) you can do a single speed conversion without the need for a chain tensioner device. The derailleur can be removed, chain shortened and tensioned properly by adjusting the position of the rear wheel. The chain should be able to move 0.5 inch up ...


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