Questions tagged [derailleur]
Mechanism to move the chain from one sprocket to another.
765 questions
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What are the pros and cons of internal gears?
I've had my hybrid 24-speed for a bit over 3 years now, and just last weekend, when looking for a bike for my wife, discovered internal gears. Suffice to say it blew my mind when I saw 7-speed ...
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What's the efficiency of hub gears compared to derailleurs?
What's the efficiency of hub gears compared to derailleurs? I know that hub gears are not as efficient. Apart from being heavier, how much will I lose in performance if I use hub gears?
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Perfectly setting up gears - how?
Every time I have my bike serviced, the bike shop sets up the gears on a stand in their workshop. The gears change perfectly on the stand, but when the bike is on the road, the rear derailleur doesn't ...
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Is there such thing as an automatic transmission for bikes?
Has anyone ever designed or manufactured an automatic transmission (or automatic shifter?) for cycling?
I imagine such a device would automatically change the gearing to allow the rider to maintain ...
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How to calculate the capacity of a rear derailleur
It's easy to calculate what capacity of a rear derailleur will be needed based on the size of the big and small chainring and the big and small cog. What about the converse question, how to calculate ...
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Why has indexed shifting displaced traditional friction shifting?
I really don't like indexed shifters, at least on the front. They're harder to adjust, more sensitive to cable stretching, and limit the number of gear combinations you can use (because you can't ...
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Are there real-life alternatives to the chain+derailleur combo?
I was reading an article about the CeramicSpeed’s Driven concept and, while not interested in the efficiency part, the chainless system reminded me of something I was wondering for some time: are ...
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Is it normal for my derailleur cables to cross over on the down tube?
I've just picked myself up a Specialized Allez Sport 2014 road bike from Evans Cycles (UK).
I test rode the bike and I'm happy with the bike, but when I got home, and flipped the bike over to make a ...
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Relative efficiency of different commute bike setups
My interest is in long distance commuting (e.g. more than 50 km a day) and the relative efficiencies of different commute bike setups (e.g. drop bars vs flat bars, fenders vs no fenders, panniers vs ...
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Chain slipping off derailleur jockey
Last week, I had to abandon a training ride due to my chain slipping off my rear derailleur jockey wheel. This would only happen when shifting, and most often when either shifting chainrings or ...
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When to change derailleur pulleys?
A friend said me that if you have one part in a very bad condition like a cassette and then you put a new stuff like a new chain it will destroy the new stuff very quickly. A LBS said that I should ...
user652
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If a derailleur cable snaps on a long ride, how can I keep going?
A couple weeks ago I rode around Crater Lake, a 35 mile ride with over 4500 feet of cumulative elevation gain – the sort of ride you really want functional gears for.
The night before my rear ...
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How do I prevent the rear derailleur from slipping gears?
What's the best way to tune the rear derailleur of my bike to stop slipping gears? It seems that every time I re-adjust it, the middle/upper gears are perfectly aligned, but the lower gears never ...
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Beginner breaks rear derailleur, what might have gone wrong?
I broke the rear derailleur on a borrowed bike. I'm trying to understand why.
Until two months ago I knew nothing about bicycles. I bought a worn down cheap second hand bike. It took me way more time ...
15
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What options do I have if my rear derailleur breaks when I'm out on a trail?
I ran into an unfortunate situation earlier this week. I was out on a mountain bike trail, alone — just me and my hardtail. I'm pedaling, when I suddenly hear a CRUNCH and my bike stops. The hanger ...
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How efficient is string bike? Is this really a revolutionary bike?
Bicycles are getting evolved with good technologies or methodologies as the period changes. Now, this one bike, so called string bike has been introduced, which doesn't have chain, derailleur but ...
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Why are derailleur jockey wheels commonly made of nylon?
Almost all derailleurs seem to come from the factory with nylon jockey wheels . What is the rationale for the use of nylon (rather than alloy or aluminum)? Is it merely weight savings (which would ...
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Bike is shifting on its own
Ever since I got my bike (Surly Long Haul Trucker), it has been prone to shifting on its own. This is almost guaranteed to happen when I stand up on the pedals, and happens regularly when sitting as ...
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Which pulley is which on my Shimano STX RC derailleur?
I disassembled my rear derailleur to clean it; when I removed the sprockets they basically looked the same; both jet black and caked with all sorts of black grease-like-stuff. I figured they were the ...
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How can you identify if a Shimano rear derailleur is medium or long cage?
I have a 2013 Shimano XT rear derailleur. It is part of a 2x10 drivetrain. How can I find out if it is a medium or a long cage one? The picture below shows the derailleur.
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Is there a downside to spoke protectors?
A few weeks ago, the derailer on my touring bike caught on the chain and ripped itself off the frame. (See the link below for more info on the incident.) The spoke protector was cracked in half by ...
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Is it worth buying a high end light bike (8.5 kg) from 80' vs recent mid range bike (10kg)
I want to acquire my first road bike with a limited budget (~400€) but I'm faced with a lot of choices, found an old vitus 979 equiped with campagnolo chorus, a little rusty but really pretty and ...
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Mechanic says not to use top three/bottom two gears or the chain will throw
I just bought a BTwin Fit 5, all stock, fresh from the distributor, Decathlon. Took it for light pacing at the store and things seemed OK. About 100 metres out the door, I shift up to the top end of ...
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Bike chain slips in a strange way
I bought a new bike about a month ago. And it made a strange sound from the first ride , I thought the sound was because it was new and will disappear with time but it didn't. The sound is like a ...
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Selecting a front derailleur: parameters
The spec sheet for the Shimano Alivio FD-M430 front derailleur contains a number of points that I don't understand.
What does "Maximum capacity: 22 teeth" mean?
Why are "Top gear teeth" constrained ...
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Ultegra RD-R8000 derailleur chewing up shifter cable - WTH?
I have an Ultegra RD-R8000 (GS cage) that has chewed up multiple shifter cables (Dura Ace and Jagwire) at the cable bolt. Seems that when in a high gear (11t chainring) the cable bends over the clamp ...
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Why do I constantly have to re-index gears?
I've got a road bike with a high end 11 speed groupset that is about 3 years / 30,000 km old. Chain and cassette have both been replaced recently (i.e. 500 km ago).
What I'm experiencing is a constant ...
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What is the average lifespan of rear derailleurs?
What is the typical life cycle of mid-range rear derailleurs, assuming no accidents?
More precisely, what's the average mileage after which it's better to replace it rather than doing tuning all the ...
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Moving from Shimano 9- to Shimano 10- speed
I'm thinking of changing the 9-speed Tiagra rear mech on one of my (road) bikes to something, still Shimano, but 10-speed.
The obvious replacements I'll need are cassette, right-shifter and chain. But ...
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Chart for bicycle component quality?
I'm not very familiar with all the different component groups available and wondered if there's a chart that ranks their quality (or price).
So I'd know that Shimano 105 is the same level as SRAM ...
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Does anyone make dummy batteries for eTap AXS derailleurs?
I just got a new Specialized Roubaix Expert with SRAM parts. I discovered that lengthy car rides drain the batteries because the derailleurs are triggered into activity by motion.
Solution? Take the ...
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How do I adjust my rear derailleur (Shimano SIS) when it is only slightly out?
It has been a while since I had my bike serviced and the gears are sometimes slightly out of perfect alignment. This results in the occasional mis-shift. I also think the change in seasons have ...
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Apart from the size, is there any difference between chains for derailleurs or for single-speed / internally geared hubs?
I might need to replace my bicycle chain (see this question). The store where I've bought components before (cyclecomponents.com) seems to be entirely marketed to derailleurs, and I have an internally ...
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Rear derailleur shifting poorly, skipping gears
I've got a Shimano Sora on a 8-gear cassette, and have odd behavior and skipping, shifting under stress.
This started with a trip to the mechanic for a tune up which replaced the chain. I had some ...
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Is it okay for my rear derailleur to be as "compressed" as this when in the lowest gear on the bike?
Recently replaced the cables on this old road bike. When indexing the cable I notice how compressed this derailleur is and the two cogs are almost touching - it certainly doesn't look right to my ...
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How do I locate and loosen the rear derailleur hanger bolt?
Context:
I need to remove my rear derailleur so that I can attach an alignment tool and straighten things out.
Images of the rear derailleur while the bike is upside-down:
http://www.zooomr.com/z/...
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Why does my rear derailleur keep breaking?
I upgraded my rear-mech with a new cassette, chain and new cables a few weeks ago since then i've mangled two rear mechs!
Both times I've just been riding along; not in a big gear; not at the ...
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Can a road bike's rear derailleur be used for either a 9 speed cassette or 10 speed cassette?
I currently have a 9 speed 11-25T cassette on my road bike. I'm thinking about switching to a different cassette with more teeth on the climbing gear. The cassette I'm currently look at is a Shimano ...
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Is my chain too long?
I'm in the process of setting up a new drive train. When using the smaller chainring and smallest sprocket (hence least amount of utilized chain), the chain brushes up against the bottom of the ...
user1480
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1
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Why aren't derailleur hangers made into standard shapes?
That small piece of metal can render a bike unrideable, and sometimes a repacement is impossible to find.
There are standards for headsets, bottom brackets, brake mounting points, OLD and dropouts, ...
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Setting light to a derailleur
At 3:30ish in this video, they set light to a front derailleur. Why? Degreasing it? Waxy lube that needs melting in? I can't think of a good reason. Any ideas?
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Why do current, entry-level shimano rear derailers have large-diameter pulleys?
I have seen (and recently bought) entry-level rear derailers from Shimano (Tourney for MTB, 2300 for road bike), and I keep wondering why they are making these parts with such large pulleys.
I don't ...
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I failed to replace my chain at the proper interval. Will I have to replace my whole drivetrain?
My bicycle is a 2012 Specialized Secteur. It has 6000 miles (10000 km), and I have never replaced the chain.
I recently began noticing that the chain always seems out of alignment with the rear ...
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2
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Simultaneous clang, hesitation and drop when I pedal with any weight
Background: New chain, new bottom bracket, new front derailleur, new shifters, new brakes.
This is a cheap Walmart Mongoose that I'm trying to keep riding and upgraded some of the components recently, ...
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Derailleur adjustment: front or rear first?
When adjusting both front and rear derailleurs, which should be done first?
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Which limit screw is which?
I had to replace my front derailleur on my mtb. Now I just need to adjust it however the limit screws are not marked. Does anyone know if the L limit screw is closest to the frame? Or is that one the ...
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Problem with chain skipping without trying to shift (even with new chain and gears)
I have a mountain bike where the chain intermittently skips when put under load on the middle (and very rarely on the smallest) chain ring. It is not related to shifting.
I've taken several steps to ...
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Why do deraillers require a freewheel?
I've seen fixies with internal hubs, but a non-freewheeling rear wheel with deraillers seems to be unrepresented:
| Freewheel? |
Derailler? | Yes | No |
...
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Road Shifters, Mountain Rear Derailleur?
I have a road/cyclocross/commuter frame that is currently spec'd with road components - all Shimano 105, with an Ultegra rear derailleur.
The cassette (10 spd) tops out at 27 teeth, and the rear ...
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Effects of jockey wheel sizes & types
I'm wondering about the variations in jockey wheels / derailleur pulleys and what differences they make; There's a lot of conflicting and confusing information out there, so I'm after some general ...
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