30 votes

Are there real-life alternatives to the chain+derailleur combo?

Belt drive + Internally Geared Hub is a popular combination. Existing systems are based around a gates carbon belt drive. See the Breezer Beltway series bikes. Also Reeb Cycles began offering belt ...
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  • 17.6k
30 votes
Accepted

Is it worth buying a high end light bike (8.5 kg) from 80' vs recent mid range bike (10kg)

Although I support keeping older bikes in circulation in general, this particular bike comes with some caveats. One of my riding buddies had a very similar bike. The Vitus 979 is a bonded aluminum ...
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  • 24.1k
20 votes
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Is it normal for my derailleur cables to cross over on the down tube?

This is one of those questions that can start arguments between bike mechanics--to cross or not to cross the derailer cables. Crossing appears to be becoming more common on new bikes, if the cables ...
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  • 971
19 votes

Is it worth buying a high end light bike (8.5 kg) from 80' vs recent mid range bike (10kg)

Depends what is your goal, but personally, I'd go for the modern one. Maybe for this budget, you can find something second hand with Shimano 105, that would be also an option. The reasons are: weight ...
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  • 6,705
18 votes

What options do I have if my rear derailleur breaks when I'm out on a trail?

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 ...
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18 votes
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Is it common for derailleur limit screws to drift over time?

They absolutely can vibrate loose. Derailleurs vary in how good they are at resisting it. Ones with no plastic retention element and where the screws turn with almost no resistance are the worst about ...
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17 votes

If a derailleur cable snaps on a long ride, how can I keep going?

"Nothing is so broken you cannot make it worse" - breaking a perfectly good chain in the field, miles from nowhere, with a light weight emergency tool, would be my very last resort. This will only ...
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  • 39.9k
17 votes

Mechanic says not to use top three/bottom two gears or the chain will throw

You have a double front, right? The usual advice is to not shift into the highest 3 gears in the rear cassette when in front the chain is on the large chainring, and to not shift into the smallest 3 ...
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  • 12.9k
16 votes
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Bike chain slips in a strange way

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 ...
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  • 12k
16 votes

Are the Shimano derailleurs sold on Ali Express genuine or fake?

You pays your moneys and you takes your chance Answer Maybe genuine, but just as likely not. Essentially by buying discount, you're circumventing any quality and control process from the brand owner....
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  • 99k
14 votes
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How efficient is string bike? Is this really a revolutionary bike?

The general idea of "lever drive," or a reciprocating pedal motion instead of a rotary pedal motion precedes even the invention of the modern diamond-frame bicycle--consider the Special Star from 1886....
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  • 24.1k
14 votes
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New bike is making rattling noise

The noise happens every time your foot is in the same point of rotating the pedal. It sounds to me like the chain is catching on the front derailleur once per rotation. Not unusual and not difficult ...
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  • 12k
13 votes

What options do I have if my rear derailleur breaks when I'm out on a trail?

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 ...
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  • 99k
13 votes
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I failed to replace my chain at the proper interval. Will I have to replace my whole drivetrain?

Yes - after that mileage you will need both a new chain and new cassette. A new chain on the old cassette will not mesh right, and accelerate wear on the new chain. Depending how much chain elongation ...
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  • 99k
13 votes
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Why do I constantly have to re-index gears?

The most likely causes are cable friction and derailleur hanger misalignment. Indexing adjustment has gotten more sensitive to both as the speed count has increased. Derailleur hanger misalignment ...
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12 votes

Password protect Shimano Di2?

This is an odd question. The sentiment that the only security here is physical security is correct. Think about the following: The Shimano Di2 components are not mated/matched to a specific computer ...
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  • 689
12 votes
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Derailleur On A Single Speed

The derailleur is there to act as chain tensioner. In a frame intended for derailleur the rear wheel can't be moved to tighten the chain, so a separate spring-loaded chain tensioner is needed. The ...
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  • 19.4k
12 votes
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10 speed rear derailleur only shifting 7 gears....losing my mind

I believe your problem is a mismatch of cable pull ratios between the shifter and derailleur. The rear derailleur actuation ratio is how far the shifter cage moves for a unit length of cable pulled. ...
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12 votes
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Why is low sprocket minimum 28t for a Shimano 105-GS?

The key aspect of the GS cage is the length of the cage. The other key aspect of derailleurs is the geometry of the parallelogram. Because the design has been adapted to suit more modern gearing ...
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  • 12k
12 votes

Shifting direction is different for front and rear shifters

The reason why shifting is arranged this way: Shifting to a larger chainring at the front gives a higher gear ratio, shifting to a larger sprocket at the rear gives a lower gear ratio. Shifting to ...
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12 votes

Can my belt drive frame be converted to a derailleur setup?

There is no good way. One could imagine ways of contriving a low-end claw-type derailleur on. Don't do that. Nexus hubs are usually reliable. In some places in the world, there are lot running around ...
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11 votes
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How can you identify if a Shimano rear derailleur is medium or long cage?

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 ...
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  • 8,767
11 votes
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Mechanic says not to use top three/bottom two gears or the chain will throw

Not using the upper and lower gears is a very effective solution. Stupid, but effective. Traditionally one would simply use the limit screws (at the rear derailleur, often marked L(ow) and H(igh)). ...
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  • 2,542
11 votes

Is it normal for my derailleur cables to cross over on the down tube?

I have seen this frequently and routed my cables this way. By routing the shifter cable from the right side of the handlebar around the stem to the cable boss on the left side of the frame (and visa ...
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  • 111
11 votes

Change gear on a shimano Schwinn Ranger, not sure what Allen key size to use?

The allen is almost certainly metric. Both 2.5mm and 3mm are reasonably close to 7/64 inch. 3mm is a very common size on bikes. If you are going to do any work on a bike you need metric allen ...
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11 votes

Bike chain slips in a strange way

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 ...
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11 votes

Is it worth buying a high end light bike (8.5 kg) from 80' vs recent mid range bike (10kg)

I'll weigh in as the single person in this thread who actually seems to have ridden, and owned, multiple Vituses. I love them, always have, mainly for their history, their gorgeous looks, their light ...
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  • 111
11 votes
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I lost one of the rear rear derailleur hanger screws, what could be the cause, and is it safe to ride before I replace the bolt

Yea, the QR will hold it on tighter then the screws could ever dream of. If you ever need to remove the wheel though, be extra careful as the one remaining screw has a higher risk of breaking when it ...
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  • 10.7k
10 votes

Which jockey wheel on top?

Here's a photo of RD-M970 from behind. As you can see, the slotted (guide) pulley goes to knuckle and solid one (tension) to the bottom of cage. I'd align the arrows with chain movement direction that ...
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10 votes

How to make a derailleur work in opposite directions?

When you switch to the crankset behind cogs, you need to move the derailleur above the cogset. Think of it as rotating the entire drive train 180 degrees forward or flipping the entire bike over the ...
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  • 19.4k

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