24

As a chain wears out, the distance between links gets bigger (this is what chain wear tools measure). As this is happening, the chain will grind the cogs to match the worn chain (distance between teeth increases). This is why your gears might not feel so bad, but then they get much worse when you put on a new chain. The new chain's links do not line up with ...


21

I think these may be what you're looking for. FYI, a lot of this information is available with a little searching. Depending on what exactly you are looking for, you might want to look up a document for a specific cassette as the numbers might be slightly different. Spacer widths (From Shimano tech docs) 8 Spd: 3.00mm 9 Spd: 2.56mm 10 Spd: 2.35mm (1.0mm ...


17

They are there to help facilitate shifting. Basically, the ramps you see help when going from a smaller to larger sprocket by catching the side plates of the chain to help the chain be pulled up onto the larger cog. Another place where you will see atypical teeth is in the front; some are shorter/different shaped than others to help shifting as well. ...


14

Assuming you have Shimano-compatiple Hyperglide cogs: No, you can't. The cassette body is not symmetric, the cassette fits in only one position. You could resort to adapt the cogs with a file, though. But shifting will be problematic at least, the cogs have certain indents to make shifting smoother.


12

Shows some wear, but looks OK. All teeth look symmetrical and so do the spaces between them. Really worn teeth look like a swept back shark dorsal fin or develop a visible burr. Do a Google image search for 'worn chainring teeth' and you'll get plenty of examples.


10

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 happens when you pedal forward.


9

The problem is that any rear cluster designed for indexed shifting has directional cogs. There are ramps embossed on the sides of the cogs to catch the chain pins and lever the chain up to the next larger cog when the chain is shifted. If you somehow reverse the cogs these ramps will be on the wrong side of the cogs and will be running the wrong direction.


9

Here are some points taken from the literature: Mechanical efficiency is usually 88-98% for majority of deraileur systems (when clean,lubricated and new) Drivetrain efficiency decreases with smaller rear cogs, Highest efficiency can be reached at high torques and low cadence, Chainline effects are negligible, imposible to note with measurement apparatus, ...


8

The cable that moves a mechanical derailleur is counteracted by a spring. To the best of my knowledge the "leave it on the smallest sprocket" theory suggests that the spring is sitting with the least amount of tension on it. The same is true for the cables. Because they have the least tension they are more likely to maintain adjustment over periods of ...


8

I've done the opposite to a lot of riders - I had a chainset of unknown mileage and rather than guess, I simply rode the whole thing into the ground. Shifting got progressively worse over time, but it wasn't linear. There were certain gear combinations that slipped more under normal load, and others that slipped under heavy load. Climbing a grade became ...


7

Chains for modern bicycles all have a 1/2" pitch - the distance from roller to roller or from pin to pin. However, multi-speed bicycles have rollers that are 3/32" wide (or narrower), while many single speed drivetrains (fixies, track bikes, BMX) have rollers that are 1/8" wide. Similarly, there are chainrings and cogs which accommodate wider or narrower ...


7

Gear inches. Gear inches are, for better or worse, the most commonly recognized way of making the kind of comparison you're trying to make here, which one is harder to pedal. Gear inches are simply how far one complete rotation of the cranks moves the bike forward. The higher the number, the harder it is to turn the cranks. You hear people make reference to ...


7

To answer the question as asked: You'll have a Shimano Nexus gear hub, so you need a sprocket compatible with that. (Any reasonably competent mechanic should have been able to tell you that!) Sheldon Brown has a page on Nexus and Affine geared hubs which includes info on sprockets: https://www.sheldonbrown.com/nexus-mech.html. You should be able to find ...


6

The key property is hardness. For uniform materials (like cogs), hardness directly affects wear resistance. The harder the metal the longer it will last. Some digging around wikipedia suggests that typical Brinell hardness values are: pure aluminium 15HB, 6061-T6 aluminium (heat treated) 95 HB mild steel 120HB, 4130 CroMo steel 183-217 HB (90-96 ...


6

The outer ring looks like a lock ring. This should help you get it off:


6

First, to remove a cassette freehub does require a specific tool. The Park Tool version is called the FR-5. There is no need for more than one kind of grease. Use any light bearing grease like the Park Poly Lube 1000. There is a good set of instructions here on how to do the rebuild. From Park Tool's repair help site: Hub Overhaul and Adjustment ...


6

I'm Ryan with Gates Carbon Drive. The fix is not difficult, but there are a couple of things that I would recommend. Simply removing the 4 chainring bolts is not the best course of action. I would recommend removing the rear wheel from the dropout. If you are unsure about this, we have put together a video here: http://www.gatescarbondrive.com/tech/...


6

Tricky one. You will go through several chains before going through a cassette. A worn chain can be measured quite easily with a gauge. Measuring wear on a cassette is more difficult. It is usually the middle set of sprockets which wear first - due to their more frequent use. If examined carefully - you may notice the teeth on them thinning.


6

That's a freehub body. Look on the hub for the model of hub you have, and then you can use that to find the appropriate freehub body model by looking at the documentation of the hub.


6

According to the late great Sheldon Brown, yes you can change an individual sprocket in a cassette, at least for Shimano. Some cassettes have small bolts or rivets holding the gears together, but this is for convenience. Most Shimano cassettes made in the '90s or later have a feature called Hyperglide (probably a registered trademark) that enables smoother ...


6

In that context, Top sprocket is the smallest one on the cassette, which gives you the Top or highest gear. (You would think they would match terms Low and High or Top and Bottom.)


6

Yes, the stretched chain wears the chain ring and sprockets to match its pitch. It's recommended to use a chain gauge (such as this one by Park Tools) so you can replace your chain before it's stretched enough to do significant damage to the rest of the drive train. If you do let the chain stretch too far, you'll need to change the cassette/rear cog and/or ...


5

It is a derailleur pulley, and fairly worn out one at that. The easiest way to find a fitting replacement is to buy a set from an aftermarket manufacturer that comes with adapter shims for different derailleurs. You can simply try different shims until you find the one that fits. They do come in different teeth counts. From the picture it looks like this ...


5

If the Shimano freewheel didn't fit, it means that your bike uses French threading for the freewheel (which isn't surprising given that it has a Maillard freewheel; the other non-bmx standards are interchangable). You're basically out of luck and need a new wheel (or at least new hub). Depending on the hub, you may have to re-space the frame(*), since 6 ...


5

It's also possible he has a Maillard Helicomatic hub (http://www.yellowjersey.org/helico.html) in which case it wouldn't be compatible with ANYTHING. You can usually find replacement freewheels and lockrings for those on ebay. At the moment they're not as expensive as I thought, about $50 for a freewheel.


5

A great deal of engineering has gone into making shifting smooth and predictable. Up until ~1984, shifting was done by feel and sound: the shift lever moved continuously through its range, and you moved it until it caught the adjacent gear. Different brands had different actions, and you had to develop some technique. In 1984, Shimano rolled out "indexed ...


5

You'll need enough spacers to compensate for the width of the cassette and maybe readjust the rear derailleur. Your LBS mechanic will normally have a box of spacers, especially those from discarded 10 and 11 speed cassettes are convenient for fine adjustments. I run a 6 speed cassette on a Tackx Flux with an early 1980s racebike. It works without any ...


4

Yes you can, at least with some old cassettes. I have done this myself on a old racing bike from the 80s and it worked like a charm. Disassembling the cassette was a pain though... and I accidentally broke one of the plastic spacers so I replaced that with some copper ring I had lying around.


4

Running 1x9 is a great idea. I have done it with relatively good success. There were always times on big rides i wish i had a granny.I also intially had issues on chain drop. Because the 9 speed rear, bumpy and rocky terrain can knock the chain off when the derailleur would slap. To prevent chain drop on the front, you can run a bash guard, and an N-gear ...


4

Getting a 7-speed (or indeed any) Campy cassette wouldn't do you much good anyway since the rest of your drivetrain will be Shimano. As you've discovered the two don't mix. (Or rather, they are not supposed to mix and you can expect problems if you do try to mix them. Never say never, I guess!) I reckon your cheapest option could be to visit your LBS and to ...


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