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25

In 2001, Kyle and Berto published a comparison of the mechanical efficiency of several configurations of derailleur and internally-geared hubs in Human Power, which you can find here. Among the systems tested were a Shimano MTB derailleur system, a Sturmey-Archer 3-speed hub, the Shimano 7-speed Nexus hub, and the 14-speed Rohloff hub. MTB derailleur systems ...


18

Centerlock largely exists because since the beginning of modern disc brakes for bikes, Shimano has more or less alone had a weird cautionary take on the physics of rotor bolts theoretically being able to loosen in the six-bolt design. That's why their six-bolt rotors have always come with various retention systems for the bolts that nobody else bothers with. ...


17

If the nuts are rounded they're stuffed. You want to remove the nuts but not damage other things, like axles. I'll assume you're talking about axle nuts, but the same ideas apply to all nuts, bolts, and even screws to some extent. So your nuts look something like this: Clean the flats up with a file. Use a medium flat file and smooth off the lumps of ...


15

That kind of rim damage indicates over-worn brake surfaces. Whether you should replace the whole wheel is a strictly economical question which is hard to answer in general. Wheel building services and components prices differ in different countries; somewhere it is cheap to rebuild a wheel at a mechanic; somewhere buying a new wheel is cheaper. Given that ...


14

Children's bikes are usually designed with easy gearing appropriate to children. As Chris H said - they are not usually assembled by people who care that a bike is assembled correctly. From the factory it seems like everything is always too tight. My guess is that there is something that can be adjusted to make things better. Flip the bike over so it's ...


13

If you're going to be respacing, I'd suggest an alternative method from sheldon's 2x4 method. Use a threaded rod with washers and nuts. It's far more controlled and easier to keep your frame aligned, plus you can keep it in the stand as you work. See here If you need to adjust the dropout alignment, you can adjust thusly


12

From Stan's NoTubes FAQs on wheels and rims: Why is my cassette digging into my freehub body? Stan's freehubs are made lightweight using aluminum like many other brands. We recommend using cassettes with a rigid alloy carrier (XTR, XT, XO, etc. - Figure 1) for the largest sprockets. Cassettes with individual cogs (Figure 2) may mark the ...


12

Updated based on your edits and comments. The severed piece of metal circled in the 3rd image is one of the cage plates, and was originally attached to the lower (idler) pulley bolt. Beyond replacing the derailleur, there is no additional damage there. It really does appear that you may only need to replace your derailleur (and chain). Other items to ...


11

As already said, Shimano used to manufacture Silient Clutch rear hub. But that has been stopped a few years ago, so if you manage to source one - you are lucky man. I used to have one of them and it was truly silent. It was heavier than standard shimano LX hub, but it was silent and with instant engagement. Also I used Chris King hubs. If you put a lot of ...


11

I've just rebuilt a totally stock Shimano wheel set and it had locknuts touching cones all over the place. Go for it.


11

Advantages of 6-bolt: Not being patented by Shimano means more vendors offer compatible wheels/disks. Torx bolts require a smaller tool which is often included in many multi-tools so one can always have one on the road. Advantages of Centerlock: Faster installation and removal with a cassette tool; no need to fiddle with 6 separate bolts No need to have ...


11

That's a bit of a mess. Looks like the chain dinged up the hub, freehub body (that the cassette mounts on) and the spokes. The freehub body is removable, and you could possibly use a fine file to remove any metal burrs that are keeping the freehub from rotating. What is far more worrying is the state of the spokes. All the drive side spokes are gouged and ...


10

Benzo and Glenn Gervais are right on, but I thought I'd include a photo for any visual learners. This is a typical fixed/free, high flange rear hub. Quite often they're available in 120mm and 130mm OLD to fit different width dropouts. These hubs generally have solid axles without quick releases to prevent the hub from slipping and slackening your chain. The ...


10

Shimano/SRAM 11 speed cassettes are wider than 8/9/10 speed ones. So yes, you need a new, wider freehub body, unless your old one was not very old and used a spacer to fit a 10-speed cassette. People with non-Shimano brand hubs are less likely to find replacement freehub bodies, it seems, leading to replacement of the whole hub, or even the whole wheel if ...


10

It depends. If an inexperienced person such as your regular consumer does it, it could take a few hours especially if you don't have the proper tools or preparation. If an experienced person at the shop does it with their tools, it could take half an hour if all the spokes are the right length, it's a standard lacing, or they've done the same wheel before. ...


10

A security nut is exactly what it is. I've seen similar ones on public bike share bikes. As to where you get the tool for it, no idea. Other ones I've seen have been shrouded; this looks like you could get a pipe wrench on it to replace it with a normal one.


9

That particular Shimano freehub can be disassembled, but it is quite a job to get it back together afterward. There are around 80 2mm bearings in two different locations in the freehub, and a skilled and practiced mechanic has roughly a 60% chance of opening without losing parts, and successfully getting it back together. The good news is, there is a tool ...


9

As you're not clear on road vs mtb, there's two answers. For 11 spd road drivetrains Shimano uses a 1.85mm wider hub with the drive side flange closer to the centerline to compensate for the additional width. Using a spacer allows the wheel to be backwards compatible to fit a 10 spd cassette. You can't fit a 11spd freehub in place of a 10spd freehub unless ...


9

A couple more pros of centre lock: Finned rotors One big difference is that you can't get the finned Shimano Ice-Tech rotors used on the road bike groupsets in a 6-bolt configuration. E.g: or I've had brake fade on my Shimano RS685/785 set up on descents in Wales and wanted to try the finned rotors, but my hubs are 6-bolt. You can make a centre lock ...


9

One disadvantage of 6 bolt is that you can torque one side just a bit more than the other which can cause the rotor to be just a bit warped. Center-lock torques evenly by design so there’s no risk.


9

Is there a small hole that was covered by the ring? If so it covers a lubrication port. Many old Raleigh, and other utility type hubs came with such a port.


9

Thru Axles are a standard for wheel fasteners that was introduced fairly recently for MTB and later for road bikes. Today thru axles come typically in 15 mm or 12 mm diametres. If you mean thse, they are indeed always hollow. Any solid bolt with such a large diametre would be excessively heavy. Even when using light magnesium alloys. The whole innovation ...


8

The best suggestion I can make is to read "The Art of Wheelbuilding, by Gerd Schraner". As for materials: Use aluminum, double walled rims. They are stronger, lighter, and believe it or not easier for a new wheel builder to get true and round than steel rims will be. In addition, steel rims for a road bike will be difficult to come by in new condition. ...


8

Some axles [Maillard, Campag etc.] have a keyway along the threaded portions. An internal-tabbed washer slides on , between the cone and the locknut, to prevent locknut rotation also spinning the cone itself. It's a good system; and in that case, the tabbed washer should be used. With Shimano hubs, where the keyway-&-tab system has been abandoned, the ...


8

Place a single leading spoke and a single trailing spoke- both on the same side of the hub- to get your placement correct. That way you only have to unthread two spokes if you're off. Once you've got it right, unthread the leading spoke if you're planning on lacing trailing first or vice versa and proceed as normal with lacing.


8

Each kind of grease will perform best at a certain temperature. And is designed for a certain speed of movement of the parts it is used at to reach and not exceed that temperature. So yes, it is worth it to use the special grease for bikes or get an other kind of grease that is designed for the speeds/temperature your parts will get. I found that when a ...


8

I don't have specific experience with this one, but the pictures suggest it works one of two ways: From where you're at now, you bonk the end of the axle on the non-drive sufficiently hard and the axle slides out, possibly taking the freehub with it, or if not then letting it be removed. You put the 5mm allen in the drive side end and a cone wrench on the ...


8

If the shell is aluminum and we're talking about the whole thing and not just the bearing races, the literal answer is flat out no, because aluminum doesn't have a fatigue limit. It will crack eventually. As to the question of can a hub bearing race, real or hypothetical, last literally forever in any kind of use, that's the kind of question everyone likes ...


8

How bad are the damages, can you identify what specifically appears damaged and in need of repair? Is the frame and hub okay to keep and just needs a new derailleur? From what I can see it's a derailleur replacement and possibly a chain replacement - depending on how twisted the links are. In the larger circle there are scrapes on the drop out but I can't ...


8

Its a rear wheel security axle nut, with an anti-rotation washer underneath. I see a band brake or a roller brake, and a Shimano Nexus (8?) internally geared hub, which are reasonably valuable, hence the security nut. If you want to get it off with a minimum of damage, I'd make a tool. Get an old set of bootpinch pliers and round off the cutting faces ...


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