Kakva su vam iskustva sa takvim menjačima koji su česti na stranim city bajsevima?
Da li je to moguće popraviti ako nešto ne radi kako treba. Umem da servisiram skoro sve na bajsevima, ali nisam to odavno radio, a jurim nove gradske bicikle za sebe i ženu, a dosta povoljnih bajseva ima takve menjače.
Evo ovde sa Wikipedije prednosti i mana, ali značila bi mi više "živa reč" od korisnika ovakvih menjača. Naravno, tu je Sheldon Brown https://www.sheldonb...rnal-gears.html
Advantages[edit]
Disadvantages[edit]
- Hub gears are sealed within the hub, which protects them from water, grit, and impacts. Thus hub gears usually require less maintenance and can be more reliable over time than comparable external derailleur gear systems, which may require more adjustments and replacement of parts (front chainrings, rear sprockets, narrow derailleur-chain).
- Hub gears completely avoid the danger of collision with the spokes and wheel-collapse that derailleur systems can suffer.
- Hub gears can change gear ratios when the rear wheel is not rotating. This can be useful for commuter cycling with frequent stops and for mountain biking in rough terrain.
- Hub gears can be simpler to use for inexperienced riders, because there is generally only a single shifter to operate and there are no overlapping gear ratios. By contrast, modern derailleur systems often have two shifters, and require some forethought to avoid problematic gear combinations.
- Hub gears can be manufactured to include a coaster brake (though not all hub gears are available with coaster brakes). This is not possible with derailleur systems, because the chain cannot transmit a backwards pull.
- Hub gears provide a means for shifting gear ratios on drivetrains incompatible with external derailleurs such as belt drives and shaft drives.
- The single chainline allows for a full chain enclosure chain guard, so the chain can be protected from water and grit, and clothing can be protected from contact with the lubricated chain.
- The single chainline does not require the chain to bend or twist. As a result, the chain can be constructed differently, with parallel pins instead of barrel-shaped ones.[18] Line-contact between the bearing surfaces, instead of the point-contact of a derailleur chain, greatly extends the working life of all components.[citation needed]
- On bicycles with fixed chain-lines, no chain tensioner is required, eliminating a part that could otherwise become damaged in rough terrain- an advantage for off-road cyclists. Where a tensioner is required, a short cage is usually sufficient to take up the chain slack.
- The single external sprocket means that the wheel can have a hub with more distance between its flanges and be built with no or much less dish, making it laterally stronger than a similar wheel with narrower flange spacing and more dish to accommodate multiple sprockets.[19] The hub shell of gear hubs is also often of a larger diameter than that of derailleur hubs, meaning the spokes on such wheels may be shorter.[19]
- It can be hard or impossible to select another gear whilst pedalling, because a release of pressure is required to enable a change in this case.
- The rear wheel cannot be completely separated from a bicycle with hub gears without also disconnecting the gear cables, which complicates the process of fixing a flat.
- The hub gear is an integral part of the wheel and it is not possible to change the wheel without also changing the hub gear.
- Hub gears are more complex and usually more difficult for the rider to repair, especially at the roadside.[4]
- Hub gears are typically more expensive than derailleur systems.
- At commuter/recreational power levels, current hub gears are typically about 2% less efficient than reasonably maintained derailleur gears.[20][21]
- Hub gears tend to be heavier than derailleur systems with equivalent gearing characteristics, and the additional weight is concentrated at the back wheel. On rear-suspension bicycles in sporting use this unsprung weight may adversely affect traction and braking.
- Hub gears are generally incompatible with quick release mechanisms/skewer axles.[1]
- It is sometimes possible to select no gear when changing gears with a poorly adjusted gear cable, which results in a complete loss of drive.