Cookie Consent by Free Privacy Policy Generator

Anonym

Alles über Umwerfer: Unterschied zwischen den Versionen

Aus WikiPedalia

Alles über Umwerfer (Quelltext anzeigen)

Version vom 13. September 2018, 13:29 Uhr

118 Bytes hinzugefügt ,  13. September 2018
Überschriften und Werbung...
(Übersetzungsanfang)
(Überschriften und Werbung...)
Zeile 14: Zeile 14:
The front derailer does its shifting using the upper run of the chain; the rear derailer, using the bottom run of the chain. The upper chain run is the section that transmits pedal power to the rear sprockets, so if you are pedaling forcefully, the chain is less able to bend sideways due to the tension. That is why it is essential to ease up while shifting in front. This is not so much an issue with rear shifting, because the rear derailer does its work with the lower, slack run of the chain.
The front derailer does its shifting using the upper run of the chain; the rear derailer, using the bottom run of the chain. The upper chain run is the section that transmits pedal power to the rear sprockets, so if you are pedaling forcefully, the chain is less able to bend sideways due to the tension. That is why it is essential to ease up while shifting in front. This is not so much an issue with rear shifting, because the rear derailer does its work with the lower, slack run of the chain.


There are more complications involved in choosing a front derailer than with a rear:
{{#widget:AdSenseT}}
Mounting


==Komplikationen bei der Wahl des richtigen Umwerfers==
===Montage===
There are 5 different mounting types for front derailers, depending on the seat tube diameter of your frame, among other things:
There are 5 different mounting types for front derailers, depending on the seat tube diameter of your frame, among other things:


    1 1/8" (28.6 mm) clamp-on. (This is the traditional, standard type for most road bikes and older MTBs).
*    1 1/8" (28.6 mm) clamp-on. (This is the traditional, standard type for most road bikes and older MTBs).
    1 1/4" (31.8 mm) clamp-on for mildly oversized seat tubes.
*    1 1/4" (31.8 mm) clamp-on for mildly oversized seat tubes.
    1 3/8" (34.9 mm) clamp-on for oversized seat tubes, common on aluminum frames.
*    1 3/8" (34.9 mm) clamp-on for oversized seat tubes, common on aluminum frames.
    "Braze-on" units mount on a special slotted tab, which may be brazed, bolted or glued onto the frame.
*    "Braze-on" units mount on a special slotted tab, which may be brazed, bolted or glued onto the frame.<br> Braze-on mounts will limit your options for choosing different chainring sizes. Braze-ons permit some limited range of vertical adjustment, but not always enough.
*    "E-type " Shimano units have a bracket that is held on by the bottom bracket retaining ring. These also use a special braze-on to stabilize the derailer.<br>    E-type mounts allow adjustment for chain slope, but do not permit any adjustment at all for chainwheel size, so you generally need to use exactly the size chainrings that your E-type front derailer was designed for.


    Braze-on mounts will limit your options for choosing different chainring sizes. Braze-ons permit some limited range of vertical adjustment, but not always enough.
===Zugverlauf===
    "E-type " Shimano units have a bracket that is held on by the bottom bracket retaining ring. These also use a special braze-on to stabilize the derailer.


    E-type mounts allow adjustment for chain slope, but do not permit any adjustment at all for chainwheel size, so you generally need to use exactly the size chainrings that your E-type front derailer was designed for.
*    Traditional front derailers are "bottom-pull", operated by a cable running up from the bottom bracket area to the derailer.
*    "Top-pull" derailers are operated by a cable running down from above. This design is mainly used on mountain bikes, with the intent of avoiding running the cable under the bottom bracket, where it is exposed to spray kicked up by the front tire.
*    Some older designs use a loop of cable housing running from a stop near the bottom of the down tube. This design hasn't been used since the mid-1970s. Fortunately, it isn't difficult to work around this. If you want to mount a modern derailer on a bike intended for this type of mount, just ignore the housing stop near the bottom of the down tube. Run the bare cable under the bottom bracket and up to the derailer's anchor bolt.<br>    If you are worried about protecting the paint under the bottom bracket, there are two easy ways to protect it.
**        Easiest is to use a short length of "floating" housing, a piece of housing perhaps 2-3 inches (50-75 mm) long under the bottom bracket. This does not need housing stops at either end. The tension on the cable will make it stay in place.
**        A more elegant solution is to install a modern plastic cable guide under the bottom bracket. Normally, such guides are secured by a 5 mm screw, so you would need to remove the bottom bracket mechanism, then drill and tap a 5 mm hole for the screw. This is easy to do.


Cable Pull
===Kettenneigung===
 
    Traditional front derailers are "bottom-pull", operated by a cable running up from the bottom bracket area to the derailer.
    "Top-pull" derailers are operated by a cable running down from above. This design is mainly used on mountain bikes, with the intent of avoiding running the cable under the bottom bracket, where it is exposed to spray kicked up by the front tire.
    Some older designs use a loop of cable housing running from a stop near the bottom of the down tube. This design hasn't been used since the mid-1970s. Fortunately, it isn't difficult to work around this. If you want to mount a modern derailer on a bike intended for this type of mount, just ignore the housing stop near the bottom of the down tube. Run the bare cable under the bottom bracket and up to the derailer's anchor bolt.
 
    If you are worried about protecting the paint under the bottom bracket, there are two easy ways to protect it.
        Easiest is to use a short length of "floating" housing, a piece of housing perhaps 2-3 inches (50-75 mm) long under the bottom bracket. This does not need housing stops at either end. The tension on the cable will make it stay in place.
        A more elegant solution is to install a modern plastic cable guide under the bottom bracket. Normally, such guides are secured by a 5 mm screw, so you would need to remove the bottom bracket mechanism, then drill and tap a 5 mm hole for the screw. This is easy to do.
 
Chain slope


The slope of the chain relative to the front derailer is affected by the seat tube angle, bottom-bracket height and size of the rear wheel. Derailers are specified for different angles. The issue is most critical with small-wheel bicycles, and can result in the chain's dragging on the bottom of the front derailer's chain cage. A braze-on or E-type front derailer can work around this problem.
The slope of the chain relative to the front derailer is affected by the seat tube angle, bottom-bracket height and size of the rear wheel. Derailers are specified for different angles. The issue is most critical with small-wheel bicycles, and can result in the chain's dragging on the bottom of the front derailer's chain cage. A braze-on or E-type front derailer can work around this problem.
Large-Chainring Size
===Das größte Kettenblatt===


Front derailers shift best when they are mounted as low down as is possible without having the cage foul the teeth of the chainrings. In particular, the bottom edge of the outer cage plate should be closely matched to the curvature of the largest chainring.
Front derailers shift best when they are mounted as low down as is possible without having the cage foul the teeth of the chainrings. In particular, the bottom edge of the outer cage plate should be closely matched to the curvature of the largest chainring.
Zeile 53: Zeile 48:


If you have unusual gearing requirements, and are handy, you can reshape the outer cage plate with a grinding wheel to match a non-standard large chainring.
If you have unusual gearing requirements, and are handy, you can reshape the outer cage plate with a grinding wheel to match a non-standard large chainring.
Double/Triple
===Zweifach/Dreifach===


Double and Triple Front Derailers
[[Datei:Frontderailers23.jpg|center|Zweifach- und Dreifachumwerfer]]


Modern derailers are optimized for either double or triple chainwheels . The shape of the shifting cage is tailored for the application intended.
Modern derailers are optimized for either double or triple chainwheels . The shape of the shifting cage is tailored for the application intended.


    A "double" front derailer has an inner cage plate that extends down only slightly farther than the outer plate.
*    A "double" front derailer has an inner cage plate that extends down only slightly farther than the outer plate.
    A "triple" front derailer has an extended inner plate that goes down considerably lower than the outer plate. The extended plate greatly improves shifting from the small to the middle chainring, because it acts closer to the middle ring.
*    A "triple" front derailer has an extended inner plate that goes down considerably lower than the outer plate. The extended plate greatly improves shifting from the small to the middle chainring, because it acts closer to the middle ring.


"Double" front derailers will work with triples, but if the middle ring is much smaller than the big ring, they will be balky shifting up from the small to the middle chainring. They do, however, work well with "half-step-plus-granny " setups, where the middle ring is only 3-5 teeth smaller than the outer ring.
"Double" front derailers will work with triples, but if the middle ring is much smaller than the big ring, they will be balky shifting up from the small to the middle chainring. They do, however, work well with "half-step-plus-granny " setups, where the middle ring is only 3-5 teeth smaller than the outer ring.
Zeile 66: Zeile 61:
Modern "triple" front derailers have interference problems in half-step-plus-granny setups between the extended inner plate and the inner chainring. "Triple" front derailers are generally optimized for a specific difference between middle and large chainring.
Modern "triple" front derailers have interference problems in half-step-plus-granny setups between the extended inner plate and the inner chainring. "Triple" front derailers are generally optimized for a specific difference between middle and large chainring.


    Shimano's "10-speed" triple front derailers are optimized for a 13 tooth difference, typically 52-39.
*    Shimano's "10-speed" triple front derailers are optimized for a 13 tooth difference, typically 52-39.
    Most other Shimano front triple derailers are optimized for a 10 tooth difference between middle and large ring.
*    Most other Shimano front triple derailers are optimized for a 10 tooth difference between middle and large ring.


Surprisingly, the size of the "granny" chainring has little effect on derailer performance. Many cyclists customize their "road triple" cranksets by installing a more-useful smaller ring in place of the 30 that comes stock. The only limitation here is that the chain must not bottom out in the chain cage. This is generally not a problem if the large chainring's tooth count is in the mid 40s. It may be a problem if the large chainring is larger. A "compact" cassette whose smallest sprocket has 11 teeth can get around the problem by allowing the use of smaller chainring without sacrificing the top end of the gear range. With today's cassettes that have 8 or more sprockets, you can still have narrow steps between speeds, and a large sprocket with as many as 34 teeth for a low bottom gear.   
Surprisingly, the size of the "granny" chainring has little effect on derailer performance. Many cyclists customize their "road triple" cranksets by installing a more-useful smaller ring in place of the 30 that comes stock. The only limitation here is that the chain must not bottom out in the chain cage. This is generally not a problem if the large chainring's tooth count is in the mid 40s. It may be a problem if the large chainring is larger. A "compact" cassette whose smallest sprocket has 11 teeth can get around the problem by allowing the use of smaller chainring without sacrificing the top end of the gear range. With today's cassettes that have 8 or more sprockets, you can still have narrow steps between speeds, and a large sprocket with as many as 34 teeth for a low bottom gear.   
Zeile 77: Zeile 72:


See also my Article on "Speeds."
See also my Article on "Speeds."
Indexing Road/MTB
===Indexiertes Schalten Straße/Mountainbike===


The ratio of cable movement to derailer movement differs with Shimano's "road " vs. "MTB " front derailers. This can cause indexing problems if you use a "road" front derailer with upright handlebars or a "MTB" front derailer with drop handlebars. This is a concern if you are running an indexed front shifter, such as Shimano STI or RapidFire shifters.
The ratio of cable movement to derailer movement differs with Shimano's "road " vs. "MTB " front derailers. This can cause indexing problems if you use a "road" front derailer with upright handlebars or a "MTB" front derailer with drop handlebars. This is a concern if you are running an indexed front shifter, such as Shimano STI or RapidFire shifters.
Zeile 87: Zeile 82:
Also, JTek makes a Shiftmate adapter designed to convert between Shimano's "road" and "MTB" components, offering another solution.
Also, JTek makes a Shiftmate adapter designed to convert between Shimano's "road" and "MTB" components, offering another solution.


Trimming
==Trimmen==


As you shift the rear from side to side, the angle of the chain changes where it approaches the front. Sometimes, this results in the need to "trim" the front derailer.
As you shift the rear from side to side, the angle of the chain changes where it approaches the front. Sometimes, this results in the need to "trim" the front derailer.
Bikegeissel
Bürokraten, editor, Administratoren
15.340

Bearbeitungen

Abgerufen von „https://wikipedalia.com/index.php/Spezial:Mobiler_Unterschied/14792“