add bike repair blog entry

input/blog/2022/2022_05_21_bike_spokes.md

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+title: Blog
+post: Bicycle Repair
+description: Replacing broken rear wheel spokes
+date: 2022-05-21
+comments: true
+---
+
+Driving back home from work on Thursday I suddenly heard a strange noise and felt a wobbly sensation on my bike.
+Taking a closer look, it turns out two spokes in the rear wheel have broken.
+
+<!--%
+lightgallery([
+    [ "img/bike_spokes_1.jpg", "Bike before the repair" ],
+    [ "img/bike_spokes_2.jpg", "Broken spokes" ],
+])
+%-->
+
+Over at the [Toolbox Markdorf](https://toolbox-bodensee.de/) we have a bike repair stand and a wheel centering stand, as well as other bike-related tools.
+So I drove over there to do the repairs.
+
+<!--%
+lightgallery([
+    [ "img/bike_spokes_3.jpg", "Rim in centering stand" ],
+    [ "img/bike_spokes_4.jpg", "Empty holes of broken spokes" ],
+])
+%-->
+
+On the gear shift side, a small plastic disc prevents the spokes being taken out.
+It can simply be pulled off and put back on afterwards.
+
+<!--%
+lightgallery([
+    [ "img/bike_spokes_5.jpg", "Plastic disc on gearbox" ],
+])
+%-->
+
+Removing the brake disc requires a special tool by Shimano, called the ["Lock Ring Tool TL-LR10"](https://amzn.to/3NjrZXA).
+Fortunately I already bought that when I rebuilt my wheel.
+
+<!--%
+lightgallery([
+    [ "img/bike_spokes_6.jpg", "Shimano Lock Ring Tool" ],
+    [ "img/bike_spokes_7.jpg", "Opening Lock Ring with a Wrench" ],
+    [ "img/bike_spokes_8.jpg", "The removed brake disc" ],
+    [ "img/bike_spokes_9.jpg", "Hub without brake disc" ],
+])
+%-->
+
+Here you can see the two broken spokes, next to six unused ones I still had left over, because my rim only needs 32 spokes.
+
+<!--%
+lightgallery([
+    [ "img/bike_spokes_10.jpg", "Two broken spokes next to new ones" ],
+])
+%-->
+
+Normally I would have centered and tensioned the rim and spokes myself, but unfortunately [Philipp](https://www.phschoen.de) borrowed the [Spoke Tension Meter](https://amzn.to/38zNXqJ) from the Toolbox Bike Workshop, and I was not able to reach him on short notice 😉
+
+But then I remembered that I saw a small local bike workshop in Markdorf, [Fahrrad Hienerwadel](https://www.fahrradhienerwadel.de).
+So I quickly went over there and brought my prepared rim, only needing to center and tension the rims.
+The shop owner was able to do the job quickly on-the-spot, in less than 20min with 15€ having been exchanged, I was on my way back to the Toolbox.
+
+He did a good job centering the wheel.
+I put the tube and tire back on and pumped it up, using an old emergency compressor from a Mercedes I salvaged, fed by a 3S Quadcopter LiPo.
+
+<!--%
+lightgallery([
+    [ "img/bike_spokes_11.jpg", "Checking the fixed rim" ],
+    [ "img/bike_spokes_13.jpg", "Pumping up the tire" ],
+    [ "img/bike_spokes_14.jpg", "Finished wheel" ],
+])
+%-->
+
+Back home, I just had to put the wheel back in the bike frame.
+Now it's good to go again!
+
+<!--%
+lightgallery([
+    [ "img/bike_spokes_15.jpg", "Bike without back wheel" ],
+    [ "img/bike_spokes_16.jpg", "Bike after the repair" ],
+    [ "img/bike_spokes_17.jpg", "Bike after the repair" ],
+])
+%-->
+
+As I mentioned above, I already completely re-built my rear wheel with new spokes a while ago, in September 2020.
+The tools for this were ordered by the Toolbox and are now available there, namely: repair stand, centering stand, tension meter and spoke wrench.
+
+Here are the verbatim notes I made back there, with some specs of my bike and wheel, as well as some useful links if you want to rebuild your wheel as well.
+
+    Centurion e-Fire 408 Tour (??)
+    https://marktplatz.bike/CENTURION-E-Fire%20Tour%20408%20%7C%20Modelljahr%202017
+
+    Schaltung:
+    Shimano Alfine SG-S7000- 8
+    https://newwheel.net/questions/pages/viewpage.action?pageId=57671795
+    https://bike.shimano.com/en-EU/product/component/alfine-s7000s700/SG-S7000-8.html
+
+    Muttern: Rechts Blau, Links Gruen
+
+    Felge Laufrad:
+    Alexrims MPD-14, 36 L. (??)
+    28″ / 622
+    ETRTO 40-622
+
+    32 Speichen, 3-fach gekreuzt
+
+    Original Speichen: 1.2mm Durchmesser
+    Ersatz Speichen von Werkstatt: 2mm Durchmesser
+
+    Passende Spannung fuer Stahlspeichen mit Toolbox Messgeraet:
+    ca. 22 bis 24 (oder 21 bis 25)
+
+    https://www.sheldonbrown.com/wheelbuild.html
+    http://www.fa-technik.adfc.de/Werkstatt/Einspeichen/index.html
+    http://www.kreuzotter.de/deutsch/speich.htm
+
+    Durchmesser des Kreises durch die Speichenenden D = 600 mm
+    Durchmesser des Nabenflansch-Lochkreises d = 92.6 mm
+    Abstand Flansch - Mittelebene a = 28.65 mm
+    Anzahl Speichenkreuzungen k = 3
+    Speichen-Anzahl n = 32
+    Speichenlänge = 286.0 mm
+
+    286mm ist die korrekte Laenge!
+
+Even though I heard bad things I have to say rebuilding a wheel is not that hard.
+Just read through some tutorials on the web or watch some YouTube videos on the topic and try it yourself!