Servicing a bike
Broken derailleur cable
Recently my rear derailleur cable broke in the middle of a ride. Good thing it was on a Saturday morning, and a bike shop was only a few kilometers away.
The symptoms leading up to the moment it actually broken are pretty simple: all of a sudden, I could no longer shift to the 2 rightmost speeds. The explanation must be that the cable was so worn out that it would not slide properly/completely. After the symptoms appeared, it took about 50 gear shifts for the cable to actually break. When it did so, my rear derailleur suddently shifted to the rightmost speed (the hardest). Fun!
Rim cracks at spokes (wheel problem)
This one is pretty hard to identify at first. For me, gradually over some rides I started noticing like a rubbing noise. The noice would be there regardless of me pedaling or not (can be hard to hear when not pedaling because of the freewheel).
Turns out this is a very common problem with wheels. Can't be fixed, all you gotta do is replace the whole wheel (or rim if you like to build wheels).
My wheels are the entry-level ones from Mavic, the Aksium. It looks like the entry-level wheels from DT Swiss (P1800 spline) are better made. Or maybe I should get the mid-level DT Swiss PR 1400 DICUT 21 or 32? In their OXIC version? Supposedly it breaks better, with the right blue pads from DT Swiss.
Tips for buying wheels
- "Centerlock" is a disc brake technology
- Look for clincher wheels, not tubular
- Careful with the freehub compatibility, for me it needs to be compatible with Shimano HG-L (cause I have 11 speeds)
How to true a wheel and fix spoke tension
Don't forget to re-align bladed spokes for best aerodynamics.
As to the tension, this website recommends:
- 90 to 110 daN (daN = decaNewtons) for a front wheel
- 90 to 110 daN for a rear wheel right side (cassette side)
- the tensions of the spokes on the right side (cassette side) is round about 70% higher than the tension on the left side, (NB: if the spokes are the same)
After asking Mavic directly over the phone (because no information available online), they recommend the following:
- Rear wheel right side (cassette side): 90kgs, +/- 10kg
- Rear wheel left side, and front wheel: 80kgs, +/- 10kg
State out of the factory for a rear wheel Mavic Aksium
They're not the best wheels out there for sure. Check out the default truness, both the radial trueness (saut in French) and lateral trueness (voilage in French) are off.
The average tension was as follows:
- Right side (cassette-side): 46.7, measured with a calibrated Unior 1752/2 tension meter
- Left side: 51.05, measured with a calibrated Unior 1752/2 tension meter
- Front wheel: 283-mm long, 2mm diameter (as measured by me)
- Rear wheel right side (cassette side): 283-mm long, 2mm diameter (as measured by me)
- Rear wheel left side: 301-mm long, 1.2x3.0mm blades (as measured by me)
Adjust front Shimano 105 derailleur