28
votes
Accepted
Loose spokes after only a few rides
Unfortunately, most bikes are only rated to 300lbs or less. However, if this is a new bike, you should take it back to the shop and get them to fix it. They can't claim they didn't know you were a ...
- 17k
28
votes
Accepted
What are the counter-intuitive surprises an amateur bike mechanic encounters, after pedals and cables?
More grease is not always better. Attracts excessive dirt and stuff.
Well-greased bearings don’t spin smoothly by hand. Lots of amateur mechanics under-lubricate or use too thin of a lubricant because ...
25
votes
Accepted
Infeasibility of a mechanical wind-up spring KERS (Kinetic Energy Recovery System) for bicycles
Ain't gonna happen.
If you want to store energy of a 100kg cyclist+bike going at 40 km/h (plausible if you want to brake at the end of a downhill), you want to store:
0.5 * 100 * (40/3.6)^2 = 6170 J
...
- 20.5k
15
votes
Reverse Gear in Bicycles
Such a hub exists for trike and quads . Pedal forward with 3 or 5 gears then having a coaster brake to stop . At full stop with the brake engaged continued backward pedal pressure will cause the cycle ...
- 266
14
votes
What are the counter-intuitive surprises an amateur bike mechanic encounters, after pedals and cables?
Anyone tinkering with bikes needs to be aware of the perverse variety of standards (how many bottom bracket standards are there now?); that multiple actual sizes can be indicated by the same nominal ...
12
votes
Broken stem tube – LBS "just" lowered handlebars. Is this safe?
Here's how I would fix the problem. This could all be done by somebody with basic tools and basic knowledge.
Get a quill-threadless stem adapter and a new stem. This will allow you to fit the new ...
- 21.9k
12
votes
Infeasibility of a mechanical wind-up spring KERS (Kinetic Energy Recovery System) for bicycles
The idea looks nice at first glance, but the deeper you get into the details, the less attractive it becomes:
You need to be able to modulate your brakes. As such, you need some transmission between ...
12
votes
Is it okay for my rear derailleur to be as "compressed" as this when in the lowest gear on the bike?
There's no issue with it looking like that while in small-small. It's very normal.
The derailleur's total capacity number defines what large/large combination is supported while still allowing the ...
- 87k
11
votes
Loose spokes after only a few rides
I completely agree with the accepted answer of @David Richerby from personal experience.
As a heavier rider (~22 stone) for many years, I also found with a couple of different bicycles that the rear ...
- 211
10
votes
Broken stem tube – LBS "just" lowered handlebars. Is this safe?
What you have now is a bit of a hack, but it could be good temporarily so long as you don't over-stress things somehow, and if you can tolerate the lower handlebar. (Note, I haven't seen how your ...
- 53.9k
10
votes
Accepted
Chain popped out of derailleur and wrapped around itself - how? why?
Looks fixable - take the lower jockey wheel off (3mm allen) and clean it thoroughly by scratchng the dirt off (most satisfying) and then with something liquid (hot water+dishwash or some solvent)
Use ...
- 129k
9
votes
Accepted
Shimano Deore hydraulic brake problem
The part that popped out is one of the pistons.
There should always be a bleed block in place between the pistons when bleeding the brake. Immobilizing them this way is what prevents overfill and also ...
- 87k
9
votes
Pad spacer and mechanical disc brakes
No, mechanical disc brakes do not auto-compensate for pad wear like hydraulic brakes do. They will fully retract every time, pads or no pads.
- 16.9k
9
votes
Accepted
Is buying a used bike bad if you are not expert?
I don’t think it’s a bad idea, but be prepared to repair stuff.
Things even a novice should be able to check:
Frame and fork without damage (i.e. no cracks or dents, nothing bent). Small paint chips ...
- 28.7k
9
votes
Is it okay for my rear derailleur to be as "compressed" as this when in the lowest gear on the bike?
Maybe your chain is too long. It’s always hard to tell from photos.
If there is still tension on the chain in the smallest sprocket + smallest chainring combination it’s probably fine. You’d need a ...
- 28.7k
8
votes
Accepted
How to reassemble a completely disassembled brake caliper?
Here's a version of you picture with labels on the parts I'm probably not using the correct names but these will work for this purpose.
I'm assuming you know where each part generally fits but are ...
- 75.9k
8
votes
Accepted
Wrench to be used with a bottom bracket tool?
The tools being used there are:
Bottom bracket tool
Large socket to engage with the large hex head on the BB tool
Sliding T-handle socket driver
Some bottom bracket tools such as the Park BBT-22 ...
- 75.9k
8
votes
Accepted
Replacing an FSA chainring
The main limiting factor is chainstay clearance. If your chainrings touch the chainstay it will wear and weaken and eventually fail. So the first thing is google your bike frame and see what maximum ...
- 129k
8
votes
Loose spokes after only a few rides
Spokes getting loose is not a laughing matter. The more spokes get loose or break, the more uneven the load is distributed to the spokes, and the more likely other spokes are to get loose or break. ...
8
votes
Stripped brake mount on fork lower
Regardless of whats wrong - a brake is a critical component of your bike and you should not take risks.
If your brakes are malfunctioning, stop riding the bike until its fixed.
Don't be tempted to ...
- 129k
7
votes
Accepted
Freezing headset cups to ease installation - does this actually work?
According to this link the thermal expansion of aluminum 6061 is 13 micro inches/(inch x °F). A headset has a diameter of 1.125 inches, and circumference of 3.5325 inches. Assuming you change the ...
- 21.9k
7
votes
Accepted
Are my cable disc brakes knackered?
Usually what causes this (literally no braking, firm lever feel, lever nowhere close to bottoming) is an error in brake setup or adjustment wherein the brake caliper's armature is being pulled to the ...
- 87k
7
votes
What are cheap options for an extra set of brake levers for mechanical disk brakes?
Presumably you have drop bars. Inline brake levers are your only choice. The only places to mount extra levers on drop bars are tops. With inline levers installed you can reach levers from the drops, ...
- 75.9k
7
votes
Stripped brake mount on fork lower
I am going to assume you're talking about a stripped post mount.
As others have said, don't ride even a little with only one bolt. That risks overloading the remaining bolt and causing a brake failure ...
- 87k
7
votes
What are the counter-intuitive surprises an amateur bike mechanic encounters, after pedals and cables?
In my experience, BSA and T47 cups are counterintuitive, and it is the right side cups that are left threaded, I.e. opposite to the case for pedals.
Note that the original question was more broad, and ...
7
votes
Accepted
How do I get off my totally stuck freehub body?
Just to be clear, the part shown on your pictures is called a freehub body (black cylinder with splines). It incorporates the ratchet system enabling the hub to engage one way and to disengage the ...
- 4,159
6
votes
Accepted
New Bike + Disc Brake Shuddering: Cause and Fix?
Skipping the "proper" bedding in process can do this yes. Bedding in brake pads impregnates the rotor surface with material. There is a particular process to do it because you want a good even layer. ...
- 9,342
6
votes
Accepted
Is it normal for a bike to skid even after both brakes are applied?
To answer the question shortly: yes, it is normal.
When braking, the inertia of the rider (and the bike) causes the load on the rear tire to decrease. It leads to lower friction against the surface, ...
- 76
6
votes
Mechanical disc brakes lacking stopping power
I have TRP spyres and while I find they perform better than BB7's when properly adjusted, they are very sensitive to adjustment. They have a very narrow range between rubbing the disk and too far away ...
6
votes
Why does my chain have a single hollow pin?
Its not a master link - that's probably the one-use pin that was used to close the chain the first time.
This is what a Shimano pin looks like after its been snapped off. There's a clear difference ...
- 129k
Only top scored, non community-wiki answers of a minimum length are eligible