Hot answers tagged

29 votes

Frame failure sudden death?

If an aluminium frame has to be bent back into alignment, it's trashed. Aluminium cannot be deformed without causing weakness in the material. If the bicycle repair shop literally hit the seat stays ...
23 votes
Accepted

Is it safe to use a bike tire that was on a wheel that got tacod?

It should be perfectly safe to re-use the tyres. Many tyres are stored folded/twisted in their packaging to save space. I would however recommend carefully inspecting each tyre first, checking for ...
  • 17.7k
17 votes
Accepted

Recently had a slow-speed crash - wondering if I should replace my helmet

It is generally recommended to inspect a helmet and replace if necessary after an impact. Inspection involves pressing on the outside shell looking for areas where the foam is compressed and taking ...
  • 17.7k
16 votes

Is it safe to use a bike tire that was on a wheel that got tacod?

Tyres are flexible in all directions so tacoing the wheel won't in and of itself damage the tyre. However, in real life, it's hard to taco a wheel in an accident without pushing the bike sideways ...
16 votes

What do I do when I am unsure if damaged carbon fiber is safe to use or needs replacing or repairing?

Carbon fiber composites are made up of sheets of carbon fiber filaments. These are usually impregnated with resin. To make CF structures, manufacturers will cut up the sheets, then lay them up onto a ...
  • 23.3k
14 votes

What's the proper science-driven way to treat mild scrapes/abrasions (that have a bit of dirt in them) from a mountain biking crash?

Briefly, a quick rinse with clean water, and possibly dressing it, are probably all you need to do on the trail. This assumes a day visit to a typical trail centre or cross country riding near to ...
  • 49.5k
13 votes
Accepted

Bending back a bent head tube - is it worth trying?

Not to disparage any of the very knowledgeable people here, but the best you'll get from a couple of pictures on the internet is a "good guess", or maybe even an "educated guess" but in my mind that's ...
  • 1,453
13 votes

Bending back a bent head tube - is it worth trying?

I personally wouldn't ride this frame. The degree of localized distortion means the steel will be work-hardened at that point and will fatigue, crack and the front of the bike will collapse under you. ...
10 votes

Bending back a bent head tube - is it worth trying?

The frame has undergone plastic deformation, which took it close to failure, and there might be small points of failure hidden under the paint, for all we know. The fact that it has completely buckled ...
  • 25.6k
10 votes

Frame failure sudden death?

For the long term, that repair should not be trusted and the point of weakened aluminum is correct. However, if this is your only transportation and you can't get anything else immediately, I would ...
  • 301
10 votes
Accepted

Post crash damage assessment: can I keep this carbon fork and this front wheel?

I can't see the marks on the fork to which you are referring. They may not show up well in photos. The rim brake track appears to have some road-rash damage. I would remove the tyre/tube, and gently ...
  • 109k
9 votes

Total brake failure - trying to understand what happened

Since recovering from my crash, I've put a bit more thought into this. I replaced the calipers, rotors and pads, with Avid BB5s - so very similar to the Promax ones that were essentially copies of ...
  • 49.5k
9 votes

Bending back a bent head tube - is it worth trying?

The degree of crumpling is relatively unusual and suggests a thin walled, high strength tube selection, which also frequently goes along with handbuilt frames. The material property that is the ...
8 votes

What's the proper science-driven way to treat mild scrapes/abrasions (that have a bit of dirt in them) from a mountain biking crash?

Simple skin abrasions/grazing: Symptoms: bleeding, can still walk. Sit the patient down out of the way. Let the blood flow for a short time to help push out embedded debris. Rinse the area with ...
  • 109k
7 votes
Accepted

Safety guidelines when using MTB clipless pedals on a road bike

This answer is for SPD pedals, which are the most common MTB pedals. Other systems do not have multi release cleat, and some don't even have adjustable springs. First: make sure you do not have multi-...
  • 20.9k
7 votes

How do I stop people blaming me for a crash?

I dispute your claim that the collision was entirely the pedestrian's fault. Of course, the pedestrian shouldn't have stepped into the road without looking. However, you, as a road user in a busy city ...
7 votes
Accepted

Replacing Ultegra R8000 'long cage' derailleur (crash repair advice)

The Evans site is in error. Generally road derailleurs come in SS (short) and GS (medium) versions. The SGS long types are found in MTB groups. Your derailleur may be scraped up but not bent and ...
7 votes
Accepted

Falling over on carbon frame bike -- likely to cause damage?

In practice, there is one thing I've seen enough to call it a pattern: aero/teardrop carbon seatstays and chainstays cracking near the joints after being flexed excessively during a crash. Some of ...
6 votes

Replacing Ultegra R8000 'long cage' derailleur (crash repair advice)

A medium cage is fine with 11 up to 34. It may have been marketed by E. as a long cage. BTW: check the derailleur hanger, it might be bent. Also, don't throw the bent derailleur away. It could still ...
  • 8,193
6 votes

How do I stop people blaming me for a crash?

Note: this answer is not trying to determine or attribute blame for the incident, rather it focuses on why the general public may attribute more blame to “cyclist” than may seem appropriate to the ...
  • 30.1k
5 votes

How do I stop people blaming me for a crash?

Have you noticed when people (especially road users) have confrontations in anger, they’re usually not listening to what the other person has to say? Normally each party is forcefully putting out ...
  • 12.3k
5 votes

Falling over on carbon frame bike -- likely to cause damage?

Any lightweight road frame of any material can be dented very easily. As long as you don’t see a mark on the frame indicating that it touched the ground, there’s nothing to worry about.
  • 13.2k
5 votes

Post crash damage assessment: can I keep this carbon fork and this front wheel?

The wheel may well be ok and is not too expensive to replace in any case. The fork could be ok, but it's asking alot of this format to get a good answer. if the steerer tube is carbon, i would be ...
  • 12.2k
5 votes

Would It be fatally dangerous to ride with this dent [Pictures]?

My opinion is, in short: buy a second bike. The long version: if biking is so important to you that you can't wait 8 weeks to have it inspected by someone who is really qualified to answer, having ...
  • 11k
5 votes

Is this a crack? Came off my Carbon frame for the first time

While one can't really be certain without performing an X-ray inspection, I think it's pretty safe to say this one is just a paint chip. The two later-added photos show the location and size of the ...
  • 13.2k
4 votes
Accepted

Total brake failure - trying to understand what happened

This is purely a hypothesis Firstly, i'm going to work under the assumption that the pads are either organic, or some sort of organic/ceramic hybrid compound. I can't actually find pure ceramic BB5 ...
  • 17.7k
4 votes
Accepted

Front Fork Won't Stay Centered

Presumably what is happening is that the stem bolts are not providing enough clamping force of the stem onto the steerer, and the stem is moving off center. You can check the alignment of the stem and ...
3 votes

Total brake failure - trying to understand what happened

I believe this could have happened due to brakes overheating. I am fairly certain that by continuously dragging the rear brakes you could have overheated them. You should investigate the rear brake ...
3 votes

Replacing Raleigh record ace forks circa 1978

I've worked on two bikes with crash damage, and helped bring them back to rideable. Please post some clear and well-lit pictures of your bike. We also need to know how the crash happened - was it a ...
  • 109k
3 votes

Safety guidelines when using MTB clipless pedals on a road bike

I use MTB shoes and pedals (Crank Bros Candy) on the road all the time and have never had a problem. I don't see why MTB style pedals would present a greater risk of the cleat coming out of the pedal ...

Only top scored, non community-wiki answers of a minimum length are eligible