A failed stealing attempt left my Bianchi Via Nirone 7 road bike with an ugly damage to the frame. The bike is still in place, and it hurts me every time I go to the bike shed. They removed the front wheel and twisted it 90 degrees, with the back wheel all the way up. The Kriptonite 2 D lock bent, but did not give in. Same for the frame. There is a big dent on the top tube of the frame.

I am considering buying a frame and having it replaced.

  1. Any suggestions on which tools I could use to remove the jammed Kriptonite Series 2 lock?

  2. When looking for frames, what are the technical specs that I have to pay attention to if I want to be able to re-use the fork, the seat tube and the pedals?

  3. How unsafe is it to use the bike with a dented frame?



2 Answers 2

  1. An angle grinder with metal cutting disk (or abrasive disk) will remove a U-lock in about 30 seconds. It is shocking how easy it is to cut through the shank. The one consolation is that it does make a lot of noise and a lot of sparks (and requires either a power cord or an expensive battery grinder), otherwise more thieves would be using them. If you do not have access to an angle grinder (and don't want to stop by your local bike shop, auto mechanic, or police station, all of whom will undoubtedly have one), then a hacksaw with a new blade (or two) will eventually cut through, although it may take up to half an hour of vigorous sawing.

  2. You should be able to bring over most of your previous components. However, be aware that bottom bracket sizes/types have changed considerably, the caliper distance (reach) and mounting style of brakes have changed, and there are peculiarities to seat tube and front forks based on country and year. Thus, unless you are replacing an early 1990s Italian road frame with an early 1990s Italian road frame (for example), you may find limited component capability. Pedals for almost all recent bikes (except some cheap BSOs and children's bikes) are standardized thread so those will come over fine.

  3. Yes, dented frames are dangerous -- especially aluminium and carbon fiber as their failure modes can be quite dramatic. Steel frames tend to fail more slowly (and can be re-welded).

tl;dr: Things that you can bring over (in general): Handlebars, brifters, seat, pedals, crankset, seat, front and rear derailleurs (with caveats).

Things you might not be able to bring over (unless your bike is the same era/style): bottom bracket, steerer/stem, seat stem, brakes, forks.

  • Don't crankset and BB go together (if you can still use one, you can still use the other)?
    – Holloway
    Jun 1, 2015 at 8:50
  • 2
    Not necessarily. The shell length and the spindle offset requirements may change between frames but the crank could still work. Conversely the bottom bracket may be fine but the crank might cause a chainline that's incompatible with the frame.
    – jqning
    Jun 1, 2015 at 13:16
  1. Angle grinder or hydraulic/pneumatic cutter.
  2. Head tube diameter and type of headset (threaded, threadless, integrated etc see http://www.parktool.com/blog/repair-help/headset-standards) yours appears to be 1 1/8" threadless. (Also since you are reusing a fork you'll need to know the head tube length and headset stack height to make sure your fork steering tube is long enough), seat post diameter, pedal spindle diameter and thread pitch most likely 9/16-20 which is standard. . (However, it's unlikely that these are the only components you can reuse)
  3. It can be dangerous because it can fail. Imagine your bike disappearing from under you but since it doesn't actually disappear you get tangled up in torn metal and you go sliding down the road together.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.