Hi all, A car pulled out of a junction and went into my sons Marin bike. He went over the bonnet but thankfully was fine. However the bike was unridable. He took it in later that day to the shop he bought it and the mechanic gave it the once over. He said the crank bent inwards and the frame was slightly bent. He recommended my son ask the lady who drove into him gets him a new bike as frames are so expensive. However to cut a long story short the lady who hit my son kept vanishing off the face of the earth and my son only had her phone no not her address as in the shock of the accident didnt ask for full details. However he left a message on her phone threatening to involve the police and she got her boyfriend to ring and an arrangement was made to buy him a new bike. However they did not turn up. My son realised the next course would be small claims and decided to get the bike looked at again which he hoped would strengthen his case. However this shop has said there is no bend in the frame, only the crank. Now he has no idea what to do. He is worried that there is a tiny bend that may compromise the bikes integrity or the original mechanic cooked up the story of a bend in order to secure a bike sale for his shop. How is a bend diagnosed if its not visible? Should he get another opinion? He has lost confidence in the bike but also now lost confidence in making a claim.
You really have 2 questions: How damaged is the bike? and How to squeeze the repair or replacement cost out of the lady?
The second answer is easy. If you put any value on your own time you probably aren't going to get enough money from this lady to come out ahead. I wouldn't count on getting anything.
As to the first question: What happens if you try to install a replacement crank? You have one opinion from a mechanic who has seen the bike and thinks the crank is all that's wrong. If the crank fixes the bike, you're good-to-go. If it doesn't, you'll be out the cost of the replacement crank in addition to the original crash damage. That's not good but at least you'll know for sure that a new frame is necessary.
For safety's sake, please do have the fork/steerer tube inspected VERY carefully by someone that knows what they are doing. It may have been weakened or cracked in the collision. Also, look at the head tube lugs/joints.
If the frame was only slightly tweaked and took a slight set by the crash it 'may' be possible to cold set it.
+1. It is difficult for the average person to determine if there is damage to the frame. We used a table that had adjustable supports on it. The table would be set up for a particular brand of bike and the frame would be set on the tubes from one side. It would then be reversed and set on the tubes from the other side. Any variation of more than 1/32 of an inch indicated that the frame was bent. A visual inspection of all of the lugs, looking for cracked paint or stressing of the lug was also done. The fork was removed and the steerer tube would be checked to ensure that it was straight and also that the forks were in line with the tube. The last thing would be to check the down tube for any signs of damage as this is usually the part that gives in a collission.
I have ridden a slightly bent frame for years. It is more fun to ride now than it was brand new. The slight bend changed the geometry just enough to make it much more responsive and livelier. It is definitely not a ride for a novice or someone faint of heart. Years ago I was quoted a price of $20.00 to straighten it, but it is much more fun the way it is.
Hi all, A car pulled out of a junction and went into my sons Marin bike. He went over the bonnet but thankfully was fine. However the bike was unridable. He took it in later that day to the shop he bought it and the mechanic gave it the once over. He said the crank bent inwards and the frame was slightly bent. He recommended my son ask the lady who drove into him gets him a new bike as frames are so expensive. However to cut a long story short the lady who hit my son kept vanishing off the face of the earth and my son only had her phone no not her address as in the shock of the accident didnt ask for full details. However he left a message on her phone threatening to involve the police and she got her boyfriend to ring and an arrangement was made to buy him a new bike. However they did not turn up. My son realised the next course would be small claims and decided to get the bike looked at again which he hoped would strengthen his case. However this shop has said there is no bend in the frame, only the crank. Now he has no idea what to do. He is worried that there is a tiny bend that may compromise the bikes integrity or the original mechanic cooked up the story of a bend in order to secure a bike sale for his shop. How is a bend diagnosed if its not visible? Should he get another opinion? He has lost confidence in the bike but also now lost confidence in making a claim.
Please help!!! 🙁
One way to check a frame is true is to run a string from one rear dropout around the head tube and back down to the opposite dropout. Then you can take measurements from the string to the frame tubes. You may have to do some disassembly to do this but it works.
One way to check a frame is true is to run a string from one rear dropout around the head tube and back down to the opposite dropout.
Minimal disassembly, just remove the rear wheel and seat tube bottle cage if necessary. This is the way the best mechanics measured steel frames for cold-forging in the olden days. There are other measurements, too, but if this one is right, chances are the bike's OK.
Find a good shop or a bike builder in your area. They should have an eye for the obvious damage to the frame. This may not cost you anything... if they think the frame looks ok on visual inspection without disassembly then I would replace the crank, either with a new one or used one or loaner... ride the bike and see if it tracks ok riding no hands. If it does I would 'ride on'...
One other thought is that we don't know how straight this bike was to begin with... especially the alignment of the head tube > seat tube > rear triangle, which is what the string method will diagnose.
If the frame is ok perhaps the reduced cost of only a crank replacement will coax some money out of the driver~! one can hope...
