Giant Crankset, anyone else with problems?

[thewoobie]

I bought an '04 Giant Yukon back in January. I have mostly been riding it to and from classes which is about 2 miles several times a day. So let's say I put anywhere from 8-10 miles on it a day, 5 days a week. Until recently, no trail riding which is really pathetic but that's another story. About a week after buying the thing I notice the crank is coming loose but I'm in the middle of nowhere and don't feel like walking several miles because I'm already late for an appointment. So I pedal with one leg on the side that isn't loose. Take it to the shop I bought it from, they tighten it because I didn't have tools on me. It comes loose again within 5 miles. Take it back, they say it's wallowed out and needs to be replaced, it'll be covered under warranty. So from this point on I'm really watching it and tighten it pretty religiously.

Fast forward to this last weekend. I was riding a pretty steep hill climb and notice the crank grinding on my bottom bracket. Shit. Now I'm really pissed. Take it in, the tech claims that since it showed signs of not being torqued correctly I have to foot the bill. So I get a slightly upgraded new crank on a bike I purchased less than a year ago and it's only been ridden on the street up until this point. I've never had this problem before with cranks, I've only worn them down after riding them 100x further than this one made it. Anyways, any suggestions on how to keep those damned bolts tight other than to keep tightening them? One theory I have is that I weigh a decent amount (225) and the cranks that come stock on these bikes can't handle the torque I put on them with the weight. Who knows.

Overall, I'm not very impressed with this bike thus far because of this incident. Anyone think I should contact the maker and see if they'll rebate me or something? I realize you gotta pay to play but after just spending several hundred on a new bike you would think it could last me more than 6 months without a fairly significant component failure. Matt

[christyle]

Chances are both those crank sets are square taper Bottom Bracket designs. Square taper is old-school/new-school cheapo, so they aren't that great if theyre on a newer bike. Ive had square tapers before, if it ever is even the slightest bit loose, it will start to round the hole in the crank and will never stay on for long again. I was in a 45 minute race once with a square taper BB, came loose 3 times, i tightened it and kept going.

Solution: splined interface. I run nothing but ISIS spline stuff and have never had a problem with rounding them, even after riding them when fairly loose. Get a cheap setup from somewhere like jensonusa.com, pricepoint.com or the like and forget about them. Its an easy install if you have a 1/2" drive ratchet, the ISIS crank puller and the correct tool for the install. You need a special tool to install the bb and theyre different for different brands. Take it to a shop and they'll charge an arm and a leg, as im sure you already know.

As far as reimbursment for the tweaked ones, tough luck, doubt it will happen. PM me or aim (goinscaryfast) me if you have any more bike questions, I work in a shop.

[Traveller]

Another tip is to use blue loctite on the thread of the crank arm bolts. Another thing I do is I check and tighten my crank arm bolts (Campy Record square taper) on a weekly basis.

In a pinch, you can use adhesive aluminum tape (used by duct makers) to tighten things up. It'll get you around until you can get a replacement. I put a couple thousand miles on a bike with this mickey mouse fix, but eventually it started clicking again so I had to get another crank arm.