Bicycle Mechanics - Crank fell off while riding!

So after some root/rock bashing with the bike (forest trails) i desided to get a drink from a store (lidl, german i think) well, after the forest ride (5km or so) im on the road on the way to this store... and my crank just flies off while pedalling! theres this hex bolt that holds it in and i guess that came loose... its a truvative firex... oh its the crank with out the chain rings... whats going on here??? should i check for somthing else that might come off?

thanks, lol scared the ***** outa me, oh and now its knocking (i can feel/hear it) a bit every coplete cycle/pedal (revaloution)

If the crank-arm fixing bolt was loose enough to allow the crank arm to come right off during a ride, then you've probably ruined the crank-arm / bottom-bracket interface as well. In other words, you might be able to put the crank-arm back on, but you'll never get it properly tight again -- it'll just keep working its way loose. That's probably what the "knocking" sound you refer to is -- you're flexing the crank-arm against the bottom bracket spindle and ruining it some more.

If I were you, I'd toss the crank arm and bottom bracket and install new ones.

A new BB is not usually necessary. Hardened steel spindle vs. alu crankarm is no contest. You should be able to snag a new arm relatively inexpensively at your local shop.

Call Truvative, they will gladly send you replacements. There was a tech bulliten about the Truvative splines interface and how to properly torque it. I have seen many come apart.

Ah, good call. Forgot that they were hooking people up on those.

Firex is most likely square taper, in which case the recall/warranty does not apply.

If the crank-arm fixing bolt was loose enough to allow the crank arm to come right off during a ride, then you've probably ruined the crank-arm / bottom-bracket interface as well. In other words, you might be able to put the crank-arm back on, but you'll never get it properly tight again -- it'll just keep working its way loose. That's probably what the "knocking" sound you refer to is -- you're flexing the crank-arm against the bottom bracket spindle and ruining it some more.

If I were you, I'd toss the crank arm and bottom bracket and install new ones.

+1

Tim

well obiosly(sp) im going to check up on warranty, and then make the lbs take a look at it and see what went wrong... lol first my seat post and now the crank... maybe i should have gone with the hoss... lol