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Strange problem from a new build

Steve_FSteve_F Posts: 682
edited August 2010 in MTB workshop & tech
I finished building up a Saracen Zen that I bought off eBay with a combo of bits I had lying around the flat and more new bits than I intended!

Bottom bracket and cranks came with the bike.

As soon as I turned the pedals I felt a strange feeling in the rotation in the pedals. Best way to describe it is an ovalised feeling. First guess was that the crank arms were different lengths. They're not.

Tried to remove the cranks and BB but couldn't get them to move (not sure exactly how they should come off - Truvativ Howitzer cranks and presumably a Truvativ BB but it doesn't say).

Thought now is that there is a problem with the cranks and BB which are seized but wanted to see if anyone recognised the symptoms before attacking it with a big hammer!!

Oh yeah, the cranks will only spin a few times when upside down with no chain on and try spinning back when they get to a certain point before stopping.
Current steed is a '07 Carrera Banshee X
+ cheap road/commuting bike

Posts

  • nicklousenicklouse Posts: 50,675 Lives Here
    either the bearings have been crushed by using incorrect spacers or the BB sheel need facing to allow the bearings to run true.

    arm removal is by self extracting bolts or ISIS/octalink crank puller. BB removal is by External BB tool.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Steve_FSteve_F Posts: 682
    Thanks very much Nick.

    Those BBs don't look too expensive so once I get it removed I'll get it replaced.
    Current steed is a '07 Carrera Banshee X
    + cheap road/commuting bike
  • nicklousenicklouse Posts: 50,675 Lives Here
    remember to check the info on the current one as there ate 2 versions that give different chainlines. 50-52mm

    and only Howitzer BB are compatible with the cranks.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Steve_FSteve_F Posts: 682
    Well, if only life was that simple.....

    Took the bike into Halfords to get the cranks removed as I don't have that tool. The second guy to look at it instantly says 'you do know the cranks aren't on straight?' they weren't - couldn't see that for obviousness!

    Nice easy fix I think, whip the crank off and straighten it. Of course not! Extractor won't screw in as the thread is knackered. Needs to come off so they try anyway - threads stripped as expected.

    Off to B&Q for a hacksaw to cut the crank off. Budget build was getting towards/past my top end before now I'd have been as well getting a new bike! Hopefully I can salvage cranks off one of the frames in my flat but I'm betting against it just now!!!
    Current steed is a '07 Carrera Banshee X
    + cheap road/commuting bike
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