blazed said:
I bought it from Halfords and the front wheel wouldnt spin because it rubbed so bad, then i thought ill take it to an LBS and get a full service. I did yesterday which was £40, when i picked the bike up he told me the parts are mismatched and theres nothing that can be done about the rubbing short of changing them.
At the time i wasnt paying much attention but thinking about it now why would they design bikes with mis matched parts that make the chain rub. So this guy lied to me?
Well, the rear derailleur and cassette are mountain bike parts and the chainset is a road bike part. That much is true. I can't see from the picture what the front mech is and the specification doesn't say. However I'd expect it to be a road bike part because the front mech and the chainset need to match quite closely.
Having said that Boardman do not make crap bikes, so basically if neither Halfords nor your LBS could set it up properly then they're both incompetent. It isn't rocket science, and it isn't even difficult.
Vertically, the front mech needs to be set so that it clears the big chain ring by about a millimetre. fore and aft, the front mech needs to be exactly in alignment with the chainset. The limit screws need to be set so that the chain does not overshift off. And thats about it.
Having said that, if the left hand shifter has only two or three detents (as too many have these days), then you will get rubbing when on the big chain ring and the largest two cogs at the back, or on the small chain ring and the smallest two cogs at the back. That is normal and nothing to worry about, although it puts less strain on the chain if you avoid these extreme crossed gears. If the shifter has more than two detents, then when you hear the rubbing, trim it!