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Boardman Hybrid Comp users please

CritchCritch Posts: 60
edited December 2012 in Commuting general
Greets all,

I have a Boardman Hybrid Comp that I use for commuting to work. Overall, I am pleased with the bike for the money it cost, however I've just noticed something that might be amiss with the front mech, crank or chainring and would ask other Boardman users for their advice on this bike.

In top gear on the outer front chainring I get chain rub on the outer, inside edge of the mech cage for about half a revolution of the crank. Ive checked for noticeable chainring warp and bent cranks and while there is obviously some movement during its rotation I can't really pin it down other than that there is some minimal lateral movement.

Then I noticed that the tolerances on this bike are damn tight. When the front mech is on the outside chainring I get about 1mm clearance between the mech cage and the crank arm as it comes over the top. Surely this is too tight? If I adjust the front mech to prevent the chain rub in top gear it means that the crank arm is almost touching the front mech during its rotation giving me about 0.5mm clearance. In comparison on my road bide I get at least 10mm clearance between the crank arm and the front mech when its on the outer chainring. The front mech seems to be seated accurately and in the right position/angle on the seatpost tube.

Can you comment on yours and help identify whether something is amiss with mine before I go back to Halfords. Thanks.

Posts

  • The clearance on my Hybrid Comp (large frame in case there is a difference) between the outside edge of the front derailleur cage and the crank arm is very tight about 1mm as you describe. I tried adjusting mine for a little more clearance, by adjusting the limit screw, but this resulted in it not shifting to the large cog as well (or not at all). So in my case 1mm clearance is about the limit.

    Watching the chainring as it rotates it does appear to wobble ever so slightly, but I think this may just be an optical illusion caused by the different profile of the teeth around the circumference of the chainring.

    Also, depending on what gear combinations you use you will get a slight amount of rubbing on the front derailluer cage (I know I do) e.g. large-large / small-small. These are so called "cross-chain" combinations and it's not really recomended that you use them anyway.

    I've never had issues with the setup on mine, so I think it's perfectly normal that tolerances are pretty tight.

    If your bike is still within its warranty period then it may be worth popping it in to Halfords for their opinion.
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