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Issues with Giant Rapid 2 (2011)

DebashDebash Posts: 2
edited January 2012 in The workshop
Dear all

I purchased a Hybrid bicycle, model “Rapid 2” ( ... 298/44051/) made by Giant Bicycles, Taiwan. I purchased the bike about 2 weeks back. The bike comes with “Shimano Tiagra” rear derailleur and “Shimano R453” front derailleur, with Shimano R440 shifters.

I noticed that while riding there are constant noises coming from the chain ring brushing against the derailleur/ jockeys, with the gear combinations of:

a) 2nd gear in the front (2nd chain ring) and 7,8,9 and 1st gear in the rear
b) 1st gear in the front (smallest chain ring) and 9th gear in the rear
c) 3rd gear in the front (biggest chain ring) and all gears in the rear

I brought the cycle to the shop and asked them to fix it and ensure that for all the gear combinations there are no noises. I was told that there will always be some noise arising from chain ring brushing the derailleur/ jockeys with certain gear combinations, and it cannot be avoided in road and hybrids. He claims to be trained by Shimano and Giant and also claimed that he can demonstrate that even bicycles costing $10,000 and above have this problem. He asked me to tell him as to which combinations I use while riding and he will tune it to ensure that there are no noises only for those combinations.

Wanted to check with you guys if you face the same issue for certain gear combinations (especially those mentioned above) any Shimano component set (Shimano Tiagra rear derailleur and Shimano R453 front derailleur) will make such a constant noise arising from Chain ring brushing against derailleur / jockey. If yes, then if anyone can provide a technical explanation as to why this happens.

In my view, a new bicycle with all new components should not have any noise coming from components brushing against some parts. If this indeed is normal, then I should have been informed about this before I purchased the bicycle.

Would appreciate your views. Thanks in advance.



  • There are many schools of thought, but cross-chaining (i.e. biggest chainring/biggest sprocket, smallest chainring/smallest sprocket) is generally agreed not to be a good idea as it stresses the chain sideways which its not good at doing..

    It should be possible to set it up so that, on a triple, the middle chainring and all sprockets run quietly, but you will usually get some noise if you cross-chain it on the top or bottom 3 sprockets in the cassette and the chain will rub on the inner or outer of the front mech, and/or on the jockey wheels. Much depends on the size of the gate on the front mech and the chain-stay length. On a longer wheel-base bike the angle of the chain is less pronounced so will rub less, whereas on a racer with a shorter wheel base it may well rub more (but then would probably have a compact or double rather than a triple)

    So the short answer is he is not entirely wrong, depending on the design of the bike you may always get some rub, but its possible to set it up so that there is minimal rub in the usual gear combinations... of course setting it up so it is quiet on the bench may not be perfect on the road, depending on how much the BB and frame flexes when you are putting the power down, which is also related to your weight and your cycling style... flexing is always more prevalent on a lower end bike... simple fact, more expensive frames flex less

    Chain choice has a bearing on this; the correct chain for the Tiagra RD4500 rear mech/HG50 cassette will be a Shimano 9speed HG53 chain with a chain line of 45mm, but it seems Giant chose to fit a narrower HG73 chain which can handle a chain line of 50mm (chain line is the offset from front to rear). This is probably to minimise front chain rub but will be noisier on the Tiagra rear mech. If front mech rub is the main issue you could use a HG93 chain which is narrower still and less likely to rub (but see why this isn't a perfect solution either, also more info on mechs here too) but this will also be noisier & wear more on the Tiagra rear.

    The info for the R453 mech is here and the shifters here

    A final note: My commuter bike has the same set up... I get little noise once its all set up right, but after new cables its noisy for the first few weeks as the cables stretch a little and the adjustment needs tweaking every week, thereafter it needs tweaking about every 6 weeks as parts wear, but then I am putting 150+ miles a week on it! I would strongly advise you learn to do these adjustments yourself, also read the bit in the Shimano tech doc on trimming.
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  • deswellerdesweller Posts: 5,175
    It is normal.

    Because it's a chain drive, the front rings are selected so that there is quite a lot of overlap between the gears at the back. This is to avoid driving the chain diagonally too much; the correct way to use the system is to switch between chainrings at the front in order to achieve the gear ratio you want without applying too much lateral load to the chain. If it's rattling a lot then you're in the wrong ring at the front.
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  • cooldadcooldad Posts: 32,599
    Debash wrote:
    In my view, a new bicycle with all new components should not have any noise coming from components brushing against some parts. If this indeed is normal, then I should have been informed about this before I purchased the bicycle.
    It is, and no you shouldn't.
    I don't do smileys.

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  • tonye_ntonye_n Posts: 832
    Quite normal on triple chainrings unfortunately. That is why the front mech and front shifter will have some sort of trimming mechanism built-in to the shifting action. You will get the hang of this with time.
    You will also get the hang of how to setup a triple system to minimise chain rub on the mech and chainrings with time.

    And no.... there should be no expectation that the LBS would have informed you of this unless you had also paid for a basic lesson in drive train setup.
  • pdwpdw Posts: 315
    As others have said, some noise in some gears is normal, but what you describe sounds excessive.

    What exactly is it that's rubbing? Normally it's the chain rubbing on the front derailleur when the chain is at an angle due to the gear selected at the rear. The jockey wheels are at the back and not normally a source of noise.

    Some front shifters have a trim function that effectively give you two positions for some chainrings, depending on which gear you have at the rear. On a nine-speed, I'd expect to be able to use at least seven gears at the rear on each chainring without chain noise.
  • MrChuckMrChuck Posts: 1,663
    Normal. At the risk of sounding a bit condescending, learn to use your gears properly and it will cease to be a problem.
    That said, front derailleurs can be tricky to set up so there is of course the possibility that something is not quite right, but even when perfectly set up you can expect some noise. The key thing is that there is no reason to be in the gear combinations that would cause it.
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