giant rapid 1 has rattling shifters

[Jason]

Has anyone experienced this on a flat bar bike with Shimano Tiagra 2x10-speed shifters and Shimano 315 hydraulic disc Brakes with 160/140mm rotors.
The issue I have is a rattle coming from the left hand combo, especially over poor road surfaces. It's very annoying and I'm not getting much joy from the Giant store.
Dropped the bike off again this morning, and requested they strip that area down to find the rattle.
The bike is only 2 months old, so what are my rights in regard to getting this fixed to my satisfaction?
My 29er has similar shifters and they are silent , so the initial fobbing off won't work in that all bikes have a little rattle

 

[Cycleops]

Sounds like something might be loose. The bike shop should be able to find it and it’s still under warranty.

 

[Jason]

The store just rang back and says they can't hear anything, apart from the brake handle and he says that cannot be adjusted. Even a new lever will do the exact same thing???
I'm a little lost as to what I should ask him to do next, so he has suggested some grease on the pivot to damp that movement down - any suggestions from you mechanically minded folk?

 

[ColinJ]

I had something similar on one of my bikes. It has a Campagnolo rather than Shimano groupset and I don't know if Shimano works the same way, but my brakes use the tension in the brake cable to pull the brake lever back to its normal position. One of my cables got gunked up so there was quite a lot of friction which the spring in the brake calliper was unable to overcome. If I pulled the brake lever back, I could feel the stickiness in the cable but once I had done that the rattling stopped until I operated the brake again. If your brakes work the same way, check your cables!

 

[Jason]

thanks ColinJ - it's a new bike and only used on roads, so cannot be gunk in the cables, but will ask them to check that

 

[ColinJ]

thanks ColinJ - it's a new bike and only used on roads, so cannot be gunk in the cables, but will ask them to check that

I suppose that one of the lengths of cable might be kinked or crushed in some way, introducing unwanted friction? If you pull the brake lever very gently do you feel any unexpected friction? My brake lever stuck until I pulled harder and then it suddenly operated.

 

[Jason]

picking it up tommorow - to be fair Giant Crystal Palace just rang to follow up, even though the bike is in Giant- Radlett. will try your suggestion :-)