Shouldn't use two extreme gears? I purchased a new Mountain bike a month ago and noticed after a week or so the gears were starting to slip, this was expected because of stretch in cables and wear in etc so I took it in for a tune up at the place of purchase and when I got it back the gears were still slipping in places.
I then took the bike to a local mechanic and he said that I shouldn't be using the gears on the high extremes ie the two smallest cogs at the back because of the angle of the chain. I will admit I am no expert but in all my life I have not heard this, is this true?
Thanks
Thanks to all that answered! and to add to my question to clarify some points, i have 3 chain rings on the front and the slipping sensation is more like a clunk from the front crank when i put pressure on the pedals, its not a constant noise. this happens on a flat surface so its impossible to use this gearing on an incline.
It only happens when i have the chain on the small front ring and either of the two smallest back cogs.
I also get a 'ghost' gear shift when i use the middle front chain ring and either of the two smallest back cogs.
There seems to be polarising opinions about cross chaining which i will look into but either way i think i should be able to use all my gears if i want too. yes?
Using the smallest chainring with the smallest sprocket or the largest chainring with the largest sprocket should indeed be avoided. It’s called “cross chaining”. It’s less efficient and causes slightly increased wear and noise. On the small-small combination it can cause chain slap (because the chain will be almost slack) and on the large-large combination the chain is almost taught, so getting something like a twig caught in your chain can easily cause the rear derailleur to snap.
However cross-chaining is not very bad and it should work just fine. Just avoid it if you can.
Of course if you only have a single chainring it can’t be avoided and you should just use the gears when you need them.