Chain rings worn?

[Ajax Bay]

Just buy new chainrings, as @si_c has said.

 

[mynydd]

Thanks, decided to do that and had a hell of a job getting the chainring bolts out and most of them have threaded. Is this normal?

 

[Ajax Bay]

Can be, if they've never been out before. Normally they're installed with threadlock in so you have to be careful with fitting tool both sides (eg allen key and flat) to avoid 'jump out' and damage. Replacement bolt/nuts are inexpensive.

 

[mynydd]

Thanks for the reply. I think all things considered I'm probably better off getting the entire thing if I can source one cheaply enough.
So am I right now in thinking that any shimano triple will be ok, and that a new sora will be the equivalent of the old tiagra I've worn down?

 

[Ajax Bay]

Think you're right: the extra cost of the bolts tip the balance. You don't need to target Sora btw; as well as all old Tiagras, a new Tiagra 10sp will work fine and any old (ie not spanking new) 105 10sp triple for that matter. (The new Shimano 105 groupset has made the jump up to 11-speed and there's a triple chainset in the line-up).
Or a non Shimano one compatible with . . . one that's a fit for your BB bearings (HollowTech II?) of course.

 

[sidevalve]

Bits - check E Bay

 

[fossyant]

If you use a 9 spd chain on a 10spd it will not be so good as the 10spd chain is narrower. You will find it is cheaper it buy the whole chainset rather than individual rings - you need Sora which is 9 speed

Makes no odds as most after market chain rings are 9/10 speed compatible stamped on them. I use 9/10 speed rings with a 9 speed chain on an 8 speed cassette.

 

[Ajax Bay]

Could do a lot worse than this (currently 40% off and same as the Sora one (3503?)):
http://www.chainreactioncycles.com/shimano-tiagra-4703-triple-10-speed-crankset/rp-prod137766
http://www.chainreactioncycles.com/shimano-tiagra-4703-triple-10-speed-crankset/rp-prod137766
@fossyant and @Spoked Wheels have already said/corroborated that a 10sp chainset will be fine with a 9 speed chain (we disagree with @lpretro1 's first point in this regard).

And to quote Sheldon Brown:
"New Chainrings, Old Chains
Going the other direction, using wider chains with chainrings intended for narrower chains is not generally a major problem if there's only a one- or two- generation difference. The only problem you might run into is that the chain will be more liable to rub on the inside of the bigger chainrings in the small/small crossover gears, gears you shouldn't be using in any case."

 

[mynydd]

Thanks for all the input, much appreciated, and helpful.
Have ordered the one you suggested @Ajax Bay plus a new cassette.
Happy new year all