Replacement of crankset

[Whiskeyano]

I have a specialized sirrus w Tiagra 9speed Rd..I want to replace the crankset, a sugino brand with the same Tiagra cranks or any shimano that would match..what other things to watch out for?.. I need suggestions pls ..thanks

 

[vickster]

Any particular reason why you want to replace the crankset or have a need to?

You need to know what sort of bottom bracket you have

 

[Cycleops]

It’ll likely be a square taper BB. You can simply replace with another square taper crankset or you could go for Shimano‘s newer Hollowtech design which has outboard bearings rather than inboard, it’ll be lighter than ST. The bearings screw into the BB shell and come with the crankset. You’ll need a special Hollowtech bearing tool. Once installed you may need to readjust the hi-lo screw-in on the front derailleur and also the height if the chainring is larger or smaller, which also applies to if replacing with a ST chainset.

BTW to the forum.

 

[C R]

It’ll likely be a square taper BB. You can simply replace with another square taper crankset or you could go for Shimano‘s newer Hollowtech design which has outboard bearings rather than inboard, it’ll be lighter than ST. The bearings screw into the BB shell and come with the crankset. You’ll need a special Hollowtech bearing tool. Once installed you may need to readjust the hi-lo screw-in on the front derailleur and also the height if the chainring is larger or smaller, which also applies to if replacing with a ST chainset.

BTW to the forum.

The axle in a hollowtech system is integral to the driveside crank, but the bottom bracket itself, the bearings, need to be bought separately.

 

[Cycleops]

The axle in a hollowtech system is integral to the driveside crank, but the bottom bracket itself, the bearings, need to be bought separately.

That’s what I assumed when I bought a Hollowtech Deore triple from Evans last year but when it arrived it was included. No mention was made on their website and when I phoned they couldn’t confirm. either way. I can only assume others are the same.

 

[C R]

That’s what I assumed when I bought a Hollowtech Deore triple from Evans last year but when it arrived it was included. No mention was made on their website and when I phoned they couldn’t confirm. either way. I can only assume others are the same.

I got a Sora chainset and it didn't include the bottom bracket, it may depend on the particular model, or maybe time limited offers.

 

[Ajax Bay]

Tiagra 9sp is 4400/4500 and the cranks are square taper (diamond orientation).
Select any other road square taper chainset - they will all be fine with your 9sp drivetrain. If you look on the reverse (inside) of the current cranks you will see its length eg 170 (mm). Suggest you get the same unless you are 5'7" or less when 165s or 160s would be in proportion (and 'fit' better). Also the current chainset is probably a triple (three chainrings). Get the same (or research why to or why not).
I'd recommend Spa Cycles ones as quality AND vfm. I'd be amazed if you can do better than this one: https://www.spacycles.co.uk/m8b0s109p2000/SPA-CYCLES-XD-2-Touring-Triple-Chainset and £39!