Help - New groupset, what's compatible?

[Matthew Creighton]

Hello,

I'm currently a building up an old bike. I want to replace the groupset but am on a budget. I am going to get the shimano sora sti 3300 8 speed double shifters, but need advice on what cassette, rear and front derailleur and chainring/crank to get.

Any help would be greatly appreciated.

Cheers,

Matt

 

[RecordAceFromNew]

I am going to get the shimano sora sti 3300 8 speed double shifters, but need advice on what cassette, rear and front derailleur and chainring/crank to get.

It is impossible to give you a decent answer without knowing what gearing you want, which in turn is dependent on how fit/heavy you are and what terrain you want the bike to tackle. The lowest and highest gears, combined with whether you want the relative lightness and simplicity of a double, the somewhat greater range of a compact, or the maximum range and choice a triple (which impacts your left shifter choice) chainset can afford will influence the type of front mech you should get. The chainset also determines what bottom bracket you need.

Your seat tube outside diameter and the frame's cabling route will also determine the front mech clamp and pull configuration.

The gearing requirement also informs what rear cassette (I am assuming your rear wheel has a freehub not freewheel since you are talking about 8 speed shifters) you need, which can be anything from a compact racing cluster to a wide range mtb cassette. All 8 speed Shimano or sram cassettes will fit any current Shimano standard freehub, but the range of the cassette and chainset will influence the rear mech you need.

So perhaps you might want to start from here and here?

 

[Matthew Creighton]

Well the bikes won't be heavy at the start, but eventually I'd imagine they will gain wait. We would stil be hoping to average 12-13 mph a day. I have basically decided that I am going to go for a sora 3400 9 speed triple shifter, sora 9 speed rear and triple front. But my dilemma now is what chain ring size to go for. I obviously need a triple, but that is the extent of my knowledge. What ratios would work best for the system I am about to purchase? I am trying to keep the cost to a minimum, so I am not looking anything too expensive!

Cheers

 

[RecordAceFromNew]

Well most triple road chainsets, especially lower cost, standard offerings, are 50/40/30. You should avoid mtb triples because they tend to have smaller large ring, which are designed to work with mtb front mechs, and which do not work with road sti triple shifters; and that is before considering the need to mess with different chainline.

I can see you have moved on to 9 speed. For reasons which imho clearly have nothing to do with cost of manufacturing or cost of sales, 9/10 speed cassettes, mechs, chains and shifters are usually quite a bit more expensive than 8 speed ones. Also 8 speed chains and cassettes should last longer than 9/10/11 ones. I am mentioning this only because you said you want to keep the cost to a minimum.

Finally for the cost conscious low end Campag brifters are generally competitively priced. But if you go Campag you will have to ensure the rest match. That doesn't necessarily mean you must have Campag freehub/cassette/chain/rear mech (because cross compatible exceptions exist) or chainset, but you should price in Campag front mech.

 

[Matthew Creighton]

Hello,

Right I have purchased everything bar the chainset and rear cassette - got a 9 speed sora and triple front, although I'm still confused about the chainset. By keeping costs to a minimum, what would be best? I have want the 50 39 30, but they are quite rare from what I can see, and quite expensive. The other option is 52 40 30...how much difference will this be? Could I potentially go for a larger MTB set? Iv seen one or two with around 48 35 30? Is that possible?

Cheers

 

[jowwy]

Hello,

Right I have purchased everything bar the chainset and rear cassette - got a 9 speed sora and triple front, although I'm still confused about the chainset. By keeping costs to a minimum, what would be best? I have want the 50 39 30, but they are quite rare from what I can see, and quite expensive. The other option is 52 40 30...how much difference will this be? Could I potentially go for a larger MTB set? Iv seen one or two with around 48 35 30? Is that possible?

Cheers

shimano 105 and tiagra triples are 50/39/30 - mtb or hybrid sets are normally 48/38/28

i would go for the tiagra if cost is an issue.....if cost isnt an issue, then ultegra triple is 52/39/30.

 

[Matthew Creighton]

Right, had a look, the Tiagra is def a potential then. Tell me this though, will a 48,38,28 be compatible with the groupset I have? I'm just thinking because of the weight on my bike, I will need lower gears than higher?

Cheers

 

[Bong]

Road triples (Shimano at least tend to be 50-39-30). I have just been looking for an "old" 9 speed Tiagra triple but was unable to find one with 175 mm cranks. However, for Sora which is the new 9 speed Shimano, you can try http://www.merlincycles.com/bike-sh...hainsets-road/shimano-sora-road-chainset.html where they have Sora double and triple chainsets, some in stock and some out, some including BB ( £33) and some not (£27). I have emailed for notification of when my preferred one is in stock. 170 mm triples are in stock. Hope this helps. It is an excellent price.

 

[jowwy]

Right, had a look, the Tiagra is def a potential then. Tell me this though, will a 48,38,28 be compatible with the groupset I have? I'm just thinking because of the weight on my bike, I will need lower gears than higher?

Cheers

i dont see any reason why it shouldnt be - you would just need a shorter chain than the one required for a 50/39/30