How to undertand Group set Ex: Shimano 34/11

[tdcadillac]

hello
I want to buy my first ever bike. I quite learn alot but asking and great people helping out.
I was advised that 105 is better than a tiagra. How to understand those groupset difference so I can tell myself is sora, tiagra or 105 is good for me.
thank you

 

[si_c]

Sora has 9 speed at the rear, Tiagra has 10 speed and 105 11 speed. This means you get slightly more gears at the back with each step up in price.
Edit to add: They get slightly lighter in weight as well with each step up, but you're talking a few hundred grams at most, or less than a packet of biscuits.

Note this doesn't mean more range of gears, but that the steps between them when you change gear are smaller. This is useful for racing or if you ride really long distances, but in terms of how fast or how hard or how comfortable your ride is it won't make the slightest difference. I have all three, and if I'm pushed 105 is better at shifting than the other two, but it's a very very very small difference and it's probably because I spend a bit more time keeping that bike maintained

Up until recently I had a commuter bike with Sora on it which I rode for nearly 20k miles and at no point did I feel like I needed a more expensive setup - in fact Sora is pretty much the sweet spot for commuting as it's the cheapest to get replacement parts for, although Tiagra is getting there.

The reality is that they will all perform very well and I wouldn't feel the need to buy one over the other there are more important considerations to have like whether you like how well it fits your or whether it fits in your budget.

 

[steveindenmark]

This link may help you if you scroll further down. If you need to know in the future search for Shimano or SRAM heirarchy.
https://www.cyclingweekly.com/group-tests/road-bike-groupsets-buyers-guide-142789

 

[rogerzilla]

105 is better quality and should last longer. Quality control is also better higher up, although it seems to kick in *above* 105 or Deore level these days; 105 or Deore hubs are normally maladjusted "out of the box" these days.

11 speed is of little interest to me. I have 7 speed on three bikes and it's just fine.

 

[Cycleops]

@Dogtrousers has given you a pretty comprehensive run down and as @si_c says even entry level Tiabra will give good performance if adjusted properly. If you’re racing you might want Di2 but it’s very pricey. Once above entry level the law of diminishing returns kicks in.

 

[tdcadillac]

This is useful for racing or if you ride really long distances, but in terms of how fast or how hard or how comfortable your ride is it won't make the slightest difference.

sorry if my question is stupid but if it useful in racing how come it doesn't make difference in how fast you go?

 

[si_c]

sorry if my question is stupid but if it useful in racing how come it doesn't make difference in how fast you go?

Because the steps between the gears are smaller when you change gears it's easier to keep the pedals turning at the same speed, and your legs don't lose momentum as much. It's not so much of an issue for leisure or fitness riding as it's unlikely that you'll be turning the pedals so fast. Think of it the same as if in your car you change from 1st to 2nd as the jump to 4th would be too much.

Not so much of an issue for those of us who aren't riding at that level.