group sets...an idiots guide

I do a lot of riding a and wouldn't fancy more than a short stretch over 20% on 34x26, especially at the end of a long ride. Extra teeth on the cassette will definitely help you winch up the steep bits.

According to the Shimano website, the largest sprocket that the Sora derailleur will handle is 27 teeth. If you want a larger range on the cassette it looks like you'll need a Tiagra rear mech too, unless someone on here has experience of successfully squeezing in more teeth than the stated maximum in the manual. I have never tried it myself.

A gear calculator will give you an idea of the difference that adding or removing cogs makes. Sheldon Brown has a good one: http://sheldonbrown.com/gears/ Check out the rest of the site, it's mine of useful information.

If you were to upgrade the whole groupset you would get slightly smoother operation, an extra gear or two to make changes a little less of a clunk between sprockets with big gaps, an increase in component quality and a weight saving that would only make a difference to the most dedicated racer. As ever, the law of diminishing returns applies. In my opinion, the likes of Shimano 105 and Campagnolo Veloce give the best value price and performance balance but that's just my experience. Others will set the bar elsewhere according to their own budgets and riding styles. Some will buy top end kit just because they can, because they like showing off or because they like knowing that they have the best available or the best that they can afford. All of these are valid reasons, anyone who rides competitively knows that it's the legs that really do the talking. For the rest, it's a case of finding that balance of price and performance to give the best experience every time you swing a leg over your bike. A test ride from a shop or on a mate's bike will help you make up your mind. Each manufacturer makes their parts interchangeable across large parts of their range so as long as you stick to the same number of gears you will be able to upgrade a bit at a time. My best bike has a mix of 10 speed 105, Ultegra and Dura Ace and they all work perfectly together.

Yes but Obree is rather special and does things his own way. If that was the best way, the other top riders would all be doing it.

Graeme Obree reckons 8 is the optimum number for a cassette.

If you happen upon a good deal when your current setup is getting long in the tooth then an upgrade might be a good move. But you're looking at the whole shebang - STIs, chainset and more, which is a big outlay.

There was a guy who came to a few of our 10 mile TTs last year on a Carrera TDF with 8-speed gearing. The basic spec and fewer cogs didn't appear to hold him back.

I'd go with the advice of just switching the cassette. 105 is better but its a lot of bucks just to feel that a gear change seems more crisp particularly given its around £400.

Hmmm, that reads rather like a sales brochure to me.

If it's the latest 9 speed version of Sora then 105 is probably a little better but not by much. The weight difference is insignificant and any improvement in power transfer is in the mind. The benefit would be more marked if you're on 8 speed groupset.

Ha. It's the difference in shifting that would be the most marked, I think. My ex rode an Allez with Sora and it was just horrible changing gears on it. I've ridden 105 bikes and that's a lot, lot better. You want your group to respond when you drop a cog to put in a burst on a hill, right?
I'm not suggesting an upgrade right away; for now a bigger block on the back will improve things. But it's definitely something to aim for on the next bike. And there's always a next bike.

It's worth thinking about upgrading your group at some point though. Even a mini jump to 105 will make life far more fun - better shifting, stiffer and more efficient power transfer, weight saving, etc etc.

Totally agree with gkam84 just change the cassette which will give you a much lower gear and you'll be able to spin up walls

What's your current set up for gears?

Looking around it should be 50/34 compact and then 12-26 9 speed on the rear??

If that's the case, its pretty simple to give yourself more range without costing a fortune, just switch out the 12-26 on the rear for a 11-32

http://www.parker-international.co.uk/2440/Shimano-Tiagra-HG50-9-Cassett...

So that'll give you better range for climbing and its the cheapest way to do it.

If you really want to get into full groupsets and the differences. What you can and cannot do, they I'm quite happy to help, but its 2.45am and I need some beauty sleep