Gearing upgrade advice
thebouy Posts: 61
in General Chat
Hi all, and a happy 2011. I would be grateful for some advice on upgrading my gears. I have a specialized allez elite with compact double gears. I'm not really sure what the compact refers to, but have found that the gearing isn't really 'high' enough for me as its too easy to sit there spinning in top gear. My chainring is 34~50 and my rear cassette is 12~25. Is it possible to upgrade these, and if so what should I look for and any idea on price would be really helpful. Thanks
Compact refers to the Big and Little ring on the front - otherwise called the Chainring -
The 50 means there are 50 teeth on the big ring and the 34 means there is 34 teeth on the small ring.
The same applies to the Cassette, 12 teeth on the small cog, 25 for the Big cog, and 12-25 means the gears will step up in number of teeth from 12 to 25.
A normal double chainring has 53 teeth on the big ring and 39 teeth on the small ring.
On a chainring (front Cogs) the higher the number of teeth the harder it is and faster you will generally.
On the Cassette the higher the number of teeth the easier it is....
I would run a 53/39 on the front and have a variety of cassettes according the type of ride your going to do.
11-25 generally will suit any course other than the hilliest courses, then you may opt for 11-26 or 27.
11-21 or 23 will be more suited for a flat course.
I would recommend always running an 11 as it gives you that extra bit of speed down long descents that you can sustain a big gear on.
Go for Shimano 105 or Ultegra both bullet proof. Not sure on price, but you can sometimes pick up 2nd hand bargains on here or the 'Alternative Forum'
On issue you may have is automatically buying a 10 speed cassette ie 10 cogs, when you may only have a 9 speed cassette.
You'll also need to raise your front mech a bit and will need a new chain that is slightly longer.
What he said above though - get a double and non of this nancy boy compact stuff.
P.S. I'm half a nancy boy with a 52 and a 39........
However yes I would definitely be interested if you could lay your hands on a cassette please; would really like an 11-25t for a 9 speed.
I alas have dodgy knees and originally had a 53/42 which is a beautiful combo but couldn't pull the top gear 53/12 for long so was usually using 53/13 (42.2kph). I now run a 51/11 compact (47.9kph) and even when dropping down to a 51/12 (44kph) I feel more comfortable and faster than with my standard. There is less strain on my knees and it is also about 50g lighter - rotational mass at that. I also have more flexibility and can swap between my 50 and 51 outers and 39 and 36 inners with 11-23, 11-25 and 12-28 cassettes. I'm still rubbish but happier, more comfortable and faster rubbish
I forgot to add your current set up 50/34 and 12-25 is great for a wide range of conditions but for racing I think the spread is a bit wide at a 16T difference whereas the 53/39 has a 14T spread, a 50/39 is closer still at 11T, a 50/36 will give the same spread as the 53/39 but I wouldn't go swapping chain rings yet.
Anyway, I reckon go for the cassette change first, I think you will see the top end gain that you are seeking, 47kph from 43.kph, but sacrifice very little on the mid and low end. See how that goes before you go through the expense of swapping the chainset.
Zacnici, thanks also for the very detailed advice. I hadn't heard of Sheldon Brown before, but a mate did much the same calculation for me yesterday and also reckons that a cassette upgrade would be the most beneficial in terms of performance/cost. Also, sympathy for the knees. I don't know if you remember my name but I did my first tri June 2009 (look up my post titled 'Confessions of a newbie'), was on this site regularly, and then had knee surgery a week later (not as a result of the tri!) which didn't work, and I kind of dropped off the radar for a while. I had another op May this year and am now hopefully on the mend and beginning to start training (and posting) again.