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Double vs Compact

jecooperjecooper Posts: 30
edited October 2012 in Road beginners
My Felt Z85 was delivered with an FSA Vero Compact 3pc, 50/34T chainset with Shimano 12-30T cassette on the back but i'm finding that i never use the granny ring. I don't ride many hills as i spend most of my time in surrey/richmond park and find the drop down to the granny ring so big that i prefer to grind it out in 50-30 than start switching. So i was wondering if it would be worth looking into a double chainset to upgrade my compact, tempted to get a shimano 105 to finish off the bike with full 105. I was a bit surprised to see the biggest (?) double being 53/39, i spose i was expecting a few more teeth.

so basically my naive beginners question is, will upgrading from 50/34 to 53/39 be a huge jump, or only a slightly incremental difference? i can do the maths and understand the ratios but would rather some experienced opinions, perhaps people who have made a similar switch in the past. cheers

Posts

  • Buckie2k5Buckie2k5 Posts: 600
    what happens if you decide to go somewhere hilly. with a double you might not make the top ;)
  • Buckie2k5 wrote:
    what happens if you decide to go somewhere hilly. with a double you might not make the top ;)

    then i'd feel like an idiot! but i was kind of assuming that if i never even use the top end of my granny ring, then there will be plenty of scope at the bottom end for big hills, even if i do increase it to 39 teeth, once again, not an assumption based on huge experience.
  • jibberjimjibberjim Posts: 2,810
    Just change the inner ring to a 36, that will give you the same difference as 53x39 cost massively less, and not leave you in as much trouble in the hills - and there are plenty of hills within 2 hours ride of Richmond Park where I very much doubt you won't be significantly faster up with a compact.

    If you're a grinding style of rider you'll get up any hill in almost any gear eventually - you'll just be a very long way behind those guys with appropriate gearing.
    Jibbering Sports Stuff: http://jibbering.com/sports/
  • danowatdanowat Posts: 2,877
    Compact for training, double for racing.
  • zx6manzx6man Posts: 1,092
    I did the opposite and found the uphill gears better so I could get up them seated, and for downhill blasts a 50/11 is plenty
  • mercia_manmercia_man Posts: 1,368
    Keeping the same cassette and switching from 50/34 to 53/39 will effectively give you one higher gear at the top end - an overdrive for going faster downhill - and one less at the bottom end - giving you a new bottom gear roughly equivalent to your current second gear. The gap between the two chainrings is slightly less so you won't have such a big jump and there will be less need to double shift (front and back).

    Only you can decide whether it's worth spending quite a lot of money on a new chainset to gain a gear at the top end and lose your low bottom gear. You'll probably have to lengthen your chain as well to cope with the bigger chainset.

    Personally, I like a bailout bottom gear. But then I live in a hilly area and enjoy cycling holidays in the mountains.

    As jibberjim says, you could fit a 36 inner ring to your chainset relatively cheaply. That would slightly reduce the jump between rings while still leaving you with a pretty low bottom gear. But I still don't reckon it would be a value for money change.
  • jibberjim wrote:
    Just change the inner ring to a 36

    cracking idea, feel a bit stupid for not even considering this. for £20 i'm happy to pick up a new inner ring just to give it go and see if it makes a difference.

    It's more the jump than the range which is stopping me using the 34 at the moment, will upping to 36T give me much of a difference or should i opt for a 38T?

    Thanks for the replies so far, i realise that upgrading the whole chainset for this would be a little unecessary, my wallet thanks you!
  • smidsysmidsy Posts: 5,273
    edited October 2012
    Lots of guys in our club run 52/39 and swear by it.

    They reckon a 53 is too much. They also prefer to use the 39 and spin for most of the ride only using the 52 for real the fast stuff/downhill etc.

    I am stull running a compact and always seem to lose time, they assure me it is far better to go 52/39.
    Yellow is the new Black.
  • John.TJohn.T Posts: 3,698
    " Grinding out on 50/30" is not a good idea. It puts a lot of strain on the ring and chain. It is not unheard of for rings to fold under strong riders. Also if you end up struggling there is nowhere to go easily. Changing rings under load and on the big sprocket is just asking for the chain to come off.
    Your 50/30 is just about the same as 34/21.
    Try this calculator to see what gear overlap you have.
    http://www.gear-calculator.com/#
  • mercia_manmercia_man Posts: 1,368
    As the big jump between chain rings is your issue, I'd go for the 36 ring. You would get a small but noticeable improvement in the front shift and would would still have a low enough bottom gear for going up mountains.
  • nweststeynnweststeyn Posts: 1,574
    Don't mean to sound patronising but... Why don't you work on your shifting a bit. If you're shifting down to the 34 then do it in conjunction with changing up at the back by 3 or 4 gears. This way there won't be much of a jump. If you're riding 50 x 22 and change to 34 x 22 then yeah it's a big jump, but it'll be the same kind of issue changing from 52 x 22 to 39 x 22.
  • jibberjimjibberjim Posts: 2,810
    smidsy wrote:
    I am stull running a compact and always seem to lose time, they assure me it is far better to go 52/39.

    Lots of guys in my club say the same - but I don't lose any time to them with my compact.

    You may well have the wrong gears, it's unlikely though, it's almost certainly simply that the fitness and gear selection preferences are different.

    Gear preference is individual, wrong gearing can make you slower easily, but it's not realistic to narrow your gearing range and to get a boost of speed - the tiny difference in preferred cadence at a particular speed in the middle of a block is not going to make material differences to your performance - it might make spinning along at a particular easy speed more comfortable - that's most relevant on flat roads rather than the undulations that apply to most of us.
    Jibbering Sports Stuff: http://jibbering.com/sports/
  • smidsysmidsy Posts: 5,273
    In my case it is almost certainly fitness, but they say that I am making it hard work for myself with the compact and that I would benefit from a 39 smallest chainring as opposed to the 34 on my compact. I can see how this will increase my general speed for a given cadence but I do not see how it benefits overall (as hills etc come into play).

    I was simply passing on what more experienced riders are telling me.
    Yellow is the new Black.
  • jibberjimjibberjim Posts: 2,810
    smidsy wrote:
    I can see how this will increase my general speed for a given cadence.

    But it won't - because you'll simply select a different gear that gives you the same speed and cadence - the one your fitness allows. It won't do anything to your speed at all.
    Jibbering Sports Stuff: http://jibbering.com/sports/
  • nweststeynnweststeyn Posts: 1,574
    As you say about not seeing the benefits overall, I'd say you're right. A 39 would give you no more 'quick' gears than you already have by using your 50, and I'm pretty sure you're not riding 'maxed out' at 50 x 12 and losing time on them... I'm no speed demon though, so what do I know... I do have a 52 but rarely sit on my 12 unless descending.
  • flasherflasher Posts: 1,627
    jecooper wrote:
    I don't ride many hills as i spend most of my time in surrey/richmond park and find the drop down to the granny ring so big that i prefer to grind it out in 50-30 than start switching.


    You need to get out more, plenty of hills within an hour or so from Richmond Park that would see you using the 34.
  • drlodgedrlodge Posts: 4,824
    nweststeyn wrote:
    Don't mean to sound patronising but... Why don't you work on your shifting a bit. If you're shifting down to the 34 then do it in conjunction with changing up at the back by 3 or 4 gears. This way there won't be much of a jump. If you're riding 50 x 22 and change to 34 x 22 then yeah it's a big jump, but it'll be the same kind of issue changing from 52 x 22 to 39 x 22.

    +1 There's nothing to gain by changing from 34 to 39 inner chainring, you just lose low end gears. Better would be to stay with the compact chainring and move to a closer ratio cassette.

    I'm using 34/50 with 13-14-16-18-21-24-28 and have no issues shifting between gears, and can easily do the "double dump" by shifting the chainring and shift up or down two gears on the rear at the same time.
    WyndyMilla Massive Attack | Rourke 953 | Condor Italia 531 Pro | Boardman CX Pro | DT Swiss RR440 Tubeless Wheels
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  • nweststeyn wrote:
    Why don't you work on your shifting a bit.

    I think this is a fair point, the root cause of this problem is probably that i let myself get trapped at 50/30 too often and prefer to grind it out as its not too tough rather than go for a double switch halfway up the hill. until i did the sums today i didn't realise how much crossover there was, i will work on starting the hill in a 34/12 combo or similar giving me easier shifts down into geometries which don't try and snap the cogs.

    cheers for all the replies guys, very helpful indeed. as for getting out more, i don't doubt that for a second but living in clapham means 2 laps of richmond park is a solid 28miles. I'm working on building up the mileage but only had my bike for about 8 weeks now. Aiming for 100 next summer so i'm sure i'll have plenty of chance to explore further
  • unixnerdunixnerd Posts: 2,864
    Your cheapest option would be to fit an 11-28 or even 11-25 cassette. I have a compact with an 11-28 and find I don't always need the bottom gear even on the Cairngorm ski road. Plus the 50/11 is higher that your current top gear. I'd certainly do that before spending even more on a new crankset.
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  • John.TJohn.T Posts: 3,698
    You should not be using the extreme chain cross gears. That is the big/big and small/small combinations. If you look at the gear calculator that I linked to you will see these (and the next ones) are greyed out. I do use the second sprockets but really try to avoid using the end ones.
  • Just a suggestion to consider.
    Why not change the cassette to an 11-25T which close up the ratio's nicely and be a much cheaper upgrade.
    You would also be able to swap your cassette back over if you do decide on hilly sportive.
    "You really think you can burn off sugar with exercise?" downhill paul
  • lotus49lotus49 Posts: 763
    Instead of changing your gears, why don't you find some hills?

    I know there aren't as many hills down South as there are round here (we don't really have any flat bits at all in this part of Yorkshire) but Box Hill is in Surrey and if that was good enough for the Olympics, it's probably worth a ride.
  • fludeyfludey Posts: 384
    But if you really do want a compact fancy Ultegra with 39/53 172.5 arms covered a mere 340 miles before I swapped it to a compact as my cassette was only a 25 and wanted same gearing on both bikes.
    If interested drop me a pm :D
    Felt AR4
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