Compact chainset 39/50 - convert to standard double?
JackPozzi
Posts: 1,191
I've recently bought a new bike, which came with 39/50 chainrings at the front, which I'm now realising are a bit smaller than I actually need for most of my riding. Is it possible just to fit some larger chainrings, or do I need to replace the whole chainset? If the later is the case, can someone provide some information or links to information as to what this entails so I can assess whether to attempt myself, or to put in into the LBS?
Edit:
Just noticed that someone else has asked the same question, but in reverse, where do you find the inforamation on what size chainrings will a specific bolt circle diameter?
Edit:
Just noticed that someone else has asked the same question, but in reverse, where do you find the inforamation on what size chainrings will a specific bolt circle diameter?
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Comments
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Do you really mean you need higher gearing ! RESPECT
I don't see why you can't put a 52/53 on the outer if you need the higher speed. What is the smallest on the back ?A new cassette may be the answer.0 -
Not too much respect required unfortunately, most of my riding is in Essex, so nothing major to climb! The new bike is next years summer and TT bike, but I took it out on todays (pretty slow)club run and didn't use the small ring at any point, so I figure I might need a few more teeth for when the speeds pick up again next year0
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Save your money, 39/50 should do you fine.JackPozzi wrote:Not too much respect required unfortunately, most of my riding is in Essex, so nothing major to climb! The new bike is next years summer and TT bike, but I took it out on todays (pretty slow)club run and didn't use the small ring at any point, so I figure I might need a few more teeth for when the speeds pick up again next year
If you have a 12 or 13 smallest rear you should be able to get fast enough with that unless you intend to sprint for 40 miles
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If it's 39/50 it's probably a standard double which will be either 130mm (Shimano) or 135mm (Campag) BCD.
I find a 50T a really useful outer ring - with a 12T in the cassette you are pretty much at 30mph for 90rpm, so I seldom spin out, but there is a low enough gear to not need the inner ring much in the places I ride (n essex/s cambs).
Neil--
"Because the cycling is pain. The cycling is soul crushing pain."0 -
Is this in the beginners forum? Just how much of a beginner are you!!!0
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Well, been riding since February, but was fortunate enough to get up to a semi-respectable speed fairly quickly. Unfortunately my technical knowledge concerning bike bits and how they go together is still firmly rooted in beginner territory, bordering on clueless!0
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What did you decide to do? I would personally leave it as you may decide to ride somewhere that isn't as flat as where you live and will struggle. I live in the Lakes and couldn't cope with anything less than a compact for instance.0
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As someone else said, it is probably easiest to change the cassette, depending on what you have on the back wheel at the moment. If your smallest cog at the moment is a 12 then try fitting an 11-21 cassette if you are on Shimano. If you are still undergeared then you should be able to get a larger chain ring later without problems.
BTW, if your chainset has 39/50 I expect it is probably a standard 130bcd chainset, ie not a compact.0 -
I suspect a low cadence being ridden
As stated above, 50 x 12 will give 30mph at cadence of 90 so either your a champion already or your doing less than 90 rpm
I have not met anyone who finds 50 x 13 under geared yet 0
