I assume this means the big ring has 53 teeth and the small one has 39 teeth.
Like a good slowtwitcher, my small ring is in primo condition. My big one is missing a couple of teeth and are looking rather worn. My biggest gripe with the set-up was that I always felt the big ring was geared too low, and too close to the small ring. Looking around online, I see that I can buy just the big ring, and the biggest size they have is 55t.
I am not mechanically inclined, nor do I have much knowledge of how a bike works, other than I spin the pedals in a specific direction and the rear wheel starts turning (provided the chain hasn’t slipped off).
My questions:
Can I change just the big ring from the 53 to 55 teeth without issues?
Is going up about 4 percent in size going to even be noticeable (I have my doubts)?
Are there other things I need to take into consideration before I buy the 55t?
Are there better, similarly priced options? My biggest gripe is that on downhills and even slight downhill inclines, I find myself hitting 110-125 cadence and bouncing too much. I like to draft motorized vehicles from time to time (don’t worry, I don’t do the strava stuff). Half of my typical training bike ride is with a slight tailwind, so I find myself looking for a higher gear often on the flats. I am not by any means fast (20 mph avg at Honu 70.3), but when I’m hauling, I hate not having the gearing I’m looking for.
Smallest sprocket out back is a 11T according to the print on that sprocket.
If you’re man enough for a 55t… go for it. I think 56 is about as big as you’re going to find from the big companies… Somewhere like Fiberlyte could probably make you one as big as you wanted… of course past a certain point you’d need to go to a 42 in the small ring. You should be fine with a 55/39 though.
I really really doubt that you are missing teeth, you would not be able to shift and you would toss the chain left and right.
I find myself hitting 110-125 cadence and bouncing too much. I like to draft motorized vehicles from time to time (don’t worry, I don’t do the strava stuff).
LOL, I will often take US20 out of Rockford to the east, just so that I can motorpace 18 wheelers. Maybe one day I will grow out of it, I hope not though. 45mph on a flat road for a mile or so being sucked along buy a semi is nothing but a blast.
If you bounce at 120rpm you may be able to smooth things out with a bit of spin work, but I would do that on a Spin bike not on the road (I can get over 220rpm on a Johnny G spin bike - it aint pretty but I can do it). That being said, there really is no reason to keep pedaling at those speeds if you are going down hill and not applying power, nor maintaining a speed - as would be indicated by the fact that you have no tension on the pedals as you spin that fast.
It means the big ring has 53 teeth and its designed to shift best (in terms of ramp/pin locations) with a 39 tooth small ring.
Will it still shift fine if I go up to 55 without changing the small ring?
Are you sure it’s actually missing teeth? Even on new chainrings not all the teeth are the same size, some look stubby to help with shift timing.
You know what? You’re right. I went back and looked more closely at the big ring and noted that the “missing teeth” I was refering to were look much more like extremely short teeth and there are three of them, spaced out evenly right next to each chain ring bolt so I stand corrected. However, my sprocket teeth has a wave pattern to it and some are shorter/wavy then others which clearly shows my sprockets are worn out (I came from a motorcycling background). Time for a new chain as well, will be replaced along with the big ring.
Are you really hitting ~45mph (120RPM on a 53x11 with 700c x 23mm tires) on slight downhill inclines???
Apparently. I didn’t realize it was that fast though. Feels more like high 30’s, low 40’s. I don’t pay much attention to my gps at those speeds. I hate having to stop pedaling because I’m spinning too fast to be able to smoothly and safely apply any more power to the drivetrain during downhills, drafting or slight inclines with a tailwind.
I do some basic smoothness drills with my group and on the trainer but once I get above a certain cadence, it just gets stupid and inefficient.
I’ll keep at it and go with the 55t. It’s only a 4% increase in gearing - I don’t see why some of you are getting your panties in a bunch.
53t is enough gear even though I find myself unable to always continue to apply power smoothly or adequately at higher speeds during descents/tailwind/drafts? Granted, it’s only 2-4 percent of a given ride, but I hate having to stop applying power during those times. Based on that, I think it’s enough reason to go up in the big gearing.
The shifting part has me worried though. How bad will it be, what will it be like, etc. I don’t shift out of the big ring often. I don’t remember how many times I did at the last 70.3 but at the last oly, it was only once, and at an upcoming oly, it will only be two times.