The recent thread on cadence and power and efficiency and stuff got Andrew and I talking and I was commenting that I have been experimenting with trying to ride with a very low cadence, less than 70 to work more on the pushing muscles. Unfortunately, the speed keeps coming up which keeps bringing the cadence up and if I am on any kind of downhill it is pretty much impossible. So, Andrew goes home and digs around and comes back with a 63 chain ring for me.
My bike is now outfitted with a 63/39 front combination with a 26/12 in the back. First ride should be tonight. This might be interesting. Stay tuned.
Last year when i was doing a lot of 53x12 50-60 cadence work outdoors I wish I had that gear combo too. I got sick of riding the brakes down a zillion rollers I never even noticed before.
Good luck!!
Ray
What derailleur do you have that even allows that?
Actually, I have a Shimano 105 that came with the bike. It looks like it will work ok as long as I avoid crossing over from the 52 to anything about 14 or less where the chain will rub the derailleur bottom. I will put up some pictures when I can get a camera, since someone asked.
So, I took it out for my first ride. 20 mph in the 63/12 and 700c tires is a cadence of about 48. So, if I can get to riding these at a cadence of 90-100 like most people race, I should be going about 40 mph and can have less than a 3 hour bike split at Kona!
Shifting was not a problem. The only issue I had is if I cross over to some of the bigger cogs in the back the chain isn’t long enough and it bound up and I needed to stop and fix it. Need either a slightly longer chain or a slightly smaller large ring or just need to be aware and not shift up to far when in the big ring.
The only issue I had is if I cross over to some of the bigger cogs in the back the chain isn’t long enough and it bound up and I needed to stop and fix it. Need either a slightly longer chain or a slightly smaller large ring or just need to be aware and not shift up to far when in the big ring.
Now show us a pic of your RD pulley orientation.
With a 24 tooth differential you might need a long cage.
Thanks for this Frank. Keep us posted with your anecdotal experience. I work in academia but i like to see people just trying stuff to get us talking rather than some of the elitist writing I’m seeing more frequently on some threads on this forum which is eliminating peoples interest. Can you let us know what you are trying to do here. Riding obscenely large gears seems to be a british fetish for us over here !
The only issue I had is if I cross over to some of the bigger cogs in the back the chain isn’t long enough and it bound up and I needed to stop and fix it. Need either a slightly longer chain or a slightly smaller large ring or just need to be aware and not shift up to far when in the big ring.
Now show us a pic of your RD pulley orientation.
With a 24 tooth differential you might need a long cage.
I will say, in the few rides I have had so far I really like it. I did some mild slope climbing today and felt really strong at a cadence of 65 in the 63/15. Rode away from Andrew who was trying to follow me at a cadence of 100.
I am going to get a longer chain tomorrow so I can gear down without fear of binding everything up. This should not be a problem of having a slack chain when on the small ring and crossed over to the small cog as the chain starts rubbing against the big chain ring when I get to about 14. I will submit a picture of this set up and the RD when I get a chance.
l will say, in the few rides I have had so far I really like it. I did some mild slope climbing today and felt really strong at a cadence of 65 in the 63/15. Rode away from Andrew who was trying to follow me at a cadence of 100.
I will say that you could have used a 55/13 and saved yourself all the hassle.
There’s no point in getting the 63 unless a 55/11 just isn’t quite doing it for you.
Rik, I think that from reading the other thread what Frank is trying to do is to generate power going downhill !
I am too lazy to check the gear inches 55x11 vs 63x12 …
Rik, I think that from reading the other thread what Frank is trying to do is to generate power going downhill !
I am too lazy to check the gear inches 55x11 vs 63x12 …
That’s OK - it’s late.
I am going to get a longer chain tomorrow so I can gear down without fear of binding everything up. This should not be a problem of having a slack chain when on the small ring and crossed over to the small cog as the chain starts rubbing against the big chain ring when I get to about 14. I will submit a picture of this set up and the RD when I get a chance.
I am looking forward to seeing it. I have always preferred the big ring, but have been spending more time on the 39 to get my cadence up.
It seems to me that because your jump from 39 to 63 is bigger than the range on many triples and larger than the span of any cogset, you can’t be keeping a short cage RD in its intended operating range (usually about 90 degrees).
l will say, in the few rides I have had so far I really like it. I did some mild slope climbing today and felt really strong at a cadence of 65 in the 63/15. Rode away from Andrew who was trying to follow me at a cadence of 100.
I will say that you could have used a 55/13 and saved yourself all the hassle.
There’s no point in getting the 63 unless a 55/11 just isn’t quite doing it for you.
Rik
Well, I didn’t have an 55. If you will read the original post, a 63 showed up so I decided to try it.
Second, this was an experiment that, as I have thought about it think might “solve” four problems. 1. spinning out on the fast downhills (which would especially work if one went 63/11), and, 2. eliminating redundancy in the gearing choices, and 3. keeping the cadence down so those training with PowerCranks can keep training their ability to “push”, since some think this is a drawback with PC’s, and 4. help people to train at a lower cadence to improve pedaling efficiency, something we were recently talking about here.
If the two front gears are too close together then the actual number of available gears goes down (on my original IM bike the two front gears on my “10 speed” were a 50 and a 42 which I didn’t understand at the time was really an awful choice and lowered the number of available gears on my “10 speed” from 10 to 6). Most people think because they have 2 rings in front and 10 in back they have 20 gears available when, in fact, they only have about 12. Increasing the size of the front gear from 52 to 63 probably increases that choice from 12 to 15 on the current “20 speed” bikes. So, in the sense of range, this is similar to going to a triple up front without actually doing so. Does nothing to hurt the small gear ratio while giving increased capability on the large gear size and keeping all the middle gear capability.
I am going to get a longer chain tomorrow so I can gear down without fear of binding everything up. This should not be a problem of having a slack chain when on the small ring and crossed over to the small cog as the chain starts rubbing against the big chain ring when I get to about 14. I will submit a picture of this set up and the RD when I get a chance.
I am looking forward to seeing it. I have always preferred the big ring, but have been spending more time on the 39 to get my cadence up.
It seems to me that because your jump from 39 to 63 is bigger than the range on many triples and larger than the span of any cogset, you can’t be keeping a short cage RD in its intended operating range (usually about 90 degrees).
As I have thought about it I think you can under most circumstances. I am going to have my chain changed today to something a little longer so I will see. The reason this will work I think is because most of your riding will be in the middle gears and you will only need the “extremes” when climbing steep hills or trying to go fast on the downhills. This change does not affect what you will do on the uphills but gives you more flexibility on the downhills. This change, as I see it, is more about giving the rider more choices and flexibility in both racing and training.
