Has anyone else noticed that they’re faster using compact cranks? I don’t just mean faster climbing hills or on hilly courses – I’m talking about faster across the board on nearly all courses.
I recently put a set of compact cranks on my Soloist to help with my climbing – or at least that was the intended reason. As a MOP cyclist and a lousy climber I wanted to be able to get up the hills at IMMoo (or anywhere else) more easily, so I decided to give them a try. Funny thing is I’ve noticed myself somewhere between 0.5 to 1.0 mph faster on just about every course I ride – including my only-very-gently-rolling typical out and back from my house where ‘hills’ are completely a non-issue.
I certainly wasn’t expecting this, so I did a little self-evaluation to see what the reason might be and I think I figured it out right off the bat. I’m typically at my most comfortable cadence and pace right in the middle of the gearing range. Prior to the compact cranks, I probably have to admit that I unconciously avoided shifting up to the big ring – even when I could or should – because I knew I’d have to shift down again at the next roller.
Now, with the change in gearing, I find myself camping out on the big chain ring MUCH more frequently and staying there for extended periods. This allows me to shift up into even higher gears on the flats without all the “fuss” of changing rings on the front (the occasional double-shift has disappeared altogether). Anyway, seems to me I’m just spending more time in the upper range of my gears and my bike splits are showing the effects.
I was expecting to climb more easily, I wasn’t expecting speed. Anyone else experience this pleasant surprise?
I was thinking my bike was splendid. Your reply really frosts my shorts. I am shocked that you would back hand my pride and my bike with such an ill comment.
I used to get dropped on the hills on our group rides by the fast guys. Compacts solved the problem for me, (plus I got stronger), so now I’m right up there with them. In fact, I’m now one of the “fast guys” in the group. Never was on 53/39.
They seem a lot faster to me, although gearing is just gearing, so there can’t be anything magical about them except that the gear ratios work better for me with the power cycle I produce. They just work a lot better for me. Period. I rode 53/39 on a borrowed bike recently and it just didn’t feel right. I like that compacts allow you to stay in the big ring longer.
I’m also running Q rings in 50/36. I’ll swear by this combo.
I was thinking my bike was splendid. Your reply really frosts my shorts. I am shocked that you would back hand my pride and my bike with such an ill comment.
I used to get dropped on the hills on our group rides by the fast guys. Compacts solved the problem for me, (plus I got stronger), so now I’m right up there with them. In fact, I’m now one of the “fast guys” in the group. Never was on 53/39.
They seem a lot faster to me, although gearing is just gearing, so there can’t be anything magical about them except that the gear ratios work better for me with the power cycle I produce. They just work a lot better for me. Period. I rode 53/39 on a borrowed bike recently and it just didn’t feel right. I like that compacts allow you to stay in the big ring longer.
I’m also running Q rings in 50/36. I’ll swear by this combo.
Gearing is gearing. I just switched from a 40/48T Qring to a 40/54T Qring setup. On my 2x20min workout today I went 315W average compared to 308W the week before, which is 100% consistent with recent gains. The only disadvantage of the bigger big ring is that on my shorter intervals I typically start at ~16-17mph at the bottom of a hill. The bigger ring puts me at about 65rpm to start compared to about 75rpm with the smaller 48T. Accelerating up to ~23mph takes more torque at the start of the interval, which makes it harder to keep up the power at the end of the interval. It’s probably just as good of a workout so I don’t care.
The only reason that the 36/50 combo might be faster is if you have a very narrow powerband and have to stay at 90-93rpm for instance. At 90rpm and 11-23 your speed would be:
39T: 25.2 24.3 22.5 20.9 19.5 18.3 17.2 15.4 13.9 12.7
36T: 23.2 21.3 20.7 19.3 18.0 16.9 15.9 14.2 12.8 11.7
If you look at the spacing between them, the average spacing for the 36T at constant RPM is 1.42mph and the spacing for the 39T is 1.54mph. This is not coincidentally the same 8.5% difference between the 36 and 39… I.E. with a smaller front ring your pedaling speed is easier to keep within an “optimal range.” I think it’s the Qrings…not the specific gearing.
I agree with Paulo…just do like me and get a 48 tooth big ring, or better yet, a 46 tooth like I have on my commuter bike…you don’t really need compact for that!
I have a set on a bike and I don’t mind them. I bought a bike that had them two years ago and I didn’t realize the cranks were compact until I had it home. Although I could easily change them out, they are still on there. The only problem is that it takes time getting used to what gear you should be in. Wtih a 53/39 - 11/23, I always know where I am, with a compact it takes time to find the right spot between the big ring and small ring.
Not true, I know FSA sells a 50T 130BCD Chainring and I found the following from a website selling FSA compact cranks.
With a standard 130 bcd crankset, the smallest chainring you can mount is a 38 tooth. On a 130 bcd crankset one can run a 38/50 or 38/48 (a gearing commonly used for cyclocross). It is possible to do the reverse – convert your compact cranks to standard. 39/52 chainrings are available for 110 spacing.
Now I am totally confused. I was going to replace my 5 year old shimano ultegra cranks this winter with compact cranks, as I am in the same boat the OP was. Should I go ahead and replace them, or can I change the big ring to a 46T-48T?
Never used FSA rings. Looked at the post responding to mine with the FSA link, and it seems like they have rings that will work with shimano 130BCD bolt pattern. I have shimano compact cranks, but got them for the small ring (34T) for climbing. and I think that the smallest you can get on a 130BCD is 38T. If your only issue is that the big ring is too big, I’d try an FSA ring. If the small ring is also too big, may want to go to compact.
I went through the same thing 2 years ago. I had a set of Zipp cranks, and put Stronglight 50/38 rings on it. At that time, that was the smallest (for both rings) I could find for 130mm BCD spacing. Turned out the 38 was too big, so I just went with compacts (50/34). I’m not saying I did an exhaustive search, but I was not aware then, nor am I aware now of any BIG rings smaller than 50T for 130BCD.
You are pretty well wrong here. If you want, you can put even a 38 tooth (smallest) ring as the BIG CHAINRING on a regular 130 BCD crank…or course in this extreme scenario, you’d end up with 38 outer and 38 inner.
Actually Truvativ makes a 130 BCD 48 outer 38 inner cyclocross crank that comes with ISIS.
Seriously, I believe that aside from a few bullet fast age groupers and pros, most of you dudes are way over geared. The 53x12-14 are totally useless gears for most of us in triathlon…if you are going 60 kph, you may as well coast and save the legs for the run.
I am actually considering going to a 46/34 front ring combo (what I currently have on my commuter bike), but with an 11-25 cassette in the back. The 46 big with an 11 rear cog is actually bigger than the 48-12 combo I currently have. Best of all, with the 46-23 combo (big to “almost big”), I end up with a ridiculously small 54 inch gear (46 divided by 23 multiplied by 27 inches) while still in the big ring. The downside is that my cluster would not be as tightly coupled as I would have to lose a gear somewhere in the middle to get the 11, but it would be no more loosely clustered than running a 9 speed 12-25 which is what I previously had before the upgrade to 10 speed.
