prj71

Just recently picked up a flat road bar bike...2015 Giant Fastroad Comax 2 10 speed. It came with 50/34 in front and 12-30 cassette. I have been going on some group rides with people and for the most part I can hold my own. But a couple of flats and down hills I would spin out. Seems most everyone in the group is running 11-28 cassette with 50/34 chainrings.

Is this the common setup or ??

I'm thinking of swapping out my cassette to 11-28

10 Wheels

Cassettes are easy to change out.

Marcus_Ti

Define "spin out". Unless you're 120RPM+ on the crankset you're not spunout. And even in a group ride, unless you're on the TdF you are not going 63km/hr (40MPH) on flats, which is what 700x23c tires at a 120 cadence in a 50-12 gets you.

An 11-28 versus a 12-30 is rather negligible. Will get you 9% higher gear (maybe 5kph spunout), and a 7% lower low gear. "Negligible", because if you're bombing down an 8+% downhill long enough you can simply coast to gain more speed in an aero-tuck.

PepeM

You're spinning out a 50-12 on the flats? That gear should get you to 40mph at 120rpms. You must be a beast of a rider.

With that said, 50/34 and 11-28 is a common setup, and changing a cassette is easy and fairly cheap, so if you want to go that way by all means do so.

rm -rf

Changing to an 11 cog high gear won't solve your problem. Perhaps you mean "ran out of power" instead of "spinning out".

When I'm just cruising along, I'll have cadences in the low 80 rpm range. But to keep up with a fast group ride, I need to be in the mid-90s, and 100-105 on the sprints.

To get used to faster cadences, try shifting to one cog easier from your normal selection, which will speed up your cadence. See how that feels after a few rides. It takes some getting used to.

11 cog
Most riders can pedal a cadence of at least 105 rpm or more when "spinning out".

At 105 rpm:
The 50-12 high gear is 34 mph.
The 50-11 high gear is 37 mph.

But many riders don't have enough power to go much beyond 30 mph, even for a few seconds. So a 50-11 is only usable on downhills. And once you are in the mid-30 mph range on downhills, you might as well coast. A lot of pedaling effort downhill in the high 30 mph range will only a few mph to your coasting speeds.

34-12
My first reaction to all the bikes sold with a 11 cog was "marketing". But there is one advantage to having an 11 cog: you can use the 34-12 without extreme cross-chaining, and that extends the range of the 34 chainring up past 20 mph. Useful.

rpenmanparker 

I think you meant 7% HIGHER low gear.

Marcus_Ti

My brain hurts.

Dear coffee gods, please save me.

prj71

I am on the hills.

Rest of the group couldn't keep up on the hills but once we got to the top and either went flat or down hill a lot of riders passed me up and I couldn't keep up. So my thought was either I was out of power after leading the climb or I need that one higher gear.

Thanks for the insight everyone. Maybe I need to work on my power and cadence.

gregf83 

The issue, if it occurs, would happen on a long hill with a small (1 - 2%) slope where you still have to pedal to keep up. I find higher cadences easier to maintain at high speed so never had a problem with a 50-12 but also don't have any long stretches of -1% to deal with.

PepeM

What was happening? Were you trying to go faster but you just couldn't push any harder/pedal any faster, or were you spinning at such an uncomfortable cadence that you were bouncing on your seat and couldn't keep control of your pedaling?

prj71

A little of all of that. Probably need to work on it.

PepeM

I wasn't there so I cannot really know, but I honestly doubt running out of gears was your issue. Even at 90rpms, which is a very comfortable cadence for pretty much everyone, the 50-12 would get you to 30mph. Is this a group full of Cat1 racers? Even they don't go 30mph on the flats consistently.

Marcus_Ti

Bingo. More is going on.

Short of seeing a Garmin file...the most likely guessable cause is a much lower sustained cadence than the OP thinks they're doing. A 90 cadence sustained and consistently takes conditioning and training to do. Lots of folks suffer from pedal/coast/pedal/coast disease as well, so they aren't actually even sustaining whatever cadence they think they're driving (The Stravistix plugin is great for spotting this).

In a group ride, could also be the OP isn't holding the wheel tight enough to draft.

Might also be the aerodynamics of flat versus roadbar fit. All else equal, the drop-bar bike can be more aerodynamic. as you can get lower for longer.

prj71

Looked at my stats on the bike computer and average cadence was 60rpm, Average speed was 19mph and top speed was 32mph. Sounds like I definitely have some work to do and maybe I'll leave the cassette alone for now. You guys have been helpful.

Group road biking is new to me. Been spending the majority of my time on the mountain bike, but trying to mix it up a little with my new road bike purchase.

Darth Steele

hmm.. my guess is that you are a lighter/smaller guy compared to most in the group.. On the hills you killed them but then on the flats and downhill where power to weight is less important and even beneficial (downhill) they got their revenge.

I know, I know, I know... the 41 hates power meters but I will say get one. My goal is to keep my cadence 90-105 while generating my target power numbers

Unless I am sprinting in a race I seldom touch my 12 cassette

mcours2006

So if you're doing 60rpm, I guess 90 could be considered 'spinning out'. Makes sense.

prj71

5'8" and 195 lbs. Some guys lighter. Some guys heavier.

redfooj

tuck

gregf83 

If you're leading the group up the hill it's likely because you are riding closer to your limit. A little better pacing might be required, i.e. don't go so hard up the hill and you'll have more energy to keep up when the speed picks up.

Are you comfortable drafting (within a foot or so) other riders? That will also save your energy.

ypsetihw

what you really should do is take that flat bar bike back to the store and get a proper road bike with drops. you are not spun out, you are not spinning fast enough and you are sitting up in the wind. no cassette is going to fix that.

ypsetihw

Average speed of 19mph at 60 cadence sounds terribly uncomfortable, and I'm sure your knees will soon be protesting, if they aren't already. Where is your data from? Strava? Garmin? Cycling computer?

Also, what distance did you cover? 19mph AVERAGE is pretty high for a group ride, especially if there is climbing involved, and even moreso on a flat bar bike. On our 30 mile group ride last night, with basically no climbing, we only AVERAGED just above 18mph, and that included LOTS of surging to 25-28mph sometimes for several minutes at a time.

Average speed is useless and is highly variable depending on wind, road conditions, climbing, drafting, etc. HR and Power are more accurate measures of your actual effort, which translates better to how well you are performing. At the end of the day, if other people are riding away from you, there's all the proof you need. Changing cassette isn't going to change that.

PepeM

60rpms is pretty low. Most people probably do ~90rpms, but there is no magic number. I think you should try to bring that number up. Don't go too crazy and try to go 100rpms right away, but trying to spin at ~80 will be good for you. It will probably feel awkward at first but after a short while I'm sure you'll see the benefits. Definitely leave the cassette alone for now.

Apart from that, as others have mentioned, there is a lot to group riding. Being left behind on the flats as a beginner is fairly common, and in your case probably has more to do with lack of pack-riding skills. Main thing to work on is to get good at drafting. That will save you tons of energy. Pacing is also important. I'm also one who tends to do well on the hills, but going too hard and then being dropped once the road flattens does you no good. It's all about using your energy when it is needed and saving it when possible.

merlinextraligh

Your problem is two fold:


1) you need to raise your cadence,


2) you need an actual road bike. You're having trouble keeping up on flats and descents because your flat bar bike is less aerodynamic. You bought the wrong bike for fast group rides.

cthenn

Wow 60 rpm average? I don't think I could go that low if I tried. All I know is I'd get sick of turning over too big a gear all ride long. You gotta bring that up to at least 80rpm IMO. Agree with above, if you are "comfortable" at 60rpm, then yes, 90 will feel like a blender. Try raising it...your legs and knees will thank you.

prj71

Yes