Expert advice on gear ratios needed for an amateur!

[Emazing]

I have a super gravel bike it has a Sram XX1 set up and the cassette is 11speed 10-42 and the chain ring is a 42 teeth. 
 

Today we did a fast race and for the first hour I averaging around 42 km an hour. At around 50 km my legs felt absolutely exhausted “ blown “and I had to pedal slowly the whole way home another 70km! I also had some cramp in my thigh. 

can someone tell me if the cadence is too high for this gearing or is it OK and basically I’m just an unfit old fart? 💨 

I climb up hills well and generally on rides around 40 to 70 km my averages around 28 to 30 km an hour, dep on elervation. 

do you think my gear races are correct or do you think the cadence is too high and this is what’s causing me to blow? 
 

Any good input will be welcome thank you so much

 

[ChrisF]

With a 42 11 combination a fit rider can maintain 40km/h for long stints.  45 to 50 km/h is done at higher cadence, but still well within the realm of fit racers.

 

I had to work at my cadence ... I can now do 100rpm for a couple of minutes, i.e. up Hellshoogte.  But then I need to let up a bit and catch my breath ... then again, I have a long way to go to try and keep up with the fast crowd ....

[RobertWhitehead]

7 minutes ago, Emazing said:

Snip

 

So what's your cadence to average 42? I can just imagine very high. If it was me, and this is just my opinion: I would increase the ring size upfront but also increase the cassette size at the rear. The reason for the double whammy: bigger gear upfront means harder in the climbing department with slower leg speed. So going for a 46 or 50 at the back will help (I know what you're going to tell me , you're going to tell me that the SRAM is going to give issues to make this change) but alas, this is what I would do 

[DieselnDust]

can you pot the ride data?

You could have blown for any number of reasons but the most common is just not being fit enough for the effort exerted....

[Frosty]

https://www.bikecalc.com/archives/development-meters.html
 

use this website to put your gearing into. This will tell you how many meters you will cover with each full rotation.

https://www.bikecalc.com/tables/index.html

the second link allows you to calculate the speed at a specific cadence.

[Emazing]

8 minutes ago, DieselnDust said:

can you pot the ride data?

You could have blown for any number of reasons but the most common is just not being fit enough for the effort exerted....

I don’t have much data because I just have a  basic Garmin and it doesn’t have cadence or power.  My first hour and bit at around 40-48 km/h average my legs were burning 🔥 and then from around 52km my speed drops to 30km/h and from 70 km-115 around 23km/k. 

[Emazing]

16 minutes ago, Frosty said:

https://www.bikecalc.com/archives/development-meters.html
 

use this website to put your gearing into. This will tell you how many meters you will cover with each full rotation.

https://www.bikecalc.com/tables/index.html

the second link allows you to calculate the speed at a specific cadence.

Thank you for these calculation graphs, but I’m not able to understand the answer in correlation to what’s happening to me

[Emazing]

52 minutes ago, RobertWhitehead said:

So what's your cadence to average 42? I can just imagine very high. If it was me, and this is just my opinion: I would increase the ring size upfront but also increase the cassette size at the rear. The reason for the double whammy: bigger gear upfront means harder in the climbing department with slower leg speed. So going for a 46 or 50 at the back will help (I know what you're going to tell me , you're going to tell me that the SRAM is going to give issues to make this change) but alas, this is what I would do 

Yes my cadence is high. As soon as it is “long open road flat or downhill”  I get dropped!! Uphill I am relatively fast with no real tiring issues. 

Edited February 18 by Emazing

[DieselnDust]

10 minutes ago, Emazing said:

I don’t have much data because I just have a  basic Garmin and it doesn’t have cadence or power.  My first hour and bit at around 40-48 km/h average my legs were burning 🔥 and then from around 52km my speed drops to 30km/h and from 70 km-115 around 23km/k. 

you heart rate and calorie data would be good coupled with speed over terrain

[Emazing]

23 minutes ago, DieselnDust said:

can you pot the ride data?

You could have blown for any number of reasons but the most common is just not being fit enough for the effort exerted....

I generally get dropped on the open flats and the down hills but on the uphill, there is no issues.

 

 

[NC_lurker]

13 hours ago, Emazing said:

Thank you for these calculation graphs, but I’m not able to understand the answer in correlation to what’s happening to me

42x11 at a cadence of 90 rpm results in a speed of approximately 44km/hr.

That's not an overly fast cadence, assuming you regularly train at that and quicker. However if the majority of your cycling is done at a much slower cadence then sitting at 85-90 rpm is going to elevate your HR and fatigue you faster.

If you use the tables supplied you can get an indication of cadence & resultant speed using different gearing. Take note of a couple. Then when you're training try maintain certain cadences based on the speed & gearing you've noted.

Edited February 19 by NC_lurker
Spelling

[Frosty]

1 hour ago, Emazing said:

I don’t have much data because I just have a  basic Garmin and it doesn’t have cadence or power.  My first hour and bit at around 40-48 km/h average my legs were burning 🔥 and then from around 52km my speed drops to 30km/h and from 70 km-115 around 23km/k. 

Is this by any chance the Ride for Sight race that you did?

[Emazing]

10 hours ago, DieselnDust said:

you heart rate and calorie data would be good coupled with speed over terrain

 

[Me rida my bicycle]

I think it could just be pushing to hard to keep up with the bigger geared bikes. Could also be why it's easier to keep up on the hill's as they have to work harder. Gravel bike is never really going to be able to sit with road bikes, you have most likely more weight and rolling resistance and not big enough gearing. 

I don't think it's your fitness but if you want to mix it up with those people it would be best to have similar equipment. 

[Koos Likkewaan 2]

I am no expert on this, but this is my takeaway from all the stats provided

1) With your gear ratio, 42km/h ave. is only an average cadence of 84. Not terribly fast, so can be managed if you are fit.

2) The info provided shows a fairly low heart rate and only zone 2 & 3. Was this a training ride, or the actual race you are referring to ? Not seeing a reason to pop with these.

3) Have you ever considered that, like me, you might have fast twitching muscles and just not build for long endurance efforts at high intensity ?

I can do efforts on the gravel bike at 45km/h average (42 x 10) for about 20 minutes then I am done, but this is due to me being a "sprinter" and not a "long distance" type.

[Emazing]

21 minutes ago, Me rida my bicycle said:

I think it could just be pushing to hard to keep up with the bigger geared bikes. Could also be why it's easier to keep up on the hill's as they have to work harder. Gravel bike is never really going to be able to sit with road bikes, you have most likely more weight and rolling resistance and not big enough gearing. 

I don't think it's your fitness but if you want to mix it up with those people it would be best to have similar equipment. 

Absolutely, I think you’re right because I fly up the hills and it’s only really on the straights where my cadence is high and there should be no reason why I can’t keep up with the bunch.