Need advise for upgrading front cog

[novetan]

I'm using a folding bike Tern Verge S11i, front cog 46T with rear cog Shimano Alfine 11 speed (9T to 34T). Most of the time I'm using between 8 and 9 gear and my av. cadence is 80. I felt its about time I need a bigger cog to give my lung a lower heart beat. Would you recommend a front cog 50T or 52/53T? Would jumping to 52T or 53T too great a difference from my present one?

 

[oldbobcat]

This bike uses an internally geared rear hub, so it uses a single-speed chain. I imagine a shop could measure your crank arms and determine if they can order a track chain ring that will fit. But you will also need a longer chain, which could mean sacrificing the BioLogic FreeDrive feature.

Really, I can't give you more specific advice without seeing the bike in person. It is, as are all folding bikes, a bit of an odd duck. Take it to bike shop and see what they can do, or learn to pedal faster. Seriously, everyone who rides a bike can do their legs and heart a favor by simply learning to turn the pedals around faster.

I just read some more detailed specs on that bike and saw that its stock gear range is 26-106". 106" is a mighty big gear. I go that high only at speeds above 29 mph. Learn to pedal faster. Your legs will be grateful.

 

[jpr95]

^^^ +1. Shift down, spin up. 80 RPM is not pedaling very fast at all.

 

[novetan]

Originally Posted by oldbobcat .

This bike uses an internally geared rear hub, so it uses a single-speed chain. I imagine a shop could measure your crank arms and determine if they can order a track chain ring that will fit. But you will also need a longer chain, which could mean sacrificing the BioLogic FreeDrive feature.

Really, I can't give you more specific advice without seeing the bike in person. It is, as are all folding bikes, a bit of an odd duck. Take it to bike shop and see what they can do, or learn to pedal faster. Seriously, everyone who rides a bike can do their legs and heart a favor by simply learning to turn the pedals around faster.

I just read some more detailed specs on that bike and saw that its stock gear range is 26-106". 106" is a mighty big gear. I go that high only at speeds above 29 mph. Learn to pedal faster. Your legs will be grateful.

Tks for reply.

The general belief (not sure whether using right word after I chance upon below article) was that we have to emulate the pro which generally produce 80 to 100 rpm and goes into extreme drive mode of 120 rpm in TT. So if I pedal at 80 rpm and complaining about not getting fast enough, I'd have recieve advise to peddle faster. This is contrary to below article and I sum up as:

We have to mirror our cadence according to our power output. I'm small build and mere mortals and at most generate 150W unlike those pro which goes as high as 400W to 500W. In the article, I was advised to use 60 rpm with my 150W output. Any faster cadence doesn't help and will in fact drain off my energy.

http://www.pponline.co.uk/encyc/cycling-training-can-your-pedalling-technique-make-you-a-more-efficient-rider-42241

Although I use mainly gear 8 and 9, I still have 10 and 11 gear as reserve. When I switch to either 10 or 11, I find its extremely taxing on my leg which I realised I don't have the muscle to peddle faster than my current 80rpm on 8 or 9 gear.

So my question is:
1) Will changing from my current 46T/11T to say 52T/11T much easier on my leg than 46T/9T (which is gear 11)
2) My cadence 46T/9T is abt 48 rpm. I like to give that article a try to reach a cadence of 60. Hence toying with the ideal of changing the front cog.

Appreciate any good advise instead of simply throwing away good money.

 

[qdc15]

A larger chainring will make it harder for you to achieve your goals.

 

[dhk2]

Originally Posted by novetan .

So my question is:
1) Will changing from my current 46T/11T to say 52T/11T much easier on my leg than 46T/9T (which is gear 11)
2) My cadence 46T/9T is abt 48 rpm. I like to give that article a try to reach a cadence of 60. Hence toying with the ideal of changing the front cog.

Appreciate any good advise instead of simply throwing away good money.

1) You can easily calculate the gear ratio change in going from 46 to 52 chainring. Just divide 52/46, and you'll find the 52 is 13% "bigger". These means that for any given gear on your rear hub, changing to a 52 chainring will lower your cadence by 13% (and increase the load-force on your legs by 13%). To achieve any given roadspeed, there is no "free lunch"......if you pedal at lower cadence, you place more load on your legs, like having to lift a heavier weight with each pedal stroke.

2) When you say "my cadence 46/9 is about 48 rpm, I assume you mean this is your cadence when pushing about as hard as you can sustain. This implies to me that gear is "too big" for you. To reach a cadence of 60 rpm at the same road speed, all you need to do is shift "up" to a rear gear of : 60/48 x 9, or 11.25T. To achieve a better, more normal cadence of 85 rpm, just shift into a gear of : 85/48 x 9, or 16T.

Bottom line, there is no need to buy a bigger front chainring now. If you ever get to the power/fitness level where you can easily spin your top gear (46/9) at 100 rpm or more, then it's time to install a bigger front ring. Until then, save your money.

 

[novetan]

Originally Posted by dhk2 .


1) You can easily calculate the gear ratio change in going from 46 to 52 chainring. Just divide 52/46, and you'll find the 52 is 13% "bigger". These means that for any given gear on your rear hub, changing to a 52 chainring will lower your cadence by 13% (and increase the load-force on your legs by 13%). To achieve any given roadspeed, there is no "free lunch"......if you pedal at lower cadence, you place more load on your legs, like having to lift a heavier weight with each pedal stroke.

2) When you say "my cadence 46/9 is about 48 rpm, I assume you mean this is your cadence when pushing about as hard as you can sustain. This implies to me that gear is "too big" for you. To reach a cadence of 60 rpm at the same road speed, all you need to do is shift "up" to a rear gear of : 60/48 x 9, or 11.25T. To achieve a better, more normal cadence of 85 rpm, just shift into a gear of : 85/48 x 9, or 16T.

Bottom line, there is no need to buy a bigger front chainring now. If you ever get to the power/fitness level where you can easily spin your top gear (46/9) at 100 rpm or more, then it's time to install a bigger front ring. Until then, save your money.

Dear Sir,

Thanks you so very much for a well explained theory. You save me the money. There is no short cut. I better put on my training shorts.

Thanks again

 

[dhk2]

novetan, yes, time to put on the training shorts and ride in the lower gears (bigger cogs in back). If you start increasing your cadence on training rides, I'll bet you find that a steady 80-90 rpm will feel comfortable pretty quickly.

By the way, I'm guessing english isn't your first language? Do you mind sharing where you are from?