Advice on Vendetta gearing

[LarryOz]

wow - 40 on the back 39 on the front

Since this is thread on gearing, I guess I had to chime in.
I have a 50/34 with 11x36 on the back (bottom really).
The 50 teeth on the large chain ring is just not enough for going downhill. I wish I had 52 or 53, as I can't really pedal fast enough to go much faster than about 38. But that might be because of my crank length too and flailing too much compounded with the fact that my knees are bent at 60 degrees which throws off my balance some at hi revolutions. A 40 in the mix would make sure I had enough to get up Mount Mitchell! Maybe most of that will be fixed after tonight!
The 40 just looks sooooooo big!

Please don't kick me off this thread since I don't have a V. Does it count if I want one?

Ok - I am done...

 

[Rick Youngblood]

Hey Robert, I use a 42t Wolf

Hey Robert, I use a 42t Wolf tooth components from this site http://www.wolftoothcycling.com/ - I also have 40t I've tried. Love these big cogs. Seems to be more companies producing them these days. The sift from 36t to 42t is butter and I could not tell any difference in loss of shifting performance between the 2 sizes.

I would suspect I may not need the 42t on the Vendetta, but we will see. BTW I removed the 11t cog instead of the 17t as recommended used a 13t locking ring.

Hey Larry, if you are peddling at 38 mph, that's good right. In my 53 Q and 13t cog combo 30 mph and I'm spinning like a mad man.

 

[ratz]

I don't believe I said....

I don't believe I said "old" at any point. Larry and Eric must just be sensitive

. 50 is the age in the power meter test history. Perhaps we all just need to volunteer to be tested and give them better data. Middle age in this family is 55; I plan to water ski at 80 and ride a bike at 100. That's why I'm I want to keep the power going.

 

[Robert Holler]

Rick,
Good to know the 42T

Rick,

Good to know the 42T shifts well!

Ill have to look into that company too - these do seem to be gaining popularity. Of course the best way to get better at hills is to ride the hills!

;-)

Robert

 

[John Tolhurst]

But, as you go to these super

But, as you go to these super wide cassettes you lose the tightness of the ratios in the cruising range, and that makes it harder to keep the heart rate and power output at optimum. it would handy if we could widen the comfortable cadence range - working on that one.

 

[Rick Youngblood]

I agree John - my game is to

I agree John - my game is to get fitter, but in mean time I've got to get up the hills. I've also notice that over the course of 3000 miles on the Silvio, my strength has been increasing, and what I'm staring to see is I'm beginning to run on smaller cogs up the hills. The future will tell, but I expect I will not need those big cogs out back (or up front as it would be on the Cruzbike) someday soon.

Robert ~ Of course the best way to get better at hills is to ride the hills! That's so true, and also to up the effort over time to increase strength and stamina.

 

[ratz]

I like the blended cassette I

I like the blended cassette I just tried.

I was trying to cover both needs. I setup my 10 speed cassette custom on the vendetta: 11,12,13,14,15,16,19,22,25,28 Up through 16 it's an nice cadence cruising pack; and the 19-29 are the climbing range. One nice thing about is that it makes it really obvious when you change sections; since it's hard to look down at the wheel that is very handy if you loose track of what gear you are in.

I'm pretty sure I can cleanly shift a 5T gap so you could make a 11,12,13,14,15,16,17,22,27,32 that would shift fine. Put one of those rotor 34/52 on the front; and that's a pretty wide set of gears.

 

[Robert Holler]

Joghn, Indeed - this is why I

John,

Indeed - this is why I have a second drive wheel so I can make a swap depending on the ride. Here in Portland where I live it is either going up up up or down down down. Unless I head out east where the grades are flatter.




Robert

 

[John Tolhurst]

The other gearing wierdness

The other gearing wierdness is how big an increase in power output is needed on a 10% gearing step when you are fighting air, compared to when you are fighting elevation. change up 10% at speed and power output needed jumps 1.1 cubed. Change up 10% on a hill and power output needed jumps 10%. This suggests that big percentage changes in the low end of the gearing is better than having them on the tall end. I am sure there is a mathematician out there on the verge of preparing a function that will suggest an optimum gear spread on the cluster.

 

[snilard]

John Tolhurst:
It's really

John Tolhurst:
It's really interesting idea. But I think that You are correct with power but not with gearings.
When you are climbing steep hill in 10 kph 10% higher power will mean something like 10% more speed = 11 kph. Let us say that in this speed you are just fight gravity. So if you want to stay on pedaling frequency you will need 10% smaller cog.
When you are cruising at 40 kph and you higher your power by 10% your increase in speed will be just about 3%. Let us say that main resistive force is air drag in this speed. So you will need just 3% smaller cog.
There are a lot of simplification but It thing that my idea is clear. So I think that usual cassettes is to low in progression. In 10 sp, SRAM cassettes is a little bit more progressive than Shimano but still to low I mean.

I have got 9 sp 11-32 Shimano cassette on my RWD recumbent and I don't like it's jumps at my speed on flats (25 - 35 kph). I have got aluminum freewheel body on my hub so I have to use cassettes with large cogs on shared carrier. So I cannot experiment with my own cassette cogs spacing.

 

[Ivan]

Larry, I noticed the drop in

Larry, I noticed the drop in HR too - due to more efficient recumbent position. And also due to lack of familiarity with new platform. Now approaching a year, I can get my HR into the high range that I was riding with my DF. I tend to get there only when chasing riders stronger than me, especially on group rides. The good thing is that I am keeping up with a train that I couldn't have kept up with on my DF. So if you want to ride, you can. I think it takes longer than a couple of months on our Vendetta-Silvios!

 

[Charles.Plager]

But, as you go to these super

But, as you go to these super wide cassettes you lose the tightness of the ratios in the cruising range, and that makes it harder to keep the heart rate and power output at optimum.

Huh. If only they invented a crankset with three rings in front instead of two to combat exactly this problem...

I really like the Silvio with the 74 BCD triple. Now you can get yourself some nice bail-out gears for climbing.

 

[Robert Holler]

Ultimately - you have to be

Ultimately - you have to be able to maintain a forward MPH to keep balanced. Too much "climbing" gears and you fall over. This becomes more pronounced on steeper inclines as your body gets angled backwards and balance becomes even harder to maintain anyway.

I have seen people spinning madly at max heart rate going barely walking speed, typically weaving all over the place. In my opinion it is time to walk at that point and also do some more strength training.

That point is different for everyone depending on what cadence you can spin at comfortably without blowing up and how good you are at the slow speed thing. And what your terrain is.

Here in the Portland hills it is either going up up up and then down down down. My goal is to try to gear to be comfortable up the hills enough to have some gas to power down the other side.

;-)

 

[John Tolhurst]

Huh.  If only they invented a

Huh. If only they invented a crankset with three rings in front instead of two to combat exactly this problem...

I really like the Silvio with the 74 BCD triple. Now you can get yourself some nice bail-out gears for climbing.

Shimano solved the problem with their beautiful hollowtech triples, while Sram convinced the world that a double would do if you had a wide range cluster.

My personal priority is close ratios at my cruising speed over slightly undulating ground or with moderate head-teail winds. And then hill gearing, I don't need to go very low. For my low body weight and as long as I don't tackle steep stuff of more than a one or two kilometers duration I am fine. So I run 34/50 and 11-27.

 

[Rick Youngblood]

If someone decides to go with

If someone decides to go with a triple on the Vendetta or Silvio, I would recommend going with the Ultegra 6703 or the Tiagra 4603, because the granny is a 92 BCD - they use a proprietary middle chainring that doubles as an interface for small/inner chainring mounting (in otherwords, the small inner ring is bolted to the middles ring - but the smallest ring is limited to a 30 tooth. Otherwise, if you use a standard 130/74 bcd crankset, you have to use spacers and and then offset the crankset to clear the "Chainstay Ring Clamps" with the 74bcd chainring - I did this and did not like it because it crossed up the chainline on the big cogs - and also I did not like the aesthetics of it. With that said, I did read where others have had success with the using the standard 130/74.