silvio 2- how slow can you go?

[timt]

This is a question for those of you with experience on the silvio 2 platform.

How slow can you ride? At what speed does it go from stable to a struggle to ride in a straight line?


Why?
Visiting relatives in the hills in SW Pennsylvania over the weekend got me thinking about climbing long grades.

If the grade is long, you slow down to a power output you can maintain. If the hill is steep enough and you can gear low enough, eventually your forward speed is too slow and you fall over. What is that speed?

You can put a 24 tooth granny ring on the Silvio 2. Coupled with a 32 tooth sprocket that gives you around 20 gear inches and a low speed around 4 or 5 mph (assuming 70-90 rpm cadence). Ignoring friction and wind, that's 130-170 watts on an 8% grade.

So you can gear for long 8% grades. The power requirement is very manageable. But will the bike stay upright?


I currently have a Rans V3. That's a long wheel base bike with 26" wheels. Below around 7 mph things get pretty wobbly. That limits me to 5-6% on long grades. I can do shorter steep hills. In the flatlands of lower Michigan this is not a big issue. But if I were to travel or tour it would limit me.

 

[Andrew 1973]

Great riding in SW Pennsylvania

That area is my home (Pittsburgh area native) and in July I had the opprtunity to ride on some of my favorite roads. What a difference from the mostly-flat South Carolina where I currently reside.

I am not sure how low you can go with a granny gear on the Silvio, but I found that wheel slip was a bigger limiting factor than my gearing or speed. I was able to climb hills in a low 34 x 30 combination at a crawling speed, but once my wheel lost traction, I was walking the rest of the way.

 

[Charles.Plager]

On both of my Cruzbikes, I

On both of my Cruzbikes, I can maintain less than 3 mph.

If the hill is very steep, I sit up to put more weight on the front wheel. A small amount of wheel slippage can still happen, but it usually won't stop me from climbing. I do have a lot of trouble starting on steep hills.

I find that having very low gears is important for not slipping on steep hills.

 

[timt]

oh yeah, wheel slip

I hadn't thought that wheel slip would be a factor that soon.

I assumed wheel slip would be more of an issue on the shorter hills where you pedal hard and try to crest the hill before you burn out.
For this question, I'm thinking about the long grades where you accept that you can't grunt your way up the hill. So you slowly and aerobically grind your way to the top. Maybe the gap between the two modes is narrower than I imagine. But that's why I'm asking the people who have the experience.

"How slow can you go on a silvio 2" is still an open question. The minimum speed of the bike is a factor in gear ratio selection. There's no need to put in a combination so slow I can't stay upright.

Charles can do about 3mph on his softrider and/or mantis. Does the Silvio 2.x geometry allow similar speeds?

Andrew, I grew up in Penn Hills and my parents are still there. Sunday I was wandering back roads from PH to my sister's place near Butler and realized I couldn't do that trip on my current bike. Every time I go back to visit the hills are a shock.

I'm just dreaming until I get past the Christmas bills.

 

[Andrew 1973]

About wheel slip

Hi Tim. Nice to meet a fellow Pittsburgher on here

Allow me to add that wheel slip was an issue on long climbs on PA backroads that had loose gravel. In my opinion, hard efforts on short, steep sections are manageable once you get a feel of how to adjust your position and power output. I do not enjoy the position, but wheel slip can be managed by pulling the torso to the bars so that your back is not against the seat back. This position also seems to engage the muscles differently, providing the closed position similar to sprinting on a DF bike and allowing yoy to power tgrough the pedal stroke.

Regarding low speeds, I don't have enough experience on the 2.0 to speak to its handling. I might guess that once getting uswd to the nuances of the relined position, the bike would be similar to ride up a long, slow climb. However. This is just a guess and I am sure thosenwho are better acquainted with the 2.0 will offer theor feedback.

 

[iow]

my lowest  gear on  my S2.0

my lowest gear on my S2.0 (27 inches) is approx 5.5 mph @ 70 cadence. no problems with balance at this speed as long as i can maintain traction, which would not be an issue climbing an 8% slope at a steady 170 watts.