Agilo velomobile
- Ersteller anotherkiwi
- Erstellt am
- Beiträge
- 4.091
So a suspension test drive. I am unfit and have a heavy cold so performance was not the goal this time. The new setting of the rear damper sags as per Rockshox recommended 25-30% - open the door and jump up and down on the step beside the seat to get the reading 
My GPS came along for the ride but other than the top speed and the distance we do not agree on much because the averages are calculated stop time included... and the altitude is not set correctly so I drove for a while at -61 metres... We do agree on 13% (average) gradient leaving home.
It (will be) easy to maintain 30+ km/h average on the flat. I finally get the thing about the effort required to reach a certain speed then relaxing as you maintain that speed, I got to 35-36 km/h with a little effort in 6th gear and stayed there with much less effort for 500 metres. The only way to validate how much less effort would be with power meter pedals, maybe I will get around to doing that one day. A RR passed me so I upped my cadence and had no problem catching back up with him at 32 km/h. So I confirm that Agilo is between 15 to 25% faster than my Azub T-Tris 26* on that section of road. Today the weather is bad so they are not at the beach and there was much too much traffic which is one of the reasons I turned back earlier than planned.
Unfit and with a badly set up Bafang I averaged 5.3 Wh/km. One must pedal VERY slowly to get assistance from the motor and it did most of the work on the way home today. I am optimist that I can reach 3 or less Wh/km average when I can pedal at my preferred cadence after my little voltage modification.
The gear box is not run in and yes! It got unset again... The low gear with the 42T is slightly more comfortable but confirming the gear calculator estimations 52-39T will be what I mount next. When the motor comes out again for more shims
The brakes seem to be settling in, not as hot today when I arrived home despite the -13% average gradient back down the hill, I try not to go over 30 km/h there to stay in control so I am on the brakes most of the way down.
I have air in my face but 26ºC is more like trike weather than VM for me.
* My Azub is not a speed demon with big fat tyres and a 3.8 kg hub motor in the rear wheel but it does average 26-27 km/h over the same road.
My GPS came along for the ride but other than the top speed and the distance we do not agree on much because the averages are calculated stop time included... and the altitude is not set correctly so I drove for a while at -61 metres... We do agree on 13% (average) gradient leaving home.
It (will be) easy to maintain 30+ km/h average on the flat. I finally get the thing about the effort required to reach a certain speed then relaxing as you maintain that speed, I got to 35-36 km/h with a little effort in 6th gear and stayed there with much less effort for 500 metres. The only way to validate how much less effort would be with power meter pedals, maybe I will get around to doing that one day. A RR passed me so I upped my cadence and had no problem catching back up with him at 32 km/h. So I confirm that Agilo is between 15 to 25% faster than my Azub T-Tris 26* on that section of road. Today the weather is bad so they are not at the beach and there was much too much traffic which is one of the reasons I turned back earlier than planned.
Unfit and with a badly set up Bafang I averaged 5.3 Wh/km. One must pedal VERY slowly to get assistance from the motor and it did most of the work on the way home today. I am optimist that I can reach 3 or less Wh/km average when I can pedal at my preferred cadence after my little voltage modification.
The gear box is not run in and yes! It got unset again...
The low gear with the 42T is slightly more comfortable but confirming the gear calculator estimations 52-39T will be what I mount next. When the motor comes out again for more shims The brakes seem to be settling in, not as hot today when I arrived home despite the -13% average gradient back down the hill, I try not to go over 30 km/h there to stay in control so I am on the brakes most of the way down.
I have air in my face but 26ºC is more like trike weather than VM for me.
* My Azub is not a speed demon with big fat tyres and a 3.8 kg hub motor in the rear wheel but it does average 26-27 km/h over the same road.
- Beiträge
- 16.624
Yes, this is how the average speed is calculated:
Distance / (Time(Arrival) - Time(Departure))
To consider only speeds > 0 km/h (or > 20 km/h or > Mach2) may flatter one's vanity, but does not even come close to the truth.
- Beiträge
- 4.091
Yes, yes of course...
I just wanted an idea of the average speed on the flat section. Next time I will drive there and then start the GPS. There used to be an "average speed in movement" option by section in my software but I have apparently changed versions so I guess I have to go back in the settings again.
Today over the whole drive it was 18.81 km/h. To achieve 26 km/h average the trike climbs much faster (17-19 km/h) and everywhere else I pedal like a donkey. I have to learn some more and improve a couple of things before Agilo is ready for donkey mode
I just wanted an idea of the average speed on the flat section. Next time I will drive there and then start the GPS. There used to be an "average speed in movement" option by section in my software but I have apparently changed versions so I guess I have to go back in the settings again.
Today over the whole drive it was 18.81 km/h. To achieve 26 km/h average the trike climbs much faster (17-19 km/h) and everywhere else I pedal like a donkey. I have to learn some more and improve a couple of things before Agilo is ready for donkey mode
- Beiträge
- 4.091
After sleep:
- an air damper sag % is specified for MTBs, these often take the full system weight on the rear wheel on landing after a jump (sometimes huge...)
Now those are not typical conditions one would experience in a vélomobile (yes I know about the Dutch vélomobile jumping competition...). So the only advantages of having a hard rear suspension is 1, no suspension pumping when pedalling hard and 2. better handling when driving hard and fast. With remote lockout one could arguably set the damper quite soft for comfortable every day driving and lock it out when climbing hills.
What do you think?
- an air damper sag % is specified for MTBs, these often take the full system weight on the rear wheel on landing after a jump (sometimes huge...)
Now those are not typical conditions one would experience in a vélomobile (yes I know about the Dutch vélomobile jumping competition...). So the only advantages of having a hard rear suspension is 1, no suspension pumping when pedalling hard and 2. better handling when driving hard and fast. With remote lockout one could arguably set the damper quite soft for comfortable every day driving and lock it out when climbing hills.
What do you think?
- Beiträge
- 5.965
Will Your budget suppert another damper?
Anyway: i would figure out the optimum by trial an error. Chrisol for example needed some larger pressure than i needed to for his (former) GoOne, but that was with electic suppert and therefore pretty heavy.
And i acutally use most of the available range of the damper - just because of a few meters of bad road at 30 km/h.
- Beiträge
- 4.091
What budget? Yes I read somewhere that you can break air dampers. I am still a beginner so I am below 20 km/h on bad sections.
Yes I read somewhere that you can break air dampers. I am still a beginner so I am below 20 km/h on bad sections.
- Beiträge
- 4.091
I went away for the weekend so I had a bit of time to think about my next steps.
Climate and vélomobile:
Bodo Sitko sent me this description of the ventilation system in Agilo:
The view from above into the vehicle interior shows how the seat ventilation works. Fresh air enters the interior through the foot holes in the floor and through a gap under the windshield. The stale air finally escapes from the vehicle through the air-permeable seat cover and the perforation in the seat surface. Moist air is kept away from the windows and the driver's back stays dry.
I don't have foot holes (yet) but the front light is not fitted and there us an air entry at the stagnation point. I also have air coming in from the top of the windscreen. I sweat a lot, mostly because of stress and yet so far my back has been amazingly dry so I can confirm subjectively that the system works well.
We have been having very cold weather - 16ºC -> 22ºC is not typical for a month of July. The Basque coast is not very hot but air temperatures are usually between 22º and 26ºC at this time of year. There is a huge difference between air temperature and the temperature you feel in the sun and as well as me sweating away my stress I am also slightly cooked on sunny days. So the next step is to take the windows out and cover the top half of the windscreen and the side windows with UV protective film.
In any case the traffic is not drive-able until the end of the school holiday and this year is even worse than usual because we have all the tourists who usually go to other countries...
Bafang BBS01:
I need to get some more shims into the velomobiel.nl BB holder because the motor is still moving on the drive side - at the moment I have 0.2 mm shims. It only moves significantly when climbing and also because I am not at my preferred cadence. I briefly had cadence measurements when I had mounted a KT Bluetooth controller and my average was 94 RPM. I knew it was over 87 RPM because I had back EMF problems with the motor on the upright pedelec even with a full battery. So this month I will be over-volting the motor to 44v which gives me a 22% increase in RPM or 91-95 RPM depending on battery charge.
Gearing:
The Alfine 8 with double chainring was always a cheap hack to get the necessary gear range. It works but unfortunately where I need small jumps I have the largest - 22% jump between 5th and 6th gear. I am finding it really easy to push the 30 km/h of the 5th direct drive gear and I am sure that I am capable of pushing the 36 km/h of 6th gear (I have done it briefly) constantly on flat terrain. I am convinced that a Rohloff equipped Agilo would be able to drive between 29 and 36 km/h on flat roads with little effort and getting to that speed would be much easier with the 13.6% jumps between gears.
to be continued...
Climate and vélomobile:
Bodo Sitko sent me this description of the ventilation system in Agilo:
The view from above into the vehicle interior shows how the seat ventilation works. Fresh air enters the interior through the foot holes in the floor and through a gap under the windshield. The stale air finally escapes from the vehicle through the air-permeable seat cover and the perforation in the seat surface. Moist air is kept away from the windows and the driver's back stays dry.
I don't have foot holes (yet) but the front light is not fitted and there us an air entry at the stagnation point. I also have air coming in from the top of the windscreen. I sweat a lot, mostly because of stress
and yet so far my back has been amazingly dry so I can confirm subjectively that the system works well.We have been having very cold weather - 16ºC -> 22ºC is not typical for a month of July. The Basque coast is not very hot but air temperatures are usually between 22º and 26ºC at this time of year. There is a huge difference between air temperature and the temperature you feel in the sun and as well as me sweating away my stress I am also slightly cooked on sunny days. So the next step is to take the windows out and cover the top half of the windscreen and the side windows with UV protective film.
In any case the traffic is not drive-able until the end of the school holiday and this year is even worse than usual because we have all the tourists who usually go to other countries...
Bafang BBS01:
I need to get some more shims into the velomobiel.nl BB holder because the motor is still moving on the drive side - at the moment I have 0.2 mm shims. It only moves significantly when climbing and also because I am not at my preferred cadence. I briefly had cadence measurements when I had mounted a KT Bluetooth controller and my average was 94 RPM. I knew it was over 87 RPM because I had back EMF problems with the motor on the upright pedelec even with a full battery. So this month I will be over-volting the motor to 44v which gives me a 22% increase in RPM or 91-95 RPM depending on battery charge.
Gearing:
The Alfine 8 with double chainring was always a cheap hack to get the necessary gear range. It works but unfortunately where I need small jumps I have the largest - 22% jump between 5th and 6th gear. I am finding it really easy to push the 30 km/h of the 5th direct drive gear and I am sure that I am capable of pushing the 36 km/h of 6th gear (I have done it briefly) constantly on flat terrain. I am convinced that a Rohloff equipped Agilo would be able to drive between 29 and 36 km/h on flat roads with little effort and getting to that speed would be much easier with the 13.6% jumps between gears.
to be continued...
- Beiträge
- 213
Don't mix spring and damper functions! The spring supports the static load, while the damper controls the dynamic movements of the suspension. Typically the damping in compression is lower than in rebound. This is to allow a good shock absorption. This also explains the specified sag of about 20%. If there is too much sag, the upper part of the stroke will never be used as the high rebound damping will prevent that, you might however reach the compression end stop more quickly.
Note that shocks with a suspension travel of only 38mm are installed on MTBs with limited suspension travel, so not designed to do big jumps.
You could increase the sag, but I would limit it to 50% max. Don't forget that you will occasionnaly take some load/luggage in the velomobile as well.
- Beiträge
- 4.091
There is no spring, it is a 200 gram air shock with manual hydraulic lockout. The shock is capable of 275 lbs so about 125 kg load.
I am at 30% sag and the Rockshox manual say 25% plus or minus 5 % so for the moment I am within specification. No more test drives before the 15th of August, there are too many tourists in their SUV's on the roads, much too dangerous...
I am at 30% sag and the Rockshox manual say 25% plus or minus 5 % so for the moment I am within specification. No more test drives before the 15th of August, there are too many tourists in their SUV's on the roads, much too dangerous...
Zuletzt bearbeitet:
- Beiträge
- 4.091
In English that would be rather be a "damper"
spring: an elastic device, typically a helical metal coil, that can be pressed or pulled but returns to its former shape when released, used chiefly to exert constant tension or absorb movement.
If there were elastomers in there I would have conceded your point
spring: an elastic device, typically a helical metal coil, that can be pressed or pulled but returns to its former shape when released, used chiefly to exert constant tension or absorb movement.
If there were elastomers in there I would have conceded your point
- Beiträge
- 2.164
I guess
both, as ist's probably a gas spring, plus, as the gas must squeeze thru a small hole, the resulting friction provides the damping.
Air in a closed space is an elastic device, also like a steel coil, with only minor losses. And there is an oil damper inside. If the air would damp, it would get very fast very hot, considering the mass of air.
- Beiträge
- 4.091
We could discuss semantics for a very long time but air is not a device it is a fluid, like oil, and in the English language if you say "spring" people always have the image of a metallic coil. Air shock or air/oil damper are the correct terms. Agilo should have a spring, an exaForm to be precise, but I jumped on the occasion of having an air shock here on the forum and saved several hundred grams in the process.
Sorry, but that needs to be 'rectified'
Fluids are incompressible, metal is bendable (and can return to it's origin form sometimes), air ist compressible, but the characteristic is indeed different to an ideal spring, which is linear compressible. An air spring has a progressive compression curve, so it get's harder, the more it is compressed. To have a more linear response, you need a big air chamber or a special mounting geometrie, where the lever of the damper get's bigger, the more it is compressed.
- Beiträge
- 7.403
Nope!
Actually, I think (might be wrong) you don't want a linear suspension response. A progressive suspension is just fine.
- Beiträge
- 213
This is how a typical MTB shock looks like:
The air chamber is the spring. The advantage vs. a coil spring is its adjustability and its non linear stiffness. The damper is located inside the inner tube. The damping is created when the oil circulates through the small orifices in the piston valve. The small nitrogen gas chamber inside the damper is used for the volume compensation: when the rod enters the damper, the excess of oil needs to go somewhere, so it compresses the gas.
Note that I have been working for almost 30 years in the R&D department of the n°1 automotive shock absorber manufacturer...
The air chamber is the spring. The advantage vs. a coil spring is its adjustability and its non linear stiffness. The damper is located inside the inner tube. The damping is created when the oil circulates through the small orifices in the piston valve. The small nitrogen gas chamber inside the damper is used for the volume compensation: when the rod enters the damper, the excess of oil needs to go somewhere, so it compresses the gas.
Note that I have been working for almost 30 years in the R&D department of the n°1 automotive shock absorber manufacturer...
- Beiträge
- 4.091
Basic Course of Thermo-Fluid Analysis 06: Chapter 3 Basics of Flow - 3.2.1 Compressible/incompressible fluids
Chapter 3 Basics of Flow III 3.2 Characteristics o...
www.cradle-cfd.com
I quote: Remember that a fluid can be a liquid or a gas.
That is also what I learnt in physics class at high school.
Rockshox Monarch