Carbon Silvio Concept
- Thread starter Mark B
- Start date
WhiteSilvio
Well-Known Member
I have to agree in general with the comments about the Silvio by "the blogger". Living in a hilly area, it is certainly hard to keep up with the guys on their lightweight devices up hills.
The hills are definitely the deal breaker, for me and apparently for the "blog author". Do we know who it is?
Nearly every Saturday I do a 60km ride with a DF group. For the first 8 km or so, I quite often lead the way. Although there is a hill in this first part, I compensate for it with superior downhill speed and better aerodynamics on the flat.
But then we come to a particular hill, which isn't outrageously steep or long, and by the time I reach the top the guys are 100 m or more ahead and accelerating downhill. I make up ground as we go down the other side and head for a second hill, but if I'm not with them, then it's all over. And this is all exacerbated by traffic lights! If you aren't there at the same time and miss the lights it really hurts. Curses on the traffic lights. ( I suppose that occasionally they allow one to catch up too. But usually they seem to conspire and work against one!) The trouble is there are hills all over the place, and they don't go away! Well not often.
I generally average 28-29kph for the ride, the faster people do low 30s.
If I could get up the hills a little quicker I'd stand a better chance of staying with the group.
Things have improved a little lately because I've lowered my weight about 2.5 kg, (Well how many fingers do you need? No no, just kidding. I haven't resorted to removing body parts. Just unnecessary fat supplies) And this has definitely improved my average speed about 4%, which doesn't sound a lot, but is actually significant.
I have some more unnecessary fat supplies which I can live without but, in the end, I can only go so far; maybe another 3kg.
There are one or two bits on the bike, that, now winter is over and the sun comes up at reasonable time, could be removed, lights etc, but there isn't really significant weight to go here.
So
Bring it on I say! (Affording it may however be a problem, but one can dream a little.)
Well ta for now,
John R.
WhiteSilvio
Well-Known Member
Hi Mark,
Harold aka "cycleguy"? (The chap who joined the forum the day after I did?)
What are your impressions of Harold's assessment of the Silvio, particularly for climbing, Mark? I know you sing the praises of the Silvio for climbing, I've read your ride reports, and maybe in the recumbent world it is a very good climber, but, how does it compare with the whole bike world? You're familiar with DF bikes and recumbents.
Would you like a lighter Silvio? Maybe you'd like to say "I'm on a Vendetta?"
Ta,
John R.
Mark B
Zen MBB Master
I think a lighter bike would obviously climb better. That being said, I think the Silvio is among the better climbing recumbents I've had the pleasure of riding. I might be a little faster on an upright than on the Silvio as it currently stands, but probably only 1-2 mph. How much $$$ is that worth, especially for a recreational cyclist?
Mark
WhiteSilvio
Well-Known Member
Hi Mark,
I agree that "buying speed" with a lighter bike can end up costing big dollars.
The upright/DF group have the advantage at the moment, the price of mass produced carbon bikes has certainly come down over the past few years by my observations. It wasn't that long ago that a CF road bike was a fairly pricey item. But now one can find some fairly reasonable full CF bikes for very reasonable prices, about the same as an alloy bike with CF fork and CF chain stays and seat stays from about 4 years ago (very roughly).
I guess for the moment I shall go down the path of reducing my mass, rather than the bike mass. And also improving my fitness.
Bryan at BROL seems to agree that the Silvio is in the upper echelon of climbers, not more than a few appear better.
1-2mph faster on a DF bike is all I am talking about, it makes the world of difference.
Thanks for the comments.
I still think the the UCI, and probably DF frame manufactures in cahoots with the UCI, have a lot to answer for in banning recumbents. They could well be the dominant form of cycling now if that decision hadn't been made all those years ago.
Well I'll get down off my soapbox now.
John R.
gannet
Member
This one sure will be worth watching, There are good precedents for serious carbon bents.
http://www.m5-ligfietsen.nl/site/EN/Models/Carbon_High_Racer/ . And their low racer, and medium racer.
To be able to claim 'fastest and lightest production bicycles' plus 8 or 9 world records is not bad....
Will be interesting to see how the front wheel drive will compare.
http://www.m5-ligfietsen.nl/site/EN/Models/Carbon_High_Racer/ . And their low racer, and medium racer.
To be able to claim 'fastest and lightest production bicycles' plus 8 or 9 world records is not bad....
Will be interesting to see how the front wheel drive will compare.
Hi all,
yes, that blog about the Carbon bike is mine! I am amazed anyone found it already. It's only been up a few weeks.. I haven't been able to respond for awhile because my home computer crashed and it's been ahwile getting back online.
I hope the intent for the carbon version is understood... Among recumbents, the Silvio is an excellent climber and even against many DF bikes it climbs great. My only concern is the above average grades I experience here in North Central MA and southern New Hampshire. Lots of insane 15-18% grades and MANY long 10-14% grade hills. It is among these types of hills that I feel the extra weight is a detriment. I've amassed quite a bit of knowledge since the site first went up and will be updating it shortly. I built a Fiberglass test version just to get a feel for working with the fabric and epoxies. Not bad. I took the side view of the frame from Blender and enlarged it using MS Visio which goes across multiple pages. I then made templates out of fiber board and used them to cut out a foam core with a hot wire cutter. The foam core was just extruded polystyrene, used for insulation. It cuts great with a hot wire saw. I since made a small mod to the frame design and will be doing another mock up next week. I have 2 weeks off for Xmas, getting most of it done then. Practicing in fiber glass first... much cheaper then carbon! But even with fiberglass, the strength using West Systems epoxy is amazingly strong and light.
I'll be updating it more often with pictures and video's.
I am a HUGE fan of Silvio and will be keeping and riding mine... just want to try a lighter version in carbon... its been a blast learning about it. not even sure yet, how/if it will turn out... still a long way to go.. but very doable from what I've seen.. found some great people that have helped in learning about working with CF.
Harold
yes, that blog about the Carbon bike is mine! I am amazed anyone found it already. It's only been up a few weeks.. I haven't been able to respond for awhile because my home computer crashed and it's been ahwile getting back online.
I hope the intent for the carbon version is understood... Among recumbents, the Silvio is an excellent climber and even against many DF bikes it climbs great. My only concern is the above average grades I experience here in North Central MA and southern New Hampshire. Lots of insane 15-18% grades and MANY long 10-14% grade hills. It is among these types of hills that I feel the extra weight is a detriment. I've amassed quite a bit of knowledge since the site first went up and will be updating it shortly. I built a Fiberglass test version just to get a feel for working with the fabric and epoxies. Not bad. I took the side view of the frame from Blender and enlarged it using MS Visio which goes across multiple pages. I then made templates out of fiber board and used them to cut out a foam core with a hot wire cutter. The foam core was just extruded polystyrene, used for insulation. It cuts great with a hot wire saw. I since made a small mod to the frame design and will be doing another mock up next week. I have 2 weeks off for Xmas, getting most of it done then. Practicing in fiber glass first... much cheaper then carbon! But even with fiberglass, the strength using West Systems epoxy is amazingly strong and light.
I'll be updating it more often with pictures and video's.
I am a HUGE fan of Silvio and will be keeping and riding mine... just want to try a lighter version in carbon... its been a blast learning about it. not even sure yet, how/if it will turn out... still a long way to go.. but very doable from what I've seen.. found some great people that have helped in learning about working with CF.
Harold
Hi Everyone...
I just posted an update to this blog... the "carbon Silvio" concept...
http://www.compositefibercentral.com/blog.aspx
I updated it with the latest version.. the bike has been redone in another drafting package... Rhino 3D... much better. with a bunch of notes on books etc...
Much more to come... Feedback welcome!
Harold
I just posted an update to this blog... the "carbon Silvio" concept...
http://www.compositefibercentral.com/blog.aspx
I updated it with the latest version.. the bike has been redone in another drafting package... Rhino 3D... much better. with a bunch of notes on books etc...
Much more to come... Feedback welcome!
Harold
Re: Carbon Silvio Concept - Thumbs up
I guess I'd ask why a Silvio isn't lighter in stock form? I presume it's the seat but I wouldn't expect that to add 3 kg (comparing it to aluminium DFs like my wife's Orbea, weighing 8 kg) To weigh nearly 14 kg suggests that the frame kit has been made up with heavy components? Or am I missing something?
Somewhere on this Forum I read that a Silvio should be able to be built up at around 11 kg - still 2 kg up on the 'average' road bike.
The concept of a carbon frame seems sound to me and I'll be interested to hear the finished weight. It will also be interesting to get weight compensated roll down data, because one of the features of the Silvio is the suspension, which is claimed to reduce rolling resistance.
There have also been suggestions that the seat should be laid back more. I disagree. The bike is already faster downhill and on the flat and laying the seat back will reduce rider power for climbing - you just make the bike slower up hills and less comfortable.
Will the carbon version be faster....? We wait in anticipation!!
I guess I'd ask why a Silvio isn't lighter in stock form? I presume it's the seat but I wouldn't expect that to add 3 kg (comparing it to aluminium DFs like my wife's Orbea, weighing 8 kg) To weigh nearly 14 kg suggests that the frame kit has been made up with heavy components? Or am I missing something?
Somewhere on this Forum I read that a Silvio should be able to be built up at around 11 kg - still 2 kg up on the 'average' road bike.
The concept of a carbon frame seems sound to me and I'll be interested to hear the finished weight. It will also be interesting to get weight compensated roll down data, because one of the features of the Silvio is the suspension, which is claimed to reduce rolling resistance.
There have also been suggestions that the seat should be laid back more. I disagree. The bike is already faster downhill and on the flat and laying the seat back will reduce rider power for climbing - you just make the bike slower up hills and less comfortable.
Will the carbon version be faster....? We wait in anticipation!!
JonB
Zen MBB Master
Re: Carbon Silvio Concept - Thumbs up
I think that a focus entirely on weight is bad, and makes us forget why we drive a recumbent in the first place - COMFORT.
DF (Diamond Frames) are NOT comfortable, more like directly uncomfortable, if not a hellish torture to ride on.
It is certainly possible to make a bike lighter, just look at http://www.recumbentblog.com/2009/12/04/test-of-time/ which tells of a M5 original prototype in Carbon from 1984 which apparently only weighs 7.6 kilo or 16.76 pounds. But i dont think it looks as cool as a Silvio, or as comfortable. And it has that long chainline :-(
Further more i think that if you drive in a rough environment then one of the differences between a stiff unsuspended bike and a more soft suspended bike is that on a stiffer bike in rough a larger part of your brain and muscles will be used to keep your body comfortable, where as on a softer bike you can relax more and use the resources for pedaling.
Finally i think the body gets more tired faster on the stiff bike because it often uses muscles to cope with the environment. This too drains resources. But it will probably only show up in long extended rides.
I think that a focus entirely on weight is bad, and makes us forget why we drive a recumbent in the first place - COMFORT.
DF (Diamond Frames) are NOT comfortable, more like directly uncomfortable, if not a hellish torture to ride on.
I can see multiple reasons for why the Silvio frame is heavier than a DF:
- Overengineering to allow for heavier riders, or just to avoid a lawsuit.
- not as refined frame, because of limited engineering resources
- not enough computer power/knowledge to really calculate tight material/design limits
- maybe a triangle as the one in the DF just is naturally stronger than the open "V" you sit in on the Silvio
- not perfectly weight optimal material/design choice.
- Suspension
It is certainly possible to make a bike lighter, just look at http://www.recumbentblog.com/2009/12/04/test-of-time/ which tells of a M5 original prototype in Carbon from 1984 which apparently only weighs 7.6 kilo or 16.76 pounds. But i dont think it looks as cool as a Silvio, or as comfortable. And it has that long chainline :-(
The DF has been refined for a centry. And refined with big money. By many different engineers. Ofc. the design gets to be nearly perfect. The Silvio is brand new and designed by just one guy. Impressive, but give it time to get nearer perfect.
Suspension also helps keeping the wheel connected to the road and not up in the air where it has no traction. A dampened suspension is even better at this.
Further more i think that if you drive in a rough environment then one of the differences between a stiff unsuspended bike and a more soft suspended bike is that on a stiffer bike in rough a larger part of your brain and muscles will be used to keep your body comfortable, where as on a softer bike you can relax more and use the resources for pedaling.
Finally i think the body gets more tired faster on the stiff bike because it often uses muscles to cope with the environment. This too drains resources. But it will probably only show up in long extended rides.
Can you elaborate more on why laying the seat back will reduce rider power? Do you have any kind of proof for this? Preferably a scientific study.
If you loose the weight savings from your own body, then you will probably be even faster.[/]
<<Can you elaborate more on why laying the seat back will reduce rider power? Do you have any kind of proof for this? Preferably a scientific study.>>
This is not a scientific answer, but I have observed consistently that the power output I generate is directly related to the angle between my thighs and chest... the closer that angle is, to a point, the more power I generate. So on the Silvio, I get more power buy pulling my chest closer to the handle bars, decreasing that angle. It has to do with the amount the glutes are stretched it seems. If you are laying down in more of flat position, the glutes are not stretched and can seem to pull as hard to generate the power. But when the body is more closed up, the glutes do generate a lot more power.
This seems to be the case on a DF bike as well. When one stands up to go up a hill, that is doing the same thing as pulling your chest closer to handle bars on a Silvio. When you stand up, your butt goes up and your chest goes down slightly, closing that angle and stretching the glutes more.
Just observations that seems to be consistent and make sense...
Harold
This is not a scientific answer, but I have observed consistently that the power output I generate is directly related to the angle between my thighs and chest... the closer that angle is, to a point, the more power I generate. So on the Silvio, I get more power buy pulling my chest closer to the handle bars, decreasing that angle. It has to do with the amount the glutes are stretched it seems. If you are laying down in more of flat position, the glutes are not stretched and can seem to pull as hard to generate the power. But when the body is more closed up, the glutes do generate a lot more power.
This seems to be the case on a DF bike as well. When one stands up to go up a hill, that is doing the same thing as pulling your chest closer to handle bars on a Silvio. When you stand up, your butt goes up and your chest goes down slightly, closing that angle and stretching the glutes more.
Just observations that seems to be consistent and make sense...
Harold
<< Yes, but just lie all the way down and move the bottom bracket up. Maybe with a smaller wheel, so you can have it almost but not quite touch your groin. Then the angle is still there. >>
Sure... what ever orientation works... I had measured those angles on a DF and on the Silvio and they are the same... just rotated back on the Silvio...
And as far as speed, I am just looking for additional speed climbing with the less weight... speed on the flats with the Silvio is great as it is...
Harold
Sure... what ever orientation works... I had measured those angles on a DF and on the Silvio and they are the same... just rotated back on the Silvio...
And as far as speed, I am just looking for additional speed climbing with the less weight... speed on the flats with the Silvio is great as it is...
Harold
philsummers
New Member
Jon,
If you move the bottom bracket up than the seat has to go back or down I think, unless I'm missing something here.
Harold's comments seem to mirror mine. I can climb easier on the GRR in a more upright and closed position than I can on the T-Bone. The flip side is that I climb faster on the Bone. If I rode lots of hills I would dump the weight and if mostly flat or rolling then 10 more pounds as long as it is aero will not bother me.
If I compare the layout of the Cruz and the Bone as below I would have to lengthen the chain stays a lot to keep the seat the same. My feet are not on a level with my butt and at anything over 20mph it starts to have an effect.
Just extend a line back from the bottom peddle and see how much leg is hanging below your back end. I can't move the seat back so I am going to try to extend the peddles and just scootch down. With the power tap on a no wind day I should be able to see the difference in power needed to keep the speed on at 20 plus mph.
Here is a shot comparing the Cruz to the GRR. Whoa....will that fairing fit?
....and that's why you have to have a fairing on a TE if you want to go fast!
Cheers
Phil
If you move the bottom bracket up than the seat has to go back or down I think, unless I'm missing something here.
Harold's comments seem to mirror mine. I can climb easier on the GRR in a more upright and closed position than I can on the T-Bone. The flip side is that I climb faster on the Bone. If I rode lots of hills I would dump the weight and if mostly flat or rolling then 10 more pounds as long as it is aero will not bother me.
If I compare the layout of the Cruz and the Bone as below I would have to lengthen the chain stays a lot to keep the seat the same. My feet are not on a level with my butt and at anything over 20mph it starts to have an effect.
Just extend a line back from the bottom peddle and see how much leg is hanging below your back end. I can't move the seat back so I am going to try to extend the peddles and just scootch down. With the power tap on a no wind day I should be able to see the difference in power needed to keep the speed on at 20 plus mph.
Here is a shot comparing the Cruz to the GRR. Whoa....will that fairing fit?
....and that's why you have to have a fairing on a TE if you want to go fast!
Cheers
Phil
JonB
Zen MBB Master
That is correct. I probably forgot to mention that.
You can put a fairing on a Silvio. Others has done it.philsummers wrote: Here is a shot comparing the Cruz to the GRR. Whoa....will that fairing fit?
....and that's why you have to have a fairing on a TE if you want to go fast!
I wonder how the Silvio stakes against the x-stream.
philsummers
New Member
Jon,
...an interesting comparison with the x-stream. My opinion just from reading about the bike leads me to believe that it would be faster on the flats and perhaps even on the hills. Extreme hills might go the the Silvio.
I have always wanted something like the GRR except with a higher BB. I tend to get recumbut on the GRR after several hours of serious riding. I put the Hurricane seat that I have on the Bone on the GRR and while very comfortable I could not get the power as noted by Harold...opening up the hip angle too much. So the x-stream solves that problem. I may get an X-stream 26 next year just to see how it goes.
What are your thoughts?
Cheers
Phil
...an interesting comparison with the x-stream. My opinion just from reading about the bike leads me to believe that it would be faster on the flats and perhaps even on the hills. Extreme hills might go the the Silvio.
I have always wanted something like the GRR except with a higher BB. I tend to get recumbut on the GRR after several hours of serious riding. I put the Hurricane seat that I have on the Bone on the GRR and while very comfortable I could not get the power as noted by Harold...opening up the hip angle too much. So the x-stream solves that problem. I may get an X-stream 26 next year just to see how it goes.
What are your thoughts?
Cheers
Phil
JonB
Zen MBB Master
My thoughts is that climbing with your arms makes the Silvio win. And that on high speed descend you will feel safer on the Silvio because the front wheel is not so far out. + the Silvio wins on comfort because it has suspension. Probably also noise since the chainline is short. Also on storage, since i heard the x-stream is very long.
Maybe, just maybe this doesnt apply to the current silvio because it is not as optimized as the x-stream is, simply because RANS made bikes much longer than John did.
