Modifying the reach on the Silvio

VeloLEV

Member
Greetings my friends! I've been brewing this idea for some time, and the more I ride the Silvio the more I want to try it. On my Rans Rocket I modified the steering using Volae bars and the Terra Cycle stem and riser. This enabled the "Superman" recumbent position. Other than aerodynamics there are several comfort improvements with this design. On the original Rocket bars, the "Praying Hamster" position is employed, elbows bent with the controls in your face. My primary dislike stemmed from working out with my elbows bent and arm pits closed since I sweat alot in these areas. The modified position allowed me to open both my elbows and arm pits to the wind, immediately solving the sweat issue. Its back now with the Silvio, at least for taller riders like myself. My solution involves replacing a single part on the Silvio with a new one, moving the bars to a position in FRONT of my knees instead of behind them. While sprinting or climbing hills I have discovered that lifting my back off the seat puts more weight on the driving wheel and seems to generate more power from resting muscle groups. However my arms are already bent and just end up bent further in this position. I feel more power would be available if I had to reach for the drops. This would allow use of the hoods as the primary position, some use of the curves outside the flats and the drops would actually require me to pull myself off the seat back to use them. Also I could use standard bars (instead of the WTB Mountain/Road bar I currently have or the On One Midge bar) opening up additional possibilities. I have slashed together an ugly Photoshop rendition to give you an idea of my plan. The replaced part is yellow in the picture. What do you think?
 

JonB

Zen MBB Master
Try it on. For better pulling

Try it on. For better pulling power i would suggest placing the handle bars such that they are on a straight line from the bottom bracket to your shoulders, but i am not sure that gives you sufficient ventilations in your arm pit.
 

Doug Burton

Zen MBB Master
Hi Lev, The increased TFT

Hi Lev,

The increased TFT angle will probably interfere with your front derailleur operation.

An alternative is to put a stem on the TFT and move the bars forward that way. The TFT-stem is a 30mm tube, which is not too common. One approach it to use a piece of 1 1/8' stiff aluminum tube (28.6mm) (7005 or 6061 T6), or 2014 (expensive) and use seatpost shims to match the lower tft and pivot clamp to it's diameter. Then you could use a lightweight long-reach stem (maybe a CF road stem at 45 degrees, mounted upside down) to get some additional reach.

Long-reach road bars may help, too...

Best,

Doug
 

trapdoor2

Zen MBB Master
One big problem with your

One big problem with your proposal would be that you're eliminating the strong triangle and creating a weak polygon. Pedalling forces are severe and the add-in you propose would need to be very, very strong (compared to the rest of the system). Even if you made it strong enough, you're adding a lever arm into a system that isn't designed for it...it could cause other failures.

Doug's recommendation is far better. Keep the TFT triangle as it is and adapt an adjustable stem to the upper portion of the TFT. A 31.8mm stem would take a mere .9mm (0.035") shim...ought to work fine...if you can get one long enough.

http://www.nashbar.com/bikes/ProductDisplay?storeId=10053&langId=-1&catalogId=10052&productId=174784&cm_mmc=1204522-_-Bike%20Parts-_-Nashbar-_-NS-ADJS&mr:referralID=57a28aef-5461-11de-8759-000423bb4e95
 

John Tolhurst

Zen MBB Master
Ideally you would leave it as

Ideally you would leave it as it is to retain the solid tetrahedral structure, and the direct linkage between handlebar and crank. I can't decide which is more important! What I can say is that achieving the stiffness between grips and pedals is more difficult that maintaining the ridgid triangle. At least I think it is.

If you are going to go custom, you could look at a new pair of bars, that gave you a longer reach, if nothing is around like that.
 

WhiteSilvio

Well-Known Member
Just a thought. Is doing what

John Tolhurst wrote:
Ideally you would leave it as it is to retain the solid tetrahedral structure, and the direct linkage between
handlebar and crank. I can't decide which is more important! What I can say is that achieving the stiffness
between grips and pedals is more difficult that maintaining the ridgid triangle. At least I think it is.

If you are going to go custom, you could look at a new pair of bars, that gave you a longer reach, if
nothing is around like that.

Just a thought.
Is doing what Doug suggested, or I think he suggested, and coming off the TFT with a suitable "member", any different to the way the Freerider handlebar is arranged?

I'm assuming that the Freerider handlebar and mount doesn't compromise the integrity of the front "power triangle"? Or indeed introduce a lack of stiffness between the grips and the pedals?

I have to say that I have looked at my Silvio, since VeloLEV suggested the repositioning of the hand(s) position, and although I have to say "breaking" the power-triangle doesn't seem like a good idea from a structural point of view, I did wonder if the straighter arm/superman stance could lead to benefits ergonomically and possibly from a power generating point of view.
The problem as I see it is that moving the bars forward would also require them to be raised (if a horizontal handlebar member is used) to allow for clearance of the knees. This would vary from rider to rider, but that is the way I see it without actually experimenting/tinkering at all. (Too much work for the moment).

Any thoughts, anyone??

Regards John R
 

JonB

Zen MBB Master
WhiteSilvio wrote:
       I'm


WhiteSilvio wrote:
I'm assuming that the Freerider handlebar and mount doesn't compromise the integrity of the front "power
triangle"? Or indeed introduce a lack of stiffness between the grips and the pedals?

I have a Freerider and i think you assume wrong. I think that the Freerider setup does introduce a little less stifness between the grips and the pedals.
 

VeloLEV

Member
Again I appreciate all the

Again I appreciate all the excellent input. I did consider the fact of front derailleur issues, but looking again at the image it becomes much more obvious. Sometimes hearing the words and thinking for a week or more brightens the mind. I did also consider adding a stem and it is feeling more plausible for sure. It would look more like this:


---and would accomplish a similar result. The R&D continues...
 

WhiteSilvio

Well-Known Member
VeloLEV wrote:
      It would


VeloLEV wrote:
It would look more like this:

I think that is a pretty good idea. I imagined that you would use a stem from a regular steering setup and slide it on to the TFT. I haven't measured anything to know if it would work easily but I reckon it is important that the front triangle remains intact.
I'd really like to see what you come up with VeloLEV and look forward to seeing some graphical evidence.
And hear what the result feels like.

Best of luck,
John R.
PS Just tried this with a "spare" handlebar stem. The 30mm diam. handlebar end fits reasonably neatly on the TFT tube (could need a very thin shim to add some grip), but the other end off the DF steering stem is a little small and not capped in the same way. I guess it's 1.125in. (measured the inside as 28.55mm). Could really do with two capped 30mm ends so the angle rise wouldn't be a problem, (probably would help) and you could use "standard oversize" handlebars. Do you have such devices in your shop or are all the steering stem ends 1.125in.?
 

super slim

Zen MBB Master
Would an option be to have

Would an option be to have shorter cranks (155mm ) instead of 175mm (Std) so that the knee does not rise so far. The handle bar stem could then be pushed down 20mm. This would keep the line from the shoulder to the handlebar closer to the line of hip to pedal, so more of the resultant arm pulling, results in extra force on the pedals.
See the photo of Maria in the 12 hr race with extended arms AND legs.

The disadvantage is that the cadence would have to be increased by 175/155 or from 80(175) to 90 (155) for the same power, if the pedal force is the same.
 

WhiteSilvio

Well-Known Member
Modifying the Reach: Next Step

Hi All,
Well this topic hasn't moved on for a pretty long time. But I for one have taken a step forward with modifying the reach of my Silvio.

Has anyone else gone down this path or a similar one?

In a previous post Jun. 19, 2009, I suggested that I might alter the reach by using a stem coming off the Telescopic Front Tube (TFT). I think this arrangement was what others were talking about earlier in the thread. I've probably gone about this in a "different" way to the ideas that others may have had but none the less I have finally reached a working arrangement.

I ended up using a MTB 1.5in. stem with an oversize 'bar 31.8mm diameter end fitting on it. I guess this is pretty common for MTBs.

The stem I used was a SRAM Truvativ unit 100mm long and 5deg. angle, so I have a small range of adjustment with the angled stem, with the major adjustment coming from the positioning of the stem on the TFT.

To fit the 1.5in. steerer tube end to the TFT I had an aluminium sleeve/spacer made up which slides onto the TFT and then the stem fits on that. The sleeve has a lengthwise narrow slot in it to allow it to tighten onto the TFT tube when the stem is clamped up.

Well I have been riding with this arrangement since mid April and I have now covered over 700km. And so far all is to my liking.

I feel that this setup has allowed me to get my arms in about the right position, for me, relative to my shoulders. I find it comfortable and to my liking. YMMV.
(You can see my position of the old setup in my avatar picture.)

This position has allowed me to get clearance on my knees relative to the 'bars and also has the additional benefit of allowing operation of the STI gearchange levers without there being any contact with my kneecaps, something that occasionally happened with my old arrangement which used "standard" road 'bars in the standard Silvio handlebar mount fitting.

Just by way of information I tried the Gary Origin 8 'bars earlier but couldn't get comfortable with them; I suffered from sore wrists and finally abandoned them after about 1000km of persisting with them. I guess if the GO8 'bars are okay for others that is the way to go. I think the aerodynamics of the traditional road 'bars is better, but I haven't proved or disproved that either way.

My general feeling is that the straighter "Superman" arm position gives an improvement in the aerodynamics. Again without any kind of way to test this it remains speculation on my part and as they say "open to conjecture". Ah well.

I am including a couple of photos of the new arrangement as cross-eyed stereo images. I have given a little advice (with a previous posting on this forum) on how to look at this style of picture and more information on how to view is available on the WWW. Don't worry if you can't see the 3D picture, just look at either "half" of the pictures.

If one goes down this path to alter the reach of the handlebars, one other advantage is that it doesn't alter the front derailleur positioning in any major way. If you have a good setup for the derailleur now this will generally not affect that setup.

Now all I have to do is see if I can find a replacement piece of 30mm TFT so that I don't have to have the old handlebar fitting in front of me.
(I am a little reluctant to just cut the fitting off the TFT in case I want to sell the bike sometime. Doesn't seem likely at the moment.)
Is there a specification, material and sizes, for this tube John? I might be able to source something if I know what it is made of.

Well regards to all.
John

PS: Still trying to work out how to upload images to go with this post. Did it on the old forum but I haven't figured it out here yet.

There is a "Tab" on the Image button, which says Upload, that looks like it should work like the old system, but it comes up with an error along the lines of "you haven't supplied a URL". Well I'll have to think about that one. It's probably blindingly obvious when you know, but for the moment I remain ignorant as to how to upload pictures. Although I did think that I was getting somewhere when I got the message that the file I was uploading was too big. I'll try again when I'm on the computer with the required images.

Deleted small photos but unable to upload larger ones. Error message says that the file size, 145KB, will exceed my disk quota of 1MB. How can this be?
 

John Tolhurst

Zen MBB Master
> Deleted small photos but

> Deleted small photos but unable to upload larger ones. Error message says that the file
> size, 145KB, will exceed my disk quota of 1MB. How can this be?

Because of your previous picture uploads. I am reviewing those settings.
 

WhiteSilvio

Well-Known Member
Posting space

Hi John,
So does the current, unless you've changed it recently, 1MB cover all posts that I have posted?

Or is 1MB for that current post eg each post?

This particular post is one that maybe you(?) brought over from the old forum, where I had all the pictures that explained what I had done with the reach change. But that is a bit beside the point regarding "space" for posting.

The total for the old post on the old forum was probably around 1MB.

So why didn't the pictures "come up" when reposted here? They only seem to have come across as thumbnails.

I notice that the pictures of Doug's Quest showed up okay, and yet other pictures show up as a file name which when "clicked upon" shows the picture. I don't understand this yet.

More instructions would be good. Is there a Help section somewhere?

Regards,
John.
 
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