tailbox question on silvio "tt" bike

J

jeebus

Member
I don't usually notice the new blog entries, so I only just now read the one titled "Starting at the back" about making a more reclined silvio with a lighter rear end. I love the idea, and was wondering if a tailbox would be a consideration on the new reworked rear.

People always say a tailbox or tailsock is beneficial on bikes that don't have super steep recline angles. On the silvio I don't think anybody has come up with a good solution for that. I don't know what bike features it takes to make a good tailbox/sock but I think that could be a consideration for a pure go-fast machine.

I know you talked about a disk wheel a while back, and I've always assumed a tailbox does more, but I don't guess I know that. Also I just broke a rear spoke a couple weeks ago so that makes me think about the durability of a disk wheel too.

Mark
 
JonB

JonB

Zen MBB Master
johntolhurst wrote: yeah, and about one third the cost, right? :)
Click to expand...
Of course ;-)

But i dont expect you to make a tailbox, you previously said bikes only. But there might be an idea in working with somebody like Novosport.de so they can make a box that fits.
 
A

Alex Apostolou

New Member
I have begun prototyping a tailbox for my silvio and would be interested in collaborating on the exercise.

The constraints I am following are (not in any priority):
- lightweight
- safe in the event of a crash
- easy to attach and remove
- stay within the styling/lines of the bike
- adapt to variations in rider height and width
- low cost/low tech
- adaptable structure which can be changed as more awareness comes to hand
- do as little damage to the bike as possible

So far, I have build the frame out of fibreglass rods mounted via p-clamps on all but 3 existing screw holes, which have been drilled at the top of the seat back. It extends about 80 cm from the seat back, at this stage and has 3 sets of parallel rods mounted on each side of the bike to create the bottom, middle and top dimensions. The bottom and middle rods are a constant 4 mm, while the top set vary from 2 mm at the seat back to 5 mm at the tail, to achieve a more appropriate curve. This was to be covered under a tensioned kite fabric, but I have opted to start with some heavy duty shiny lycra/spandex fabric. A solid tail, like on the Zokra, seems too much like a lifestyle at this stage (although, if I was younger...).

I am intending on making two versions, one that goes from the seat backwards and the other that will go from the head tube, over the shoulders and around the waist and then back, to create a kind of 3qtr fairing.

The plan is to swap the fibreglass out for carbon fibre with magnesium fittings once it's all working, but at 110kg, a few extra grams here'n there won't affect my speed record on the flat.

So, if this sounds of interest, I'd be happy to show you what's happening and open for the feedback/input.

Cheers,
Alex
 
Mark B

Mark B

Zen MBB Master
meercat wrote: I have begun prototyping a tailbox for my silvio and would be interested in collaborating on the exercise. <SNIP>

So, if this sounds of interest, I'd be happy to show you what's happening and open for the feedback/input.

Cheers,
Alex
Click to expand...

I'm interested in your progress!

Mark
 
JonB

JonB

Zen MBB Master
Mark B wrote:
meercat wrote: I have begun prototyping a tailbox for my silvio and would be interested in collaborating on the exercise. <SNIP>

So, if this sounds of interest, I'd be happy to show you what's happening and open for the feedback/input.

Cheers,
Alex
Click to expand...

I'm interested in your progress!

Mark
Click to expand...
i am interested in pictures.
 
B

Brewmaster

Active Member
Hey Alex,
Folks up here in the great NW have been using small diameter aluminum tubing used for tent poles as the tail box frame. In conjunction with rubber tubing for the joints, a lightweight curved frame is possible without the danger of fiberglass or carbon fiber shards if you wreck. Search Aerowing in the Easy Racers forum for pictures.....
Jamie
 
WhiteSilvio

WhiteSilvio

Well-Known Member
meercat wrote: I have begun prototyping a tailbox for my silvio and would be interested in collaborating on the exercise.
The constraints I am following are.......
So, if this sounds of interest, I'd be happy to show you what's happening and open for the feedback/input.
Cheers,
Alex
Click to expand...
A couple of pics would be good. :) :geek: They help one "picture" the project.
Regards,
John R.
 
Mark B

Mark B

Zen MBB Master
Brewmaster wrote: Hey Alex,
Folks up here in the great NW have been using small diameter aluminum tubing used for tent poles as the tail box frame. In conjunction with rubber tubing for the joints, a lightweight curved frame is possible without the danger of fiberglass or carbon fiber shards if you wreck. Search Aerowing in the Easy Racers forum for pictures.....
Jamie
Click to expand...

Yeah.... I'd rather be skewered through than get shards, too! ;)

Mark
 
A

Alex Apostolou

New Member
Hi Jamie,

In response to some self-preserving thoughts I had about getting skewerered, I ran nylon/rubber tubing over all the fibreglass that goes anywhere near the rider. What I do fear is that aluminium wouldn't give the curve that is possbile with the variable diameter fibreglass, though perhaps a good sharding will end up convincing me otherwise. While the tubing probably won't help much, it is a lovely black, just like my bike.

While waiting for the heavy-duty spandex/lycra to arrive to cover the frame, these few photos show what I have so far. You'll notice a "draw-string" down the centre of the frame. This is to compress the structure, raise the carbon-fibre rods below, and create the right shoulder width and height for the current rider. Also, I need to shape a tapered foam-rubber tail-piece which will, if magic is alive and well, re-laminate the two streams of air. Oh, and you might notice that heavy duty marine hinge, designed to allow the top and bottom sections to move independently without stress.

Cheers,
Alex
 
A

Alex Apostolou

New Member
My we live and learn...

Had the whole thing ready to take the lycra. Measured the fabric and pinned it in the right place and then positioned it to slide over the frame. Inch by inch the fabric worked its way down until it had hugged the frame (think Anaconda-style hugging). Stood back to get a sense of proportion, and, well yes, there was none. The shape deformed completely and where it didn't, the most unsightly bulges appeared. So, it's back to the drawing board. But it won't be long before the next version rears its head, so stand by.

Alex
 
J

jeebus

Member
I know I more-or-less disappeared after starting this thread, but I've read your progress with great interest. What you're trying to do looks great and I'm glad to hear the update even if it hasn't worked out as hoped yet. Best of luck with the project and keep us updated.

Mark
 
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