Sofrider "V 1.2"

[MrSteve]

Alright, peectures:

Side view, showing the fibreglas seatpan I moulded off the stock alloy pan,
the seat angle I have settled on and the new chainstay I fabricated that
moved the bottom bracket a little higher than my hip socket.

Rear quarter, showing the BB-seat angle relationship and my very cheap, very light
wheel cover: pink insulation, cut to fit, primered (to hide the pink color) and lashed
to the spokes.

Front view of the chainstay I made... and a glimpse of the rider!

Bottom bracket height; new, longer chain stay.
The other wheel cover, the one most people don't see....

And those are the three front chain rings, the middle one gets half the wear.
The small one is helpful for restful spinning up some of the really steep
local hills, when I'm tired!

Nice pictures, eh?
Sis did a great job!


-Steve

 

[Doug Burton]

Wow! How cool is that?!!!!!!!!!!!!! :shock:

More details about the cool chainstay assembly, man!

Very well done!

 

[John Tolhurst]

:ugeek: :ugeek: :geek: I absolutely love it! :twisted:

if you are into more aero you cold lose the kick stand and get the pump and bag up onto the back of the seat if there was room.

is that a high pressure slick on the back and a stock 65psi Sofrider V1 tire ont he front? A pair of high pressure narrows will also be noticable to your cruising speed.

can you get wheel covers on the front wheel? not suggested for a road bike, but with a pair of legs on the front to dampen out side winds forces, may be ok.

Hey, thanks for the phots.

 

[MrSteve]

Hardtailcruzer wrote: Wow! How cool is that?!!!!!!!!!!!!! :shock:

More details about the cool chainstay assembly, man!

Very well done!

-Pretty cool, actually, when the mercury dips below 40F.!

-Details...I built it off-the-cuff, "on-the-fly", so to speak.
I had and still have, a lot of leftover 1/2" softwood plywood, from
my subwoofer project.

The "wishbone" shape of the chainstay is one piece of 1/2" ply, as straight
as I could make it, from the top pivot to the dropouts. I wanted to avoid
dealing with flex, side-to-side.

The 'aero' shape of the new chainstay is provided by more 1/2" ply,
glued to the back of the one-piece plywood chainstay.
They also keep the thing rigidly aligned in the fore-aft plane.

The top pivot is just a piece of copper waterpipe that fits reasonably well,
attached to the new chainstay with about 24 layers of 6 oz. fibreglass
cloth set in polyester resin.
This rigid fibreglass component handles all the torque loads and the
shock loads quite well.

The aluminum plates that tie the bottom ends of the chainstay are just
some plate I had lying around, cut to fit the ends of the chainstay
and epoxied into place.
I'm using bolts, washers and nuts to form the pivot between the chainstay
and the dropouts.

This new chainstay is a mockup, a proof-of-concept model that has
lasted beyond all expectation.
Two months of riding, some on very challenging gravel roads.

I may never get to build the swoopy, sexy-looking composite chainstay,
if this mockup keeps going strong!
:shock:

Thank you for the compliment!


-Steve

 

[MrSteve]

johntolhurst wrote: :ugeek: :ugeek: :geek: I absolutely love it! :twisted:

if you are into more aero you cold lose the kick stand and get the pump and bag up onto the back of the seat if there was room.

is that a high pressure slick on the back and a stock 65psi Sofrider V1 tire ont he front? A pair of high pressure narrows will also be noticable to your cruising speed.

can you get wheel covers on the front wheel? not suggested for a road bike, but with a pair of legs on the front to dampen out side winds forces, may be ok.

Hey, thanks for the phots.

Definitely into aero... gee, you noticed!


I like the kickstand more than I hate it.
-Hate it, 'cause, well, it's in the wind and it weighs a little bit.
-Like it, 'cause, well, I use it every day to park it out of the way in the garage,
it saves me a few bucks buying rope, screw-eyes, sheaves and the like,
and: it looks geeky... while passing roadies!

Still thinking about the tool-bag mount and moving the air pump:
mostly still busily enjoying my new lightweight, un-pitted seat pan!

Yes, It's a stock 65psi Kenda on the front, with a 85psi slick on the back.
The front Kenda gives me good traction and good handling on my long gravel driveway.
It's a compromise: faster with the slick on the front (but very scary on gravel)
or more secure in the gravel (but a bit slower on the macadam).
Safety first!
($%^^#^&%*)
:roll:

I did a lot of testing with cardboard wheel covers.
Here's how it breaks down, on my Sofrider V1:

-no wheel covers: stock speed, easy to service the spokes, not very sexy.

-front wheel cover: untried. I have mega-miles of experience on faired
single-track vehicles in side winds. This would be dangerous, in my opinion.
I think a composite mag wheel in front would be awesome.

-rear wheel cover: definite speed improvement, and, most surprising,
much more stability.
The rear wheel covers must be both acting as a splitter-plate to tame
turbulence and to balance the effect of having the legs poking out into
the wind, in front of the wheel...as well as removing spoke-drag.
In side winds, the rear wheel covers act like a fin, like the vertical fin
on the tail of an aircraft.
Very nice!
(Sexy too.)

I'm contemplating moving up to 700C wheels...but, with the lower
rolling resistance comes even greater average speed:
I'd like to mount a front disc brake on a 700C wheel, should
I make the move from the stock 26" wheel to 700C.

This bike is already pretty fast, pretty impressively fast,
for what is, essentially, a hot-rodded dirt-bike!
:lol:

-Steve

 

[Peder Torgersen]

I like you’r modifications! The rear wheel cover what material is it? A front wheel cover was that a bad idea? Is one of your future projects a tailsock for even more speed improvement? :idea:
Pictures are very informative it’s good having a sister!

Peder

 

[Kamatu]

I like the look. That wheel cover, is it stock insulation foam board?

 

[MrSteve]

The material used for the wheel covers was purchased at Home Depot and is
fan-fold 1/4" foam insulation. It's pink.

Now I know that Home Depot's competitor, Lowe's, stocks the same sort
of thing, fan-folded 1/4" foam insulation, but it's BLUE.

Both the pink and the blue foam has a thin clear plastic skin laminated
on one side. No doubt a vapor barrier.

This material is lighter than the usual corrugated plastic, lighter even
than cardboard and much quieter running.

Being foam, it's not as rugged as plastic.
But it's so cheap, quiet and good-looking!

Interestingly enough, I just learned (Googling "fanfold foam insulation")
that it's used by hobbyists to build flying model airplanes!

-Steve

 

[Kamatu]

Ok, you have given me a new product to go look for the next time I go to the Home Depot.

 

[Mark B]

Yak,

First of all, I apologize for weighing in so late on this... I was out of town, using somebody else's computer, yada, yada, yada.

GREAT JOB!!!! Love it! With your obvious skill at working the glass, how long before the progression to CF? That front chainstay arrangement is begging for the CF treatment, you know that, right? Same for the seat pan.... Looks really cool, but CF would be SUPER cool and how about ditching the seat rails arrangement for connection to the seat post? Not criticizing, my friend, but complimenting; you gots skills!!!

Mark

 

[MrSteve]

Thanks Mark!

Yes, of course I wanted (still want!) to eliminate the
seat rails, especially the four bolts, their nuts and washers that attach the seat to the rails.
All it takes is time, down-time, time better spent riding.
If I had another bike to tinker with, that'd be different.

Here's where this train of thought goes:

The bike really would climb a bit better if the swing arm
was extended a few inches: I bet I could build a lighter swing arm...
narrower too... just like the swing arm on the V2, only it'd be more
aero.

The rear shock could be relocated behind the wind shadow of the seat;
for that matter, it could be exchanged for an air shock.
Steel springs are heavy.

I never adjust the TFT anymore: the front end would be much lighter
with a custom-length composite boom replacing the telescoping
boom and it's clamp.
Besides, I never plan to hit anything, so that ought to be O.K.

Then there's the steering: all those round tubes dragging through the air.
Teardrop cross-sections are much more aerodynamic.

Tail sock....

F-40 style, dust-bin fairing....

Body sock....

Might as well build a frame!
:!:
Hmmm... I wonder how dear aircraft-grade spruce is?
:twisted:

-Steve

 

[defjack]

That bike looks great.Next month I will be taking a hack saw to my Giant conversion and make a new top tube out of plywood and fiberglass.The seat will be lowered to 24 in. Jack

 

[MrSteve]

defjack wrote: That bike looks great.Next month I will be taking a hack saw to my Giant conversion and make a new top tube out of plywood and fiberglass.The seat will be lowered to 24 in. Jack

...So, how's your new frame hunt going? You've got the right idea, in my opinion!

And, to stay on topic?
My proof-of-concept plywood chain stay is still working fine,
no problems, very dependable:
I'll never get to make the pretty composite part in my head, at this rate.

Another bonus of having the bottom bracket up at the level of my hips
has become apparent.
My feet break the slipstream, the icy, cold slipstream.
As a result, my legs are warmer this Winter than they were last Winter.


(Cool...!)

-Steve

 

[MrSteve]

Sofrider "V 1.2" Update

It rained for a solid week, last month, so I bit the bullet and built
my wood/fibreglas composite chainstay.
Finally.

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The prototype worked so well that I felt no need to build a new chainstay
from scratch, so I worked the crude plywood prototype into a svelte,
aerodynamic, stiff and finished form.

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The new composite chainstay will cure on the bike for the winter
until it gets painted next Spring.

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The front end feels very solid.
I'm very pleased!

My bike is on it's second drive chain and it's second set of tyres.
The wheels are holding up pretty well, which is a shame!
I really want to upgrade them.

My home built fibreglas seat pan is holding up very well,
but I'm planning on replacing it with a new wood-composite seating system
which incorporates all the mounting points/hardware.
Or not:
I may just build a new bike frame....

Ride on,

Steve

 

[Mark B]

Nice, Steve! I want to play with carbon fiber!

Mark