How Low Can you Go?

[MrSteve]

Here's the back story:

Last weekend, while staring at my Sofrider V1 and dreaming of fairings,
I thought about frontal area.
Aha!
Something to do... I can reduce frontal area!

And I did, by fiddling with the 'seat post' height and the seat back angle,
along with the mounting bracket.
Doing this, I easily relaxed the seat back from it's 45 degree angle
another eight degrees or so.

Thanks to the user-friendly and simple TFT, adjusting the X-seam (measurement from seat back to the pedal)
was a snap.

My impressions?
My bike is faster now, an average of one mile per hour faster.
It accelerates downhill quicker, reaches top speed more quickly and has a faster top-end.
There was no penalty as far as pedaling power, due to the different seating position.
I can still climb hills with the same expenditure of effort.

The bike feels new(er) so, there's a new-bike excitement.
Feels different, twitchier: due to the lower center of gravity.

The only downside?
My neck does more work to support my head in this more reclined position.
Not a big deal for me, as my neck is overdeveloped... all those years spent
supporting my head, wearing a full-face helmet, struggling constantly
against the 80+ mile-per-hour head wind.

So, back to the question posed by the Subject line of this post:
How low can the seat-back be lowered?

I'm going to try it for myself, eventually, of course.
But I know (I assume) that the original test-rider(s) have already done so,
and so my question.
Is there a point of diminishing returns?
Does a head rest do more than simply provide a place for the head to rest?

Inquiring minds want to know!

Besides, speed is fun.
More speed is more funner.



-Steve

 

[John Tolhurst]

I think the limit is from both comfort and power delivery.

The seat is not really designed for lower than 45, and at lower tha 45 the more open position seems to slightly deactivate the torso. A Silvio at 55 deg seat angle might be more aero and slightly less on the peak power.

 

[MrSteve]

johntolhurst wrote: I think the limit is from both comfort and power delivery.

The seat is not really designed for lower than 45, and at lower tha 45 the more open position seems to slightly deactivate the torso. A Silvio at 55 deg seat angle might be more aero and slightly less on the peak power.

Aha.
Thank you, John.

I remember chasing chassis squeaks last Summer, concentrating on the seat pan for a day.
I replaced those rubber washer/grommets with a custom synthetic rubber gasket
I'd cut from a sheet of the stuff.
There was some scuffed metal between the bolt-holes, indicating that some metal contact
was taking place.
Now, with the gasket running interference between the two pieces of the seat pan,
that took care of any noise coming from there.

That's how my seat pan handles the more open angle....

55 degrees on the Silvio, eh?
I'll compare the relationships of bottom-bracket to seat-pan between the Silvio
and the Sofrider, then make another adjustment!

Once again, Thank you.


-Steve

 

[Doug Burton]

Jack's done a lot of research around seat recline...

I'm about to alter my Sofrider seat mount to duplicate teh Silvio operating angles... means raising the front of the seat pan a tad...

 

[MrSteve]

Alright, I have my sliding bevel out,
universal angle guide (fancy protractor),
plumb bob and bubble level.

That and a little time....
:twisted:
But first, I rebuilt the rear light that a year's worth of vibration
has destroyed. Just like repairing plastic fairings, only different.


Thanks for the hints, guys!


-Steve

 

[defjack]

This is as low as I would go.Feels great and no butt pain even after 20 miles or so. Jack

 

[MrSteve]

defjack wrote: This is as low as I would go.Feels great and no butt pain even after 20 miles or so. Jack

My seat is a few degrees more upright than yours is and, like you, I'm loving the ride.
This is my impression after riding in this new position for a while.
I'm liking it!

But....
The bottom bracket felt too low.
Sprinting tended to move my torso up the incline of the seat back.

So, naturally, I fabricated a longer front chainstay to move the bottom bracket up!
Adding a few inches of chain to accommodate for the new chainstay and
I was back in business.

Now, sprinting and hill climbing just press my torso more firmly into the seat back.

My Cruzbike is well on it's way to becoming some sort of FWD mid-racer!

-Steve

 

[Doug Burton]

As Mark would say,

Pictures, man, pictures!

 

[MrSteve]

Hardtailcruzer wrote: As Mark would say,

Pictures, man, pictures!

I feel the social pressure, really I do, to go out and buy a camera.
-Not gonna happen.

I'd rather buy stuff that works rather than a machine I'll seldom use.

Here's what I mean: my 35mm format film camera dates from '84.
I can count the number of rolls of film I've run through it, on one hand.
One roll is still undeveloped!

Anyway, I have a week's worth of rides in, using the long front chainstay
(the only functioning chainstay on a Cruzbike).
It's holding up well, is functioning perfectly and my muscles can now
mash the pedals up hills really well.

I recommend this mod.

-Steve

 

[Mark B]

yakmurph wrote:

Hardtailcruzer wrote: As Mark would say,

Pictures, man, pictures!

I feel the social pressure, really I do, to go out and buy a camera.
-Not gonna happen.

I'd rather buy stuff that works rather than a machine I'll seldom use.

Here's what I mean: my 35mm format film camera dates from '84.
I can count the number of rolls of film I've run through it, on one hand.
One roll is still undeveloped!

I hear you and will make one small observation and let it go. Film cameras are a PITA because they are film cameras. You have to buy the film, which has limited shelf life, which can affect the outcome of your pictures. Then, you get overly selective of the pictures you take because you don't want to waste your film which costs x to buy and develop, then, you have to take it to the place to be developed and remember to go back and pick up your pictures. It really is a pain. With a digital, you take as many pictures as you like, you get your picture immediately, it costs nothing after the cost of your camera and memory media, which is probably less than you paid for your 35mm. So, stop with the excuses, already, and show us some pictures!! :lol: :lol:

Just kidding.

Kinda.

Mark

 

[MrSteve]

Logical, Mark.
Nice try.
My memory is much more than any photo ever was or will be.
I mean, there are reams of pictures in this house that I have not seen for decades.
Don't need 'em.
Nope, don't need, use or want cameras.

I'll share my knowledge, such as it is-
but I'll not spend money I don't have on something I won't use.

Pretend I'm some sort of primitive radio transmitter...
use your imagination.

-Steve

 

[Peder Torgersen]

yakmurph wrote: Logical, Mark.
Nice try.
My memory is much more than any photo ever was or will be.
I mean, there are reams of pictures in this house that I have not seen for decades.
Don't need 'em.
Nope, don't need, use or want cameras.

I'll share my knowledge, such as it is-
but I'll not spend money I don't have on something I won't use.

Pretend I'm some sort of primitive radio transmitter...
use your imagination.

-Steve

Would it be possible to get a relative or a friend that has a camera to take pictures? Then you don’t have to invest in a camera? Some people like to take pictures and would probably like to take some pictures of you on your Sofrider or just of you’re Sofrider? Then you can load them on the forum if they send them to your e-mail and some of us on the forum that don’t have a good imagination would easier see your riding position. If the idea is inappropriate you have to excuse me and you don’t have to answer it.
Peder

 

[MrSteve]

Peder Torgersen wrote:

Would it be possible to get a relative or a friend that has a camera to take pictures? Then you don’t have to invest in a camera? Some people like to take pictures and would probably like to take some pictures of you on your Sofrider or just of you’re Sofrider? Then you can load them on the forum if they send them to your e-mail and some of us on the forum that don’t have a good imagination would easier see your riding position. If the idea is inappropriate you have to excuse me and you don’t have to answer it.
Peder

It's an option, sure.
My relatives are staying away in droves.
Hard times; some are dealing with their own lives;
others are far away.

Same with friends.

It's a cultural thing, I think.
(Not very flattering for the local culture!)

It's depressing to deal with Alzheimer's....
(I'm caring for our demented mother.)



But, should someone show up with a digital camera, I'll trot out my
bike and get 'em to snap a few pictures!
:twisted:

-Steve

 

[JonB]

Hey, i got the solution. Get a speeding ticket or maybe run a red light (careful) where there is some Automatic Traffic Control that takes a picture of you and your bike. Then you got the picture :-D

 

[Mark B]

How about using the webcam you used for your avatar pic?

Mark

 

[MrSteve]

For those of you who've read through this thread for the first time:

On Thanksgiving day, 2008, my sister took several nice photographs
of my modified Sofrider V1.

You can see them posted in the thread titled,
"Sofrider V1.2"

Thank you,
and
ride safe,

-Steve

 

[Peder Torgersen]

yakmurph wrote: For those of you who've read through this thread for the first time:

On Thanksgiving day, 2008, my sister took several nice photographs
of my modified Sofrider V1.

You can see them posted in the thread titled,
"Sofrider V1.2"

Thank you,
and
ride safe,

-Steve

Here are the pictures; http://www.cruzbike.com/forums/viewtopic.php?f=4&t=603
You have made a good modification that’s one good thing about this forum shearing good ideas and showing them. I feel sorry for the car driver that wanted to stop you and ask about your Sofrider! Maybe next time you will have some time to talk with him if he should spot you speeding on your Sofrider?

Peder

 

[JonB]

Peder Torgersen wrote: Here are the pictures; http://www.cruzbike.com/forums/viewtopic.php?f=4&t=603
You have made a good modification that’s one good thing about this forum shearing good ideas and showing them. I feel sorry for the car driver that wanted to stop you and ask about your Sofrider! Maybe next time you will have some time to talk with him if he should spot you speeding on your Sofrider?

Speeding? Better hope it is not a police officer.

 

[MrSteve]

Thank you, Peder, for posting the link to the pictures.
That saves me some editing!

You know, I've thought about that curious car driver
-and my response.
I'm thinking that I'd rather be speeding on my bike
than talking about my bike!

Yes, I was pressed for time... riding is so fun that
I take full advantage of all the time available.
So, I love to speed...put on the miles... and hate to stop!

:lol:
I would love to be stopped by a cop!
That has never happened to me -on a bicycle.
Makes me wonder about any possible fine?!
:lol:

-Steve

 

[Mark B]

The pics were great, say thanks to your sis! Loved the mods you did!

I've stopped and talked to drivers many times. Not just recumbent questions, but on my touring ride (uprightbike), too. I have no issues answering people's questions. I guess I have more time to share.

Mark

 

[wordy]

Re: How Low Can you Go? Camera hijack! Long!

Mark B wrote:

yakmurph wrote:

Hardtailcruzer wrote: As Mark would say,

Pictures, man, pictures!

I feel the social pressure, really I do, to go out and buy a camera.
-Not gonna happen. I'd rather buy stuff that works rather than a machine I'll seldom use.
Here's what I mean: my 35mm format film camera dates from '84.
I can count the number of rolls of film I've run through it, on one hand.
One roll is still undeveloped!

I hear you and will make one small observation and let it go. Film cameras are a PITA because they are film cameras. You have to buy the film, which has limited shelf life, which can affect the outcome of your pictures. ....snip....
Mark

My first career was as a photo technician/photographer.
I resisted digital photography as the Devils Spawn for many years until I more or less accidentally used a 4 MP Nikon Coolpix.
Now I'm a convert - I've got a Nikon D60 DSLR and a Panasonic Lumix TZ3 - I use them both a lot and I've sold a lot of images locally.
I can do more in 15 minutes with a digital camera and photoshop than in a day with a film camera and a darkroom.
I won't prattle on but - http://www.flickr.com/photos/brecumbent/

Now - back to seat angles.

I've just purchased a Softrider and I'm climbing the learning curve. I find it VERY comfortable - nearly as comfortable as my P-38, which for me epitomises efficiency and comfort.

My neck dislikes anything lower than 30 degrees. Headrests/neckrests are a big compromise, because with your head back and resting on a headrest, every time the seat moves sideways, so does your head. This messes up your balance.
Also due to my age and wearing multi focal spectacles, a very low seat angle means I'm looking out of the bottom of my prescription - which is for 'near.' So everything is blurred. I find very low seat angles are uncomfortable.

I make an exception for the Optima Raptor low racer because I only ride it to annoy the local DF riders and make them work hard. The reality is that the Raptor doesn't transfer the power as well as my P-38 (flexy boom,) so the aero effect is useful on the flat, downhill or in head winds, but up hills the P-38 is faster - and more comfortable.

Speed only matters to me when I'm riding with DF'ers. They ride in a pack anyway and on a recumbent, you can sit in and keep up. A 'bent is usually less efficient up hills where you may struggle to keep up with 8 kg DFs and a higher seat angle and stiff frame is better.

Therefore, coming to a long winded and personal conclusion - a Silvio/Cruzbike riding with a pack of DF bikes won't gain much from a really low seat angle and may in fact be slower overall if the seat is reclined too much.

You can probably achieve the same speed (as a lower seat) by scrunching down and keeping your elbows in and/or fitting narrow bars with SIS levers.