Seat positions

Recumbents and all feet forward machines

Seat positions

Postby Ricco » Fri Sep 19, 2008 12:17 pm

Hi all have a question for recumbent riders, most likely those with hard seat experience.

Some history. Have been playing with recumbents for a few years now. Only serious riding done in the last few months though. 150 ks a week avg. not more than 250 in a week yet, considering endurance riding in the future.

Got a little more refinning to do first though, bike and not sure the engine is'nt getting a little old, though more likely is to do with trying to ride to fast to soon.

Problem, seat adjustment for leg length. Unable to get it right, though am only using sand shoes at this point and this could be a factor? Though have riden tours in sand shoes on MTB's. Generally ride too quick for casual lot, so wear casual gear and MTB slows me down. Though not sure that ability is still there?

Seat angle changes settle point of back side if nothing else is moved.

Had my seat inclined too much and too short, changed too what I understand to be too reclined for strength work(Nathan Campus ring road) and too long. Did not account for length given in laying the seat back.

Taken three weeks to recover from ride to coast. Bugger!

All thoughts gratefully received :)
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by BNA » Fri Sep 19, 2008 12:39 pm

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Postby Kalgrm » Fri Sep 19, 2008 12:39 pm

Hi Ricco,

What is your question?

Cheers,
Graeme
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Postby vonhazza » Fri Sep 19, 2008 12:49 pm

Hi Ricco I have a Cruzbike with a hard seat and set my leg lenght up simular to a DF, that is Bum at the back of the seat leg straight and heel on the pedal.
this gives me a slight bend in my knee when riding on the balls of my feet.(I ride clipless)

Any chance of some pictures to get a better idea of your positioning.
Steve Cruzbike FWD.
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Postby Ricco » Fri Sep 19, 2008 2:16 pm

[quote]Any chance of some pictures to get a better idea of your positioning.

Yeh, got to work out how the camera and the computer can get together first, will try tonight mate have never posted pics before :? .

Thanks Steve, set up as per DF but I find climbing and flat work make small differences in my seat position on the bike. And seems more critical than I have ever experienced on DF.

Can set anyone up on a DF and dial them in within a day or so. But just can't seem to evaluate small differences well enough to make fine tunning possible on bent.

Thought maybe BB or something was out of line and this was my problem. Though as far as is possible to make out, seat measurements relevant to BB are all within 5 mm of each other, and given you will never sit in exactly the same position on a seat thats should be oka?

Graeme Hi, my question

Realy after thoughts on findings so far:
Seat incline shortens postion? and vis versa?
Length seems more critical due to variable positions afforded bents?
DF If you rest on the seat no hands and relaxed you pretty much all ways settle in one place, not difficult to dial in from here or similar base.
Resting or relaxed position on bent harder to establish, hence my questions.

Me and relaxing don,t go well together, this could be the problem. Try to relax on bent and me feet drop off the pedals :P
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Postby bradwoodbr » Fri Sep 19, 2008 2:21 pm

I do the same as Vonhazza. Once that length is established and secure. I test it by pushing against the seat with heel on pedal to ensure that under a load situation the leg length is going to work. Any adjustments I make are under 5mm.

I recommend you adjust for leg length after seat setup is completed. Also reset your leg length everytime the seat position is changed. Opening and closing the body position (angles of the seat) does affect leg length position.

Cheers
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Postby vonhazza » Fri Sep 19, 2008 5:14 pm

Hi Ricco.

Question what is your bike?
Steve Cruzbike FWD.
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Postby vonhazza » Fri Sep 19, 2008 5:44 pm

Graeme Hi, my question

Realy after thoughts on findings so far:
Seat incline shortens postion? and vis versa?
Length seems more critical due to variable positions afforded bents?
DF If you rest on the seat no hands and relaxed you pretty much all ways settle in one place, not difficult to dial in from here or similar base.
Resting or relaxed position on bent harder to establish, hence my questions.
Me and relaxing don,t go well together, this could be the problem. Try to relax on bent and me feet drop off the pedals :P
[/quote]Hi Ricco me again.
Line 1- yes
line 2- I have not found that myself but that could be your bike is different
Line3 start with a slightly shorter set up and adjust slowly no more than 10mm at a time.
You and relaxing- avoid Coffee shops and go clipless it's much better with your feet out in front.
Steve Cruzbike FWD.
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Postby Freddyflatfoot » Fri Sep 19, 2008 7:26 pm

Ricco,
I'm having trouble working out your question?
But I'll have a go based on the info you gave.
Setup your seat son that when your legs are fully extended, they bend slightly at the knee.
Setup your seat angle conservatively to start off with.
I personally like an angle of 36 degrees, with my BB ~ 100mm above seat height.
Get yourself some clipless shoes and pedals! Or at the very least, some power straps.
Let us know what sort of bike you are riding. Handlebar position may also be having an effect on riding comfort.
Cheers!
Rob
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Postby Ricco » Fri Sep 19, 2008 10:50 pm

[quote]Once that length is established and secure. I test it by pushing against the seat with heel on pedal to ensure that under a load situation the leg length is going to work. Any adjustments I make are under 5mm.

Thamks Brad

Sort of had similar ideas on fine tuning, though loading with heel on pedal is problematic. I ride up my seat depending on how hard I push into it. :?

[b]Bent is a 700c back wheel 20inch front SWB USS(currently)
like nothing in front of us, great to see everything!

[quote]I personally like an angle of 36 degrees, with my BB ~ 100mm above seat height. Get yourself some clipless shoes and pedals! Or at the very least, some power straps. Let us know what sort of bike you are riding. Handlebar position may also be having an effect on riding comfort.


Thanks Freddy.....

Seat angle is 38 degrees and BB is 9 degrees above horizontal. Think it is roughly 80 mm above seat hieght.

Only have old racing time trial shoes, to smooth for unsure feet at this stage. Will invest in some MTB style clipless soon.

Position is great, have tried ASS & seat angles from 45 -31degrees. Current 36 degrees and USS allows hill climbing with knuckles only resting on bar tops. If I spin and don't get spooked by a car :P
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