Bicycle Mechanics - Need a cushy seat

Hi;
I've got a Trek 950, with an after-market seat I installed because I needed one with more padding.
I have not ridden the bike for years, as I have become an UltraMarathon runner, and haven't been cross-training on the bike (or anything else).
Now, I want to cross train at least one day per week, but being an Ultra runner (if you're familiar with the sport, you will understand), my body fat is way low, and I have no "padding" of my own on my butt.
So when I ride the bike more than say 25 miles, I can no longer sit on the seat, and then for days afterwards, I have trouble walking.

What I am looking for is a seat that will give me the padding I don't have on my butt, and allow me to ride up to 50 miles without having to stand for the last 25.
Maybe a combination of shock absorber and seat cushion? My bike doesn't have any built-in shocks.

Thanks for your advice.

Ultrarunner100

You need to find a saddle which fits, rather than going for additional padding, find a good LBS who offer trials of saddles, you don't say where you are, but in the UK and US, Fizik offer a test ride program so you can demo different saddles from their range. Additionally, are you wearing cycling shorts? as these offer some padding?

As jimc101 says, fit is most imortant. Here is an article which discusses saddle selection and adjustment. http://sheldonbrown.com/saddles.html

Read it and decide for yourself whether you really want a "cushy seat". You might also find that riding your tires rock-hard, as many do, is unnecessary and less comfortable.

Padding sucks. Keep riding and you'll toughen up.

Everybody I know who rides anything more than 5 miles at a time and has tried a cushy, padded seat has found out that it does not work and thrown or given it away. You need a seat which fits and supports your "sit" bones. The soft cushy seat spreads the load everywhere including on to soft tissues which will be in agony after 20 miles. I know this is counter-intuitive, but overwhelming cyclists' experience bears it out. Also, the soft cushy seat interferes with motion of your thighs. A firm seat that fits you will work. This is going to take some trial and error, perhaps, and can it take a while to get used to the seat.

Don in Austin

all the professional racers are also low body fat and they ride 120 miles in a day
and get up the next day and do it again.. for a couple weeks in the grand tours .
as said before "HTFU"

when I ride the bike more than say 25 miles, I can no longer sit on the seat,

in 25 miles you should have gotten out of the saddle and rode standing on the pedals many times.
say when the road makes a slight rise, get up rather than downshifting.

Thanks guys;
I guess I'll do some riding with the current seat before I start looking to replace it. As I said, I haven't ridden the bike for some time, as I have run every day for 480 days now. I hate to give up the running streak, but if I change that from a running to running & biking, I won't have to give up anything.
The seat I have on the bike now seems decent. It is firm.
Funny that I should be thinking towards a softer seat, when this method did not work for me in running shoes. I am now running in minimalist shoes.

Ultrarunner100

Yep, more padding is usually not the answer. That said, the saddle you have now might not be the right one for you.

Selle Anatomica Saddles are solid leather, but made so as to move with your leg.

one of The developers was a marathon cyclist, 200 mile days for recreation..

Funny that I should be thinking towards a softer seat, when this method did not work for me in running shoes. I am now running in minimalist shoes.

Yep! Padding interferes with the tactile feedback your body needs in order to figure out how to do its thing. :thumb:

Also, get some good bike shorts!

Something critical is missing above. You need to make sure the saddle position is correct. The wrong fore-aft position, tilt, and height can all affect comfort (as well as efficiency). Even handlebar height and distance can affect it as well due to weight distribution. Find someone in the area who is known for being good at fitting bicycles. If that's not available do a LOT of reading online about properly fitting a bike.

I have been a bikeforums.net member for over 12 years and I have to chuckle whenever I see threads about saddles. No matter that there have been probably thousands of posts about saddles, they always bring a long list of responses.

I agree with the comments that a softer, spongy saddle is not the answer. The best solution is a smooth leather saddle. If you feel that you something to take the sting out of the bumps, get a leather saddle with springs.

1) Proper bike fit
2) A good endurance seat that works for you (the right size, contours, etc. NOT extra padding)
3) Good riding shorts or bib (well designed chamois to prevent friction and provide appropriate support, NOT cushy padding that feels like a diaper)
4) Ride frequently increasing the duration of your ride in increments. Some soreness and discomfort is normal, extreme pain is overdoing it.