I have a new Giant Defy 1, and have had trouble finding a comfortable saddle, finally settling on a Selle Royal Ellipse Athletic, because of the long, deep channel it has, which relieves pressure on my perineum. Even still, there was some pressure, so I changed the stem from a 110mm 8° to a 90mm 25°, which brought the handlebar up a fraction and back a little over an inch. This results in a slightly more upright riding position.

The more upright position is more comfortable, but on a fast downhill run today, when moving off the drops and back to the hoods, the front end seemed a bit more squirrelly. I cannot imagine the bike coming out from under me at 35 MPH! And I noticed that, when I look down, I can see the front axle just barely ahead of the handlebar. Is it just me, or could the stem change have made my bike unstable enough to be unsafe?

Thats a pretty drastic change in length. The more upright position will feel odd at first...especially when descending at speed. I tried going with a higher stem and did not like it.

How much time did you put on the 110 before you decided it was uncomfortable?

i went through several saddles before I found one that was close to comfortable, then changed the stem to increase the comfort. Well over 100 miles in all.

Yes, changing the stem can affect the handling. Ideally, your hands on the drops should be right over the axle of the front wheel, which will put the hoods slightly forward and the tops slightly behind the wheel axle. If your hands are positioned behind the wheel axle, you'll have squirreliness because you have a bit of wheelbarrowing effect.

You might be better off putting the original stem back on and moving the saddle forward 2cm, or maybe splitting the difference (100mm stem and the saddle 1cm further forward). If these measurements get way out of whack (short stem leading to bad handling plus saddle all the way forward), then it means your frame is too big. Don't forget to recheck your saddle height if you mess with the for/aft position.

Its difficult to do an "E fit" over the internet. Is there a local shop that can help size you up?

Going from a 110mm 8 deg to a 90mm 25 deg has to put your bars up at hybrid bike height. You may feel "comfortable"...but the handling is going to be way off...as you have found. Also...did the additional bar height put more pressure on your sit bones? That was one of the things I noticed when I put my bars up higher.

I applaud you for shortening your stem.

I went from 110 to 90 but didn't notice any change in handling.

No, I don't think you have made your bike unsafe, though the handling has changed. There are a lot of discussions about stem length and a lot of responses have been that for most of us casual riders, you will get used to the changes pretty quickly. I have never, on either of my bikes, no matter how they have been configured, felt stable on the hoods, only stretched on the drops.

Having similar difficulties with saddle fit, and reach, here's what I have done:

*Swapped a lot of saddles and change riding posture
Change my posture because I have more of a swayback. Tightening my stomach, rolling my hips backward just a hair, made the whole seat fit-thing much less problematic. I know, rolling hips backwards is opposite what most people need to do. So are you slightly swaybacked in the drops, very straight, or slightly rounded?

*Moved seat way forward to put me in a comfortable position of the pedals. Should put on a zero-setback post and center the seat on the rails again. Weird, but turns out the cranks are 10mm longer than my Sekine.

*Shortened and flipped the stem from 100 to 80. Same 7 deg angle by chance. Now I have a shorter reach, a little more room for height adjustment w/o screwing up reach too badly. The whole bike feels so much more comfortable and stable because of weight distribution and posture.

Maybe a perfectly fit bike frame would have alleviated some of the problems, but not my swayback.

The LBS did fit me when I bought the bike, but as you know, there is fine tuning to do during the first few rides, and that's what I'm going through now. The biggest issue was finding a comfortable saddle. The LBS is geared toward long distance, high speed riders, and they kept pushing me toward hard, narrow saddles. Turns out my sit bones are much farther apart than average, and I need a wider saddle. Once I figured that out, I found a reasonably comfortable saddle.

Even with the wider saddle with a deep channel for the perineum, I still have some pressure on the very front of the sit bones on either side of the perineum, and on the perineum itself, thus the desire to move the handlebar in and up, so I could sit more upright, and move my weight back more onto the sit bones. It worked, but the bike is a little more squirrelly. I may go back to the original stem and move the saddle forward. I already have a zero offset post, and the saddle is most of the way forward as it is. As someone else mentioned, I might need to split the difference and get a 100mm stem. And I may STILL not have the right saddle for me! More experimenting in the works.

We had to change to a zero offset post just to get the fit right when I bought the bike. I may need to work on my posture, and perhaps, as someone else suggested, split the difference and get a 100mm stem. And I may still not have the right saddle for me - or perhaps I just need to ride more and think less and give my body time to adjust.

Lot's of things to talk about. First, what do you mean you had to change to a zero offset post to get the fit right. The seat position fit is independent of the reach to the bars. If you changed the post to shorten the reach to the bars, that was all wrong. You only change to seat position to affect the position of your hips and legs over the pedals. I'm starting to wonder if the bike is not simply too big for you, and you got sold a bad deal.

Second, a long, deep channel can help with saddle comfort but pressure on the perineum suggests your saddle may be too narrow. If the sit bones in your butt are not being supported (hanging over the edges of the saddle) all you weight is resting on your perineum. You may need a wider saddle. As I said, channels or cutouts can be valuable to fine tune comfort, but only after you get the right width.

Finally, if the bike is squirrely for any reason, do not ride it. I have experience with the speed (or aka "death") wobble up front at 35 mph downhill, and I assure you it is no fun. Luckily I was wearing brown shorts.

The more your write, the less I think you got the right bike. Check out your saddle position with a standard measure like KOPS (knee over pedal spindle). Look it up if you aren't familiar with it. No this isn't absolutely right for everyone, but it isn't so wrong either. If you are way in front of that in order to reach the bars, that bike is absolutely too big for you and needs to go back to the shop for an exchange.

Tell us some about your measurements and the bike size. I smell a rat.

When I bought the bike, we had to go to a zero offset post to get KOPS, but we did get it, with the saddle almost all the way forward. With the standard post, my knee was well behind the pedal axle. My knee is definitely not forward of the pedal axle with the zero offset post. According to the fitting, the 110mm stem was OK, as my arm angle checked out as correct with that stem. My sit bones measure 135mm apart, and my current saddle is 160mm, so I think it is wide enough. I am wondering if it is firm enough or flat enough, though.

I'm 6' 1", and the bike is a Giant Defy 1 - size "large" as recommended by Giant, but 6' 1" is the minimum height for that size. I'm messing with the stem for two reasons. First, so that I can sit a bit more upright and relieve a little more pressure on the perineum. The second is that, with the 110mm stem, I feel like I'm reaching for the handlebar, and have to get down pretty low to be able to bend my elbows a little. But maybe that's how it's supposed to be, and I'm just not used to it yet.

Fortunately, I have not experienced a wobble at high speeds. It's just that when I went from the drops to the hoods, the front end "wiggled" a bit from side to side - it just seemed touchier than I expected.

I wish I knew more about this...

When I test rode a Defy Advanced, they took some basic measurements and put on a longer stem because the M/L bike they had in the store needed it to fit me. I noticed that the handling felt odd. After that I test road a L Defy (not Advanced) that they had, and the handling went back to being extremely nice and not odd at all.

I wonder if the Defy is more susceptible to the handling changing because of stem length than other bikes are. That's how it seemed to me.

Sounds like your femurs may be very short for your height. Maybe your crank arms are a little too long for you as well. I know you may not wish to spend the money, but perhaps a pro fit would be in order.

have your femurs been shortened?

I have a 165 crank. I think a lot of bikes come standard with 172.5. A few with 170.

Try flipping the stem. With 25 degree, a 90 flipped probably will be about the same as the previous 110. I found being lower in the drops make my ride more comfortable.

But definitely yes lowering your center of gravity is going to increase stability and control. Why do you think even while sprinting, sprinters get their body of mass as low as they can even though they are out of their saddle? Or when going inton sharp turns, they go into the drops and get down even lower?

All bikes feel different when you change stem length, but you get used to it. Also, a longer stem tends to feel odd when going slow, and gets better the faster you go. Short stems feel nice and sharp on the parking lot, but can get insecure once you are up to speed. All this, of course, is when speaking of bikes with standard road/race geometry.

I've been following this thread, and was oddly unsurprised when the bike in question was finally identified as a Giant Defy. I just went through some similar gyrations when I bought my Defy 1 a month ago! I think Giant has made a Giant mess with their odd sizing.

I'm 5'9", with monkey arms and spider legs. I usually fit a 54cm pretty well, but am also comfortable on a 56cm. The first Defy I tried out was a M/L, and I loved it! The problem was that the LBS where I tried the bike was full of ********, and I didn't really want to buy from them. So, later that day, I went to another bike store where I tried out a bunch of bikes, one of which was the low-end carbon Defy in a size M. Of the bikes--a synapse, an Allez, a Caad, etc.--the clear winner was the carbon Defy. They didn't have a M/L for me to compare it to, and they didn't have any aluminum Defys in M or M/L. Anyway, eventually found a closer LBS that had a closeout on a M Defy 1 and after riding it a bit, bought it. Everyone assured me it was the right size for me, given my height. I rode that bike for two weeks, trying to get comfortable, and I just couldn't! I felt jammed up against the bars, and like my weight was WAY too forward. I tried everything, shy of swapping stems to stretch out. Eventually, after riding around with the saddle shoved all the way back beyond the end of the max marking, I gave up.

(A whole lot of stuff then happened that resulted in my driving to an LBS 80 miles away and swapping the M for an M/L.)

The M/L immediately felt better, and absolutely perfect with the seat slid a little forward, and I've been riding it for all it's worth for the last two weeks in complete comfort.

My point is this, I guess: for whatever reason, people with unusual body configurations end up on Defys that don't fit them well, based on Giant's odd ideas of what size fits what height rider. Their charts make little sense, and when you compare geometries with other bikes, it sometimes doesn't make sense at all. They need to reevaluate who fits what size based on other metrics besides height because, for whatever reason, the Defys seem to flummox people over and over.

If a M/L is right for you and you are 5' 9", then the Large that I have is probably right for me, at 6' 1". I went back to the original stem, and accepted that I was probably trying to ride in too upright a position. I need to work on my riding posture - bend at the waist and not at the middle of my back - but I think the bike is fit correctly. I'm just new to this type of bike and this type of riding, and have a lot of questions. And I have a tendency to over analyze and over think things.

Actually the bend should occur even lower than the waist if you can imagine that. Down in the pelvis. The waist is pretty high up on your torso. You want to push your hips back on the saddle and try to bend from as close to the saddle as you can.

Got it. Thanks for the advice.

I'm 5 6 30 inseam and my 1st road bike was a Defy in Size Small. Its should fit as defined by the Giant size charts so I gave it a go. Weeks into it I felt worse and worse. I tried shorter and higher stems, nothing felt completely right and XS was too small. Giant should offer bikes in more standard sizing like other with the 49,52,54,54 sizing and upwards instead of what they have.
I now ride a 52 Allez and fits me to a tee. I will stick with Specialized now, their styling is bland but the bikes ride awesome to me.

It sounds to me like you're trying to address a saddle issue by changing stems, which is the wrong approach. The stem should be adjusted to address problems with your upper body.

Your hip position determines KOPS, not the saddle location. You can typically move the saddle fore/aft 20mm without changing KOPS, simply because you wind up sitting on a different part of the saddle. Moving the saddle forward will result in you sitting on a slightly wider portion and may improve things. Experiment with consciously sitting a little fore/aft on the saddle and seeing how it feels. Saddle angle can also have a huge impact on numbness, a few degrees down my improve things for you (Or it'll feel like your continually sliding forward).

What saddle are you currently riding? There are those who are basically comfortable on any saddle and have no issues at all. And then there's those of us who its tricky to get the saddle fit dialed in. I'm very finicky with my saddle position, due to the pressure you mentioned above.

There's no such thing as "standard sizing" on modern (compact frame) road bikes. If you look at the geometry charts, the numbers are all over the place. One manufacturers "56" will be virtually identical to "54" from someone else.

The Defy sizing is virtually identical to Specialized Roubiax sizing. The Allez is a more aggressive fit, and has a smaller available size range.

I came to the same conclusion about the stem, and went back to the original. I'm working on my posture, and giving myself some time to "toughen up", since I've just started riding again, after a long break.

I've experimented with slight nose down saddle angles, but I've got too much pressure on my hands for my liking as it is, so I'm trying to break in to having the saddle level.

My sit bones are far apart, and I require a wide saddle. I discovered this after realizing that my sit bones were hanging over the edges of all those hard, narrow saddles I tried, and I tried several. A LBS confirmed my suspicion with a "buttometer". I'm currently using a 160mm wide Selle Royal Ellipse Athletic saddle. With it, I have no pain, and the discomfort I have with it is generally all over my back side - again, I think I just need to toughen up. I've tried many saddles, and this one is the first one I can stand. I've got my eye on some others to try. The Selle SMP is interesting, as are a couple by Specialized Bikes.

I found that heavily padded saddles (like the one you are on) are much worse for perineum pressure. You sink into the saddle and then the bulky padding makes contact in the wrong places. I ride a Selle SMP Dynamic, they're tricky to setup, and put a lot of pressure on your sit bones (but nowhere else). Find a shop that demo's the Specialized saddles, my guess is you'll be able to find a better saddle for not too much money (<$100).

How heavy are you? If you're under 200 lbs a saddle with less padding should also reduce the pressure. For me the trick was a minimally padded saddle, and a good pair of bib shorts (Assos). And lots more riding...