Dean V

If you are of reasonably normal proportions I would start with a set back of 80mm.
That is 80mm back from a vertical line though the BB centre to the nose of the saddle.
At your height I would say the "normal" range would be from 65 to 90mm.
If it is already 80mm or more I would say there are other issues at play as that should be enough to not have excessive pressure on your hands.

Carbonfiberboy 

You could have a look at several threads about this subject on the Fitting your Bike forum, which is the proper location for this conversation anyway. To determine if your saddle in in the correct position for you, while pedaling with your hands on the hoods, lift both hands briefly off the bars. You should be able to do this comfortably and without sliding forward on the saddle. If you can't, move the saddle back until you can. You should also continue riding comfortably while moving one hand from the bars and placing it behind your back, again without sliding forward. Get this right first and then fiddle with the stem as necessary to get that 90° angle between upper arm and torso.

Chandne

Get a bike fit done by a reputable experienced fitter. I scanned through the posts and did not see that. When I had a fit done, he raised my stem~15mm, then got me a shorter stem(110mm to 100mm) and it helped a lot. I ride bikes a size big for me and use 90mm or 100mm stems. I'm used to short stems and can descend with the among the fastest riders on any of my bikes (climbing is another story). I have also found that carbon bars with flat tops help me a ton. In fact, my most padded bar is on the comfiest bike but it is oval alloy Zipp bar. My hands only go numb on that one but after 40 miles or so. On the more race-oriented firmer bikes, they don't but I have them all switched to aero drop bars which I love. Currently shopping for a Zipp SL70 Aero which will go on the Roubaix.

Classtime 

I'm with Whyfi. Tilt the nose of your saddle up.

johngwheeler

I measured my set-back as you described at it was 75-80mm, so pretty much in the middle of your quoted range.

I did move my new saddle almost fully to the rear, so I should probably lower the saddle a bit. I have progressively been increasing the saddle height using the "heel on pedal with straight leg" measurement, but it may now be a bit high and I could be subconsciously rocking my hips to extend my leg. I should video myself on the trainer.

johngwheeler

Yes, I'm going to get a professional bike fit done. I can't go around in circles, not knowing whether it's my body that needs to adapt, or my bike that needs adjustment. Probably a bit of both, but I need an expert to sort out the bike.

I'm primarily after comfort, so this is what I will tell the fitter.

John.

Dean V

I actually have a Giant TCX in a medium and am the same height as you. Frame size is just right for me.
I have 85mm set back and a 110mm stem.
Your fit is probably different, but just to give you a rough idea.
Also do make sure your saddle is level or even pointing up very slightly.
The next size frame would be to big, especially as it is quite a jump in size from M to ML in the Giant range.

Chandne

Comfort was my goal as well, since I was having trouble riding past 15-20 miles with my setup at the time. Of course, i also had flexibility and ITB issues, caused by bad biomechanics and other issues. So the main thing was to get comfortable and identify my weak areas. The fit helped me a lot, not just because of the better fit but also identification of weak areas. The fit was down at CU Boulder by a fit guy plus the director of sport medicine, which was fortuitous. I specifically told them that comfort was the goal and that I was not interested in aero or power...I was not in any shape to work about that anyway. Now I can change things if I wanted (get lower to be more aero and put down more power) and still be comfortable but I'm not competing or anything so I mostly still work about comfort. The only thing I have not found yet is a seat that is comfy past 40-50 miles for my skinny butt. So that is the only problem I have. Like I said before, I find that carbon bars are far more comfy on my hands. Alloy bars start to numb my hands within 25 miles actually...I have to keep shifting around constantly. With my aero flat-top drop bars, I can rest on the tops for a long time with no discomfort. There is very little road buzz.

garciawork

I must be wonky... 5'9", always ride a medium, and I use an 80, and couldn't imagine going longer. But my bikes fit me like gloves, so it works for me.

johngwheeler

This is good to know. Your slightly longer setback and stem might indicate that there is some benefit to being stretched out a bit more.

What is your saddle to bar drop? I found it a fairly aggressive position after my Trek Crossrip that only has about 2cm drop, and it was hard to look forward when riding on the drops. So I flipped the stem which made it a bit more comfortable, but I have probably reduced the reach, which might indicate a longer stem to get it back to where I was!

Dean V

Saddle height from BB centre to top, 780mm. Saddle to bar drop of 110mm.

johngwheeler

Sounds like you have long legs! My inseam is 845mm and I multiplied this by 0.883 to get 746mm BB-Saddle height, which feels just about right if I put my heel on the pedal and lock my leg straight.

You've also got a lot of bar drop compared to mine (60-70mm, but I haven't measured accurately).

So I guess your'e an ideal cyclist with long longs and a flexible back :-)

MyNameIsEarl

Sounds like I'm the same proportions as you (5' 10" with 33.5 inseam). My 54 Allez (Medium) has a 110mm stem and reach is fine (a 56 left me too stretched out). I used to have a large saddle to bar drop, but ended up dropping the saddle by 5mm to help alleviate the weight on my hands. Maybe give that a try?

Regarding fit, I found this advice useful as a starting point:
1. Seat height (top of saddle to center of pedal axle) at 108-110% of inseam.
2. Saddle parallel to ground.
3. Saddle fore/aft adjusted so that a plumb bob from the bony protrusion just below the kneecap passes through the pedal axle when the cranks are horizontal. This is known as KOPS (Knee Over Pedal Spindle)
4. Front hub axle obscured by the handlebars when riding in your "regular" position (drops, hoods, or tops).
5. Top of handlebars 1 to 4.5+ inches below the top of the saddle depending on your flexibility and size.

FlashBazbo

Perfect response.

I can still remember the first time I was fitted properly using the saddle as the support / balance point (which only makes sense -- it is where your body balances on the bike). The test was getting in the drops, taking my hands off the bars, and being able to stay in position or sit up without moving forward or straining. It was a revelation. When you try to use the bars to support your weight, not only do you cause hand/arm issues, but you impair your ability to handle the bike. I became a better cyclist the instant I started using the saddle as the balance point.

autonomy

I just started experimenting with a longer stem (100 -> 120mm). I only rode it once because I'm waiting for smaller spacers to come in (doesn't pre-load the fork all the way), but the longer stem made my bike feel much more responsive and gave me confidence (i.e. it addressed the twitchiness described earlier upthread). Not sure if it's doing anything for my upper back yet, but I need to spend way more time with it.

99Klein 

Best answer to your question right here.

Wrenchmore

I'm getting a lot out of this thread, which makes me a veteran cycling dummy.
When the rain clears I'm going to work on my fit with a little more info.
Checked a bike in the house tonight and my knees seem way too far forward re the BB axle.
Lots of old injuries including back, neck and wrists, tough balancing act.
Thanks everyone...

johngwheeler

I had a professional bike fit before experimenting with stems, and it turns out I didn't need one to get the result I was after. Here is a summary of my experience yesterday:

https://www.bikeforums.net/19687055-post20.html

I had thought that my hand pressure was due to having a lower saddle-to-bar drop that I was used to, but it seems that I may in fact have been both too low, and too far to the rear.

The fitter suggested a significant increase in saddle height (25mm), which I thought was going to make the problem far worse, but he also moved the saddle forward about 20mm. With a bit of bar rotation upward to get the wrist angle right, and rotating the hoods inward, the pressure problems disappeared without any significant adjustment in bar height.

I really didn't expect this result, which goes to show that there are lots of variables in bike fit, many of which are dependent on the individual.

I think the modest fee (c. US$70) was well worth it. I'm now much more comfortable on my bike. Good result!

John

NormanF

How small? At 5'7", I ride a medium frame and it fits me perfectly. Mine is 54 cm. What's yours?

A bike is too small if its not within a manufacturer's recommended height/weight range for a given fit.

brianmcg123

That's great. Nice to hear the resolution.

zymphad

Congrats on getting comfy! What your fitter did was what I was thinking, adjusting angle of the hoods to be more inline with your wrists, and raising it more.

johngwheeler

The bike is a Giant TCX in Medium size. According to Giant's road-bike sizing chart for this bike, a medium should be OK up to 6' (183cm), or a medium-large from 5'11" (180cm). Personally I think this is a bit exaggerated, and I could have gone to the medium-large at only 176-177cm tall.

I think my medium TCX will be fine after the fit, but I was a bit doubtful at first, and so was the fitter, until he took some more measurements and made the adjustments. I have longish legs for my height, so I could have had the medium-large based on my leg length, but my torso is probably better suited the medium.

NormanF

If you're between sizes, you could go up a size. My rule of thumb if its a long tube tube, I prefer to go one size down with long legs for my height; otherwise I stick to the recommended size.

Classtime 

I'd love to see a picture of the bike in its current configuration. Glad things are working better for you.

johngwheeler

I'll try to take one this evening.