Fitting Your Bike - How SMALL Of A Fit Change Makes A Difference, For You?
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How small of a fit change is big enough to make a difference?
Here's an example. I decided to tilt my saddle nose up a bit, from slightly nose-down to flat. The change was less than 5 degrees. Within a day of riding (commuting) on the new fit, my knees started to hurt, just twinges, but persistent and repeated twinges. After a couple days of this, I figured that the change had raised the center of the saddle a little bit, so I lowered the seatpost a very small amount, about one-quarter of an inch. My knees are no longer twinging. I'm a little surprised. I know a saddle that is too low causes me knee discomfort immediately, but I didn't think a saddle just a tiny bit too high would do so. I am a little perturbed, actually, I had thought I was more robust than this.
Have you found yourself sensitive to very small changes, in any respect? Examples? Or, do you think it is just psychological, imagination?
06-20-13, 01:13 AM
It is not imaginary, but some people are more sensitive than others to small changes. For example, Mark Cavendish can deal with very big variations in saddle height, he changes it by centimeters at a time depending on what he feels is appropriate to the terrain.
I am more in your camp, small differences matter to me. For example, I will tend to get knee pain in my right knee if the cleat on that shoe is misaligned. Despite the fact that I ride with float, I have to have the cleat adjusted so that my toe is turned in fractionally. A difference of only about 5 - 10 degrees is crucial.
Saddle tilt is another. It has to be fractionally nose-up, for me, but I mean fractionally, barely visible to the eye. If it is level I will find it uncomfortable.
As for saddle height, 5mm is enough for me to notice the difference.
I ride two bikes, a folder and a road bike. The geometry of the folder
is compromised and there is not much I can do about it, I've fitted
bar ends, bars are low as they will go and the saddle is back as far
as it will go, the seat height is set to around optimum leg extension.
Consequently, I think, I can make and easily cope with fairly large
changes on my road bike, though I'm near dialing them in to optimum.
If you think you are sensitive to small changes, try some big ones.
The effects of big changes for me suggest small ones hardly matter.
06-20-13, 04:17 PM
The only really important for me is saddle height. I can feel very small (3-4mm) variations there. Others doesn't matter that much - I can feel 1cm differences but can usually adjust to them, except if I'm at the limit already. For example, changing fom a 120 stem to a 110 was a big improvement on my road bicycle.
06-20-13, 04:32 PM
As little as 1/8" in saddle height has made a difference to me, and ditto for the amount of forward tilt that relieved, um, pressure. I also find that my perception of saddle placement and comfort is influenced by my body position: when my arms are farther forward and down, I actually scoot farther back on the saddle, and when I'm more upright, I always feel like my saddle needs to come forward just a tad.
Saddle height and tilt can be CRUCIAL, as can bar height at times. There is that "sweet spot" that just FEELS right.
I have a 2-bolt-clamp seatpost; one HALF-TURN of the bolts can overdo saddle tilt! I have to have just a touch of nose-down with the Selle SMP saddle, but when I get it just right, it almost disappears (not THAT way!).... 2-3mm of bar height can make or break the ride, also.
Coming out of winter, I found myself raising the saddle more than once; wound up nearly 10mm higher! W..T...H?!?
06-21-13, 12:02 AM
1 cm on the seat and 5 degrees on the handle bars...
I just had my bike fitted, and the main thing we changed was the seat angle, tilted the front down a little. The fitter I worked with first measured things, but was very interested in what I told him about how I felt when riding the bike. We might move the seat angle move after another ride. He measured my back angle and said the bars should probably come up just a little, but since I spend long periods of time in the drop and feel comfortable there even for over an hour at a time, perhaps we should just leave it. We even discussed lowering the bars so I would spend time on the hoods. In the end the peliminary fit that was done when I bought the bike two weeks ago was good as far as seat height, distance from bars, the basics were spot on. Now it's more about me telling him what "bothers me" after long rides and see if we can tune those issues out with little adjustments
06-22-13, 01:55 AM
I talked about this in another thread. I'll just say here that I feel the differences even in discrete increments. And I'll say again here, a younger person may not be as sensitive.
06-23-13, 04:50 PM
In saddle angle it can be less than a degree, at least when I make the change. If I'm riding on the trainer and feel say, too much perineal pressure, sometimes the additional down tilt that relieves the problem is less than 1/2 degree, using a Craftsman digital level.
I have found that as cycling fitness changes over time and the distances undertaken also change, sensitivity to different measurements in bike fit also change. From a comfort point of view, stem length has little effect and nether does saddle heigth. I get a bit more power with the saddle forward several cm but that puts extra weight on my hands which is uncomfortable. What seems to make the greatest difference fo me is saddle tilt. The tinyist bit of tilt is sometimes felt right away but more frequently after 30 miles or so. In the end, it all seems to be interdependent so that one measurement effect all the others. Just recently, for the first time ever, I dropped the bar below the saddle one cm and this is the most comfortable position I've experienced 'till now. This was totally unexpected and was done to explore all options, even stupid ones.
06-25-13, 03:41 PM
Saddle tilt is probably one of the most sensitive areas that small changes can be noticed. So much so, that I set mine with the use of a bubble level and flat surface set on the saddle. I can insert metric allen wrenches between the plate and level to achieve nose height increments of 1mm. 2-3mm of nose adjustment is realatively large.
With regard to saddle height, I can certainly tell a difference in adjustments of just 5mm. As can I with bar adjustmens. But, due to the flexibility of arms and riding with them in a bent but more or less static position, bars seem to be the least important.
06-25-13, 03:48 PM
I'm sensitive to the saddle angle but that's about it. Seat up or down, forward or back, I'll change at random some times just to work the muscles a bit different but I don't see much change in comfort for plus or minus a half inch. I'm agnostic about handlebar height. I'm not young or super-fit or unusually flexible, just some people feel it and some don't.
I got knee twinges from just carrying a few boxes up stairs, moving this weekend, so it's not a matter of toughness either. So I don't think you need to beat yourself up about robustness. I'll bet it's more a matter of many hours of training from a specific position, the same muscles and same motions are highly trained so a variance is uncomfortable.
06-28-13, 12:50 PM
For me getting the saddle height and the fore & aft dialed in was the most difficult and most sensitive to change--but I have finally got it right through trial and error---so now I have dropped my bars by 3 spacers--am more aero--and this change has been very comfortable over the last rides--average 25 miles each time--and my average speed has increased by about a mph with the same level of exertion.....will play with this for awhile to see what seems to be the most efficient and productive
06-29-13, 07:53 PM
Swapped away a B17 , that I could not push back far enough, for a different saddle I could,
while retaining the zero setback [airwings suspension] seat post..
then I put the 180 cranks on in place of the 170 it came with ...
oh the things i would do to just have a 71 degree.. seat tube angle..
still feel my CofG a bit too pitched forward..
06-29-13, 08:42 PM
I've been thinking the same thing, Fiets, I'd love to get my saddle set back more!
07-02-13, 04:48 PM
This forum made me decide to experiment some more with fitment, but my experience seems quite different than most of you. I raised my seat over an inch - it kept feeling better and better, until I couldn't quite reach the pedals. That was months ago.
Now I am going to experiment, back on my quest for a more comfortable butt. I am also changing my seat - a Selle Italia Max (I've used it before and it seems mostly OK. I am currently riding a Terry that doesn't quite make it.
So I am going to start by following some traditional suggestions:
Saddle height at "0.889 x inseam" - 30.9" (down from 32)
Seat pushed forward - my forearm to finger is 20.25, but my saddle doesn't go that far forward, so I set it at 21.25 (was 22.25")
Seat angle level - nose was tilted way down
Radical changes all, but every old setting was set by trial and error on rides! Of course every one of those settings were made with the Terry saddle.
07-03-13, 05:25 AM
Very sensitive to small changes in seat tilt. Slight nose down relieves sitz bones discomfort. Not so much to height or fore/aft. Although forward of pedal spindle does allow me to spin faster.
07-05-13, 02:02 AM
I actually thought that a few cm here and there can't make so much of a difference. It is correct in some things, but other things are quite sensitive
Saddle height: I can raise the seat 1cm or lower it 1cm and not notice a difference. I rarely move the less than 5mm at a time. I might need to further raise my seat, but right now it feels pretty much ok.
Saddle fore aft: 2mm is enough to make a difference. I have noticed that I'm really sensitive to fore aft changes and I hate it when I try to get up to speed with my "beer wagon" road bike which has like 3cm less setback than my actual road bike. It burns the quads so bad. I tried finding a post with enough setback, but a rare post diameter makes life difficult.
Reach: A cm here or there, I don't notice. 3cm is something that really starts to feel. My beer wagon has a too long reach handlebar which I should swap asap. Alas, money is a problem as always.
07-06-13, 08:47 PM
For me, having the saddle 5 mm too high results in a power loss of 20 - 25%!!! (Its not just the seat height though . . . having it too high prevents me from getting into a low, aero position. If, after raising the seat 5 mm too high, I then raise the bar 3 - 4 CM, my power is then only 5 - 10% lower than at the proper seat height.)
07-08-13, 04:22 PM
Sensitive enough that if I set up seat height with thicker shoes then I need to lower it for sandals.
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