I've made a few tweaks recently. Since these changes, I shaved 10 minutes off my 14 mile (one-way) commute - and in essence, my avg MPH changed from about 10 to 14 MPH.

• Shimano M520 SPD Pedals
• Pearl Izumi X-Alp Seek Bike Shoes
• Ergon Performance Grip GC2
• Adjusted my stem 50 degrees forward

By adjusting the Ergon grips accordingly with my stem adjustment, it's still a very comfortable ride, but combined with the clip-less pedals/shoes, it turned out to be a very significant improvement.

Anyways, I'm a little anal retentive about shaving as much time off as I can from my commute and these few changes helped quite a bit.

14 miles @ 10 MPH average = 1 hour 24 minutes.
14 miles @ 14 MPH average = 1 hour
14 miles in 1 hour 14 minutes (10 minute savings from 10 MPH avg speed) = 11.35 MPH

Just saying.

Fifty degrees is a huge change in your stem position. Was this bothering you earlier? I'm guessing you have a mountain bike or hybrid?

Sorry, my math was wrong on the avg mph. But yah, ended up saving 10 minutes on the commute is the point.

For commuting, I have a Marin Fairfax (hybrid). The stem was set to 60 degrees originally, now it is set to 10 degrees. By changing 1) the grips and 2) the position of the grips along with the stem adjustment, it really didn't change the comfort factor for me. In fact, now that I've ridden with it at 10 degrees, I think that it was too high to begin with.

If he is using the typical bike computer it may well of shown a 4mph change since it only counts moving time. It doesn't count idle time waiting for lights etc.

Ah yes -- thank you! That's exactly why the difference in calculations.

Now that's interesting. I changed mine from 60 to 30 degrees, and prefer it. After a while, I moved down to 15, and it seemed a bit too much. But maybe I'll give that another shot after reading what it did for your speed.

Well, it all depends on your body measurements as well. I'm sure our body measurements are different. What works for me may not necessarily work for you, but certainly give it a shot. I spent a couple hours over the weekend adjusting the saddle, grips, stem, etc in all sorts of different positions to see what worked best for me. The current configuration seems to be my "sweet spot".

Presumably, the bike computer would have measured moving time only at the slower speed as well. In my experience, idle time on my commute is a constant, doesn't matter if my average moving speed is 10 MPH or 20 MPH, I still hit the same lights and stop signs and wait approximately the same time every commute.

I'm not doubting the 10 minutes shaved off the commute time, and I don't doubt the average speed of 14 MPH, but I'm a bit skeptical that clipless pedals and a more aggressive posture would result in an increase of 40% in average speed. I'm guessing the OP was averaging a bit higher than 10 MPH prior to the changes.

I can assure you that the numbers are accurate. I guess the other variable that I should have mentioned is that I have also been trying the past few weeks to improve my endurance so that is probably a factor as well. However, I still maintain that I firmly believe that not a single variable by itself can be attributed to the improved metrics, but rather a combination of all of the changes that I've done recently. As I previously mentioned, I spent a good amount of time over the weekend experimenting with all sorts of riding configurations and finally found that sweet spot that I can definitely tell made a significant difference in my riding style.