A friend of mine is riding consistently in largest chainring front and smallest cog rear. The corresponding teeth counts are respectively 44 and 11.
The bicycle is an Acera-level mountain bike with very light and fitting them frame. Gears shift relatively quickly and reliably.
Their average speed is about 30km/h, while commuting 20km total per day. The traffic is average.
Their acceleration at traffic light is low. However, I have observed no other drawbacks. To my surprise, the chain and smallest cog are still operational, after 1-2 years of year-round commuting - dust, snow, salt, mud, rain. (measured with a chain ruler)
Also, when it becomes impossible to ride this gear (standing up), they switch to a much much easier gear.
Is this a reason for concern? Knees, traffic safety, mountain trekking endurance, bike components wear (from most important to least important)?
EDIT: A couple of clarifications:
- The tires are 26x2.0 semi-slicks.
- It was a mistake to claim average speed of 30km/h. This is rather cruising speed. On the other hand, starting from a red light or recovering from a difficult turn takes forever (5 seconds for example).