Ravi, or Kriti, I requested some additional information on several components on the Ultra via your web based email system. Never got an answer...so throwing the same questions out here.
The rims on the bikes are what brand?
The front hub, is it a sealed unit, what brand?
Are the wheels laced with s.s. spokes?
Does not appear you are using quick release skewers, but I have not seen the bike facing in the other direction, so what is the axle attachment type?
The battery is integrated into the frame, can the battery be removed like the Bosch system and taken indoors during winter weather?
If so I assume it can be charged off the bike?
None of this information is available in your specifications listing but for many of us it is important, thus the questions...thanks.