Originally Posted by
Panthers007
Not if just testing it. But running in the big~big combo is a no~no anywho. As long as the RD isn't impacting with the cassette or similar phenomena, all should be well.
Horrible logic. Here's why:
It's a beautiful sunny spring day. The flowers are blooming and the birds are singing. There's no wind and you are enjoying your best ride ever. Cruising along in your big ring you decide to sprint up a small hill. As you approach the top of the hill your cadence drops off so you shift down. You feel a little resistance from the pedals so you push just a bit harder to get you over the top. SURPRISE! You have just inadvertantly shifted into your big/big combination. The chain isn't long enough and the easiest thing to bend is the derailleur arm. It goes into the spokes destroying your wheel and damaging your frame. As you start the long walk home a cloud passes over the sun and a cold rain starts to fall.