My first mountain bike, help appreciated
 

I currently have a Giant Defy 3 Road Bike, I enjoyed it for awhile, but I am 6'4" floating around 300lbs and this makes a road bike impossible for a daily ride. I'm looking for something to be riding to work regularly, to either trade my road bike or buy with the money I get from selling it. Now my question to yall is, would it be worth even looking at a Diamondback or Nishaki(something liek that) from Dicks sporting goods, or would I be better off buying a Trek/Specialized esque brand off of craigslist or maybe a entry level model from a bike shop(what will something like that range? I'm looking for something reliable to ride 6 miles to a from work gradually working up to 5 days a week. Thanks!

Rich
Memphis, TN

The big-name bikes are less likely to fall apart on you.

I would think an entry level bike shop quality mountain bike or hybrid might be the best option for your needs. Most quality entry level bikes are really pretty good these days, you will get something that shifts and brakes nicely and is reliable. Your probably looking at $300.00-$600.00 for something like that. Craigslist is a good option for some people but if you don't know a lot about bikes a good bike shop should be able to help. Sometimes you can get good service plans as well. I think some places, Bicycle Village for example offer free lifetime tuneups and such. Also if you haven't noticed there is a sub-forum on bike forums Clydesdales/Athenas (200+ lb / 91+ kg) where the people will have more experience with your needs.

Diamondbacks and Nishikis at Dicks are perfectly good bikes, comparable to Specialized or Treks of approximately the same price points.

I'm really into vintage Nishiki bikes, currently owning 6 of them. I keep up with the current offerings from Dicks. If I were buying a new Nishiki MTB, I'd buy the better offerings, staying away from the Pueblo level. The better models are comparable to other brands. Unlike department stores, Dicks does have an employee who is dedicated to assembling and working on bikes so the build level is better than Wally World or the Big Zero assembly in my opinion.

The Nishiki Pueblos at Dicks are pretty decent, but they're heavy bikes - they weigh about 36-38 pounds depending on size. I looked at one on Craigslist that was in virtually new condition that I could have bought for $119, but the seller wouldn't take $100. I rode it, and I liked how easily it shifted, and the ride was comfortable, and I'd say the components and the wheels were OK, but I'd probably look for something 5-8 pounds lighter for a little more, if I was going to use it for commuting.