Guys/Gals,

I want to commute but im not sure what bike to use. A mountain bike or a road bike. It will be flat. about 10mi. Let me know any ideas or opinions.

Thanks
Manuel

I personally like mountain bike a smother ride it can take pot holes better and bumps where a road bike the seat post feels like....

Welcome To Bike Forums, Emanuel!

Well what's your budget?

Is your terrain primarily paved or dirt trails or what?

* I will be communiting from Palo Alto to San Carlos.

Would go with neither of these, and look at a hybrid, takes the best of road and MTB's and ends up with a good compromise.

The problem with using a current road or MTB is if you are looking to add a rack, unless you are looking at a low end model, they don't come with the required mounts anymore. Hybrids are easier to get with discs, as the normally use flat bars, as opposed to drops where disc are still a few years a way from being common.

It will be paved. I forgot to mention. I have both an onroad and offroad bicycle..

It depends. If your ride is all road AND nice road then a road bike. My commute is all urban, all on streets, but the pavement is often horrible and I cross a few bridges with metal surface with gaps so I prefer 2.0 fat mountain tires. The gaps on those bridges will swallow a 25 or even 32 road tire, but not a 2.0 MTB tire (I tried), so that's my reasoning. My commute is also only 8 miles so I don't care much for speed.

As far as smoothness: my Surly Disc Trucker with 700x32, 80psi tires is a lot smoother than my aluminum MTB with fatter and softer 26x2.0, 60psi tires. So the tires themselves don't really add that much smoothness as the frame does IMHO. But I still prefer the MTB for my commute for the reasons I stated above.

Alright then!

In that case, if your terrain is mostly smooth with decent roads (not many pot holes, cracks, etc), then you'll want to use your road bike. Otherwise, use your MTB.

Mountain bikes can hold a heavier load and are comfortable to ride,plus you will get better cardio on it.

I rode a hybrid for a year. Now that I'm riding my refurbished MTB, I prefer the more solid feel of the MTB, the wider tires feel more stable, and the geometry is better for me.

A short wheelbase recumbent is another option. Works well for me on a suburban/urban commute.

I prefer road. MTBs just seem like so much more work.

If you don't care about having disc brakes or being the lightest, a Hybrid works great. Comfortable, inexpensive, and easily accessorized with lights, racks, paniers, etc. I currently have two mountain bikes, but they are more like hybrids.

Road, without a doubt. If you decide to go with a mountain bike, at least put road tires on it, and take off the suspension if it has any.

How are things with parts accessibility in Sao Paolo?
In my country, MTB is the only bike for which you can get parts in the same week that you order them.

If parts and service is not an issue: a hybrid, or a road bike. I ride a hybrid, because it can carry more weight when I need it (change of clothes, tools etc.).

Everyday commuter bikes are more useful with luggage racks, lights and (if you have rainy weather) fenders. With so much kit stuck on, it is better to have a dedicated commuter bike and leave your play bikes for play.
The best commuter bikes can accept medium width tyres (700cx32 or 26x1.5) with generous fender clearance. They will have a full set of threaded eyelets for rack, fenders and waterbottles. You can use hybrid, city bike, disc cyclo-cross, touring, cross-country style MTB, or winter training style road bike. Commuter bikes can use any stye of handlebar, flat, swept back, drops, aerobars, trekking butterfly bars and any style of transmission: fixed, singlespeed, internal hub gears, 1x9, 2x9, 3x9. The highest cog counts (10-11 speed) use thin chains and rings but it is hard to avoid them.

If the roads are in good condition, you might prefer a road bike. If they are crappy, the mountain bike might be better. I see mostly hybrid and MTBs at work. But I prefer a road bike. Try both, you'll figure out which you prefer. Your morning commute will most likely be with a headwind and you might find the road bike offers more aero riding position.

I like my low end mtb with a heavy duty rack. She needs some dual purpose tires as my 45km/h run this morning showed just how unstable the off road tires feel running that fast. It also has all the mounting points for racks etc. What I miss is the instant stopping power from my disc brakes on my nice bike. V brakes and 50km/h down hill runs don't fill me with confidence. I think when I get the n+1 bug my current 'best' mtb will be demoted to commuter as it rides so much nicer. With the wide range of roads/tracks I need to ride on a lockable front fork is nessecary as the bike paths I have to go on a few days a week to get work are way to uneven to ride a road bike on.

Thats somewhat of an annoying commute; avoid El Camino Real, which means you'll have to ride in one of the side roads through the industrial areas (kinda poor road surfaces, plus ugly) or go a little out of your way and take the scenic route through Alameda d las Pulgas (which is hilly)

I say go with an all rigid(no shocks) cromo steel mountain bike with slick skinny tires on it 26x1.5-1.25
good for the hills, good for the tarred over cracked roads, decent speed, comfortable, cargo capable

Not true. What about touring road bikes that are specifically designed to haul heavy loads? Many light mtbs are not designed to carry racks at all, not to mention suspension bikes.

Also not true. A rigid mtb with skinny, slick tires is almost just as easy to ride as a road bike.

As you can tell from the responses so far, every bike design has its compromises. I got a MTB for winter commuting in Denver, also about 10 flat miles. Snowy mornings, dry afternoons. Those dry afternoons were the longest 10 mile rides of my life. Fewer riding positions and more rolling resistance turned a normally effortless ride into a fatiguing one for me. It was nice riding in the snow though. After I moved out of the snow, I would never ride a fat tire bike on a road again.

It just depends on what bike you want! Choose tires as appropriate to the road, especially if the road or touring bike (if that's what you choose) has clearance for larger tires like 28 or 32.

I love riding my road bike on my 10 mile mostly flat commute, but my other hybrid style bike was fine. A mountain bike would slow me down at most 5 minutes. I really think it's more a matter of style and personal preference than anything else.

I think some qualification is in order here. Not all road bikes are great for commuting. You can commute on absolutely any bike, but a newer road bike is likely to be limited. Likewise, not all mountain bikes are great for commuting, but some are. A newer, low end mountain bike is likely to have a lot of weight and spring that don't help. I personally think entry level cylcocross bikes are the way to go.

To illustrate, this is my road bike.



It doesn't like fenders or a rack, and so I only use it for commuting when the roads are dry and I'm open to using a backpack or messenger bag.

This is my mountain bike.



It's not really very suitable for commuting because of the knobby tires and spongy front suspension. If I had to I could make it better, but I have other options.

This is my other mountain bike disguised as a road bike.



It's great for commuting (my commute is also 10 miles on paved roads), but I obviously changed a few things to make it so.

This is my cyclocross commuter.



It's also very good for commuting.

That, and what you've got...both in terms of hardware and shekels.

Just about any bike can be made commute-worthy if you pump enough cash into it.

A little more info about the bikes from the OP would be helpful in giving thoughtful suggestions, because "road bike" and "mtb" don't tell us anything.

EDIT: Andy K posted while I was typing, and illustrated, literally, my points. Very well done, Andy!

You need at least 4 bikes to even think about commuting. A back up bike for each of those would be ideal, so really, you are looking at 8 bikes just to get started.

Actually, it comes down to personal preference and weather conditions. If you ride in bad weather, use a bike that will take fenders. A rack is nice to carry stuff vs. a backpack. Slightly wider tires are great if they fit, but not critical.