[Big B]

I'm looking at trying to buy a $400 piece-o-crap road bike for commuting.

Before I go through the torture of trying to find a bike in this price range, I'd like to know how fast road bikes go anyway. I can hit 18-20mph average on my old XC mountain bike on a flat trail (Burke Gilman for you Seattle folks). So will I get at least 25mph average on a road bike?

 

[Pau11y]

Question, why not just get some slicks for your mountain bike if all you're doing is commuting? Save yourself some $300.00 +

 

[Big B]

I've got them. That's how I get 18mph average. Couldn't do it without slicks.

The mountain bike has 3" of travel, and it's old technology so it bobs. It's also not comfortable to ride a mountain bike in a hunched over position to minimize wind resistance over long distances.

I also want to go faster, and going a lot faster is worth $400 to me. Going a little faster may not be.

I've got a 15 mile commute (30mile round trip) that I'm trying to get down to 30-40 minutes. It's currently 50+min on my mountain bikes (I've got 3, slow, slower, and really slow)

 

[amateur]

If you're after a single speed, I have nothing but great things to say about the Raleigh "Rush Hour". It held up fine to 300+ miles of Gnar*Cal's finest weather.

 

[sanjuro]

I don't think you will be smoking at 7mph faster with a road bike.

I have ridden mountain bikes on the road for at least 1500 miles, but speed vs a road bike was not an issue. I toured on one, bad weather riding, or just for fun.

However, I believe you would be faster on a road bike. Larger wheels means better momentum, and the biggest complaint about 650c wheels, common on triathlon (for aerodynamics) and womens (for smaller fit) bikes, is the lack of momentum and overall speed.

 

[Reactor]

I've got them. That's how I get 18mph average. Couldn't do it without slicks.

The mountain bike has 3" of travel, and it's old technology so it bobs. It's also not comfortable to ride a mountain bike in a hunched over position to minimize wind resistance over long distances.

I also want to go faster, and going a lot faster is worth $400 to me. Going a little faster may not be.

I've got a 15 mile commute (30mile round trip) that I'm trying to get down to 30-40 minutes. It's currently 50+min on my mountain bikes (I've got 3, slow, slower, and really slow)

I went from an xc bike with 1.5" slicks to a road bike and gained 1-2 mph. That's on a 19.5 mile commute, minimal altitude change, normal riding positions on both bikes, but pushing fairly hard. I went from about 17-18 to to 19 -20mph.

 

[LordOpie]

Road bikes are 22% faster.

link

 

[Serial Midget]

Road bikes are 22% faster.

link

You know I could have sworn it was 21.9 - you might want to check your facts.

I have touring slicks on my old hartail with a SID fork - with the tires at 70psi I can do nearly the same speed as my road bike for short distances, its only when the distances exceed 50 miles that the real difference is apparent.

And Burke-Gillman is not a trail!!! City folk call anthing narrower than a street a trail... ink:

 

[Pau11y]

Big B, if you have a disc bike, then you can mount 700C wheels built on disc hubs w/ a max of around 32mm cross tires, or some form of city slickers and still get all the benefits of the road wheels on your mountain chasis. As far as the hunching over thing to cheat the wind, the effects of position becomes more and more pronounced the faster you go, but it starts to show above 20mph in calm winds. So the difference between 19 and 21 mph, is pretty small w/ respect to position. The biggest diff is going to be in tire psi and diameter.

Edit: w/ regards to your shock and bobbing, if you can, lock out your shock or tweak the rebound adjuster to the slow side.

 

[CouchingTiger]

I would not assume that a road bike will get you to 25mph avg alone over a MTB with slicks. I'd think it'll be worth a mile or two an hour over a short stretch. 25mph avg over a longer stretch (10 - 20 miles) is a very solid time trial speed. Also remember that it takes 2x the energy/power to go from 20mph -> 25mph on a bicycle because over 15mph its all about displacing air.

-Couch

 

[Big B]

Thanks for the info. Maybe I'll just keep using my Giant XTC.

 

[UNHrider]

another thing to remember is the gearing difference. if youre planning on using gears. i find that while riding my mtn bike on the road i run out of gears pretty quick. plus the added advantages of the road wheels as all ready mentioned.

 

[sanjuro]

That's a good point. I think the thing is, on a road bike, I can do 25mph without too much effort, 30 for a short period of time unless I am in a paceline. On slight downhill rises, I can easily pedal at 33-35mph

The speed of a 44x11 for a mtn bike is 29mph going 100rpm, vs 37mph for a 53x11. I used Sheldon Brown's calculator: http://www.sheldonbrown.com/gears/

Now you might say, I won't go as fast as 37 or 29mph, but if you were to keep a fast pace, particularily on downhills, you'd spin out your biggest mtn gear.

 

[Serial Midget]

Thanks for the info. Maybe I'll just keep using my Giant XTC.

Haha - my old hardtail is a 2003 XTC SE1 - with slicks it,s practically a road bike - I have even raced it with aero bars.

 

[Big B]

Unfortunately, mine is the 2001 model with 3" travel. It has the original cheap air shock, so it bounces like a trampoline when pedaling. That's another reason I wanted a road bike. I wish I could lock it out.

 

[Serial Midget]

The 2003 came with a SID Team wit 3" and a lockout - mine now sports a Sid Race with 63mm - a little extra air makes it stiff enough for the road and touring but still able to handle fire roads under the load of a touring gear while pulling a trailer. In 2001 they offered a Judy or a 80mm Sid XC. I once had a Judy on a Trey OCLV Y-22. It sucked.

 

[Big B]

Two things. First, I've been talking about the rear shock, which is just an air shock. I didn't mention the front fork because it's an old POS, and it's not the problem. Second, I think the bike is actually a 1999 model, because I can't find it on Giant's website anymore and they go back to 2000. I forgot how long I've had that thing!

It bobs, and extra air pressure doesn't fix it.

 

[Serial Midget]

OK point taken, I wasn't aware that your ride was an NRS XTC, I'm dumb. Never heard of a Judy reach shock either. Double dumn.

 

[Big B]

OK point taken, I wasn't aware that your ride was an NRS XTC, I'm dumb. Never heard of a Judy reach shock either. Double dumn.

No problem-o. Actually, it isn't an NRS XTC. NRS wasn't invented yet in '99. It's just an XTC SE2. Which they later turned into a hardtail.

It got real confusing there for a couple years.