|Differences Between Road / MTB Component Groupings?||cdnrider|
Aug 20, 2002 6:25 AM
|Probably a dumb question but bear with me as I'm only a recreational hybrid rider who likes to zip along as quickly as the legs will permit. Doing some new bike shopping and notice that some bikes use groupings considered "road" (eg, Shimano Tiagra with rapid fire sifters) while other virtually identical bikes use MTB classified components (eg, Shimano Deore/ XT rapid fire shifters). What are the main differences and do they really matter to someone riding a road/path mix (20-30 mile rides) average speed around 20 MPH?
|Gear Ratios (nm)||Chen2|
Aug 20, 2002 6:55 AM
|Well ...||Spoke Wrench|
Aug 20, 2002 7:06 AM
|The real difference is the front chainrings. The "road" grup will probably have a 52 tooth big ring and the "mountain" group will probably have a 46. In real life, the 46 will probably yield about a 113 gear inch high gear. That should take you to 20MPH.
Unless you are spun out in your hardest gear a high percentage of the time, you won't go measureably faster with the bigger road chainrings. You still have to have a motor that is powerful enough to turn the higher gear.
|shifters, brakes, gear ratios, some design points||off roadie|
Aug 20, 2002 8:42 AM
|Road shifters are generally designed to work with drop bars and the brake levers pull the amount of cable needed to activate "caliper" brakes (the kind that mount to a center bolt at the top of the fork).
MTB shifters are designed to be mounted on horizontal bars. Almost all good MTB brake levers sold these days are designed to pull linear-pull (or mechanical) discs, both of which mount on special studs fasteded to the sides of forks.
The rest of the differences are basically design tweaks for aerodymics, grit proofing, and other small purpose-specific selling points.
Not a big deal, but it explains why there's different sets for different styles of bikes. Bikes with these differences in componant sets (at the control end, not the drive train) probably won't be "virtually identical", but you may see more mixing in the drive train or wheel design.
If you are looking to do 20-30 mile long rides at 20mph on paved surfaces, you probably would be best served with a road bike. That's what they are made for. Other bikes can do those speeds and distances, but a good road bike will do it more easily, comfortably, and sustainably. What you may be seeing are "hybrid" or "comfort" bikes, which usually cobine road and MTB componants, but aren't really designed for faster, longer rides. On the other hand, some "touring" and "cyclo-cross" bikes also combine componant groups, and are probably very good for your purposes.