[Special eyes]

I have 2 Mtn bikes , a 2007 Epic Expert , a 2004 Stumpjumper Comp HT , both bikes are great.

What I can't figure is why is the HT faster than the Epic. The Epic eats up all the roots and rides great , the HT beats you in the rear a bit like hard-tails do but it is definetly faster and it handles snappier and quicker. Not only is the HT faster on the trails it's faster on the road as well, I cant figure it out and it's bugging the hell out of me. Any ideas?

 

[neblackb]

It's as easy as this. With a full suspension bike you lose a lot of energy in the suspension. A HT has more of the energy going straight to the wheels. It completely makes sense if you think about it.

 

[Hawgzilla]

HTs are also often lighter in weight when built comparatively to an Epic. Less weight translates into higher efficiency.

 

[Special eyes]

Thanks guys, yea I understand the bob concept but the brain device keeps the rear of the Epic fairly HT stiff until it's needed ,I just dont think it's the bob that's slowing it down, I'm thinking it's something in the crank bearings, I just cant apply the same power to the pedals as I can on the HT. The HT takes off like my Tarmac , where the Epic just seems more sluggish. The HT weighs 24 , the Epic is 3 pounds heavier at 27

 

[Hawgzilla]

Thanks guys, yea I understand the bob concept but the brain device keeps the rear of the Epic fairly HT stiff until it's needed ,I just dont think it's the bob that's slowing it down, I'm thinking it's something in the crank bearings, I just cant apply the same power to the pedals as I can on the HT. The HT takes off like my Tarmac , where the Epic just seems more sluggish. The HT weighs 24 , the Epic is 3 pounds heavier at 27

Three things, two of them already mentioned....

One, you are getting a small amount of bob in the Epic from it's sag setting. That is unavoidable. That tiny bit of movement eats up efficiency.

Two, the HT weighs 3 pounds less than the Epic. That is a monumental difference in the biking world.

Three, the wheelset on the HT is clearly lighter in weight if there is a 3 pound difference between the bikes. That is the most direct difference between the two bikes where acceleration is concerned.

If you think the crank bearings (bottom bracket) are hanging up, pull the chain off the cranks and spin the cranks. They should spin fast and ultra smooth. If you can hear friction, feel friction or if the cranks don't move fast and smooth, pull the cranks off the bike and clean all the build up out of there. If that doesn't help, change the BB bearings.

 

[cant fix a flat]

do both bikes have the same tires? Smoother tires do roll alot faster.