what does "bottom end power" mean to you?

[Nevada Sixx]

everyone says they are looking for extra bottom end power in a mx bike,,but since ive tried all the mods just about,, i have come to the conclusion that the aftermarket products that say you get "extra bottom" really means antistalling and a lesser mid hit", and not really extra torque for low rpm wheelie power, like an enduro bike has.. but low gearing did make a difference in my 125.. what do you guys think?

 

[Rcannon]

Bottom end power, for me, is the difference between a two stroke open class bike and a 125. That "extra" power that lets you move into third gear vs second.

 

[JTT]

I always considered true bottom end, as power right off idle, and slightly above....after that it's midrange.

ps. I've never ridden a 125 with "bottom end"...good mid, yes, but not bottom...and yes, a 500 has bottom end, as do many good enduro bikes.

 

[atc3434`]

JTT's got it figured out... its definatly the off idle power thats real bottom end to me. Try a late 90's CR250 set up to pull down low. I rode one that was a real mountain goat. You could take SERIOUS hills in second at an idle and still bring up the frontend. Yeah, a 125 with bottom... not! I'd just like some mid on my RM :)

 

[Steve47]

There's only one thing that can describe bottom end power...

1998 KX250!!!, Nothing ever came close.

The clutch was almost not needed with this bike, it was that strong.

 

[Nevada Sixx]

i had a 99 kx 250 and rode it side by side with a new kdx220, (both bikes were new),, and on a hill at quater throttle, the kx would barely pull itself up, and the kdx zipped right up with no problem. so i guess simply having a bigger piston doesnt mean you'll have strong bottom end. I guess the porting and small carb, along with lower gearing and heavier fly on the kdx made more difference. But ive about come to the conclusion that if you want "alot" better power in a certain area, its best to just get a bigger bike or differnt type of bike,, as no matter what i did,, i can still tell im on my same 125.

 

[pyromaniac]

So much talk about bottom power. Almost everyone shouts "want more bottom!". Damn cant you learn to open your throttle? Then you will have power! Much cheaper then spending money of aftermarket parts.

If i want a faster bike then i wont be looking for better bottom to mid but for top power. I mean a bike with good bottom will never be as fast as a bike with better top, unless you dont have the skills and are crawling on idle speed :)

Bottom power is really nice but nothing more than nice.

 

[atc3434`]

Unless your a dune rider, or a very talented MX rider... bottom end can mean a lot. Especially for the trail riders. Staying on the pipe all the time can give you quite a beating... its nice to be able to rely on some decent bottom when you don't feel like riding 9000rpm all day. I know how to open my thorttle, very well. But I like power opening it at the bottom too, not just up top.
Its funny you say a bike with bottom won't be as fast as a bike with more top. An '01 YZ125 is pretty much a topend screamer, and a '99 KDX220 is all low mid, nadda on top. Gearing being the same, not meaning the same sprockets, but for the same top speed topped out in 6th, these bikes were almost completely side by side all the way from a standstill to topped out. The YZ was a little quicker, but not by very much at all. Very very little. So whats the point... well, obviously bottom end counts for quite a bit, because the KDX220 doesn't have nearly the power peak of a 125... but it pulls hard and consistent at its optimum RPM range, and has TONS more torque than that 125 could dream of. So you have a bike thats got a much more rideable powerband, and about the same avalible acceleration. Also, you can pull quite a bit more gear on the 220 than on the 125, and still be able to ride much easier in the woods. Ask anybody who drag races, HP is nice, but torque wins races.

Not getting personal though... I love my 125 and don't mind fighting to stay on the pipe. But bottom end is very important depending on the application. Good food for thought anyways.

 

[Nevada Sixx]

yea, our 220 has tons of bottom power,,,
i think a bottom end bike can still turn fast laps since it was able to pull up to its top speed so easy.. a magazine pointed out that having really good bottom power can make a fast bike seem weak on top even though its not.

 

[Moto Squid]

what's bottom end mean to me??? A Thumper!!! Nothing else can compare to their "roll on" power. Its quite a nice change from my cr125

 

[EZ-Rider]

Originally posted by pyromaniac
If i want a faster bike then i wont be looking for better bottom to mid but for top power. I mean a bike with good bottom will never be as fast as a bike with better top

HUH? You might want to rethink that statement. A torquey bike will accelerate quicker be easier to ride and require less shifting. Also if it's geared properly it can be as fast as a high revver on a long straightaway. Don't believe me? Ask almost anyone that switched to a 4 stroke or anyone that rides a big bore 2 stroke.

 

[pyromaniac]

You get me wrong. Ofcourse a 500 2-stroke will be faster than a reving 125. And a big 4-stroke will be faster than a small 2-stroke. What i ment was if you have a bike, say 125cc, and want to ride faster you dont use the bottom you use the top. So you dont want a better bottom you want a better top. I mean if you feel you want to accelerate faster you dont put a higher gear in when you are bogging down but you rev it out. Any bike will be faster on top than bottom, thats kinda the idea of having a throttle :)

So if you want to go faster simply open the throttle and let it rev instead of spending money of aftermarket parts.

Also comparing two bikes running side by side is more complex than just the size of the engine and gearing. You have the skills of the rider, weight of the rider. Then you have jetting and many other things that affects the power output, suspension and most important, tires. Without traction power is nothing.

 

[JTT]

Pyro, you need to ride some older bikes sometime. It will quickly bring this into perspective. A 1980 125 made "nearly" as much peak HP as a modern 125...however, if you can go as fast with that motor as a modern "broad powered" motor, you are a good man. I've ridden both and beleive me, there is a lot more to it than just peak HP...ask the MotoGP guys if you want proof.

Following your theory, all we need is max HP, maybe 1000rpm wide, and could do away with everything else. Tuners would love you!

 

[Rcannon]

Squid, I know the thumpers run well, but compared to what?

 

They are allready allowed to be twice the size of the two strokes for racing purposes.  They still have not made a thumper with the power potential of the old KX 500. With just a minor amount of work they were over 60 hp. Stock off the showroom floor, 55 would be no problem. Low end, yes, they have it.

 

The Honda XR 650 might be able to make as much power, but again, we are back to increased displacement.

 

[SterlingYZ]

Just wanted to say RCannon has a great point. When comparing engines, displacements MUST be taken into consideration.