How important are the miscellaneous specs in bmx? Such as geo, offset, etc

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1/14/2018 3:17 AM

Stuff that sometimes isn't normally listed in bike specs unless your spending $300-$400 or more. I am a park rider, but I also have interest in dirt jumping and trails since those are available in my area. Just the trails may be a little bit too burly for a bike without suspension, almost got bucked off the trail from hitting a root sticking out the ground and there are a ton of them. Also it is painful on the wrists.

At the park I am mostly doing bowls, ramps, and the occasional wall ride along the huge slant. I want to get into grinds, and vert once I have the bunnyhop mastered. The bike I have is the mongoose l100 2018 model, and I hear it has a good geo for dirt jumps, but what about park? Will there be much of a control difference when riding in bowls with the wheels spaced out a bit on the mongoose? Or grinding a c shaped rail?


1/14/2018 4:55 AM

Yes, there are "specialized" geometries for different uses in every form of bicycling & in the sub-categories of each segment. For instance, a mountain bike frame designed for suspension will have a completely different geometry that a mountain bike frame designed without suspension. Even though they both are designed for the same and purpose. In bmx, there are differing geos for different forms of riding because some geos lend themselves to that particular style of riding. For instance, a more slack head tube angle isn't as "twitchy" & is more stable & lends itself to trails/dirt jumping where that same geo can easily be used in street riding, it isn't optimal & you might find that you have to work a bit harder to do street on a frame more specialize to DJ. What is comes down to, however, is you can ride anything, anywhere. You can (and will) get used to any geometry you ride. If you want to ride different sorts of styles, you either have one bike that is sorta in between & deal with it not being "perfect" or you have different bikes. In your case, it sounds like you really should have a DJ with some suspension and a bmx. Either that, or find trails that are now designed for a bike without suspension.


1/14/2018 6:52 AM

Oh the Mongoose L100 is perfect for dirt and park yes... usually if something is good for trails, it's good for flowy park... like bowl riding and doing big gaps... I like my bike to be a good all around bike, so I can ride everything comfortably... mine has an 11.5 bb height, 13.5 backend slammed (I have the axle at 13.75 I think now), 75.5° headtube ( it's a street frame, but I got a 33mm offset fork to make the 75.5° feel more mellow) and my bike feels great! It's good all a rounder! But yes, the Mongoose wil be great for park!smile


I don't crash, I do random gravity checks...

1/14/2018 7:26 AM
Edited Date/Time: 1/14/2018 7:29 AM

Frame Geo/ Features Explained
Fork Geo/ Features Explained

If you're a beginner, you're probably not going to know exactly what it is that you want, and you will adapt to any bike just the same as others. Geometry is more important when you're further along in your riding career and understand your own style/bag of tricks. That being said, there's a lot of specs that make learning tricks easier, so give those 2 threads a read.

Refs : SnM An1mal, GThompson121, Chuck8273, blizzbikes, bmxsteve99, kevin.brock.338, zinum, Brian_Griffin, billyhandyjunior, riverM, tomdon
Instagram : @timhankinsbmx

1/14/2018 7:57 AM

Yes, i built A dirt jumper out of my Mongoose Legion because it felt so stable. I would ride the stock bike at dirt jumps but there was no point since I had an entire bike (sans frame) sitting in the garage from a build I gave up on.

I am riding my stock Mongoose Legion as a street bike right now just to try something different but it is by no means a better street frame than my sunday street sweeper. It is very possible to make a compromise between the extremes of the geometries that favor a particular style of riding and have a bike that will be ready for anything but wont be the "Best" for jumps or street.

On the flipside, I promised myself I wouldn't ride my sunday at the dirt jumps anymore. The backend is so short I loop out on jumps if I mess up and barely land on my rear tire. The headtube angle is uncomfortably steep for going downhill meaning less stability. And the fork I chose, the r25, is a steeper offset as well. This all adds up to a tall feeling bike with a super short wheelbase. Not good for dirt jumps or anything that speed is involved.

Someone better than me could still rip it anywhere but it is not as fun as a slacker longer wheelbase bike for dirt jumps.

Its awesome for grinds and slower stuff though and thats what I like to do the most, personally.