Midriff-ter MTB...My home from May 1 - Aug 1...pg 15 !

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If you really like the bars, Have you thought about flipping the that clamped on neck upside down? That could drop the bars down about 1-1/2".
I thought of that, but the bar is actually 'inset' halfway through the stem, so it's just that bottom thickness of the stem that would be the difference, 3/4". There is no 'up ' option on this 90° block BMX stem.
 
This is why this Forum is so cool. My friend @metalchewy , MC for short, is an adept mtb rider who has ridden many of his 'klunker off-road' style builds to the extreme! He noticed that by flipping my stem upside down that I might get enough change in bar height that it would still work to use the 1978 Yamaha moto-x bars.

At first I didn't think it would, but it doesn't hurt to try. Also, I had a 10 mm spacer underneath the stem before, so that's another about 3/8" I would gain. I flipped it all and put the spacer on top, and dropped down somewhere near 1 1/2" in height of the bars! The other factor is, by lowering the bar height, I also lengthened the cock pit ( center of saddle to center of bar clamp) , which gave me a skosh more room as well.

@Jude Ephesus mentioned that the difference I was looking for might be 'negligible' (I'm paraphrasing now) with a different bar / stem combo. I always tell my bike customers when we are fitting them, that, "An inch is like a mile" on a bicycle; huge differences in fit by altering things just by a few millimeters.

Already, this feels like a better fit. I will need to get it on actual dirt before I can judge, and probably try my alternative bar / stem combo to compare. But it was definitely worth the try~! Thanks guys!

Before the changes:

midriff-ter seat bar height.jpg


After the changes and raising the seat 1/2". :

seat adjustment.jpg
 
So, help me understand the bigger front tire versus same size tires.
In most cases, except maybe a true fat bike, the fork can always take a wider tire than the rear triangle of the bike. This is especially true in aluminum frames, where the tubes are made larger in diameter / shape to be able to be light weight, but still strong. To not change the geometry of the frame too much, this often results in less room in the rear triangle for tire size. Steel frames can have a smaller diameter tube with a slightly thicker wall, and still retain strength.

The front tire also does most of the work on a mtb. Hitting rocks, encountering sandy / loose sections in corners, staying planted when sliding over wet roots or terrain; all of these are benefited by having a wider tire with a more aggressive tread pattern. Both of my tires on Midriff-ter have the same tread pattern, mostly because I was going for more of a 'truck like' look. I won't be competing or pushing myself too hard on this bike, so having a smaller knobbed and lighter weight tire in the rear for acceleration isn't needed. The rear tire has the majority of the rider's weight on it, so it doesn't inherently need the aggressive tread to work well.

In my case, this frame is originally a 29er frame. I had these wide rimmed 27.5 wheels already, and so to get close to the geometry and BB height (which accounts for pedal clearance) I had to put the largest tires I could use on the wheels to better fit the parameters of the bike. So that was another factor in selecting the 27.5 x 2.6 for the rear and the 27.5 x 2.8 for the front.
 
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In most cases, except maybe a true fat bike, the fork can always take a wider tire than the rear triangle of the bike. This is especially true in aluminum frames, where the tubes are made larger in diameter / shape to be able to be light weight, but still strong. To not change the geometry of the frame too much, this often results in less room in the rear triangle for tire size. Steel frames can have a smaller diameter tube with a slightly thicker wall, and still retain strength.

The front tire also does most of the work on a mtb. Hitting rocks, encountering sandy / loose sections in corners, staying planted when sliding over wet roots or terrain; all of these are benefited by having a wider tire with a more aggressive tread pattern. Both of my tires on Midriff-ter have the same tread pattern, mostly because I was going for more of a 'truck like' look. I won't be competing or pushing myself too hard on this bike, so having a smaller knobbed and lighter weight tire in the rear for acceleration isn't needed. The rear tire has the majority of the rider's weight on it, so it doesn't inherently need the aggressive tread to work well.

In my case, this frame is originally a 29er frame. I had these wide rimmed 27.5 wheels already, and so to get close to the geometry and BB height (which accounts for pedal clearance) I had to put the largest tires I could use on the wheels to better fit the parameters of the bike. So that was another factor in selecting the 27.5 x 2.6 for the rear and the 27.5 x 2.8 for the front.
Awesome!!!! I love learning on this site!!!!

GREAT input….. I figured it was something along those lines, but have never noticed a larger front tire on a mtb.

Good stuff!!!!
 
First test ride on dirt! YahoooOOOOOooo!



This was a cathartic moment for me. I have not ridden on an off-road mtb trail on a real mountain bike for almost 3 years. All throughout the past month of thinking about this build, which components and elements I would include in it, the overall look and feel of my end product; the culmination was my ride in the dirt today!

It wasn't a difficult trail, but it was getting back to what I have loved for 35 years; mountain biking in the woods.
 
Dang, that was quick! We're only halfway done with May and you're already hitting the trails with your bike! Nicely done OddJob!

Also, what's the tune playing in the last video? Sounds like something I'd listen to while working on my own bikes.
Thanks BFTD! The tune is 'The Thumb' by Wes Montgomery. If you listen closely , you can hear the scratching of the needle on vinyl. I used my USB friendly turntable to record this on to my computer. It's from an early album of his that I own from 1966.

OJ proving once again, time waits for no build-off!
Luke, I've got a whole summer of riding ahead of me now! I plan to get out for a spin this morning before I head to work, and tomorrow looks like rain, so the trails will be closed. The bike is riding great!
 

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