New To The MX track! Is Setting Sag A Must?

[Guest]

Help!!!!!I have been out of this sport for a long time. My last bike before my 2012 YZ 125 was a 1983 CR 125...& no when I rode my 1983 CR she was not considered vintage. So I am majorly rusty. The thing is when I rode...we just rode. Where ever there was dirt...where ever there was a trail. Tire pressure made no difference. If the tire had air it was a plus. We never touched our suspension settings...or moved handle bars. Again it was a different era. We shared gas back then, 87...89...93...what ever we could get our hands on. I remember siphoning gas out of my parents car just to ride. We didn't buy new plugs...we used sand paper to clean the old ones & used them for weeks.

The difference is now I am a lot older & the only place to ride legally is at the track. So I joined one. I feel way out of my element but I'm really starting to enjoy it. In all my years the only thing I jumped was fences (I'm trying to make a joke) but really I rarely jumped anything because there was nothing to jump on the trails behind the local supermarket. If I did jump something it was small...& half the time they were small because we had to build them ourselves ...& when I was that age all I wanted to do was ride not dig.

So...the point of my story is by no means am I clearing doubles... but I got to the point that I am not rolling them either. The guy next to me in the parking lot said I have to set up my bike. He said the first thing to do is set up sag. He didn't get into it because when I pulled into pit...he was just gearing up & heading on the track.

I say this a lot but forgive my ignorance but like I said in the title...I'm new to the track & I'm not looking to break lap times or break my leg...I just want my bike set up to my & its capability. DO I HAVE TO SET SAG? IS IT A MUST?

I ordered a new sprocket. I went up a tooth 48 to a 49.

I know some will say why am I riding a 2 stroke 125 at my age...but with age comes smarts. I feel for the time being a 125 is all I need. I am not looking to impress anyone. When I get faster...I could always move up to a 250. I love 2 strokes & will stick to them for as long as I can. That's all I knew growing up & don't want to change.

I realize I am putting my suspension to the limit being I am 175 pounds.

Any help or direction would be appreciated.

YOU GUYS HERE ON THUMPER TALK ARE A GREAT BUNCH & HAVE BEEN VERY HELPFUL THUS FAR!!!!!!!

[matt501k99]

I don't post often (this might be the 3rd time) but welcome back to the sport.  I kind of had the same type of journey.  I rode trails or open fields when i was a kid.  I rode my first track at the age of 26, broke my ribs and leg that same year.  Yes I couldn't ride a lick but tried to do what everyone else was doing - mistake.  15 years later, I ride pretty good - I'd say if I were to race it would be Vet B/C (top C on good day and last on a bad ? 

 

So stay with it!  I rode a 125 for years and I think it will make you a better rider because you have to carry your speed in corners to clear jumps etc.

 

Anyway to answer your question.  Yes it is very important if you want your bike to handle properly.  The Sag will put more pressure on the front or less (chopper it out.)

 

From the Web

There are a lot of handling problems associated with incorrect chassis set-up. The most common problem is incorrect race sag/free sag. The proper amount of race sag for a full sized japanese motocross bike is 95-100mm.  Contrary to popular belief, 2mm difference in race sag makes a dramatic difference in overall handling!

All those other things you mentioned are all important. 

 

On the suspension (from the web)

- Springs

Motorcycle suspension uses springs to hold the bike and rider at the proper height and position.  The spring rate, or "stiffness" of these springs needs to be correct for the bike,
rider weight, rider height, ability, and application.  These springs are designed to have a certain amount of sag, with the rider on the bike. This is absolutely crucial!
 

- Compression

Compression dampening controls how the suspension compresses. An adjustable valve lets a certain amount of oil through the suspension and controls the speed at which it travels through its stroke.

High speed - High speed compression dampening allows you to adjust the suspension rate when the suspension is moving at high speed. Hitting a big square edged bump will cause the forks or rear shock to move through their travel at a high speed.

Low speed - Low speed compression dampening adjusts oil flow through the base valve and would be used for tuning the suspension when you are hitting obstacles that are more rounded or perhaps landing on the down ramp of a jump, any situation where the suspension is moving though its travel at a slower speed.

Keep in mind that high and low speed suspension tuning is more about how fast the motocross suspension components are travelling in relation to the bike, not how fast the bike is travelling on the track.
 

 

- Rebound

Rebound dampening controls how fast the suspension returns to its full travel after it's been compressed by hitting an obstacle or bump. If your rebound dampening is set too fast the bike may have a tendency to kick up over braking bumps or when accelerating out of corners. If it's set too slow the suspension can pack down over a series of bumps because the shock or forks can't return to full travel quickly enough before they hit the next bump.

Edited April 9, 2014 by matt501k99

[mikerides33]

A 2012 yz125 for a 175 lb MXer is..........glorious.

I click in anywhere between 180-184lb and I could ride and love that bike all day long..... Its incredible.

Just have somebody help you get your sag right and then go rip. Nothing to do on that bike but keep everything fresh and just love it. Such an awesome bike and a great way to get your sea legs back.

Be safe and have fun.