Front end push

gharmon
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Valley, AL, USA
Edited Date/Time 8/5/2014 5:00pm
Hi guys, got a quick question about what causes front end push? I'm not really good with suspension but have seen the term used but never knew what it meant till the other night. I was racing my 07 RM 250 and noticed what I assume is front end push. I was trying to turn and it was wanting to go straight. Don't really know how else to describe it but it kind of felt like it was "pushing" straight instead of turning like I wanted it too.

What part of the suspension needs to be addressed to fix this or at least make it better? Like I said I'm not that great with suspension and have never really noticed it till the other night .
1
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IWreckALot
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8/5/2014 12:26pm
What kind of dirt were you riding on also? I'd point more towards air pressure, riding position and riding terrain.
2
Tim507
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Oregon City, OR, USA
8/5/2014 12:39pm Edited Date/Time 8/5/2014 12:40pm
Less Sag in the back moves the CG forward
Suck the fork tubes up a bit
Riding to far back - move forward
3
disbanded
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8/5/2014 12:42pm
Slow down
1
Madmax31
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Fantasy
8/5/2014 12:54pm
If you can't get a RM 250 to turn you have issues. Probably the best turning chassis every made.
6
2

The Shop

resetjet
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8/5/2014 1:17pm
Where do you have your clickers on your forks set? You may be way off. Turn them in all the way and see how many clicks it is. My buddies KX was like that and he had it way off. Maybe put it back to center and see what that does and work from there.
SPYGUY
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8/5/2014 1:21pm
If this is something you haven't felt before, I'd bet you've developed too much sag in your shock.
2
Knoby
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Wichita, KS, USA
8/5/2014 1:53pm
Madmax31 wrote:
If you can't get a RM 250 to turn you have issues. Probably the best turning chassis every made.
X2...be sure everything is rebuilt to stock specifications first. Or at least just set the clickers to the stock settings. Then set sag like SPYGUY said. If that doesn't cure it then you have problems.

On another note I have been seeing a lot of Race Shop questions here lately.
1
mx-4-2
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Manakin Sabot, VA, USA
8/5/2014 2:22pm
Tim507 wrote:
Less Sag in the back moves the CG forward
Suck the fork tubes up a bit
Riding to far back - move forward
This has been the only solid reply so far. Would suggest you repost in the race shop. Sag is a major element as Tim said. Also raising the fork tubes in the triple clamp. Make sure you are weighting the outside peg.
8/5/2014 2:41pm Edited Date/Time 8/5/2014 2:42pm
Is it pushing or chattering?

If its pushing through the turns it could be your forks to low, or you have to much compression and your forks aren't diving or your sag could be off, lowering the back of the bike.. First raise your forks, if that doesn't work take out some compression and if that doesn't work adjust your sag.

Your shock could need an oil change and sag adjustment.

Honestly a bike pushing through turns could be a lot of things, but these are the most common and easiest to fix.




gharmon
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Valley, AL, USA
8/5/2014 3:11pm
disbanded wrote:
Slow down
Sorry, I meant to put this in the race shop section.

Hey there disbanded, like RC said about Brock during supercross, If I go any slower I may tip over. LOL
gharmon
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8/5/2014 3:17pm
UpTiTe wrote:
Is it pushing or chattering? If its pushing through the turns it could be your forks to low, or you have to much compression and your...
Is it pushing or chattering?

If its pushing through the turns it could be your forks to low, or you have to much compression and your forks aren't diving or your sag could be off, lowering the back of the bike.. First raise your forks, if that doesn't work take out some compression and if that doesn't work adjust your sag.

Your shock could need an oil change and sag adjustment.

Honestly a bike pushing through turns could be a lot of things, but these are the most common and easiest to fix.




I have ridden this bike quite a bit but not on a regular basis. I normally ride a 07 CRF 250R and take this bike primarily as a backup. I had never felt this before. The dirt was the same kind I always ride in for my area. When yall say lower the tubes, how much would you start with. Like 1/4 inch?
1
JM485
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Davis, CA, USA
8/5/2014 3:24pm
gharmon wrote:
Hi guys, got a quick question about what causes front end push? I'm not really good with suspension but have seen the term used but never...
Hi guys, got a quick question about what causes front end push? I'm not really good with suspension but have seen the term used but never knew what it meant till the other night. I was racing my 07 RM 250 and noticed what I assume is front end push. I was trying to turn and it was wanting to go straight. Don't really know how else to describe it but it kind of felt like it was "pushing" straight instead of turning like I wanted it too.

What part of the suspension needs to be addressed to fix this or at least make it better? Like I said I'm not that great with suspension and have never really noticed it till the other night .
I have an 06 and have had a similar problem. Try bringing the forks up in the clamps a bit in order to drop the front end, that seemed to help me a little. Also, maybe lower tire pressure a bit or just try a different brand or tire altogether.

They are great handling bikes, but everyone has their own personal preferences, and some might experience different handling traits than others.
1
Old-Man
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Location
Colorado springs, CO, USA
8/5/2014 3:28pm
Tim507 wrote:
Less Sag in the back moves the CG forward
Suck the fork tubes up a bit
Riding to far back - move forward
Yep, Moving forks up in tighter tracks (Supercross) will give you what your looking for. Not a whole lot maybe start with 1/4" and go from there. Move forward as you drop into the turn.

A good way to get used to the bike is go to a riding area where your not around anyone and practice the same turn over and over and over.... you will find yourself getting through the turn faster every time
gharmon
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Valley, AL, USA
8/5/2014 3:29pm
gharmon wrote:
Hi guys, got a quick question about what causes front end push? I'm not really good with suspension but have seen the term used but never...
Hi guys, got a quick question about what causes front end push? I'm not really good with suspension but have seen the term used but never knew what it meant till the other night. I was racing my 07 RM 250 and noticed what I assume is front end push. I was trying to turn and it was wanting to go straight. Don't really know how else to describe it but it kind of felt like it was "pushing" straight instead of turning like I wanted it too.

What part of the suspension needs to be addressed to fix this or at least make it better? Like I said I'm not that great with suspension and have never really noticed it till the other night .
JM485 wrote:
I have an 06 and have had a similar problem. Try bringing the forks up in the clamps a bit in order to drop the front...
I have an 06 and have had a similar problem. Try bringing the forks up in the clamps a bit in order to drop the front end, that seemed to help me a little. Also, maybe lower tire pressure a bit or just try a different brand or tire altogether.

They are great handling bikes, but everyone has their own personal preferences, and some might experience different handling traits than others.
I'll be racing it this weekend so I'll give it a try. I think suspension wise that my 07 CRF250 is a much better bike. But is definitely was treated better prior to my ownership. I've never really like the way this bike handles, at least for me that is.
1
disbanded
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8/5/2014 4:07pm Edited Date/Time 8/5/2014 4:14pm
Oopsy, wrong thread!

This edited post was meant for the Malcolm Smith thread.
KMC440
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8/5/2014 4:12pm
Get a new front tire ... one appropriate to the terrain you ride most of the time.
gharmon
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Valley, AL, USA
8/5/2014 4:16pm
KMC440 wrote:
Get a new front tire ... one appropriate to the terrain you ride most of the time.
Hell I thought it was Bridgestone 403. Is that not a tire for soft/intermediate terrain.
1
8/5/2014 5:00pm Edited Date/Time 8/5/2014 5:11pm
mx-4-2 wrote:
This has been the only solid reply so far. Would suggest you repost in the race shop. Sag is a major element as Tim said. Also...
This has been the only solid reply so far. Would suggest you repost in the race shop. Sag is a major element as Tim said. Also raising the fork tubes in the triple clamp. Make sure you are weighting the outside peg.
To the OP....
1. Set the rider sag at about 103-104mm.
2. Make sure the springs are right for your weight. This is easy to determine for the rear. If your rider sag is 103-104....the static sag should be about 29-34mm. If more, your spring is too stiff. If less...your spring is too soft. Fork spring....you are going to have to get some info from a tuner, etc. I think the 07 RM250 was sprung for a 180# rider stock.
3. Set the fork height at the stock setting...to as much as 3/16"! higher. Maybe start at 1/8"...
4. Try to keep the rear mid range in the swingarm (chain length)

Once all that is where it should be...set the clickers to the mid range...and start dialing as follows:
1. Get new tires!
2. Start with Fork Rebound! Find a flat corner. Turn the forks rebound adjusters IN (2 click intervals) until the front of the bike wants to KEEP TURNING to the INSIDE of the corner, after the apex, when you are on the gas, trying to accellerate straight out. Having a very light grip on the bars helps to feel this. Once the bike wants to keep turning more than you want to on exit...take it a click out. This is your baseline.
3. Next set fork low fork speed compression. Find some choppy bumps. compression adjusters IN until the forks get harsh, then go out a click. This is your baseline.
4. Set your shock low speed rebound. Find some whoop sized bumps. Increase rebound till you feel shock packing (wont rebound fast enough....so it stays low...and starts to feel harsh). Back out a click or two. This is your baseline
5. Set your shock LS compression. Find the same choppy bumps you rode on to set up the fork's compression, and/or a good set of whoops. Turn the shock's compression clicker IN until a harsh feel is felt, then go out one click. This is your baseline.
6. HS Shock Compression. Jump a single to flat to test bottoming. Adjust in 1/4 turn increments. Once the rear is obviously stiffer than the forks under bottoming, turn it back out 1/4. After doing this, you will likely need to re-dial the low speed compression settings.

Now you have a baseline set up. At this point, you can start dialing from these baseline settings by testing on a turn track, as follows:

• Bike tends to understeer
o Forks compression too soft
o Forks rebounding too slowly
o Shock compression too stiff
o Shock rebounding too quickly
• Bike tends to oversteer
o Forks compression too stiff
o Forks rebounding too quickly
o Shock compression too soft
o Shock rebounding too slowly
• Front end washes out
o Forks compression too stiff
o Forks rebounding too quickly
o Shock compression too soft
o Shock rebounding too slowly
• Front end tends to climb out of ruts
o Forks compression too stiff
o Forks rebounding too quickly
o Shock compression too soft
o Shock rebounding too slowly

There is more than one way to get where you need to be. So...say you have determined a baseline...and you are still getting corner entry push / understeer. There are all sorts of combos to solve your problem, and not make other things worse.

For instance...you can reduce fork rebound damping, and reduce shock LS compression.

You may find however, that increasing fork compression and adding shock rebound works better.

There are endless combos... Sometimes you solve one problem...but create another. Sometimes you solve one problem...and make performance elsewhere BETTER...which is sweet.

I have found that if you get a bike working really well on flat lower to med grip corner (NO ruts)...it will be pretty everywhere on the track.




4
3/25/2023 8:47pm
To the OP.... 1. Set the rider sag at about 103-104mm. 2. Make sure the springs are right for your weight. This is easy to determine...
To the OP....
1. Set the rider sag at about 103-104mm.
2. Make sure the springs are right for your weight. This is easy to determine for the rear. If your rider sag is 103-104....the static sag should be about 29-34mm. If more, your spring is too stiff. If less...your spring is too soft. Fork spring....you are going to have to get some info from a tuner, etc. I think the 07 RM250 was sprung for a 180# rider stock.
3. Set the fork height at the stock setting...to as much as 3/16"! higher. Maybe start at 1/8"...
4. Try to keep the rear mid range in the swingarm (chain length)

Once all that is where it should be...set the clickers to the mid range...and start dialing as follows:
1. Get new tires!
2. Start with Fork Rebound! Find a flat corner. Turn the forks rebound adjusters IN (2 click intervals) until the front of the bike wants to KEEP TURNING to the INSIDE of the corner, after the apex, when you are on the gas, trying to accellerate straight out. Having a very light grip on the bars helps to feel this. Once the bike wants to keep turning more than you want to on exit...take it a click out. This is your baseline.
3. Next set fork low fork speed compression. Find some choppy bumps. compression adjusters IN until the forks get harsh, then go out a click. This is your baseline.
4. Set your shock low speed rebound. Find some whoop sized bumps. Increase rebound till you feel shock packing (wont rebound fast enough....so it stays low...and starts to feel harsh). Back out a click or two. This is your baseline
5. Set your shock LS compression. Find the same choppy bumps you rode on to set up the fork's compression, and/or a good set of whoops. Turn the shock's compression clicker IN until a harsh feel is felt, then go out one click. This is your baseline.
6. HS Shock Compression. Jump a single to flat to test bottoming. Adjust in 1/4 turn increments. Once the rear is obviously stiffer than the forks under bottoming, turn it back out 1/4. After doing this, you will likely need to re-dial the low speed compression settings.

Now you have a baseline set up. At this point, you can start dialing from these baseline settings by testing on a turn track, as follows:

• Bike tends to understeer
o Forks compression too soft
o Forks rebounding too slowly
o Shock compression too stiff
o Shock rebounding too quickly
• Bike tends to oversteer
o Forks compression too stiff
o Forks rebounding too quickly
o Shock compression too soft
o Shock rebounding too slowly
• Front end washes out
o Forks compression too stiff
o Forks rebounding too quickly
o Shock compression too soft
o Shock rebounding too slowly
• Front end tends to climb out of ruts
o Forks compression too stiff
o Forks rebounding too quickly
o Shock compression too soft
o Shock rebounding too slowly

There is more than one way to get where you need to be. So...say you have determined a baseline...and you are still getting corner entry push / understeer. There are all sorts of combos to solve your problem, and not make other things worse.

For instance...you can reduce fork rebound damping, and reduce shock LS compression.

You may find however, that increasing fork compression and adding shock rebound works better.

There are endless combos... Sometimes you solve one problem...but create another. Sometimes you solve one problem...and make performance elsewhere BETTER...which is sweet.

I have found that if you get a bike working really well on flat lower to med grip corner (NO ruts)...it will be pretty everywhere on the track.




This is SO HELPFUL. Thank you!

Question: “• Front end tends to climb out of ruts” — “forks rebounding too quickly” — do you mean the rebound clickers are backed out too far (counterclockwise) or tightened too much (clockwise).
 

I’m asking for my 23 KTM 250 SXF with XACT Air forks. Rebound adjusted on bottom of right fork leg and compression is on the top. Air pressure is on the left fork. 

-MAVERICK-
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Ontario, CA
3/25/2023 8:51pm
This is SO HELPFUL. Thank you! Question: “• Front end tends to climb out of ruts” — “forks rebounding too quickly” — do you mean the...

This is SO HELPFUL. Thank you!

Question: “• Front end tends to climb out of ruts” — “forks rebounding too quickly” — do you mean the rebound clickers are backed out too far (counterclockwise) or tightened too much (clockwise).
 

I’m asking for my 23 KTM 250 SXF with XACT Air forks. Rebound adjusted on bottom of right fork leg and compression is on the top. Air pressure is on the left fork. 

The guy you just quoted hasn't posted in close to two years. 

Donk122
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Location
CA
3/26/2023 6:58am

1/4 turn in on the highspeed. (large 17mm (I think, or 14) nut on the shock)

BobbyMyers
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Aj, AZ, USA
3/26/2023 7:43am
gharmon wrote:
Hi guys, got a quick question about what causes front end push? I'm not really good with suspension but have seen the term used but never...
Hi guys, got a quick question about what causes front end push? I'm not really good with suspension but have seen the term used but never knew what it meant till the other night. I was racing my 07 RM 250 and noticed what I assume is front end push. I was trying to turn and it was wanting to go straight. Don't really know how else to describe it but it kind of felt like it was "pushing" straight instead of turning like I wanted it too.

What part of the suspension needs to be addressed to fix this or at least make it better? Like I said I'm not that great with suspension and have never really noticed it till the other night .

Don't ask Chase Sexton about "front end push". He doesn't know shit.

1
3/26/2023 8:35am
To the OP.... 1. Set the rider sag at about 103-104mm. 2. Make sure the springs are right for your weight. This is easy to determine...
To the OP....
1. Set the rider sag at about 103-104mm.
2. Make sure the springs are right for your weight. This is easy to determine for the rear. If your rider sag is 103-104....the static sag should be about 29-34mm. If more, your spring is too stiff. If less...your spring is too soft. Fork spring....you are going to have to get some info from a tuner, etc. I think the 07 RM250 was sprung for a 180# rider stock.
3. Set the fork height at the stock setting...to as much as 3/16"! higher. Maybe start at 1/8"...
4. Try to keep the rear mid range in the swingarm (chain length)

Once all that is where it should be...set the clickers to the mid range...and start dialing as follows:
1. Get new tires!
2. Start with Fork Rebound! Find a flat corner. Turn the forks rebound adjusters IN (2 click intervals) until the front of the bike wants to KEEP TURNING to the INSIDE of the corner, after the apex, when you are on the gas, trying to accellerate straight out. Having a very light grip on the bars helps to feel this. Once the bike wants to keep turning more than you want to on exit...take it a click out. This is your baseline.
3. Next set fork low fork speed compression. Find some choppy bumps. compression adjusters IN until the forks get harsh, then go out a click. This is your baseline.
4. Set your shock low speed rebound. Find some whoop sized bumps. Increase rebound till you feel shock packing (wont rebound fast enough....so it stays low...and starts to feel harsh). Back out a click or two. This is your baseline
5. Set your shock LS compression. Find the same choppy bumps you rode on to set up the fork's compression, and/or a good set of whoops. Turn the shock's compression clicker IN until a harsh feel is felt, then go out one click. This is your baseline.
6. HS Shock Compression. Jump a single to flat to test bottoming. Adjust in 1/4 turn increments. Once the rear is obviously stiffer than the forks under bottoming, turn it back out 1/4. After doing this, you will likely need to re-dial the low speed compression settings.

Now you have a baseline set up. At this point, you can start dialing from these baseline settings by testing on a turn track, as follows:

• Bike tends to understeer
o Forks compression too soft
o Forks rebounding too slowly
o Shock compression too stiff
o Shock rebounding too quickly
• Bike tends to oversteer
o Forks compression too stiff
o Forks rebounding too quickly
o Shock compression too soft
o Shock rebounding too slowly
• Front end washes out
o Forks compression too stiff
o Forks rebounding too quickly
o Shock compression too soft
o Shock rebounding too slowly
• Front end tends to climb out of ruts
o Forks compression too stiff
o Forks rebounding too quickly
o Shock compression too soft
o Shock rebounding too slowly

There is more than one way to get where you need to be. So...say you have determined a baseline...and you are still getting corner entry push / understeer. There are all sorts of combos to solve your problem, and not make other things worse.

For instance...you can reduce fork rebound damping, and reduce shock LS compression.

You may find however, that increasing fork compression and adding shock rebound works better.

There are endless combos... Sometimes you solve one problem...but create another. Sometimes you solve one problem...and make performance elsewhere BETTER...which is sweet.

I have found that if you get a bike working really well on flat lower to med grip corner (NO ruts)...it will be pretty everywhere on the track.




This is SO HELPFUL. Thank you! Question: “• Front end tends to climb out of ruts” — “forks rebounding too quickly” — do you mean the...

This is SO HELPFUL. Thank you!

Question: “• Front end tends to climb out of ruts” — “forks rebounding too quickly” — do you mean the rebound clickers are backed out too far (counterclockwise) or tightened too much (clockwise).
 

I’m asking for my 23 KTM 250 SXF with XACT Air forks. Rebound adjusted on bottom of right fork leg and compression is on the top. Air pressure is on the left fork. 

I don’t know your forks, but read the manual to see which one slows down the rebound. Turn it one or two clicks at a time to see what it does. Also maybe a little less air in the forks. 
 

 One reason your bike is climbing out of ruts is because the forks are not coming down in the stroke. It could also be the sag is to low. 
 

 I’d set the sag and then mess with the rebound.  

3/26/2023 1:00pm
UpTiTe wrote:
I don’t know your forks, but read the manual to see which one slows down the rebound. Turn it one or two clicks at a time...

I don’t know your forks, but read the manual to see which one slows down the rebound. Turn it one or two clicks at a time to see what it does. Also maybe a little less air in the forks. 
 

 One reason your bike is climbing out of ruts is because the forks are not coming down in the stroke. It could also be the sag is to low. 
 

 I’d set the sag and then mess with the rebound.  

Thank you so much!! I’m tracking now 🙌🏽🙌🏽🙌🏽

3/26/2023 1:39pm Edited Date/Time 3/26/2023 1:43pm

I was having a lot of trouble with my '16 KX250f awhile back and I couldn't tell if it was "push" or "slide".  In other words.... too much weight on the front can make the front skid out because it can't handle the traction.  Too little can make it actually slide because it's not biting.  It's hard to tell which is which when you're trying to turn and all of a sudden find yourself eating dirt. 

What I did was ride around the track and sit WAY forward with a lot of weight on the front.  This made it much, much worse and I could barely turn at all.  So, then I sat way back and I was amazed at how well it was turning.  Obviously, I don't want to ride that way, but it told me that I had too much weight on the front.  So, I checked all my settings (which I should have done FIRST) and I found that my sag was 95 mm.  I set it to 105 mm and ta-da.... absolutely transformed that bike.  I also learned a technique that I've used lots of times since to help decide if the front is actually sliding because it's not biting or sliding because it can't handle the traction. 

You can test this while riding the circle as described in the previous post, too. 

In a related thing... I was riding the '19 KTM 150sx on a MX track and was getting bounce-back on jumps.  Just a little but just enough that it bothered me.  So I slowed the rebound down 2 clicks and not only did it fix the bounce back but all of a sudden the bike was just GLUED to ruts in turns.  I mean, I thought it was pretty good before but with 2 clicks slower rebound, then it REALLY turned.  So, don't be afraid to play with clickers. 

1

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