Author Topic: Reducing Seat Height on 2005 KX125  (Read 11789 times)

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Offline bouillion

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Reducing Seat Height on 2005 KX125
« on: March 14, 2011, 02:29:44 PM »
Anyone have experience lowering the seat height on a KX125?  Thinking of lowering my KX125 / KDX Hybrid for my daughter to race hair scrambles, how easy is it?

Thanks :?

Offline KXcam22

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Re: Reducing Seat Height on 2005 KX125
« Reply #1 on: March 14, 2011, 03:13:59 PM »
Very Easy. The rear suspension dogbones are easy to fabricate.  Making some longer ones will lower the seat.  I used a pair of  1"x 3/16" steel flatbar pieces last time I did one.  For kids it is only a temporary thing so you dont have to worry too much about making them pretty or light.  You will need to buy a metric drill to do it right. Hope this helps. Cam. 

PS  front takes more work if they are inverted forks. Other wise you can slide them up in the clamps.

Offline suicyde

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Re: Reducing Seat Height on 2005 KX125
« Reply #2 on: March 14, 2011, 04:35:07 PM »
another not so easy way is to cut the subframe, 1 inch is usually the limit to keep all the airbox etc fitting like stock.

you can also remove the seat cover and use an electric carving knife to shave down the seat foam. use a sharpie to outline how low you want to cut and get to it. just a few ideas.....

Offline PowerFiend

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Re: Reducing Seat Height on 2005 KX125
« Reply #3 on: March 15, 2011, 07:30:37 AM »
The 2003 seat is 8mm lower. I have one if interested.

Offline stevea100m

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Re: Reducing Seat Height on 2005 KX125
« Reply #4 on: March 15, 2011, 03:34:37 PM »
one thing you can do that the pros do is to lower the subframe. cut the lower tabs loose and take out the desired amount then re weld it back on. A good friend of mine did this for his son and it worked great

Offline The Flyin Hawaiian

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Re: Reducing Seat Height on 2005 KX125
« Reply #5 on: March 15, 2011, 04:23:13 PM »
The best way to do it is to send it to a reputable suspension shop and have it lowered. They put in travel limiters and revalve/respring the forks and shock to suit her better. My girlfriend has had all of her KX250s lowered 1". We just had her little sisters KDX200 lowered 1.5". We initially lowered the KDX by sliding the forks up and loosening up the shock spring. This made for a evil handling bike. She also races hare scrambles. If she is going to race it do it right! Not sure where your located but WER (Works Enduro Rider) in Northern NJ does our suspension.
A couple of 03 and 04 KXs, a few YZs, 3 PE 400s, a DR and a TS.

Offline bouillion

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Re: Reducing Seat Height on 2005 KX125
« Reply #6 on: March 16, 2011, 11:14:42 AM »
The best way to do it is to send it to a reputable suspension shop and have it lowered. They put in travel limiters and revalve/respring the forks and shock to suit her better. My girlfriend has had all of her KX250s lowered 1". We just had her little sisters KDX200 lowered 1.5". We initially lowered the KDX by sliding the forks up and loosening up the shock spring. This made for a evil handling bike. She also races hare scrambles. If she is going to race it do it right! Not sure where your located but WER (Works Enduro Rider) in Northern NJ does our suspension.

Since she would be riding hare scrambles I believe your advice may be the best route to go.  I'm located in South Louisiana and there are a couple of local suspension shops not too far away.

Thanks

Offline PowerFiend

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Re: Reducing Seat Height on 2005 KX125
« Reply #7 on: March 17, 2011, 07:21:25 AM »
How tall is she and what is her inseam? She may just need to do some minor things if she is not under 5'6" and/or short of inseam.

If she is 5'6" or taller: have the bars been adjusted closer and of the right height? Have the springs and sag been set right? Shaved seat?

The shorter subframe and lowering links will bring the tire closer to the rear fender when bottoming, and there isn't a ton of clearance stock.

I would recommend a max of 1" shorter travel, and make sure the shop knows what they are doing.

An extreme case was a guy that shaved the seat, lowered the bike 1", and also ran 19/16 wheels. I think his wife was like 5'2".

I personally would recommend a KX100 if she is 5'4" or shorter and a new rider. The smaller size and weight gives them more confidence.

Offline bouillion

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Re: Reducing Seat Height on 2005 KX125
« Reply #8 on: March 17, 2011, 02:28:38 PM »
How tall is she and what is her inseam? She may just need to do some minor things if she is not under 5'6" and/or short of inseam.

If she is 5'6" or taller: have the bars been adjusted closer and of the right height? Have the springs and sag been set right? Shaved seat?

The shorter subframe and lowering links will bring the tire closer to the rear fender when bottoming, and there isn't a ton of clearance stock.

I would recommend a max of 1" shorter travel, and make sure the shop knows what they are doing.

An extreme case was a guy that shaved the seat, lowered the bike 1", and also ran 19/16 wheels. I think his wife was like 5'2".

I personally would recommend a KX100 if she is 5'4" or shorter and a new rider. The smaller size and weight gives them more confidence.


No she is tall for a girl in my opinion, just under 5'8".  She is riding a KX100 with 3-1/2 bar risers on now. its the seat to foot peg distance that makes the 100 too small, otherwise she loves the smaller size and weight.  The 125 at its stock height is just a little too tall in that she is not confident.  When it tilts on her she has a hard time holding it up.  What are my options with the springs and sag for dropping the overall height at least an inch? How difficult?  I really never messed with suspension adjustments so I had no experience.  I just hate to shave the seat and make it any harder on the butt end than it is now!

Offline PowerFiend

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Re: Reducing Seat Height on 2005 KX125
« Reply #9 on: March 18, 2011, 05:41:05 AM »
How tall is she and what is her inseam? She may just need to do some minor things if she is not under 5'6" and/or short of inseam.

If she is 5'6" or taller: have the bars been adjusted closer and of the right height? Have the springs and sag been set right? Shaved seat?

The shorter subframe and lowering links will bring the tire closer to the rear fender when bottoming, and there isn't a ton of clearance stock.

I would recommend a max of 1" shorter travel, and make sure the shop knows what they are doing.

An extreme case was a guy that shaved the seat, lowered the bike 1", and also ran 19/16 wheels. I think his wife was like 5'2".

I personally would recommend a KX100 if she is 5'4" or shorter and a new rider. The smaller size and weight gives them more confidence.


No she is tall for a girl in my opinion, just under 5'8".  She is riding a KX100 with 3-1/2 bar risers on now. its the seat to foot peg distance that makes the 100 too small, otherwise she loves the smaller size and weight.  The 125 at its stock height is just a little too tall in that she is not confident.  When it tilts on her she has a hard time holding it up.  What are my options with the springs and sag for dropping the overall height at least an inch? How difficult?  I really never messed with suspension adjustments so I had no experience.  I just hate to shave the seat and make it any harder on the butt end than it is now!

She is plenty tall enough to be riding the bike with stock height suspension. If you lower it it will be harder to put it back to stock once she gets better.

I'll see if I can get a pic of the 2003 seat I have to show how they look. The older seat is shorter and rounded more across the top, so it allows you to get your legs down but still has plenty of padding.

The stock suspension is probably to stiff for her, not letting her weight naturally lower the bike down to get proper sag. According to RaceTech the stock bike rear spring is good for a 195lbs rider.  :-o Fork springs are good for about 165lbs with stock tank or around 145-150lbs with large tank.

Check the for sale area for a large tank for that bike.  :-D
« Last Edit: March 18, 2011, 05:45:38 AM by PowerFiend »

Offline PowerFiend

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Re: Reducing Seat Height on 2005 KX125
« Reply #10 on: March 18, 2011, 05:55:52 AM »
Just to get her started try sliding the forks up in the clamps a 1/2in. and run 4.5in. rear sag. That should give her a bit more confidence.

Going from a short bike to a tall bike is often hard at first, until they master the slide off one side to get a solid leg down.

Have her practice straddling the bike with one foot planted and only her opposite thigh/butt weighting the bike seat. She should have her planted foot angled out slightly and be leaning with her weigh onto the bike seat. With a proper rear spring this is achievable.

If she still complains, remind her that she is at least 2 inches taller than Carmichael, and Stewart.  :-D

Offline PowerFiend

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Re: Reducing Seat Height on 2005 KX125
« Reply #11 on: March 18, 2011, 06:09:43 AM »
Oh, I may have a better spring for you also. My 03 is showing as a 4.8kg, where the 05 has a 5.1kg.

I should have a new seat cover for the 03 seat, and would possibly be willing to make a trade for your seat and spring.  :-D

Offline bouillion

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Re: Reducing Seat Height on 2005 KX125
« Reply #12 on: March 18, 2011, 12:01:17 PM »
Just to get her started try sliding the forks up in the clamps a 1/2in. and run 4.5in. rear sag. That should give her a bit more confidence.

Going from a short bike to a tall bike is often hard at first, until they master the slide off one side to get a solid leg down.

Have her practice straddling the bike with one foot planted and only her opposite thigh/butt weighting the bike seat. She should have her planted foot angled out slightly and be leaning with her weigh onto the bike seat. With a proper rear spring this is achievable.

If she still complains, remind her that she is at least 2 inches taller than Carmichael, and Stewart.  :-D

She is really not complaining I'd  just really like to get rid of the 100 and see her race the hybrid which is better suited for hare scrambles. This is her on the KX before we installed the KDX motor.  I think I'll try sliding the forks and adjusting the rear sag first.

Offline PowerFiend

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Re: Reducing Seat Height on 2005 KX125
« Reply #13 on: March 18, 2011, 08:01:51 PM »
That fits her perfect, just get the suspension dialed for her light weight. She looks all of a buck ten.

Offline suicyde

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Re: Reducing Seat Height on 2005 KX125
« Reply #14 on: March 19, 2011, 04:36:45 AM »
That fits her perfect, just get the suspension dialed for her light weight. She looks all of a buck ten.

I agree, don't lower the suspension for her, she looks perfect for the bike. get it tuned.