Lowering a subframe

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10/25/2019 6:37 PM

I’m thinking of sending my subframe off to Trick Eng. to have the subframe off a 2019 CRF250r. Can anyone tell me what 7mm-8mm lowered will actually lower the rear end how much?

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10/25/2019 6:59 PM

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10/25/2019 9:36 PM

8mm is the thickness of the bottom bolt. Pull the bolt and shove it down to see.

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10/26/2019 4:29 AM

TJ 755 wrote:

8mm is the thickness of the bottom bolt. Pull the bolt and shove it down to see.

Love your high tech geometry problem solving laughing

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10/26/2019 4:35 AM

Just guessing but i would say an inch maybe two at the seat. Maybe more? Idk. Trick eng has done them - ask them.

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10/26/2019 6:10 AM

My question is why? Also won't that make the tire hit the fender/air box?

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10/26/2019 7:16 AM

I used to hit my fender on both KX and CR without lowering.

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10/26/2019 7:21 AM

I bought a used 2014 crf250r and the subframe was marked -3.5mm. My rear tire lightly rubbed the fender.

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10/26/2019 8:15 AM
Edited Date/Time: 10/26/2019 10:06 AM

My yzf is lowered 10mm which i belive is about a inch in seat height. Keeps the back end from hitting me in the ass. You don't realize how much a extra inch is until you have it.

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10/26/2019 8:17 AM

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10/26/2019 10:06 AM

Have you shaved/cut your seat height? I know that I have heard Chad Reed's sub frame is 10mm lower. A number of factory riders have the minimum seat foam, and lower sub frames. But the seat foam is easier and cheaper if the fit is not correct.

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David
774 CC Powersports Kawasaki
Factory Backing Factory Seat
Acerbis Dunlop
Sunstar Braking
MX Engine Stands
Matrix Concepts

10/26/2019 10:24 AM

rob162 wrote:

My yzf is lowered 10mm which i belive is about a inch in seat height. Keeps the back end from hitting me in the ass. You don't realize how much a extra inch is until you have it.

That's what she said.

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10/26/2019 2:13 PM

My CRF is so goddamn low in the rear all the time, i cant even imagine losing another inch!
Are you that short? Wouldnt a shaved seat get you low enough?

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10/26/2019 2:30 PM

wildbill wrote:

I used to hit my fender on both KX and CR without lowering.

Same here

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10/26/2019 3:01 PM

Used to do it to the Kawa 450 from 2010 and later to 2015 KTMs. Bike felt more stable and better handling. Both times the lower bolt was moved 5mm which got the rear end about 1/2 " lower.
On an aluminium subframe I closed the original holes with weld and after everything was reshaped, new holes were drilled and the overly long end of subframe was shortened by the same 5mm..Yes, the tire left marks in the fender but you would not notice while riding. With the 16 and newer KTM they got it right from the factory so no more mods needed

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10/26/2019 3:18 PM

What issue are you having that is leading you to a sub frame lowering? For most shorter riders or style/technique they are getting hit in the rear.

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David
774 CC Powersports Kawasaki
Factory Backing Factory Seat
Acerbis Dunlop
Sunstar Braking
MX Engine Stands
Matrix Concepts

10/26/2019 3:23 PM

BIGSHANEADAMS wrote:

I’m thinking of sending my subframe off to Trick Eng. to have the subframe off a 2019 CRF250r. Can anyone tell me what 7mm-8mm lowered will actually lower the rear end how much?

8mm shorter on the lower support bolt hole works out to about 1/2" at the back of the seat on most bikes.

Every bike has different angles and lengths so it's not the same for different years / makes / models.
If you measure the length of each side of the triangle formed by the subframe (hole to hole distances) I could calculate it for you.

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10/26/2019 3:33 PM

davidgrip wrote:

What issue are you having that is leading you to a sub frame lowering? For most shorter riders or style/technique they are getting hit in the rear.

Why do people make these threads then disappear?

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10/26/2019 4:23 PM

TJ 755 wrote:

8mm is the thickness of the bottom bolt. Pull the bolt and shove it down to see.

CPR wrote:

Love your high tech geometry problem solving laughing

Yea sucks to be short

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10/26/2019 4:24 PM

davidgrip wrote:

What issue are you having that is leading you to a sub frame lowering? For most shorter riders or style/technique they are getting hit in the rear.

zippytech wrote:

Why do people make these threads then disappear?

Some of us work job where we have to work nights and weekends

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10/26/2019 4:24 PM

BIGSHANEADAMS wrote:

I’m thinking of sending my subframe off to Trick Eng. to have the subframe off a 2019 CRF250r. Can anyone tell me what 7mm-8mm lowered will actually lower the rear end how much?

cwtoyota wrote:

8mm shorter on the lower support bolt hole works out to about 1/2" at the back of the seat on most bikes.

Every bike has different angles and lengths so it's not the same for different years / makes / models.
If you measure the length of each side of the triangle formed by the subframe (hole to hole distances) I could calculate it for you.

Thank you

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10/26/2019 4:25 PM

davidgrip wrote:

What issue are you having that is leading you to a sub frame lowering? For most shorter riders or style/technique they are getting hit in the rear.

Yes your right, it makes the rear end lower so it doesn’t happen as much

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10/26/2019 4:27 PM

zippytech wrote:

My question is why? Also won't that make the tire hit the fender/air box?

It Lowe’s the seat height almost all of Geico Honda’s have it done to them.

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10/26/2019 4:56 PM

I understand seat height. Just do the math. Honda CR250R seat height 37.8"- 4" sag = 33.8". Your inseam is X, average rider 30-32? If sag is set correctly. Lowering the sub frame will make the bike lower in the rear/fender-seat, Most Factory riders use the minimal seat foam. Lowering height when standing in proper riding position vs sliding off to one side. Just information to make an informed decision.

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David
774 CC Powersports Kawasaki
Factory Backing Factory Seat
Acerbis Dunlop
Sunstar Braking
MX Engine Stands
Matrix Concepts

10/26/2019 5:40 PM
Edited Date/Time: 10/26/2019 5:42 PM

BIGSHANEADAMS wrote:

I’m thinking of sending my subframe off to Trick Eng. to have the subframe off a 2019 CRF250r. Can anyone tell me what 7mm-8mm lowered will actually lower the rear end how much?

cwtoyota wrote:

8mm shorter on the lower support bolt hole works out to about 1/2" at the back of the seat on most bikes.

Every bike has different angles and lengths so it's not the same for different years / makes / models.
If you measure the length of each side of the triangle formed by the subframe (hole to hole distances) I could calculate it for you.

Just make sure "Pathagoras" here knows which hole is what.
Like with a diagram.

No slam on you, CWTOYOTA. I think you see what I'm saying.

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Go for it! Don't let a little thing like fear, or common sense hold you back.

10/26/2019 9:59 PM

You can also add height to the foot peg with TrickEng. Might give you a similar result.

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10/27/2019 1:26 PM

CarlinoJoeVideo wrote:

You can also add height to the foot peg with TrickEng. Might give you a similar result.

Yea I’m going to talk to them about that also. Thank you

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10/27/2019 2:52 PM

why would a guy named bigshane need to lower his bike?grin

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10/27/2019 3:55 PM

BIGSHANEADAMS wrote:

I’m thinking of sending my subframe off to Trick Eng. to have the subframe off a 2019 CRF250r. Can anyone tell me what 7mm-8mm lowered will actually lower the rear end how much?

Be easier just to grow longer legs 🦵

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