KX Riders

Maintenance & Technical => KX500 Steel Frame Conversion (SFC) => Topic started by: Enginerd on December 16, 2010, 08:01:18 AM

Title: 2005 KX 125 frame - will it work?
Post by: Enginerd on December 16, 2010, 08:01:18 AM
Hi guys,

Has anybody used a 2005 KX125 frame for a 500SF conversion? 
Is the 125 frame enough smaller than the same year KX250 frame that it won't allow the 500 engine to fit?

Thanks,
Gary
Title: Re: 2005 KX 125 frame - will it work?
Post by: jonny500 on December 16, 2010, 08:25:29 AM
any thing is possible. my first thought is that it will be tough, major mods to the cradle if not complete renew. my advice is to use 250, 250f . + there are some builds on here you could follow, never seen a 125 conversion though
Title: Re: 2005 KX 125 frame - will it work?
Post by: Enginerd on December 16, 2010, 08:37:42 AM
Any thing is possible. My first thought is that it will be tough, major mods to the cradle if not complete renew. My advice is to use 250, 250f . + there are some builds on here you could follow, never seen a 125 conversion though.
I hadn't seen a 125 done either, and I assumed that was because the cradle was small and would need major re-working. 
I only asked because I have access to a 05 KX125 that is in really nice shape, for a good price. 

I've read many of the 500SF build threads in here, and for the most part, they are all really good.

Thanks!
Title: Re: 2005 KX 125 frame - will it work?
Post by: jonny500 on December 16, 2010, 08:46:05 AM
i am part way through 1 at the moment heres my thread http://www.kxriders.com/forums/index.php/topic,8032.msg64561.html#msg64561
i pick the 99-02 250 as it looked the cheapest and easiest
Title: Re: 2005 KX 125 frame - will it work?
Post by: Enginerd on December 16, 2010, 09:19:33 AM
I picked the 99-02 250 as it looked the cheapest and easiest.
I agree, and they are a great looking bike too.  I can usually find frames on Ebay, but I can't afford to build a complete bike out of Ebay parts, or I'd have $7,000 into the conversion.  :roll:
I need to find a good roller, or even a complete bike nearby, but I'm not having much luck.

I'll check out your build thread!  Thanks!
Title: Re: 2005 KX 125 frame - will it work?
Post by: jonny500 on December 16, 2010, 09:27:37 AM
where are you
Title: Re: 2005 KX 125 frame - will it work?
Post by: PowerFiend on December 16, 2010, 09:51:22 AM
I have an 03 KX125 as my starting point, you will need a 250 cradle. The 125 cradle where it angles up just after the lower engine mount hits the cases by the ignition.

I got an older 250 frame (they are cheap) for a donor cradle, I think it is a 96/97, but anything from 98-2002 will also work.

As long as the cradle mounts to the main frame like the 125 you are good, here is one like I got:
http://www.bikepics.com/pictures/1541526/ (http://www.bikepics.com/pictures/1541526/)
Title: Re: 2005 KX 125 frame - will it work?
Post by: ZETTNORCAL on December 16, 2010, 10:23:54 AM
ENGINERD, a 125 frame would work just fine, you would have to replace the whole engine cradle though.

Tell you what,......    If you buy my 500 engine that is for sale......I will chop out the whole cradle from the 500 and send it to you.
Title: Re: 2005 KX 125 frame - will it work?
Post by: don46 on December 16, 2010, 10:36:15 AM
I would find somebody that can bend tubing and have them bend you some new rails similar to what Jfab is doing with the Aluminum should be quite easy.
Title: Re: 2005 KX 125 frame - will it work?
Post by: Enginerd on December 17, 2010, 04:33:17 AM
Tell you what,......    If you buy my 500 engine that is for sale......I will chop out the whole cradle from the 500 and send it to you.
NICE!  Then I could use either a 125 frame, or an 04/05 250F frame like you did.
Title: Re: 2005 KX 125 frame - will it work?
Post by: Enginerd on December 17, 2010, 04:33:50 AM
Where are you?
I'm in Wyoming, U.S.
Title: Re: 2005 KX 125 frame - will it work?
Post by: jonny500 on December 17, 2010, 05:32:02 AM
i dont know why but i though you were in the uk.
Title: Re: 2005 KX 125 frame - will it work?
Post by: don46 on December 17, 2010, 06:15:46 AM
if you can find a 250 frame its almost plug and play, no frame mods
Title: Re: 2005 KX 125 frame - will it work?
Post by: Enginerd on December 17, 2010, 07:57:40 AM
if you can find a 250 frame its almost plug and play, no frame mods
Don,  you do mean a 250 2-stroke frame, right? 
Not a KX-F frame I assume, because they definitely require some mods.  :roll:
Title: Re: 2005 KX 125 frame - will it work?
Post by: don46 on December 17, 2010, 08:17:05 AM
I do mean a 250 2t frame, on the 99-02 that mod could be done in a day provided you have your parts.
Title: Re: 2005 KX 125 frame - will it work?
Post by: sintax on December 22, 2010, 03:06:38 PM
I can tell you its not worth the hassle to make it work.

Will it work? Of course, but it wont be easy at all. One of the really cool things about the KX250 is how nicely it fits. Its almost like it belongs in there. I remember cutting out the front mounts on my 02 KX250 frame and tossing the engine in there. I was blown away how easily it fit in there and how "right" it looked.

I had a 2004 KX125 I was going to do the swap on, but it just would have been a total PITA. Really the only way to do it would be to do a total custom fabbed cradle. From front to rear, so you're looking at setting up all 3 mounts at that point,

If the 2005 KX125 is a roller, i'd consider buying it off you. I'm looking for a 2005 KX125 roller to swap a KDX200 in.
Title: Re: 2005 KX 125 frame - will it work?
Post by: Enginerd on December 29, 2010, 04:16:16 AM
I can tell you its not worth the hassle to make it work.

Will it work? Of course, but it wont be easy at all. One of the really cool things about the KX250 is how nicely it fits. Its almost like it belongs in there. I remember cutting out the front mounts on my 02 KX250 frame and tossing the engine in there. I was blown away how easily it fit in there and how "right" it looked.

I had a 2004 KX125 I was going to do the swap on, but it just would have been a total PITA. Really the only way to do it would be to do a total custom fabbed cradle. From front to rear, so you're looking at setting up all 3 mounts at that point,
Thanks for the info.  I appreciate it!

If the 2005 KX125 is a roller, i'd consider buying it off you. I'm looking for a 2005 KX125 roller to swap a KDX200 in.
Its a complete, ridable bike that is for sale at a local shop.  If you are interested, PM me and I'll get you the information.