KX Riders

Maintenance & Technical => KX500 Aluminum Frame Conversion (AFC) => Topic started by: 570mitch on May 09, 2010, 09:16:05 PM

Title: Tarmac AF
Post by: 570mitch on May 09, 2010, 09:16:05 PM
Finally finished my Supermoto'd AF. Its a 2007 450 chassis with a 1992 500 engine. I race the bike in the UK on tarmac, so it's got a 16.5" front and 17" rear wheel.

And before you ask, yes it has got a 4 stroke silencer on at the moment. It's off a CRF250 and we wanted to see if it let the pipe breathe better. The front pipe is a CPI sand pipe off a CR. I have never heard the engine rev so high before.

Hope you all approve.


(http://i230.photobucket.com/albums/ee165/Highspeeddiesel/KX500AF/1.jpg)

(http://i230.photobucket.com/albums/ee165/Highspeeddiesel/KX500AF/2.jpg)
Title: Re: Tarmac AF
Post by: squeak on May 10, 2010, 12:58:51 AM
Very nice. I bet that's a wicked ride.  Did you build it yourself? Let's see some close up pics of the frame mods!
Title: Re: Tarmac AF
Post by: 570mitch on May 10, 2010, 01:24:48 AM
Competed on it Saturday and the power comes in with a bang, going to try and soften the bottom end a bit.

Friend of mine did all the welding and fabrication, the exhaust was probably the biggest job. He builds trials cars and was british sidecar enduro champ a few years ago, so was full of good ideas.

The best idea was for the cylinder head mount, there's a cross member linking the frame rails and all the electrics are mounted on the top. Engine comes out again tomorrow, so will take some more pics then.
Title: Re: Tarmac AF
Post by: DoldGuy on May 10, 2010, 04:03:05 AM
570,
Definetly interested in some more pics (especially the pipe)!
DoldGuy
Title: Re: Tarmac AF
Post by: Dutch-K5 Fan on May 10, 2010, 04:11:13 AM
It's a beauty Mitch!

Any idea's how you gone smooth out the power??
Maybe a old cilinder from Paul Malin :? :?

Dutchie
Title: Re: Tarmac AF
Post by: 570mitch on May 10, 2010, 05:41:07 AM
(http://i230.photobucket.com/albums/ee165/Highspeeddiesel/KX500AF/10.jpg)
(http://i230.photobucket.com/albums/ee165/Highspeeddiesel/KX500AF/9.jpg)
(http://i230.photobucket.com/albums/ee165/Highspeeddiesel/KX500AF/Photo0020.jpg)
(http://i230.photobucket.com/albums/ee165/Highspeeddiesel/KX500AF/Photo0012.jpg)
(http://i230.photobucket.com/albums/ee165/Highspeeddiesel/KX500AF/Photo0011A.jpg)
(http://i230.photobucket.com/albums/ee165/Highspeeddiesel/KX500AF/Photo0009.jpg)
(http://i230.photobucket.com/albums/ee165/Highspeeddiesel/KX500AF/8.jpg)
(http://i230.photobucket.com/albums/ee165/Highspeeddiesel/KX500AF/6.jpg)
(http://i230.photobucket.com/albums/ee165/Highspeeddiesel/KX500AF/5.jpg)

I think a v force 3 reed valve is first on the shopping list, that should help the spread of power. But we have some ideas to try on the barrel.
Title: Re: Tarmac AF
Post by: Coop on May 11, 2010, 12:42:15 AM
That's sweet.
Title: Re: Tarmac AF
Post by: demographic on May 14, 2010, 03:48:04 AM
Competed on it Saturday and the power comes in with a bang, going to try and soften the bottom end a bit.

Friend of mine did all the welding and fabrication, the exhaust was probably the biggest job. He builds trials cars and was british sidecar enduro champ a few years ago, so was full of good ideas.

The best idea was for the cylinder head mount, there's a cross member linking the frame rails and all the electrics are mounted on the top. Engine comes out again tomorrow, so will take some more pics then.

I was just going to say that the pictures looked like they were taken in the UK, looked awfully green grass :-D

Where are you based?

Title: Re: Tarmac AF
Post by: ktmdude on May 14, 2010, 05:58:53 AM
Nice job. That looks very clean and will be very fun. You mite try a heavy fly wheel weight to smooth out power.
Title: Re: Tarmac AF
Post by: 570mitch on May 14, 2010, 09:22:40 AM
I live in Cornwall in the UK and the flywheel trick sounds promising, would probably help with traction off the line also. Barrel's away at the moment having a new coating, then a Wiseco piston in going in. I've been talked ito trying a 41mm carb aswell.
Title: Re: Tarmac AF
Post by: dave916 on May 14, 2010, 10:11:27 AM
I live in Cornwall in the UK and the flywheel trick sounds promising, would probably help with traction off the line also. Barrel's away at the moment having a new coating, then a Wiseco piston in going in. I've been talked ito trying a 41mm carb aswell.
seems like your going two different directions with the flywheel weight and big carb!  think the 92 kx5 have a pretty heavy flywheel for road racing already, the kx  PV motor should have loads of low down power [compared to CR5]  due to long stroke and KIPS,  make sure you dont have any other issues with motor, ie  leaking crankcases or carb problems
nice  bike , good luck. i will try and go see u racing some time but most of the track seems  to be a long way from LONDON
Title: Re: Tarmac AF
Post by: 570mitch on May 14, 2010, 07:40:28 PM
We have all different kinds of hill climb tracks in the UK, so you need a motor to suit fast tracks and tight twisty tracks. Benny Lindberg (Bempa) has talked of an adjustable kips also in his AF conversion document. It's going to be a year of trying different engine configurations.
Title: Re: Tarmac AF
Post by: ktmdude on May 15, 2010, 05:34:38 AM
I'm not sure about a 92, but my uncle put a 13 oz fww in his 91 and he is all smiles. I have a 11 oz in my 01 250, it defiantly improves traction. The snap is not as violent, and you have less wheel spin. Of course all my experience is on the dirt. Good luck.
Title: Re: Tarmac AF
Post by: 570mitch on May 16, 2010, 07:02:03 AM
Thanks for the info KTMdude, will take note and play around with these ideas. Next event has a flat out uphill finish in 5th, hoping to pull over 100mph with the new pipe. The bike handles much better now than in the old KX5 frame. Much stiffer but steering is really precise.
Title: Re: Tarmac AF
Post by: ktmdude on May 19, 2010, 05:42:22 AM
I can't see in the pics if you run a steering damper or not. If you don't... you should. They improve your handling, the steering is much more precise. You will really appreciate it at high speed. Scotts are infinitely adjustable so you can play with at different tracks and conditions. I don't like riding without one. Check them out. I'm sure some of the guys on the circuit use them, ask them what they think. I don't know anyone that has ridden with one that didn't like them and what they do.
Title: Re: Tarmac AF
Post by: 570mitch on May 19, 2010, 08:18:03 AM
Don't run a damper at the moment, used to with the old KX frame (the old fashioned plunger type), but our tracks are pretty smooth these days.

When I get the hang of riding with the new chassis, I may start to find a I need one then. The clamps I am using are 20mm offset as opposed to the standard 24, so it steers quickly, which may upset the stability at high speed, see how next weekend goes. Some of the other boys run dampers.
Title: Re: Tarmac AF
Post by: 570mitch on June 04, 2010, 05:19:28 AM
Latest update on my AF, sorted the problem with the bottom end power, it was a badly fitting carb to airbox. Runs smooth now up through the rev range, got to keep it from wheeling now, I'm running 14/38 gearing and it's rearing up in 5th. Adding some pics from last weekends event. Only other problem I had, was the head nuts came loose and I lost some coolant.

(http://i230.photobucket.com/albums/ee165/Highspeeddiesel/KX500AF/IMGP3498.jpg)

(http://i230.photobucket.com/albums/ee165/Highspeeddiesel/KX500AF/IMGP3669.jpg)
Title: Re: Tarmac AF
Post by: Goat on June 06, 2010, 01:22:21 PM
That bike is sick! I really like the pipe. Excellent work. Would love to see some video.
Title: Re: Tarmac AF
Post by: demographic on June 12, 2010, 09:33:00 PM
I know its a bit of a trek up from Cornwall but will you be doing Barbon hillclimb up in Cumbria this year?
Title: Re: Tarmac AF
Post by: 570mitch on June 13, 2010, 02:21:20 AM
Sorry Barbon is not in the NHCA championship anymore, their decision not ours. Plus it clashes with Shelsley Walsh. Would like to have ridden this year as it's the hills 50th year.

Brilliant hill, took FTD there in 1996 on a YZ490. You will have to be content with John McGuiness I suspect. Miss the night before just as much aswell.
Title: Re: Tarmac AF
Post by: Dutch-K5 Fan on June 13, 2010, 06:27:05 AM
How much work was it to make that CPI exhaust fit on your AF?
Looks like it's made for a KX.


Dutchie
Title: Re: Tarmac AF
Post by: 570mitch on June 13, 2010, 07:05:46 AM
Because the expansion chamber has such a big circumferance is was hard to get the header near the exhaust port. The CR header was not cut off, just a new KX header machined, inserted and welded into place. The exhaust was then hammered / scalloped to clear the frame down tubes on both sides, but the chrome plating never flaked, so it get get closer to the port. (This may upset the exhaust experts, as it will not match the bore and stroke differences between the CR and KX, only a few mm in it though i.e. header lengths, but you got to try with hybrids). The exhaust was also hammerd in to allow for the kick start, and the stinger section was cut and re-angled, but that may not be needed for a smaller two stroke silencer. Going to put a new head gasket in soon, so could take some more pics of the pipe scallops.

The bike has had alot of admirers so far, especially the pipe.

My old KX was called Daphne after her from scooby doo, anyone got any ideas for a new name for the AF.
Title: Re: Tarmac AF
Post by: demographic on June 13, 2010, 08:58:18 AM
Sorry Barbon is not in the NHCA championship anymore, their decision not ours. Plus it clashes with Shelsley Walsh. Would like to have ridden this year as it's the hills 50th year.

Brilliant hill, took FTD there in 1996 on a YZ490. You will have to be content with John McGuiness I suspect. Miss the night before just as much aswell.

Not in the NHCA anymore?  The Numpties :-(

John McGuiness was there last year on this CR450F.
(http://i583.photobucket.com/albums/ss276/demographic01/Bike%20stuff/DSC00868-1.jpg)
Along with his TT bike, seen here with a pair of keks draped over it. That wasn't racing up the hill though as I doubt it would do so well.
(http://i583.photobucket.com/albums/ss276/demographic01/Bike%20stuff/DSC00844.jpg)

I was hoping to see you and you're bike as I pretty much always watch Barbon (well, to be honest I usually just take photos of the bikes in the paddock area) these days.
Title: Re: Tarmac AF
Post by: 570mitch on June 13, 2010, 09:45:26 AM
I remember Barbon in 97, my first year on the KX, a certain Paul Bird beat me on a CR500 in a CR250 frame, a very early CR AF, but he did use tyre warmers. We banned them years ago. He offered me his old CR a very quick bike, but I stuck with the Kwacker.

Just looked at the Westmorland Club website and the KTM supermoto team are going and possibles are McGuiness, Hutchinson and Knightor. We used to to another event in the midlands the day after, that made the 400 mile trek north worthwhile, cost me two tank fulls of diesel, how much is that now!!!!!
Title: Re: Tarmac AF
Post by: demographic on June 15, 2010, 07:24:51 AM
I remember Barbon in 97, my first year on the KX, a certain Paul Bird beat me on a CR500 in a CR250 frame, a very early CR AF, but he did use tyre warmers. We banned them years ago. He offered me his old CR a very quick bike, but I stuck with the Kwacker.

Just looked at the Westmorland Club website and the KTM supermoto team are going and possibles are McGuiness, Hutchinson and Knightor. We used to to another event in the midlands the day after, that made the 400 mile trek north worthwhile, cost me two tank fulls of diesel, how much is that now!!!!!


I think Paul Bird still has the record for two wheelers up there, I didn't know it was with tyre warmers though. That explains a bit.

He was there with his WSB Kawasakis last year but they were just parked up so people could see them, I took masses of pictures of all manner of trick details on them.
(http://i583.photobucket.com/albums/ss276/demographic01/Bike%20stuff/DSC00814.jpg)
(http://i583.photobucket.com/albums/ss276/demographic01/Bike%20stuff/DSC00822.jpg)
(http://i583.photobucket.com/albums/ss276/demographic01/Bike%20stuff/DSC00821.jpg)
(http://i583.photobucket.com/albums/ss276/demographic01/Bike%20stuff/DSC00829.jpg)
(http://i583.photobucket.com/albums/ss276/demographic01/Bike%20stuff/DSC00824.jpg)

Sorry, I know its a thread about your bike, its just that I love Barbon.
Title: Re: Tarmac AF
Post by: 570mitch on June 15, 2010, 07:45:22 AM
That's OK, gives the sport some coverage, I love Barbon aswell, my father used to have the 500cc record there in the 70's, I had it in 96, Paul Bird did take in in 98 (not 97) on Tyre Warmers, he rode again in 99 and I beat him on cold tyres. Wouldn't mind some of those trick bits from Birdy on my bike though.

Just for the KX boys I have added a pic of my K5 before it was converted to an AF
(http://i230.photobucket.com/albums/ee165/Highspeeddiesel/kx.jpg)
Title: Re: Tarmac AF
Post by: demographic on June 15, 2010, 10:07:12 AM
There's a bloke who used to race up there on an ex factory SR500 which were the factory versions of KX500s.
Think it was an old Dave Thorpe bike.

I take it your 500 was about a 91 model? Looks like it by the forks.
What time did you get up the hill?
I never went till a lot later so never saw yours.
Title: Re: Tarmac AF
Post by: 570mitch on June 15, 2010, 10:29:08 AM
My best was 26.44, other KX riders there were birdy before the CR and a guy called Neil Hutchinson. I think the last time I was there was 2002. Had a few years off, just doing the odd south western event, but the new bike has renewed my enthusiasm. Trouble is these 4 strokes are quick know, but I like something different. My bike was a 92. There is a very sorry looking chassis in the corner of the garage now without an engine.
Title: Re: Tarmac AF
Post by: demographic on June 16, 2010, 10:17:47 AM
My best was 26.44, other KX riders there were birdy before the CR and a guy called Neil Hutchinson. I think the last time I was there was 2002. Had a few years off, just doing the odd south western event, but the new bike has renewed my enthusiasm. Trouble is these 4 strokes are quick know, but I like something different. My bike was a 92. There is a very sorry looking chassis in the corner of the garage now without an engine.

26.44, well done that man.

Pretty sure this is (or was cos he's got a four stroke now)  Neil Hutchinsons bike.
That's the ex works bike I was on about with the posh clutch cover, I spoke to him that when I took the pic and IIRC he said it was a Dave Thorpe SR500 bike but had since been sleeved and re-bored to about 508cc.

I think the spannie looks a bit trick too.
(http://i583.photobucket.com/albums/ss276/demographic01/Bike%20stuff/KX508withSRenginerightside.jpg?t=1276726373)
(http://i583.photobucket.com/albums/ss276/demographic01/Bike%20stuff/KX508withSRenginerightsidecloser.jpg?t=1276726422)
Title: Re: Tarmac AF
Post by: 570mitch on June 16, 2010, 07:07:48 PM
Yes I remember that bike, it is Neil's , you can see the Hutchcoat sticker on the silencer, he's got a 509cc (I think) CRF now.

Im doing Loton Park near Shrewsbury on the 10th July if that's not too far for you, failing that I'm thinking about doing Harewood neat Leeds on the August Bank Holiday, all my other events will be down south, bit nearer home.

Added a pic of me on my old YZ490 taken at Barbon in 1996, the year I took FTD
(http://i230.photobucket.com/albums/ee165/Highspeeddiesel/1996MitchellBarbon.jpg)
Title: Re: Tarmac AF
Post by: bike_boy_england on June 17, 2010, 06:20:21 AM
i have neils old bike now, i bought it off a guy in swindon in november last year, although it did'nt come with the aluminium tank. the pics are in the gallery of what it is now like, although for some reason i cant access it?
Title: Re: Tarmac AF
Post by: 570mitch on June 17, 2010, 09:07:04 AM
Hi Bike Boy, are you gonna keep the bike as it was or convert it back to mx, quick bike for hill climbing (UK style).
Title: Re: Tarmac AF
Post by: bike_boy_england on June 18, 2010, 12:06:01 AM
the bike was a little tatty when i got it, i have had the frame powder coated black, and have replaced all he plastics with black ufo, a large clarke tank, and a new pro circuit pipe. i have put lights on it and intend to get a full mot and use it for street use. i havent been on bikes for a few years and have always wanted a 500 two stroke motard. i want to get into the hill climb scene but i think i need to get my bearings on the bike before i go doing anything drastic! like i say, i created a user gallery but for some reason it has dissapeared?. your bike is awsome by the way! regards alex
Title: Re: Tarmac AF
Post by: Danger4u2 on June 18, 2010, 01:59:50 AM
I'm having problems with the gallery, might have to remove it and start over.
I have found where members have supplied a link in there post and clicked on their link and gained access to the gallery.
Title: Re: Tarmac AF
Post by: 570mitch on June 18, 2010, 08:30:32 AM
If you are near a hillclimb Alex come along and have a look, there are all standards racing. We are over run with CRF's and KTM's, there are only a couple of us greenies.
Title: Re: Tarmac AF
Post by: bike_boy_england on June 18, 2010, 09:04:03 AM
i am definately going to barbon, harewood and scarbrough as they are all pretty close to me. i hope to see you at harewood. danger, you do a great job with this site. im sure this will get resolved. alex