CRF650X pictures - No Kidding!!!
Posted September 20, 2006 - 05:54 PM
275 lbs with all fluids but no gas.
Here's the short list of changes:
-- CRF forks, both wheels, swingarm and side panels.
-- CRF 450 swingarm is upside down and fitted to a custom Ohlins shock.
-- No linkage, KTM style suspension.
-- Front and rear fenders and skid plate trimmed to slim down and remove bulk
-- Stock pipe shortened 3 1/2 inches and angled upward.
-- Airbox removed and replaced with "pod" type filter
-- Custom aluminum and plastic filler panels to replace airbox.
-- Halogen 55 watt driving light embedded in CRF number plate.
I'm fine tuning spring rates and valving now, but its already much improved. Imagine losing 25lbs or so where it counts! The frame and engine are stock, so most of the weight loss is at the ends with less unsprung and rotating mass. The CRF rear sidepanels realy slimmed down the bike and it feels totally different,.. like a CRF450 on nitrous
Posted September 20, 2006 - 06:20 PM
Posted September 20, 2006 - 06:23 PM
Posted September 20, 2006 - 06:36 PM
Posted September 20, 2006 - 06:49 PM
I thought the CRF forks would cause the frame to crack from them being so rigid?
Not what a CRF650 looks like in my mind, but looks like a fun project.
Posted September 20, 2006 - 07:06 PM
I wouldn't call a KTM suspension a step backwards. Linkage systems have devolved into almost a straight rate over the years. The little bit of rising rate at the very end is mostly good for bottoming resistance,.. great for supercross, not so important for dual sport. I actually had the CRF linkage on there but opted for the simpler, lighter, less maintenance no-linkage system.
I won't miss the couple pounds of weight and $150 worth of bearings and seals during rebuild time. The Ohlins has a PDS feature like KTM that makes damping increase at the end of travel like a linkage, and the shock geometry actually has a decent rising rate just like a KTM.
I predict linkages will get less popular for some types of riding. You have to love the no lube teflon rod ends and ability to pull the shock out in one minute.
Posted September 20, 2006 - 07:12 PM
I wouldn't call a KTM suspension a step backwards. ...
I predict linkages will get less popular for some types of riding.
KTM will be going back to linkage soon...they took steps backwards from their original linkage designs to a non linkage and will be switching back.
Either way...I want to see a 650 motor with e start slapped in a crf450 frame with a license plate... that will be the crf650 that will sell like hot cakes.
Posted September 20, 2006 - 09:17 PM
It is a "C" version, which means it was manufacutred in mid 2002.
They were slightly redesigned to the "D" version, but only a nerd like me would know something like that.
Posted September 21, 2006 - 03:16 AM
Good job, whereabouts in Michigan are you?
Posted September 21, 2006 - 08:04 AM
That's K-marts best 99 cent bicycle mirror. Not very usable, but legal. The headlight is single bulb but I have a dual pole switch marked Hi-Lo so the light flickers when I switch it. The cops always fall for that one.
I'm in Lake Orion MI. about 40 miles north of Detroit. I fussed with it all summer and actually grafted the CRF linkage and shock on first but never rode it that way. It was hard to get the chain, shock and wheel to be where I wanted and would have required that I lace the rear wheel over 1/2 in. I flipped the swingarm upside down and everything lined up and matched KTM geometry prety close. I bought 25 new Cannondale Ohlins shocks at a swap meet. I had to mix parts from a bike and quad shock to get the right length.
Only 200 miles so far. Its way oversprung on the rear but still tracked straighter through the whoops than stock. The balance on the scales is exactly 50/50 and it works better in tight woods than expected. The rear is a little higher now and I run the forks up in the clamps so it steers better in singletrack, but the swingarm is an inch longer and the steering damper make it more high speed stable than before. Wow.. more stable at speed and better turning, I can live with that.
It just feels slimmer and lighter. The real bulk is down low and less weight on the two ends now makes it easier to toss around for sure. It will take a few tries with springs and shock valving to perfect, but its got me smiling already
Posted September 21, 2006 - 12:07 PM
Posted September 21, 2006 - 01:43 PM
Posted September 21, 2006 - 03:06 PM
I admit, its something that you would expect to find in the honda prototype garage.
Why did you not just buy a crf 450r and put nitrous on it, and double your life insurance, I guess all that tooling around in the shop is kind of fun. huh!!! I can relate to the but I did it myself thing. but to call it crf650x, noway, more like woodsy650r, although it would probably do well on an eighth mile dragstrip, with a extended swingarm and some slicks. Just kidding, good job keep working on it dont never stop, its half the fun, God bless you!
Posted September 21, 2006 - 05:11 PM
Potts-- The steering stem length was good and the bottom bearing was the same. The top bearing has the same ID but a much smaller OD on the CRF. You can buy custom odd size bearings from All Balls Racing, but they could only get me down to 47mm. I made a holding fixture and turned down the bearing OD another 1mm with carbide tooling on the lathe. This left a knife edge at the top of the tapered bearing cup. I heated the frame and froze the bearing so it dropped in since there was no surface to push it in with. The XR has almost 1/2 inch of meat around the bearing so the thin top edge is well supported. Then you have to remove a huge hunk of extra aluminum on the front of the XR frame. Luckily the steering stops worked out perfect. Other than that it dropped right in
As far as time, many hours, mostly planning. I wasted a good 40 hrs getting the 450 linkage worked out before I abandoned it, flipped the swingarm over and went linkless. The geometry is within 2mm of KTM, BUT there isn't room for the length of a KTM shock unless I reworked the top shock mount (very difficult)
The deciding factor to go linkless is when I found new surplus cannondale Ohlins shocks which were the perfect length and made for linkless. I have no reference for valving, but got some idea of spring rates from KTM data. The leverage ratio is not as severe as cannondale, so I lightened the valving a bit and got close, it will take more revisions though. I have more shocks so I can re-work two and swap back and forth. The C'dale springs are too stiff so I took one and ground down the OD until the sags were right. Now I'll try it out, then have the spring rate checked and get a new spring to match.
Money wise it was cheap, I got $1000 for the XR wheels and forks so the parts washed out. I paid $45 each for new ohlins shocks!! and made everything else. The bike only cost $4500 new, so it was a bargain if you don't count my labor, or a fortune if you do
I'll post more pics in a few minutes.
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