Xr650r Trivia

Everyone knows that the XR650R has aluminum frame. My question is what grade?? Not one dealership I phoned knew. Hmmm, Is there anybody out there that knows or do I have to get in touch with the Honda draftsmans and practice my Japanese

Sounds like you're planning on some welding.

Dave

Actually yes. My engine seized up in fifth gear two weeks ago. I took the thing apart last weekend and was horrified to see the damages. My crankcase (L and R) are both damaged beyond repair. My piston is shattered along with the connecting rod, crankshaft and shaft balancer! The only thing I've got left are about two gears. Sigh. Anyhow, I can't find a replacement engine ANYWHERE. I'm planning on making a drag bike out of it if I can't find a replacement engine. All I need to know is what grade aluminum the chassis is to weld it. If it's a 6061T6, I'll have to heat treat it once I've done building the new engine supports for the replacement engine I’ve found for the drag bike. No one seems to know LOL.

The price is insane but here is an engine. Ends in a little over 2 hours http://cgi.ebay.com/ebaymotors/HONDA-XR650-XR-650-R-XR650R-650R-ENGINE-MOTOR-KART-NEW_W0QQitemZ150148480571QQihZ005QQcategoryZ35595QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

If I had to guess it would be 6061. One thing is for sure it is a weldable alloy. It could be 7020 which doesn't really need heat treatment after welding.

Thanks! I had seen that engine but wasn't too sure about the source and the price is well you said it. My guess is also 6061 but I'd like to be sure. I'm having quite a bit of fun however calling up these dealer reps that think they know it all. It really is a tricky question ?

I'm pretty sure that seller is safe. I have bought from him before, but not a high dollar item. He buys bikes and parts them out for a profit on ebay. He has been at it for a while.

I'm leaning more in the direction of 7020 as it does not need heat treating after welding. That would result in a lot of savings for Honda. I know that 7020 is used for bike frames, but I could not find anything talking about what the XR is made of.

Really? Nice Job. By it new, take it to pieces and sell them. Why didn't I think of that ?

7020 hmmm makes quite a bit of sense. There's quite a bit of welding on that thing and I doubt that they would bother heat treating each and every frame once/twice every time they build a bike. I could always get a little sample and get it tested locally I guess. I got a few friends that work at Bombardier here in Quebec but no one I know works for Honda...

99.5% sure it is a 7000 series alloy. Honda has been having frame issues with the first few years of the new model Gold Wings, and they are having to be welded under warranty. With this procedure heat treating is not required as they are 7000 series frames. I don't see Honda from a manufacturing standpoint making some frames out of 6000 and some out of 7000. Especially as the frames have some cast sections that have to be welded together. The heat treating required for 6000 series aluminium would be very expensive on a production level.

Anyway, I have had the (un)fortune of welding on my frame, and so far no ill effects (I have broke one XR650R frame, but that is one I did not weld on).

If I remember right, this was a big debate when the '97 CRs hit the showroom floor, as everyone was afraid that they could not weld on the beer can frames. It was later determined that it was okay to weld the frames.

I would guess 7003. Medium strength Al-alloy, billets can be machined or extruded / formed into specific shapes and then welded with no post-weld HT required. At the factory it's machine welded with tight Honda-proprietary process controls.

As for hand repair welding? Definitly TIG with an Argon bath on front and rear.

Not sure what alloy but here are a couple things to look at:

http://www.springerlink.com/content/e3158730rjl26316/

http://www.sae.org/technical/papers/2001-01-1884 (7003-T4)

My guess is that it is a low 7000 series number of Casting type alumuminum with a heat treat.

The T-xxxx number is the heat treat specification after the series number. These are sometimes abbreviated like 6061-T6 = 6061 T-651. The important number is the first one after the "T". You can look these up for proper heat treat temperature curves. Also, if you perform a heat treat, monitor the frame with a thermocouple (preferably multiple locations) instead of monitoring the oven temp if you can.

I would guess 7003. Medium strength Al-alloy, billets can be machined or extruded / formed into specific shapes and then welded with no post-weld HT required. At the factory it's machine welded with tight Honda-proprietary process controls.

As for hand repair welding? Definitly TIG with an Argon bath on front and rear.

I think we have a winner. I typed "Honda Aluminum 7003" in Google and many hits came back. Honda wrote some technical papers about the 2001 Goldwing frame production process using 7003.

At Honda, the frame pieces prior to welding are at least solution HT (T4). At the factory there likely is no post weld heat treat (for XRR) and they live with localized annealing in the heat affected zone. Thus the massive XRR sections.

For manual reweld (us) no one will be re-heat treating for many reasons. Solution HT temp is on the order of 875f, Argon atmosphere (or retort) is req'd, the frame would need to be chemically stripped, check & straighten after (to what?) quench. You'd scrap your frame trying.

Would be interesting to see the process at the factory. Especially the comparison of XRR to say CRF. CRF product is weight / performance critical for competitive reasons and they likely spend extra $$ during processing.