Chain eating the subframe!

WR450 '05 model

New O-ring chain and high quality sprockets, correct chain tension of 40-50mm measured from the screw in the chain schain is still "wandering" side-to-side with enough force to grind the sub-frame? &%$#@!!

A quick search revealed a few others with this problem but no real fixes.

I tried a ty-wrapped an old reinforced fuel line tube on the subframe but the chain soon wore thru that.

Alignment looks OK when a straight edge is set along the swingarm as do the chain adjusting blocks.

I've never seen so much side-to-side motion with a new chain, anyone any ideas as to the best fix other than increasing the tension and risking damaging the the countershaft?!!

Happens to all of 'em. Not much can be done. It shouldn't do enough damage to destroy the subframe.

with tears in my eyes it does the same to my aluminium frame on my '07, same answer applies sh#t happens.

Cheers

Muz

:thumbsup::busted::thumbsup:

Take an old swingarm slider and cut it to fit the lenght of the subframe and zip tie or clamp it at both ends and the chain will just glide off of the plastic that was designed to take chain abuse. :thumbsup: WR Dave.

WR450 '05 model

New O-ring chain and high quality sprockets, correct chain tension of 40-50mm measured from the screw in the chain schain is still "wandering" side-to-side with enough force to grind the sub-frame? &%$#@!!

A quick search revealed a few others with this problem but no real fixes.

I tried a ty-wrapped an old reinforced fuel line tube on the subframe but the chain soon wore thru that.

Alignment looks OK when a straight edge is set along the swingarm as do the chain adjusting blocks.

I've never seen so much side-to-side motion with a new chain, anyone any ideas as to the best fix other than increasing the tension and risking damaging the the countershaft?!!

How about using a length of bicycle tire (road bike tire - the natural curve should wrap around the frame perfectly) zip-tied or clamped to the subframe. And keep replacing it as it wears.

Your wasting your time with aluminum, rubber, or anything less then Stainless. Simply bend it into a semi U shape to fit over your tape protected sub frame and zip tie it in place with grooves cut in the top and bottom. Will last 10 times longer then anything else (that you can actually form to fit). Then just have someone weld a new layer as it wears/dents through because it will. What a *****ed up joke and Yamaha won't do anything about it.

Could email some pics of my NR set up with less then 1000 miles on it. I will be sending it in with a bud to have a new wear plate welded on it this week.

I havent had that problem since i adjusted the chain tension to the right amount - dunno if thats the same as the manual says it should be but its not too tight and its not loose enough to rub on the subframe.

Also my o-ring chain was new and i had to adjust it about 6 times and now it has stopped stretching and is perfect and doesnt rub.

What's the root cause of the problem?

I cant understand why there is so much sideways motion in the first place, its not as if the chain length is excessive.

Is it related to the torque on the 450's or do the 250's have the same problem?

Could someone post a picture of the sub-frame damage? I am curious to know where the damage is occuring. Can you hear the chain hitting the sub-frame when riding? Does it sound different then when the chain is slapping the swing arm? What brand of chain and sprokets are you using when this problem started? Does it occur on the first riding after making the change or is the chain and sproket broke in before it starts to happen. i.e. after the first couple of adjustments?

Again just curious.

wingnut16

Proper chain tension will cure 95% of the problem. When your rear suspension compresses and extends, the chain slack also changes. If things aren't properly adjusted, you'll have issues. Chain "stretch" isn't exactly stretch like a rubber band. It happens as the rollers and sprocket teeth wear and develop more slop between the mating points. Hard on and off throttle and lots of suspension movement is what creates it. It's built into the system until you get to a cerain point where the wear necessitates replacement. Follow the manual and you should be fine...SC

It has nothing to do with proper chain tension on most bikes. Yes if you are way out of spec it will happen on any bike. I had mine so tight the dealer freaked and said I would bust my counter shaft. That was after I showed him the chain was still hitting just riding around the shop and had him check the tension. He was telling me it was my fault for not having proper chain adjustment. After having to stumble on his words for a while his final reply was well we have checked everything and nothing is wrong and Yamaha says they have never had this problem before. You can not miss where it his the sub frame because it will be chewed to hell about 1-3 inches above the slider.

I beg to differ...like I said proper chain tension will take care of the large majority of the issue, but there will always be a little. I check my tension all the time and my chewage has pretty much stopped. Mine chain isn't tight and it isn't loose, it's like Goldilocks...just right. Taking your bike to a dealer isn't the best idea when it comes to getting advice. Most dealers don't have clue one. My first clue to your dealer's expertise is that he told you "Yamaha has never heard of this problem." Pure B.S., he was practicing the old technique of CYA. This problem has been around for as long as the bike has been around. Yamaha knows...SC

It has nothing to do with proper chain tension on most bikes. Yes if you are way out of spec it will happen on any bike. I had mine so tight the dealer freaked and said I would bust my counter shaft. That was after I showed him the chain was still hitting just riding around the shop and had him check the tension. He was telling me it was my fault for not having proper chain adjustment. After having to stumble on his words for a while his final reply was well we have checked everything and nothing is wrong and Yamaha says they have never had this problem before. You can not miss where it his the sub frame because it will be chewed to hell about 1-3 inches above the slider.

Identical chain wear spot, badly chewed as per dl 19.

I'll post a photie this arvo that will surprise a lot of people.

My old chain was a non-O-ring and that slapped around quite a bit.

But what was more annoying to me was that even when I fit a brand new DID O-ring chain, new supersprockets also brand new with the correct tension as per Yam manual, it make no difference!

I did some searches to see if this subframe wear happens on the yzf, and from what I can tell it doesn't. Can anybody verify this? It only seems to happen on the wr, what is the reasoning on that? :thumbsup:

Hi Guys joined this group after reading the posts on this topic. My 07 model WR was bought new in February, immediate problems (with the rectifier) meant I didnt get my new bike until mid April, however after getting home and running it in there were multiple problems so off it went again, this time back to Yamaha themselves. Seven weeks later I got it back complete with an extra 243miles on the clock (essential & rigorous testing was the explanation given!!!) following 2 hrs of use it went in for its first service. Three weeks passed, apparently because they were waiting for a screw to arrive from Japan. That was yesterday and lo & behold following a very short ride I noticed not only my subframe being eaten away but its also started on the main frame too!!

Has anyone found a solution to the problem - like the other posters my chain tension is correct, the alignment is perfect etc etc. Just 6 hours of use & 400 miles has left me with a very bad taste in my mouth. Yamaha dont want to know it seems. Do you think its worth kicking up a fuss in Japan? May I use this posting to back up my complaint/issue.

Many thanks

Al

I am sooooo p****d about all of this

Proper chain tension cured my problem too. When I first got the bike it was chewing the subframe but I haven't had a problem since I started using a little tighter spec. for the chain. Can't remember what it is right now but I made a little gauge and check it now and then. It's still plenty loose too.

The problem is chain tension and alignment, alignment primarily. Do not go by the adjuster blocks, they have been known to be off. Use the adjuster blocks to get it close (make sure you count the slashes from the rear of the block, not the front). Then measure from the swingarm pivot to the center of the axle on each side. Get these even and your chain should no longer eat into your subframe.

hey guys,

I have 2000km's on my 08 WR450F, there is no indication the chain has ever made contact with the frame ?

its my understanding the 07-08 are excatly the same ?? wonder how i don't even have a single mark... not that i am complaining...

anyone with 08 having a problem?

sorry to hear you are having it happen to you... i have seen some people do some neat tricks to compinsate.

cheers

Warts

A friend of mine cut a 4" piece of UHMW (teflon) into a channel shape for me that slides over the spot that wears. i zap strapped it in place early last year, and after 2000 plus km i still haven't had to slide it up or down. I do a Dual Sport trip each year that puts on 1100 km of backroads in four days.

I keep a pretty close eye on the chain tension as well.

Cheers

Chris.

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