Crf450 Chain Rubbing on Tire!

[CRF450RDR]

I have a 2004 CRF450 that I recently bought used. One day while riding I felt like the back wheel was breaking to the right when I accelerated. I checked the tire and the chain was rubbing on the knobbies on the side of the tire. I replaced the chain and sprockets, the old chain had a lot of side bend. The new chain is doing the same thing to a lesser degree, the tire is tracking fine the rim is not bent and the chain guides are within normal limits, HELP!

[NMdesertRacer]

Set the chain sag at 3/4-1" of slack like in the manual. Check the slack while the bike is on a bikestand.

[WEET]

Your chain is lose.

You need to adjust it as per your owner’s manual.

Please be aware that chains do not have uniform links.

In other words if you measure ten links in one part of the chain and then again in another part you will find a difference in the measurement. In order to compensate for this you need to turn the rear wheel until you find the tightest point and this is where you set your chain measurement from

[ty 520 ktm]

Measure the distance between the swingarm pivot bolt and the

rear axle on both sides. It should be equal and check bearings

in both area`s too.

[Ccarl]

Same thing happened to me before I realized you really do only need 3/4" clain slap for the adjustment. Ate my tire a little and my mud flap, but I learned to keep it to what I think is too tight. ?

[dirthead1]

This, the chain munching the mud flap and hitting the inside of the frame drove me nuts on my 04. Luckily this was fixed on the 05 CRF450...

[CR2CRF]

Remember folks, on the new Hondas (02-05) the chain is at it's tightest when the bike is on a stand with absolutely no sag; with the wheels off the ground. The chain gets looser as the wheel goes through the travel. To prove this, take the shock off the bike and move the swingarm through the travel. At fully extended the chain is at it's tightest.

Also, measure (as mentioned above) the distance between the center of the swingarm bolt hole and the center of the rear axle hole. That's the only way to assure that the axle is parellel to the swingarm bolt. Remember, the holes in the swingarm bolt and the axle are tapered from one side to the other so you have to use the center of the hole to get an acurate measure.

To make this easier, I took a 3/4 diameter piece of brass stock and turned it into a cone shape. Then I driled and taped it on the flat side. Next, I got a meteric aluminim ruler one meter long. I drilled a hole in it at 10mm and bolted the cone to it. This allows me to get a dead center reading from the swingarm bolt out to the axle. Plus I can use this to set the sag with spot on accuracy.

[2strokes_rule]

This, the chain munching the mud flap and hitting the inside of the frame drove me nuts on my 04. Luckily this was fixed on the 05 CRF450...

Huh, the 05 still does the same thing I think. I had an 04 also.

It's just something you get used to. It does it WAY less if you run the chain tight as suggested above.

Also, go to a higher quality Oring or Xring chain.

[Wayward Son]

the chain hits the mud flap on my 05.well,that is till it clearenced itslef.

[Throttlejockey]

Remember folks, on the new Hondas (02-05) the chain is at it's tightest when the bike is on a stand with absolutely no sag; with the wheels off the ground. The chain gets looser as the wheel goes through the travel.

The reason is the lower roller pushes the chain up making it tightest with the bike on the stand.

[dirthead1]

But it's not chewing the inside of the frame at all on the 05. I could care less about the mud flap and tire. It was the metallic rubbing noise that drove me nuts. I can hear the chains on CRF450s rubbing on the frame from a distance. At the track, you can hear the majority of the 04 and later CRF450s doing this. Spare me the chain adjustment pep talks too. This is a design flaw in these bikes as you shouldn't have to run less than a 1/2 inch slack to not hear the chain chewing on the frame. It's fixed on the 05 now.

[Flyin Dub]

Is there a chance that the prior owner put a 120 or larger rear tire on it instead of the standard 110? It may be that the tire is too wide for the bike.

[CR2CRF]

Spare me the chain adjustment pep talks too. This is a design flaw in these bikes as you shouldn't have to run less than a 1/2 inch slack to not hear the chain chewing on the frame. It's fixed on the 05 now.

I had an 02, 03 and an 04. I never had this problem. So I totally disagree with you "design flaw" theory. I also talked to the guys at Honda (I know a few insiders not local dealer guys) and they confirmed the chain tension needs. Also, you gotta make sure the rear axle is parallel to the swingarm bolt. If its off a bit, the chain gets thrown into the side as it's off track.

[dirthead1]

I guarantee the inside of your frame on every one of these bikes has been ground to a degree. Take a picture and post it. I have yet to see one 04 or older CRF without grind marks on the inside of the frame. Take a look you'll be surprised.

[CR2CRF]

I have looked. The all look fine. Keep your chain properly maintained and you'll be good to go.

[dirthead1]

Yeah right!

[ibfurloughed]

SOB I just went out and looked at my 03. Sure enough it has eaten alittle frame metal. I put a DID x-ring on after about 15 hrs. and I keep a pretty close eye on chain tention cause I hate the noise. It doesn't make noise now or since I put the DID on, I wonder if the damage was from the original rubber band. ?

[dirthead1]

The glut of it may probably be from the butter chain, but you'll still get some rubbing even with the X-ring or O-ring chains. There just isn't enough space between the frame and the chain. Next!

[WALKINGWOUNDED]

I read "WEET's" comment about chains not having the same length links in them. This is apparently true for other bikes as well. When I set my son's chain tension on his 85, I set it down and roll it and find a tight spot sometimes, so I have to back it off. I did not know that. It will sure help on setting chain slack the first time.

[Mike_Thomson]

Yeah its a design flaw when you don't run your chain at the proper tension??? Some people just refuse to take responsibility for anything in life. MIKE