Help with Slo3933's bike problem

[MWEISSEN]

I've been trying to help Slo3933 with a problem she just encountered on her CRF150. The bike feels like it's got a flat tire, and the whole front end tracks wherever it darned well pleases. For her, it's caused her to crash numerous times. We thought we had it the other day, but she wrote back and said the bike was fine for awhile, then started acting up again. Here's what I did:
1. My daughter has a CRF150 as well, so I could do a nice side-by-side comparison. First, making sure Slo hasn't fallen on here head once too often, I rode her bike and confirmed the thing is possessed. I then fired up my daughter's bike and has Slo ride it. She came back and said that rides much better.
2. Checked head bearings, forks, spokes, wheel bearings, triple clamp alignment, frame for benting/broken weld. All looked good.
3. I noticed that her tire would roll by hand on the rim, whereas my daughter's would not. They both have Michelin MS2 front tires, so it wasn't a tire difference.
4. I swithced wheels between the bikes. Slo's bike rode well, my daughter's sucked.
5. I let out the air in slo's tire, lubed up the rim after breaking the bead loose and pumped up the tire over-pressure to set the bead really well. My daughter's tire was a 14psi, Slo's was at 11. I put her's at 11.
6. After remounting the wheel, it seemed to ride fine, so we packed it up and thought we had it.
7. An email back from her said that the bike was fine for 20 minutes of riding, then started acting up again, knocking her off.

The next thing I suspect is that when Village put the new tire on the bike they put the wrong tube in it. Or the tire is somehow defective.

Any other ideas???

 

[Wolf Child]

is it holding pressure?

I know she almost always seems to have a flat. might wanna check it for a snake bite (pinch flat).could be a slow leaking tube.

might also be time to invest in a rim lock.

 

[slo3933]

Thanks Mark - you did a better job describing!!

Stacey

 

[YZMAN400]

What do you mean by the tire is rolling on the rim? You mean you can spin it around the rim or push it from side to side?

It almost sounds like a defective tire. I would believe a tire would be bad before a rim would be. A tire it a lot cheeper to replace than a rim to see if that is the fix.

I have never heard of a bad tire before. Ive seen them wickedly out of round before but not what you describe. But its possible.

 

[slo3933]

Don - he could push it from side to side, not spin it. It was very noticeable compared to his daughter's bike w/the same tire.

Stacey

 

[katoom125]

mark - even tho you said you checked wheel bearings - they sure sound suspect if the tube checks out OK. Especially if you can push the tire/wheel side to side.

 

[70 marlin]

New tire time.

 

[MWEISSEN]

Thanks Mark - you did a better job describing!!

Stacey

Hey Stacey, I never did ask: Did you run this tire flat for some time? If so, could she have ruined this tire, even though it's almost brand new?

Scott, the tire holding pressure was fine.

 

[slo3933]

Mark - yeah...well...yeah. I didn't realize it was pinch flatted and went and rode a couple 20 minute motos on it. I had the tube replaced after that. Scott - how long ago was it that I met you and Bonnie up at Big Air - that's when I flatted. But it acted fine for several rides after the tube was replaced (it was fine the first time we all rode at Cedar).

Stacey

 

[Wolf Child]

Mark - yeah...well...yeah. I didn't realize it was pinch flatted and went and rode a couple 20 minute motos on it. I had the tube replaced after that. Scott - how long ago was it that I met you and Bonnie up at Big Air - that's when I flatted. But it acted fine for several rides after the tube was replaced (it was fine the first time we all rode at Cedar).

Stacey

big air was the first of april.

If it's holding air and ther are NO slow leaks, like from a small snake bite.... I'd say the tire is suspect. whell bearings wouldnt be intermittent.

 

[BSWIFT]

Sounds like the side wall on the tire has broken down. Running on a flat "could" cause this to happen but most likely it is just defective.

 

[YZMAN400]

I got to take a peak at her tire today. That is strange how it rolls from side to side. Is that the correct width tire for that bike? Something is not right with that tire.

 

[Wolf Child]

Don, I dont know as I agree....

I think its a suspension issue more and more. And here's why.

Stacy said that she had a seal leaking when they pulled a fork boot, that will cause the front wheel to move laterally (remember The KDX we thought had bad wheel bearings?) also, as the oils that IS there heats up, damping will decrease causing this effect to be amplified. Remember... she rides this bike alot harder than it was designed to be riden. So her suspension is already a major hinderence since it's less than Ideal for what she needs. so take too soft, underdamped suspension... add a leaking seal, a fairly aggressive rider, and generous amounst of loose sand...you get a soil sampling machine of epic proportions. maybe the tire DOES have a broken belt or bead, but my guess is those forks need some attention.

 

[Chriskring]

What were you guys feeling? I rode the bike and didn't observe anything riding straightline or laying it over into a turn. Of course, I had the suspension further into the travel at 200 pounds.

 

[slo3933]

Trust me Chris, it's not right, be it suspension or tire or a combination of both.

Stacey

 

[slow_joe]

I just rebuilt the neighbor kids 2004 CRF150 forks. He met a Kawasaki head on out at Cedar and the guys foot peg busted a hole in his lower fork casting. I put 15W fork oil in and filled them 5.5" from the top. He said the forks are way better then they were before. I would say he is about 140lbs. Sorry I was a no show at Horseshoe Stacy.

 

[YZMAN400]

You may be onto something Joe. My kids TTR90 had almost no oil in the forks when I took them apart. Actual oil in the forks made a big differance.

 

[ChrisKring]

Trust me Chris, it's not right, be it suspension or tire or a combination of both.

Stacey

Try replacing the tire then. I can swap it for you on Wednesday night or next week. That's the cheapest solution.

Next, the fork oil height needs to be checked. It might be low on oil causing poor rebound at top out. Is it washing out on roots?

I am guessing it's the tire though due to the casing being shot from running it flat. Buy 2 new front tubes when you buy the tire so you have a back up.

give me a call

Chris

 

[slow_joe]

I can swap it for you on Wednesday night or next week.
Chris

Where is the ride at tonight?

 

[Wolf Child]

actually guys... Stacey lives here in town. She can always swing by and we can throw it on my tire changer. Save her some driving.

 

[ChrisKring]

Where is the ride at tonight?

No ride tonight for me. In-laws are in town for one more day.

I'm off for DH racing this weekend so I will not be back on the MX bike until next week. Cleared killer on Saturday after you left though. Wow, it's much smoother than landing on top and then bouncing all the way to the bottom.

 

[MWEISSEN]

I got to take a peak at her tire today. That is strange how it rolls from side to side. Is that the correct width tire for that bike? Something is not right with that tire.

That tire is the exact same tire on my daughter's CRF150, and it doesn't act ANYTHING like Slo's tire.
As far as a fork seal leak, it was an inconsequential leak. REMEMBER, in the problem solving I did:
Daughter's wheel on Stacy's bike - Stacy's bike handled fine
Stacy's wheel on Daughter's bike - Didn't handle well
Daughter's wheel on Daughter's bike - fine
Stacy's wheel on Stacy's bike - didn't handle well.

Based upon this I ruled out the forks, which had equal action between the two bikes. Bearings on Stacy's wheel were fine, spokes were fine/ rim was fine, tire rolled on rim.

I suspect the tire was ruined from running it flat, and the best solution would be to replace it.

 

[slo3933]

I'll hopefully be getting a new tire on tomorrow, then going out to test it. Anyone wanna ride?

Stacey

 

[MWEISSEN]

If I get antibiotics in the morning doctor appointment (sicker than heck since Monday, gotta be an infection), AND they kick in really good, I'd be up for an afternoon ride.

 

[slo3933]

If I get antibiotics in the morning doctor appointment (sicker than heck since Monday, gotta be an infection), AND they kick in really good, I'd be up for an afternoon ride.

Geez - you can't get a break!! Tell those bugs to leave you alone, that you wanna ride!!!

Stacey