Abnormal tire wear, looking for setup advice.

@stangmx13 Lots of good info here. Perhaps I was starting too high in pressure and the tire was too far gone to be saved when i lowered it. I used to never set pressures "off the warmers" but always off the track like you said, but was told to do it this way for the Dunlops. Live and learn I guess.

When i dropped the shock off I made sure to be clear that I like the settings as they were and to reinstall it as delivered. I measured eye to eye of the shock, preload and comp/reb clicks. I did not measure the installed length of the spring as I was not aware that could change....when I received the shock back I did double check the eye to eye, preload, and clickers and they had all been set to their previous settings, which would lead to me to believe the spring length is also correct. I dont like this as theres no guarantee which means i should just go out and re-measure sag and try to set the preload accordingly. What kind of numbers should i be looking for in terms of sag? 30%?

 

Honestly, I probably shouldn't have typed all that stuff about installed preload. Its pretty likely its installed back in the same spot. Every tuner I've worked with put its at 10mm unless someone asks for different.

What's sag? Jk. I haven't measured sag in years. IMO if the 95 spring is appropriate for your weight, track, and riding style, set it at 10mm total preload and ride it. If your tracks have lots of g-loads or you are a heavier rider, you probably need more spring instead of going to 11.5mm preload. But again, thats just me guessing because I don't know you, your tracks, or more details about your setup.

 

I'd leave the bike alone and try an 0097 rear tire at 20psi off the warmer and go from there. Looks to me like the 0129 is too soft for that track.

 

At the track (mido)... 0097 rear started at 20psi off warmer, first session no major wear but obv track isn't in yet.... rear shock was using maybe 5/8 of travel... took all.the preload out (3 turns) and second session rear felt way less squirmy when getting back on throttle... will keep you guys posted as day goes on. THANK YOU to anyone who chimed in to help.. its you guys that make the bike community so great.

 

1 session left. Track really heating up... wear is starting to come back although not as bad.... should I remove more air from the rear? Tight now I'm 20 off the warmer and 22 coming in off the track which seems ideal? Unless my Guage is reading high.... thoughts? What kind of wear is expected with too low pressure?

 

I'd check your gauge against another gauge, to make sure its accurate

 

If it’s starting to tear again I’d add 1 or 2 psi (21 or 22 off the warmer).

 

Talked to the guy who serviced my shock... he said @170lb without gear a .95 spring is too stiff for me. Does this check put for an r6? I ran this spring for a few years running good pace... thoughts?

 

Did he ask you any other questions about how the bike was handling or did he state blindly that that rate was too high?

 

He has my settings written down so I'm OK with him not asking those questions, but no, did not ask about understeer, oversteer, slow/fast traditions. Just asked my weight and spring rate and said it's too high of a rate. Asked a bit about tire pressure but thats it.
Was hoping the turnone guys would set me up but they're only at the track sat/sun so no help for me. Gotta figure out a time to get with them, destroying tires is getting old

 

Here's a question. Is shock travel relevant? Should I be changing my setup between tracks to utilize full travel?
I've done this with my forks to prevent bottoming out or to use more travel.. I write down the settings for each track so I know for next time. Is this wrong?? In the past when turnone dialed my shock I never touched it.. just preload in forks.

 

I’m 140lbs and have run a 97.5 N/mm spring at certain tracks on Dunlops. It worked great. I usually run a 95 though and occasionally a 90.

It’s never a goal of mine to use a certain amount of suspension travel. Lap time is the goal. Turning and grip are the goals. If the bike isn’t holding me back and I’m using 50% of the shock travel, it’s all good.

 

I'd be looking for a different suspension guy or at least working on communication with him.

 

@noles19 he's not my suspension guy, just an ohlins certified tech rebuilt my shock this past winter. I usually do my own maintenance but the ttx has that preload gas chamber that needs special machinery.
I use Joe from turnoneracing for suspension baseline/advice, but its been a while since I've hooked up with him and keep missing him at the track this year

 

Yeah, that's not helpful. As for different setups, pro riders use different setups for almost every track. Sometimes the changes are small, but it matters. As for your tire wear, it's not always down to the shock. Many times it's a problem with chassis balance, swingarm angle, etc. Paying a pro suspension guy for one day at the track might just solve your problem completely. Shock travel- you don't generally use shock travel like fork travel. If you have data, you look for an average position.

 

I'd first take a couple clicks out of compression. Maybe the old shock oil was like water and the new oil is significantly thicker.
Sounds like you tried IN on the compression and it made it worse. I'd try out...

Changing springs just because of a number doesn't make sense... If you like the bike's behavior mid corner where the suspension is compressed, changing the rear spring lighter will change the geometry and might have you running wide unless you chase the preload/sag. But I don't think the springs are necessarily the cause of the new wear.

Last thing you changed was the shock. It has to be the shock... Newer thicker oil, might have to open up the compression circuit for a while... Things might improve when the oil heats up though.

 

Have you run that exact tire before with different results under the same conditions with your shock prior to servicing?

 

I also think the shock is over-damped.

But for a better opinion from the internets, you should ask the tech that serviced it what valving spec is in there and post it up. Then someone will have a much better idea if your clicker settings are close enough or way off.

 

@stangmx13 The valving is C34 R5, according to the guy who serviced it.

 

Im also using R5 and could never run at 8 out. My range is 12-16 out.

We definitely ride differently, and at different tracks. But I don't often see huge differences in rebound settings at the track, especially when using the same spring. I dunno, my sample size is small compared to the suspension pros here. Let's see if someone else has an opinion.

This is a very good question.