Heatshield Shock/Exhaust on -10/-11 450...

Look at the 2011 JGR Yamaha 450, a heatshield between Shock and exhaust.

There seems to be a little problem with heat for the shock on the new Yamis.

Ivé talked to Ohlins about it and they admit that they had some issues with setting up the Rinaldi factory Yamaha´s in the GP´s aswell, the shock gets extremely warm at the end of long motos. Sure the normal exhaust of the other manufacturers also goes near the shock but on the Yamahas you have the complete exhaust back there, very near the shock.

Maybe this is a solution ?

Heatshield.jpg

If you are really concerned I am sure you can install a heat shield on your bike. I bet for the most part, people aren't going to really notice it. But It couldn't hurt to try.

There seems to be a little problem with heat for the shock on the new Yamis.

Really? What are the symptoms?

IMO, there is no issue, really, except for the perception that there is one. It's a lot like the idea that used to be prevalent that the exhaust on the older models could heat the radiators significantly, when the least amount of air flow between the two parts would in fact totally spoil the convective heat exchange between the parts. And, in that case, the exhaust was less than half an inch from the radiator in many cases.

The new YZ shock setup is very open to airflow, and even a 5 mph stream of air through the area would be enough to prevent much of any heat from crossing to the shock, it seems to me.

You might note that the shock gets hot. Well, the shock on my '06 does, too. After 30 minutes or so of riding, the reservoir is so hot it's uncomfortable, which would make it about 160-170℉, all just from suspension operation. I think a little extra shielding is a fine thing to pursue, but I don't see the heat from the exhaust as any more of a "problem" than it is in a normally configured MX bike. You probably have whole bunch of people checking the shock temperature who never though of doing it before. When they find it hot, they think the exhaust did it.

Really? What are the symptoms?

IMO, there is no issue, really, except for the perception that there is one. It's a lot like the idea that used to be prevalent that the exhaust on the older models could heat the radiators significantly, when the least amount of air flow between the two parts would in fact totally spoil the convective heat exchange between the parts. And, in that case, the exhaust was less than half an inch from the radiator in many cases.

The new YZ shock setup is very open to airflow, and even a 5 mph stream of air through the area would be enough to prevent much of any heat from crossing to the shock, it seems to me.

You might note that the shock gets hot. Well, the shock on my '06 does, too. After 30 minutes or so of riding, the reservoir is so hot it's uncomfortable, which would make it about 160-170℉, all just from suspension operation. I think a little extra shielding is a fine thing to pursue, but I don't see the heat from the exhaust as any more of a "problem" than it is in a normally configured MX bike. You probably have whole bunch of people checking the shock temperature who never though of doing it before. When they find it hot, they think the exhaust did it.

Well, I don´t have any personal experince with this heat problems so i´m not saying this or that. This is what Ohlins told me. And they said that the shock on th -10 Yamaha got alot warmer than the previous 09 version at the end of the motos.

And now seeing that JGR uses this heatshield, I guess there must be something going on huh ?

Really? What are the symptoms?

IMO, there is no issue, really, except for the perception that there is one. It's a lot like the idea that used to be prevalent that the exhaust on the older models could heat the radiators significantly, when the least amount of air flow between the two parts would in fact totally spoil the convective heat exchange between the parts. And, in that case, the exhaust was less than half an inch from the radiator in many cases.

The new YZ shock setup is very open to airflow, and even a 5 mph stream of air through the area would be enough to prevent much of any heat from crossing to the shock, it seems to me.

You might note that the shock gets hot. Well, the shock on my '06 does, too. After 30 minutes or so of riding, the reservoir is so hot it's uncomfortable, which would make it about 160-170℉, all just from suspension operation. I think a little extra shielding is a fine thing to pursue, but I don't see the heat from the exhaust as any more of a "problem" than it is in a normally configured MX bike. You probably have whole bunch of people checking the shock temperature who never though of doing it before. When they find it hot, they think the exhaust did it.

I concur 100% with grey.

Originally I was thinking that this would be a problem, I was right if you just let the bike idle and there's no air flow. In that case there is def some heat soak in the shock, but realistically when the bike is moving the conduction of heat is nill... If anything after a long moto the shock may heat up from the use of the shock, and the heat has nothing to do with the exhaust.

The heat plate looks really neat, but is useless IMO.

In supercross especially. That said, I think I can see where it would be benificial in MX on the pro bikes, with these riders being able to tell the slightest amount of shock fade.

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