Optimal Top End RPM?

[Straight_up_XTX]

I have a 09 XTX with a 1.75 backcountry track. Last season I ran the stock 21-39 gearing and stock clutching. At top end I was seeing 95-100 MPH on top end and my RMPs were I believe around 8600 RPM.

This year I geared down to a 20 tooth top sprocket with the same stock clutching and I am seeing almost the same top end (on speedo) of 95 - 99 MPH but am reving 9100 to 9200 RPM.

I know there was an RPM reduction when i installed the backcountry track last season but I honestly can't remember how much.

I like the way the sled pulls with the 20 tooth top gear but I am a little concerned about the higher RPMs. Is it OK to be running 9100 - 9220 RPM on top end?

My initial thought was that if I am not hitting the rev limiter I should be OK. So I'm just looking for some feedback.

Thanks

 

[sorenson1610]

I thought I remember reading that about 9000 is the sweet spot, anything over your power is just falling off.

 

[Nytroman]

I believe the sweet spot is between 8900 and 9200, it seems to depend on the sled. I have personally found the best results at around 9000.

 

[radianguy]

I have a 09 XTX with a 1.75 backcountry track. Last season I ran the stock 21-39 gearing and stock clutching. At top end I was seeing 95-100 MPH on top end and my RMPs were I believe around 8600 RPM.

This year I geared down to a 20 tooth top sprocket with the same stock clutching and I am seeing almost the same top end (on speedo) of 95 - 99 MPH but am reving 9100 to 9200 RPM.

I know there was an RPM reduction when i installed the backcountry track last season but I honestly can't remember how much.

I like the way the sled pulls with the 20 tooth top gear but I am a little concerned about the higher RPMs. Is it OK to be running 9100 - 9220 RPM on top end?

My initial thought was that if I am not hitting the rev limiter I should be OK. So I'm just looking for some feedback.

Thanks

I installed my Back Country and 20 tooth gear before the start of last season(the same time I did the under tunnel exhaust), I too noticed my RPM up around 9200 and figured my exhaust was gaining me the RPM. I wasn't hitting the rev limiter so I never worried about it.

Interested to see what you find out here!