Originally Posted by AntonLargiader
I have an R65 bottom end and I suspect I have some cylinders. I know I have iron ones to play around with. But is it worth giving up 130cc for?
The configuration has some advantages.
- faster spin up
- lighter. a bit
- maybe a bit more chuckable from side to side
When I ran my mild 980 against an 860 in a similar chassis there was not a lot in it.
The 980 was easier across the paddock in slow going .
Once the revs were up to low 3000s there didn't seem to be much performance difference
The 980 was stronger 5000 - 6500 but the 860 carried what power it had further into the rev band past 7200.
Peak power was probably similar in the low 70s and the 980 clearly had more area under the curve.
Lots of vibration from the 860.
For a dirt race bike is probably a very good choice.
AW certainly seemed to get some pretty credible performance out of the one he rode.
Did you miss the grunt of the 980 under race conditions?