What does yours go to?

May 16, 2011 3 Replies

Tacho goes to 9K.

formatting link


My needle stops at 7. And it doesn't go totally batshit when it gets there.

That looks quite mad.

A friend had a CBR250RR four stroke bike that redlined at 21 and a half grand. Madness. It sounded like an F1 car.

Fraser

I think he gets to about 8.5K on a motor that's redlined at 7.2K.

But has he taken it to 125% redline speed (RLS)? 26.8K.

I twice took a CB125S that's redlined at 9.5K though the red band and

1K back into the green at 12K (125%RLS). It was pulling so well at that rpm in top it didn't slow down up a hill.

Doing the calcs for port size and valve timing, the max power speed of a lot of engines will turn out to be higher than redline. Run them into the red and lol and behold there is a power peak. There's a bloke calls himself motoman with a site mototuneusa that advocates making inlet ports smaller to bring the tuned rpm down within the redline speed for proddy racing as they aren't allowed to mess with the limiter.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required