Yamaha TRX850 Enthusiasts Forum

Hi
Has anyone got a Dyno Chart of a bog stock TRX I need one BHP by Revs not road speed. Also a Dyno Chart of a K&N filtered race exhausted bike. I'm thinking of changing the gearing for my next Cadwell Park visit and I wanted to know how the power runs after 8000rpm and how to gear it.
Thanks

I'm a bit confused. How are you planning to use someone elses dyno charts to decide upon gearing for your bike?

FWIW, power on stock bikes (and those with open pipes etc) falls of pretty sharply around 8500 IIRC.

As for gearing, it really depends on how fast you are? I suspect you are not going to be fast enough to hit the limiter in top on Park straight (on standard gearing) so I'd be looking at something like 17/42 or even 16/40 (or if you really want drive out of the slower corners 16/42)

I don't recall having any problems with 17 / 42 at cadwell

I wanted to look at the general shape of the curve which will be pretty similar for bikes in a similar state of tune, basically I wanted to know how much power we have in the over rev. From what I can see on the Dyno's I have seen peak power is at 8000 ish and it starts to tail off but doesn't hit a wall or anything. This is what I feel through the seat I can keep reving through 8000 and it's not pointless like it is on some bikes (My TDR just doesn't rev past 10000) When I'm riding the TRX (I'm a big lump unfortunately) it really doesn't pull in 5th very well almost like an overdrive so I wanted to drop the gearing for a bit more shove and to make 5th usable as I kept running out of revs in 4th.
If you see what I mean
Thanks

hjp1968 wrote:I wanted to look at the general shape of the curve which will be pretty similar for bikes in a similar state of tune, basically I wanted to know how much power we have in the over rev. From what I can see on the Dyno's I have seen peak power is at 8000 ish and it starts to tail off but doesn't hit a wall or anything. This is what I feel through the seat I can keep reving through 8000 and it's not pointless like it is on some bikes (My TDR just doesn't rev past 10000) When I'm riding the TRX (I'm a big lump unfortunately) it really doesn't pull in 5th very well almost like an overdrive so I wanted to drop the gearing for a bit more shove and to make 5th usable as I kept running out of revs in 4th.
If you see what I mean
Thanks

OIC

try 17/42 for gearing

I have used that for years both on the track and road and regard it as a perfect compromise

power does tail off at around 8500 but you can overrev the engine to the limiter (about 9250 on a standard CDI)