Yamaha TRX850 Enthusiasts Forum

So V2/Over cams are like Rocking horse shit....how much more oomph did you get on the track with those cams?

I can put you on to someone who can give you an Over/V2 equivalent Bernard.
Asymmetric cam profile like the V2 but has 3 degrees less overlap but 0.2 more lift( from 0.3 to 0.5 246/253)
So you’ll gain around 15* more overlap than std plus the extra lift and intake can will be in a much more optimum timing to swallow more gas.
You Std pistons may loose a little under 4000rpm due to overlap but gain about 5hp up top. Check piston valve clearance and wouldn’t be surprised if you can shave a up to 0.5mm off the bottom of the barrels to push compression up into the 11.5’s and get you dynamic compression back up again. You’ll gain you losses back again down low and find maybe 8-10 hp up top. Getting you close to the magic 100nm/100 hp numbers
Brett is running some Ivan thye cams using another R1 profile ( 250/250 from memory )and std pistons with just 1 single outer shim for a head gasket with no P/V clearance issues.
No need to rev over 8500 as change of gear puts you right in close to peak HP

Racer-unk wrote:So V2/Over cams are like Rocking horse shit....how much more oomph did you get on the track with those cams?

Hard to say, not done any dynoing. However, I guessing it put me in the ballpark of the mentioned 95-100 hp. Having noice regulation troubles on the track I had to remove pod filters and re-fit my airbox, that took a bite out of the power but I'm still keeping up with the new RS660 accelerating down straights.

And apparently putting down black lines from rear slick getting on the throttle in turns...

Cobba...racing wise, I only go below 5000 rpm twice, when leaving the start line and at the hairpin......so power high up suits me.

Your cam contact, does he make from scratch?....cos that could be costly....ball park figure?

No they are a re-grind. Huby has the spandon framed TRX he’s building up on 1 of the trx Facebook forums. The last time I bought a some for a few guys here was a 3-4 yrs ago. Send him an email and Put “ Cobba trx “ as the subject... He’ll fill in the dots for you mate...

https://www.bergwerkstatt.de/

End of the line then. More things I could and want to do, but there's simply no finance. And in 10 years I won't be allowed to ride it anyway...

This Is how it turned out, I'm OK with that. Even if I still have a list of things I would have liked to sort.

very nice, I love it.Where did you find the carbon covers ? I'm looking for a clutch carbon cover for tdm 900, I have change the original operating mechanism for a tdm 900 mechanism

renato motocicletta wrote:very nice, I love it.Where did you find the carbon covers ? I'm looking for a clutch carbon cover for tdm 900, I have change the original operating mechanism for a tdm 900 mechanism

Thanks! The enforced covers comes from www.carbonadi.de

Well... as previously posted on FB the bike is now probably dead. Just as I got my dream track bike finished the world crashed and I had to build it back into street bike. Opted for a streetfighter configuration keeping as much track settings as possible. Soon as that was done and bike MOT'd it started overheating so season 2022 was more or less a bust.

Cleaned out the cooling system during winter, replaced ported top end and V2-cams with a used TDM head and stock cams mid summer 2023. Bike ran fine first test ride about 90 km's. Day after a camshaft seized and chain jumped 5 minutes after start, was 100 meters from home.

Patience ended, bought a low mileage TDM 2001 and finished the season on. It's now mid winter 2023 and the TRX is still sitting in a corner probably not going anywhere ever again. I've salvaged brakes for the TDM, TDMR's and Akra might get moved to the other TRX-project if I can get it to start.

Times to beat (stock shock and non-cartridge fork)
Kinnekulle: 0.59
Gelleåsen: 1.14
Sviestad: 1.01
Mantorp: 1.29
Brno: 2.30
Gotland Ring: 1.35

What a waste.

Hi jpe!

At first, I'm glad to see you back here!

But then I'm very sorry to read about the "fate" of your TRX, in which you put in so much time and effort.

I hope you keep posting/reading here and that your TRX comes to life again and/or you can get started with your other TRX project (sounds promising).

"Keeping fingers crossed" - greets from Munich!