The TRX900 Project kicks off

Please share your secrets! What mods have you made to your TRX?

Moderators: trixynut, Mincehead, dicky, phuk72, Jak, Kevtrx849

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dandywarhol
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Re: The TRX900 Project kicks off

Post by dandywarhol » Sun Aug 28, 2016 2:42 pm

Mincehead wrote:Dandy you`ll remember old `Velcro leathers` Dennis Gallacher? Not an inch of `hanging off` but a bloke that was smooth and fast and who MANY followed learning his lines and skills.
I don`t hold with moving much from centreline of the bike myself, knee down? Pffft, I see morons doing 30 mph round roundabouts, half their bodies off their cloned plastic rockets, knee sliders scraping and I can go underneath them (if there`s room) on an old Donkey. Hahahahah.
Dennis G was a joy to watch!

Haven't done much except fit a pair of CV carbs from a Raptor 660 in place of the slide/CV original setup and a Micron tailpipe. FCRs are like hobby horse shit of uber expensive new. I like the idea of a single big pumper Mikuni but need someone with better skills than I have to fabricate a manifild.
Thanks for the kind words re, track day =D>
1996 TRX 850, blue, Ohlins 46HRCLS, Race Tech Gold Valves, 0.90 springs, Venom pipes, R6 brakes............
1974 Yamaha RD250A, Candy Blue
1998 Yamaha SZR660, blue of course
1967 Yamaha TD1C 250, Blue and white

coxylaad
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Re: The TRX900 Project kicks off

Post by coxylaad » Sun Aug 28, 2016 9:59 pm

dandywarhol wrote:I re-read your post again Ian re. closed throttle cornering - I misunderstood what you were saying, I thought you were running past the apex on closed throttle :roll:
No, just carrying enough speed to the apex from releasing the brakes without having to get back on the throttle before I have reached the apex.
My technique (albeit on less powerfull bikes) is to slightly trail brake into the corner (unless it's an adverse camber corner, like on some road circuits) letting the camber help the tyre dig in then as the brake is released,
Bill does that on his R1, and thats what crafar says to do also, not right into the apex but initiate the turn whilst the brakes are on to 'steal some yards' his whole concept is making the straights longer.
I apply pretty much full throttle immediately just before the apex. Having said that, no corner is the same so the technique varies slightly.
Jesus I wouldn't dare go straight to full throttle! even on the trx I try to feed it in progressively. On the blade I think I would be put in a low earth orbit. I do have the traction control helping me out but I still like to have some manual control of the throttle. do you not push the nose of the bike wide on a full throttle?
One crafars big points on a litre bike is not to get on the throttle too early, apparently its quicker to have the bike on enough throttle to maintain the speed through the apex, turn it as tight as possible, as quick as possible, sit it up and get on the gas. it seemed to work.
This is Sunny out:

Image

If you note the track position, bill has applied the throttle earlier and is carrying more lean angle than me, and I am already picking the bike up and will get on full throttle earlier. thats the theory anyway!

The last two sessions on that last track day were on an Aprilia Tuono Gen2 on Michelin Pilot4s.
Road pilot 4s?
Within a couple of laps I had developed a different style - the braking power of the radial Brembos on wavy discs was phenomenal and although the 'bars waggled a bit, I could trail brake much harder before gently feeding in the power, again just before the apex. One advantage of trail braking is that the steering geometry steepens under braking and turn in is quicker. Next time try cornering with the clutch disengaged and no front brake - weird feeling! #-o
I got a false neutral on the mille at island bend oulton park, same next effect - brown undercrackers and some grass tracking
After around 12 laps the rear tyre was sliding out of the turns and I wasn't happy with that - nor would the bike owner if he was watching so I pulled in!! The front felt completely planted though. Looking at the tyres when I came in showed a different story - the front was in a bit of a mess while the rear seemed fine. The Michelin techniciams found the pressure to be at 42psi hot, so they lowered it to 30 (hot) and asked for some feedback. By lap 12 the rear was starting to slide a little but less than the previous session. The chart Michelin supplied on the day gave pressures of 18 psi cold for their track tyres!
The 4 year old Pilots on the wee SZR worked perfectly all day :D

42psi is huge! I run 27psi hot at the rear and 30psi hot in the front with the supercorsas.
PS That Fireplace is going some at the fast bits - hadn't realised Croft was so fast. I was there helping a friend with his Bultaco 200 at a CRMC meeting earlier in the year and had a walk round - nice track :D
the bike is geared down a little so you can knock 10mph off the top of those times, but its still shifting.


Looks like you were having a lot of fun at knock hill! Awesome stuff - you looked very consistent lap on lap. I am reasonably consistent compared to the people I ride with, but theres generally a variate of up to 2.5 to 3 seconds lap on lap!

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Re: The TRX900 Project kicks off

Post by dandywarhol » Sun Aug 28, 2016 10:31 pm

Need to remember the SZR660 is only putting out 43 bhp so cracking it full just before the apex isn't particularly violent :lol: Daren't have done it with the Tuono :shock:
I've never really been a believer or thought much about "neutral throttle" after releasing the brakes - I've mainly been on small(ish) 2 strokes where every least millisecond between coming off the brakes and getting on the throttle count. Much like running an unusual line on a quick corner on a 125 to keep the engine in the powerband on the smaller circumference of the tyre, whereas running the "right" line would result in the engine bogging down. 8)
Yep, learned a lot about tyres that day - the Tuono high pressure was for the road and Pilot road tyres - and why the rear was letting go so early and so much. some folks like the rear to spin - I'm just not used to it. I was sitting behind a ZXR7 and he was leaving darkies out the chicane at the same time the Tuono was having a wee slide to itself, so maybe it's normal on modern tyres :? Just wished I'd put the camera on the T's handlebars - it was certainly the fastest I'd ever got round Knockhill!

On the video at 10.35 I got a cheeky wave from Sir Too Tall Tel Rymer on the ZXR10 after he gubbed me on the brakes before the drop down the hill - cheeky bastard :wink: Then Ol' Stavros Parrish caught glimpse of him in the Yam Tracer mirrors and they cleared off for a bit!

Keep it on the black stuff!!
1996 TRX 850, blue, Ohlins 46HRCLS, Race Tech Gold Valves, 0.90 springs, Venom pipes, R6 brakes............
1974 Yamaha RD250A, Candy Blue
1998 Yamaha SZR660, blue of course
1967 Yamaha TD1C 250, Blue and white

coxylaad
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Re: The TRX900 Project kicks off

Post by coxylaad » Mon Aug 29, 2016 9:38 pm

haha check you out mixing it up with motorcycling royalty!

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Re: The TRX900 Project kicks off

Post by coxylaad » Mon Sep 05, 2016 10:56 am

done some work on the TRX over the weekend.

its been running a bit rough lately, and I suspected it was the cold start assembly on the throttle bodies sticking. I was correct.

Luckily I have a spare which is virtually new so I swapped it over.

Whilst I was there I had a look at all the 'stuff' that is under the tank in that area as I really havent had it apart since I threw it together a few year back.
I think I am going to have to make myself an airbox as the drawing all that air into that area is gathering a lot of dirt.


One thing I forgot to mention is that when the bike is stood ticking over and just before it gets to max temp before the fans cut in, the radiator starts to push loads of coolant into the expansion tank, which is one of my bairns old baby bottles. it then fills that full and spits coolant all over the floor.

I have installed a tank double the size of the original (500ml up from 250ml) and I will see how that goes. I heard that some guys remove the expansion tank with no bad effects. that's definitely not the case for my bike.

The only thing that is niggling in the back of my head is that when I had the lug welded onto the head I think I have ever so slightly warped cylinder head, as I get a tiny tiny weep of oil around that area, and only when the bike is stood stationary. I am a little concerned that it may be on the way out.

I might be being paranoid, but its getting a full strip down and refresh over the winter.

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Re: The TRX900 Project kicks off

Post by dandywarhol » Mon Sep 05, 2016 11:21 am

Double check the pipes aren't mixed up. The overflow and the manifold heater pipes run pretty close together from memory.
If crossed over, the coolant doesn't pressurise and pumps into the expansion tank
1996 TRX 850, blue, Ohlins 46HRCLS, Race Tech Gold Valves, 0.90 springs, Venom pipes, R6 brakes............
1974 Yamaha RD250A, Candy Blue
1998 Yamaha SZR660, blue of course
1967 Yamaha TD1C 250, Blue and white

coxylaad
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Re: The TRX900 Project kicks off

Post by coxylaad » Mon Sep 05, 2016 11:26 am

do you know which pipe show go to the expansion chamber?

I have the one that tee's off the back of the thermostat housing heading into the expansion bottle.

the manifold heater one comes from the top of the rad need the filler cap, and returns onto the head somewhere.
I believe they are right, the pipes seem to just fall into place on there.

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Re: The TRX900 Project kicks off

Post by dandywarhol » Mon Sep 05, 2016 12:13 pm

The reason I know about this is my "tooned" 900 was refitted into the frame with the pipes the wrong way round.

The pipe to the expansion pipe comes from the overflow at the neck of the radiator filler. when the pressure becomes excessive, the cap valve lifts and sends the excess pressure/coolant to the expansion tank. When the engine cools, the secondary vacuum valve on the pressure cap opens and allows the coolant to flow back into the radiator. If it's the wrong way round, the pressure goes straight to the expansion tank - the coolant cannot pressurise and the engine overheats. In my case, I'd fecked about fitting a manual fan override switch before travelling to hot Europe til I discovered the garage's feck up with the pipes - changed the pipes over - job done :D
1996 TRX 850, blue, Ohlins 46HRCLS, Race Tech Gold Valves, 0.90 springs, Venom pipes, R6 brakes............
1974 Yamaha RD250A, Candy Blue
1998 Yamaha SZR660, blue of course
1967 Yamaha TD1C 250, Blue and white

coxylaad
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Re: The TRX900 Project kicks off

Post by coxylaad » Mon Sep 05, 2016 2:19 pm

Funny you should say that as I was about to fit a manual override switch for the fan tonight!

yep I have definitely got the pipes the wrong way round.

well as least thats sorted cheers Al!

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dandywarhol
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Re: The TRX900 Project kicks off

Post by dandywarhol » Mon Sep 05, 2016 2:39 pm

8)
1996 TRX 850, blue, Ohlins 46HRCLS, Race Tech Gold Valves, 0.90 springs, Venom pipes, R6 brakes............
1974 Yamaha RD250A, Candy Blue
1998 Yamaha SZR660, blue of course
1967 Yamaha TD1C 250, Blue and white

coxylaad
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Re: The TRX900 Project kicks off

Post by coxylaad » Mon Sep 05, 2016 3:21 pm

I have done a dozen track days with it like this!

doesn't get hot enough to be a problem when you are flat out!

the only problem I have used to have was sitting waiting for the noise test

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Re: The TRX900 Project kicks off

Post by dandywarhol » Mon Sep 05, 2016 3:32 pm

Flat out, big airflow, high water pump speed..............
1996 TRX 850, blue, Ohlins 46HRCLS, Race Tech Gold Valves, 0.90 springs, Venom pipes, R6 brakes............
1974 Yamaha RD250A, Candy Blue
1998 Yamaha SZR660, blue of course
1967 Yamaha TD1C 250, Blue and white

coxylaad
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Re: The TRX900 Project kicks off

Post by coxylaad » Thu Sep 08, 2016 11:36 am

Tyre wear - discuss

Image

Since I have moved to a big bike I just cant get the tyre to run clean. The blade minced a tyre in one day. that's going to get expensive!

the tyre is not chewing so much as wiping the surface off aka cold tear. but with cold tear you reduce the pressures, I have knocked them right down to 23psi cold (27 hot).

I am struggling to make any progress with it.


any people with good tyre knowledge on here?

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Re: The TRX900 Project kicks off

Post by dandywarhol » Thu Sep 08, 2016 12:07 pm

I find this pretty accurate - I don't think you're cold tearing - you're 140 bhp through a small area tearing - go get a 660 :lol:

https://lifeatlean.com/motorcycle-tyre-wear-guide/
1996 TRX 850, blue, Ohlins 46HRCLS, Race Tech Gold Valves, 0.90 springs, Venom pipes, R6 brakes............
1974 Yamaha RD250A, Candy Blue
1998 Yamaha SZR660, blue of course
1967 Yamaha TD1C 250, Blue and white

coxylaad
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Re: The TRX900 Project kicks off

Post by coxylaad » Thu Sep 08, 2016 12:27 pm

its 165 at the back wheel actually Al but your point still holds :lol:

I have just seen a few other litre bikes and their tyres are very smooth with no debris on them.

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