GEARBOX, possibly six speed?

[Mincehead]

So, A show of hands, wants, HOPES, for a six speed close ratio gearbox please?

I`ve discussed, at length with my boss, the feasibility of having Nova Racing make a stronger and possibly 6 speed cluster for the TRX. Obviously there`s time and money involved in designing such a thing and my boss wants to know just how many the company would be likely to sell if they decided to design and make them.
I would need a FIRM order for at least SIX before Nova would take the process into design and I warn here and now the company is VERY busy as we make ALL Ducati`s latest race bike gearboxes, KTM RC250 R`s and now Mahindra`s too, along with the general bread n butter boxes continually being sold.

http://novaracing.co.uk/


https://www.facebook.com/novaracingtransmissions

Please make all responses through me, the company is currently snowed under with enquiries and promises.

I have a motor that could be in my works for all the design processes required, test fitting of components etc. We also have 3D printing technology at our disposal to model components before NC mills and other CNC machinery cuts real metal etc, saving on costs.

[cobbadiggabuddyblooo]

So why not just get them to make the 2 shafts, a selector barrel and 3 forks to work off I pivot pin?
Then you can utilise the choice of Yzf gears available which was how Yamaha YEC and Over did it.
Yzf gears fit inside the cases ok but the lengths of the shaft need to be addressed to get the clutch and front sprocket to align properly.
This is what I found with the YZF750 SP gearbox I tried to fit ( bearings located perfectly )
The yzf selector barrel itself are a tad long and won't fit plus the 3 selector forks pivot from 2 pivot pins and don't just work from 1 like on the trx.

Or even better make a selection of close ratio gears to fit the TDM 900 gearbox???
That way it's cheaper and easier and the money saved can be used to purchase a 900 motor...
You could prob use a couple of the original gears so it's only a matter of replacing maybe 4 main and 4 lay shaft gears... You can use the 6 speed shafts and selectors already fitted that way.
Be popular in the German camp ( TRX850.DE Super twins ) I reacon mate with a number over there racing.

You only have to purchase a second hand 900 gearbox then Mince.
The 900 box doesn't simply fit into the trx motor either.
I'm pretty sure it was Huby who supplied my cam shafts who managed to put an R6 box into his trx850 a while back before going down the 900 route. But a lot of work and said he'll never do it again..
Let us know if you want his contact details as you could save yourself a little time on the do's and don'ts on this challenge.

[Killerwhale]

You are correct about the R6 hell, he was the one who provided me with the preprogrammed TCIP4 many years ago!

http://www.bergwerkstatt.de/

[Mincehead]

Ah but Brian what you have to consider is the material and longevity of the standard Yamaha pinions compared to Bohler M121 or even E108 manufactured gears that Nova specialise in. That said, YES, shafts and a selector drum could also be a consideration.

[cobbadiggabuddyblooo]

At least that way with shafts and selector barrels, you can outlay either for a budget shafts, barrel kit or the whole hog complete with gears..
Bonus being the gears could be sold to yzf owner too. The guys on the yzf750 forum on Facebook would love that as the close ratio gears are as rare as hens teeth..
That's all they need.
Not so much purpose built only for a trx that way mate and gives you another sales avenue..

[Mincehead]

John Mc Phee just won Moto 3 with a Peugeot Mahindra fitted with a box `similar` (I`m not allowed to give pictures) to this one. All Nova`s handywork: https://www.facebook.com/photo.php?fbid ... 952&type=3

[Mincehead]

So, the YZF close ratio gear pinions fit the TRX input and output shafts, yes?
Brian can you send me any links or images in relation to the six speed box in the TRX?

[cobbadiggabuddyblooo]

http://www.trx850.com/phpBB_forum/viewt ... ox#p106371

I'll see if I can find any other info for you mince. I just hope it is on some of the back ups I did from my old laptop as it died a few months ago. I've prob got it scribbled down somewhere too.

I never attempted to remove the gear clusters from the shafts .
The bearings sat in the correct positions just the length where the clutch and front sprocket mounted was a 5-8mm out and that was the only alignment issue.
The YZF shafts and clusters fitted inside the TRX case perfectly just as the originals.
Above link explains about the selector barrel and forks too.

So make both your TRX850 6 speed shafts the same as the YZF shafts but you need to change the overall lengths to the same as the original TRX 5 speed shafts so the clutch mounts in the original position and your sprocket sits at the correct length for chain alignment..

Look at page 1 & page 11 of my rebuild thread for photos of the shafts in position and the lengths that need changing.
So measure from the outer face of the large bearing to the end of the input shaft the clutch mount on and the same on the output shaft /sprocket to get the correct lengths.

YZF bearings, clips, and a few other washers, spacers on the shafts are inter changeable on the TRX sharing the same part numbers plus listed as parts for both yzf/trx when going through Yamaha parts list online..

[Mincehead]

Hmmm, might have to invest in this: http://www.ebay.co.uk/itm/YAMAHA-YZF-75 ... SwU-pXqyVA

[Tarwetijger]

I have a 6speed gearbox from YEC and I've put the exploded view diagrams with part numbers online, a long time ago.
http://www.trx850.com/phpBB_forum/viewt ... f=6&t=7872
I see that the links to image hosting are not working anymore. I can't find it on my PC either so will have to make a new scan.
Will do but please be patient as I am moving house in the meantime.
It is based on the YZF750 gearbox indeed, 'special' parts are drums and selector forks, as already mentioned.

[cobbadiggabuddyblooo]

I cross referenced the yzf and TDM gearbox parts too and items like the bearings , clips and a couple of washer/spacers are inter changeable on all 3 bikes.
I'd put money on yamaha using similar shaft diameters and gear inner diameters on all 3 bikes too.
But like the YZF , the tdm900 would have different shaft lengths because they are housed in different frames. The slipper clutch I run from Sigma is listed as TDM900 ...
I you could find someone with a tdm900 motor apart and look at the selector drum, this may work as such because it utilises the 2 pivot shafts for the selector forks just like the trx.
You can see in the photo on the listing you put up Mince, the YZF has 1 pivot shaft...

For Huby to place an R6 gearbox into a TRX case, the bearings and gear clusters would need to be the same complete width as the TRX to fit into the case.
The horror section is selector drum/forks set up.
The 5 individual TRX gears are slightly wider than the R6 and TDM900 gears so they obviously made them a little narrower on the 6 speed gears to squeeze the extra gear in the same overall cluster width.

So not a cluster fuk,

I'm trying to find via other sources if the tdm900 selector barrel will work in a trx case and put the word out if the YZF gears fit on a TDM shafts too.

[Mincehead]

Cheers guys, all fuel for the fire.

[cobbadiggabuddyblooo]

TDM 900 selector barrel will fit in trx cases but that's where it stops Mince.
So 1 item you can get away with.
YZF gears don't fit onto the TDM 900 shafts.
Huby has built a few 6 speeds using R6 gears but has to manufacture new shafts and selector forks.

[Tarwetijger]

Here ya go.

[Mincehead]

GREAT, cheers Tarwetijger.