Another RED twooooo stroke. Barkas.Originally Posted by guyhockley
https://wp.ifaclub.co.uk/the-vehicles/
And crank from Syrena 104 105 car
And 1938 Steinhagen i Stransky engines from Poland, but didnt found the car
Hardcore Biker
Another RED twooooo stroke. Barkas.
https://wp.ifaclub.co.uk/the-vehicles/
And crank from Syrena 104 105 car
And 1938 Steinhagen i Stransky engines from Poland, but didnt found the car
Hardcore Biker
Hardcore Biker
Below is the picture of our inertial dyno. We've tested 23 to 35 cc engines with 2 to 12 hp at up to 25,000 rpm. It's on a mobile cart.
Lohring Miller
Forum whore
Here is our mobile dyno for 6,5 cc F3D engines. About 5hp; maximum rpm is about 36.000. Note the quick-change pipe mounting.
Hardcore Biker
A bit OT, but who (besides Nova) is making 2T race transmissions? Do the shifter kart engine manufacturers do them in house or are there a few "standard" sources that provide them to the OEMs?
It used to be that if you wanted a race transmission you could start with an RD/RZ and drop TZ parts in, or go to your local dealer and buy RS125/TZ125 parts, or maybe pick up something from a 125/250 Rotax race engine. But all those engines have been out of production for 10-25 years now.
I've heard that the NSF250R is basically using the late RS125 box, but I don't know how available bits from something like that would be, especially here in the US where GP racing is pretty much dead.
At one time in Italy you could become a m/c manufacturer by shopping at Minarelli/Franco Morini for engine, Dell'Orto for carb, Verlicchi for a frame, Grimeca for wheels, Marzocchi or several others for suspension, CEV/Aprilia for electrics etc etc and then just assemble the parts. Do the modern 2T race engine makers have a race transmission company they shop at who can supply "off the shelf" turn key primary drives/transmissions?
Many of the modern 4T transmissions have plain bearings and need a pressure oil feed to them (but not Ducati, as used in the Tularis 2T twin special) so they are not suitable for easy grafting in to a DIY project unless an oil pump is added. A transmission/clutch sized for the torque spikes of an 1100 Duc twin seems like it might be overkill (though strong) for a 125-250 2T engine. But the Ducati looks like it is about the main option for a readily available and affordable gearbox clutch for an engine project. I suspect there are other options but I'm looking in the wrong places for them.
cheers,
Michael
Low personal B.M.E.P.
Might not be the layout you want Michael - but have a look at TT Industries website. 5 and 6 speed boxes with magnesium cases even...
Sized for good HP and quite light.
Bruce Verdon's a good guy - and open to doing specials if the price is right. More interested if he sees a market.
And not far up the coast from Husa...
BTW, I've yet to see a late 4T gearbox with plain bearings. Got an example ?
Fair weather rider
TZ250 gear box parts seem still available at Yamaha (www.yamaha-original-teile.de at least has a lot). How about 250 MX stuff? KTM gear boxes are great stuff...
Moped rider
Now for something completely different. https://www.youtube.com/watch?v=JxLb3Yqqds4 https://www.youtube.com/watch?v=brT-BafQ-eg
Hardcore Biker
I've got a 2015 KTM 250SX engine and the 5 speed has a larger, instead of smaller, % drop from 4->5. I can put an entire 6 speed from an XC (not the XC-W) in and it would be an improvement but the 3rd through 6th % drops are kind of wide, all of them more than the typical Ducati (and 5->6 looks to be about 25-30% wider than would be appropriate for higher speed track use).
A complete new XC box is about US$900 for the gears/shafts/clips/shims plus the drum/forks add another $100-200. I looked at the 2013 250 SX-F fiche and that 6 speed seems possible on the ratios but it has a few bushings and I don't know if it is a drop in. The 2T 250/350 share transmissions with the 350 4T but I can't find any significant interchange with the 250-F, and later Fs are 5 speed.
FWIW, the 250SX 5 speed drops are 20, 16.7, 14.3 and 16.5% from bottom to top.
A 350 Bultaco/AJR is 25, 17, 15 and 8.
The XC has 24.4, 20, 16.4, 15.8 and 12.6% so 6th could be closer to 5th.
The "small" Duc standard street 6 speed (not the high first gear Corse) is 32.3, 20, 15.2, 11.5 and 7.7. The Duc Corse is pretty much the same but with a 28% drop when shifting to 2nd.
I have a 2003 TZ250 as 25.6, 16.1, 11.9, 8.3 and 7.4%
Those Ducati ratios look pretty good to me and are used in a good 10+ years of recent models and are plentiful on eBay. But that means making new crank cases, which could be a fun project and also let me see about adding a balance shaft, but it pushes a running bike even farther into the already hazy future.
Yes, it may well be that for the few times it gets run as a track day bike (if I get it built) the 5 speed with a fairly standard MX tune (I bought a Pro Circuit chamber that is supposed to maintain the 50 hp peak for another 1000-1500 RPM) will be fine for my mediocre riding skills, and the XC would be better. But even though I'm transitioning to "former racer" I still like to have things the way I think they ought to be. I wish I'd known more about KTM when I bought this engine, and was clairvoyant so I could see that they'd be adding an effective balance shaft in the major engine redesign for 2017. Neil's transfer port injection which is on some new KTMs would be nice to have too.
Greg, I was surprised when I looked at late Yam/Kawa/Suzuki 600 part fiches as they were my first though on possible donors. Not only are the idlers generally running on a bush (separate from the gear) but some of those bushes have internal splines to keep them from spinning on the shafts, which I'd never seen before. I looked at some photos of the parts on eBay to verify it wasn't just needle bearing details being left off the drawing. In some you can see the internal oil grooves and drillings to let oil get out to the bush/gear interface.
The TT Industries parts do have a good reputation, but isn't everything they do for pre-unit British stuff?
An XC 6 speed with tighter custom 5th and 6th gears would most likely be fine, if it was possible to get those gears designed and made at an affordable price. But for the price of those gears (and probably for less) I can get a complete Duc lower end and have clutch and primary gears too, as well as no special replacement parts.
A pal sent some primary gear parts to Ellis Moore at Moore Engineering in England to get some parts made but he told me that Ellis had a race crash last year that left him paralyzed from the chest down and he's closed his shop and his parts are coming back. Ellis was keen on one-off stuff (which Nova is not) and appears to have supplied high-quality parts at reasonable prices so his accident is a loss to the industry (as well as being tragic, I know other racers who've ended up in wheelchairs).
A friend who purchased a TZ125 last year has been telling me of some major parts that aren't to be found as NOS, and now that I'm done with vintage bikes I'd like my remaining projects to not involve massive part searches. It is difficult enough to finish things without getting hung up on "wish I could find a new one of these" issues.
So when I saw various cool 125-250 shifter kart motors of modern manufacture it had me wondering what they are doing for gearboxes, and this seemed like the place mostly likely to have someone who knows.
cheers,
Michael
Anorak
NSR250 has a cassette box and gear oiler. You can fit the alternative ratios from a early RS250
Pretty sure the shifter karts manufacturers make their own
the CR honda based shifter karts use a later engine with a early gearbox
The earlier Husaberg had very compact gearboxs based on Husky's. 4/5/6 options wide and close
one of the stonger gearboxs i have seen with decent ratios is the humble VT250 honda they used the same basic gearbox on the MVX250 triple and the CBR250.
they have a planetary gear mechanism and thin big dia gears hence they are very narrow clusters
i also think BRT make their own gearboxs for their new engines
one gearbox that does have pretty reasonable gear ratios is the GT380 they only changed two ratios for the Barton and one of them is able to be subsituted by using a GT250A second gear
the similar gearset was used over a wide range of Suzukis
Kinky is using a feather. Perverted is using the whole chicken
Hardcore Biker
Thanks for that information. I should have included that I'm looking for modern stuff. I've sold all my vintage bikes and bits and I don't intend to have them again. Been there, did that, and wasted too many years with "I wonder where I can find one of these?" issues so while it doesn't have to be 2019, parts need to still be readily available off the shelf at a US warehouse.
The Banshee has been out of production for about 10 years now I think (and has ATV-style ratios) so even that is getting a bit on the old side (to match me).
If the kart folks are doing everything in house that sounds like fairly low production quantities with subsequent higher prices, so Ducati is looking like a distinct possibility.
cheers,
Michael
Anorak
Pretty sure the Vt's probably still in production in one form or another somewhere a gearbox doesnt care how old it is only how it works.
Kinky is using a feather. Perverted is using the whole chicken
Hardcore Biker
Most gears in Italy were made by CIMA at Bologna
Hardcore Biker
Thanks Jan
http://www.cimaingranaggi.it/en
Highway Biker
The customer hecitate few months, now it is the last iteration. CNC machining would start next week. Thanks for interesting patents!
Thanks Fritz!Here is our mobile dyno for 6,5 cc F3D engines. About 5hp; maximum rpm is about 36.000. Note the quick-change pipe mounting
Thanks Lohring!Below is the picture of our inertial dyno. We've tested 23 to 35 cc engines with 2 to 12 hp at up to 25,000 rpm. It's on a mobile cart.
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