Dong Fang DF 250 RTB Bobber Information

[Roadkill]

Ya that was the flake GARDO, but his record was revoked when it was proved he was measuring his speed by invoking a shortcut through a worm hole in the 5th dimension, to yield a 90MHP 167FMM.

The title now belongs to our very own dan here; but i suspect his speedometer is also utilizing some sort of time-space altering mechanism as theorized by quantum mechanics and string theory...

That's way more complex than I imagined. I thought it was the Oval Office Theorem which states that if one person believes it, it's true.

[DanDaMan]

70 in a 250cc isn't unheard of axa , u guys just havent geared high enough , just looked only c 1/2 my front sprocket , but looks like a 17 , but if I recall rear may be 33 not 35

AND I ordered a 30 (didn't fit) because im still capped by valve float at near 75 ( very occasionally ) but if you refuse to gear for perfect conditions you will NEVER get any faster

ur gearing 13-45 stock , most u only drop a 35 rear of which adds 12% speed boost , my front alone gave me a 40% + my 18% from rear over stock , that's why my 4rth gear is as fast as your 5th

55cap stock + ur 12% = just over 60 , add 15 front adds nuther 20% , letting u near 70 when valves start floating
50 + my 58% = 80 (my stock speed started lower cause smaller rear tire , since added slighty larger rear)

and I wil ride to san anton or Houston to go for aride to prove it

be4 I dumped her I was reaching 80 perfect conditions ,but speedo read 10% fast , have since added a 10% larger front tire and regularly cruise at 60 (which is my 4th gear to 5th gear shift) engine purring and up to 75 engine screaming perfect conditions

[axa]

70 in a 250cc isn't unheard of axa , u guys just havent geared high enough , just looked only c 1/2 my front sprocket , but looks like a 17 , but if I recall rear may be 33 not 35

AND I ordered a 30 (didn't fit) because im still capped by valve float at near 75 ( very occasionally ) but if you refuse to gear for perfect conditions you will NEVER get any faster

ur gearing 13-45 stock , most u only drop a 35 rear of which adds 12% speed boost , my front alone gave me a 40% + my 18% from rear over stock , that's why my 4rth gear is as fast as your 5th

55cap stock + ur 12% = just over 60 , add 15 front adds nuther 20% , letting u near 70 when valves start floating
50 + my 58% = 80 (my stock speed started lower cause smaller rear tire , since added slighty larger rear)

and I wil ride to san anton or Houston to go for aride to prove it

be4 I dumped her I was reaching 80 perfect conditions ,but speedo read 10% fast , have since added a 10% larger front tire and regularly cruise at 60 (which is my 4th gear to 5th gear shift) engine purring and up to 75 engine screaming perfect conditions

ok dan, soon enough i will have a ported, polished, back cut. 3 angle seat, decked head. honed and cross hatched, .2 over bore, treated cylinder, all with a static 10.5CR.... then at least i will know for sure what is the approximate limits of this engine's power.

But right now i severely doubt i will ever see close to 80mph in any condition, for there will not be enough power produced to overcome the wind resistances at highway speeds, let alone a the resistance of a fat under-inflated car tire, and game of thrones back rest... Unless of course i find myself riding along side Schroedinger cat in his parallel universe...
but apparently you can, so what can i say...

ps, this is a a 229cc not 250, and not just any 250cc, a OHV push rod with all its valve train mass.
that right there is a world of difference with a true 250cc water cooled OHC engine can produce... a world of difference.

[Roadkill]

70 in a 250cc isn't unheard of axa , u guys just havent geared high enough , just looked only c 1/2 my front sprocket , but looks like a 17 , but if I recall rear may be 33 not 35

AND I ordered a 30 (didn't fit) because im still capped by valve float at near 75 ( very occasionally ) but if you refuse to gear for perfect conditions you will NEVER get any faster

ur gearing 13-45 stock , most u only drop a 35 rear of which adds 12% speed boost , my front alone gave me a 40% + my 18% from rear over stock , that's why my 4rth gear is as fast as your 5th

55cap stock + ur 12% = just over 60 , add 15 front adds nuther 20% , letting u near 70 when valves start floating
50 + my 58% = 80 (my stock speed started lower cause smaller rear tire , since added slighty larger rear)

and I wil ride to san anton or Houston to go for aride to prove it

be4 I dumped her I was reaching 80 perfect conditions ,but speedo read 10% fast , have since added a 10% larger front tire and regularly cruise at 60 (which is my 4th gear to 5th gear shift) engine purring and up to 75 engine screaming perfect conditions

Dan, The only thing that matters to me is how fast mine will go and I think with the set up I have, 60mph might be it, but I don't know cause I ride her in town only and have never had enough free space to get her to top end. Mine has only upgraded ignition, a Mikuni VM series carb, and I think a 30 rear sprocket. You have gotten most of your top end with gear changes? I am interested in knowing how that tall gearing performs in day to day riding. I would think that you spend a lot of time in the lower gears or lugging the engine. There is fixed amount of power in any engine, of course, so compromises have to be made to get that high top speed. Is it still fun to ride? Motorcycles are like girls. If you don't mind riding a cheap one, you can afford a couple.

Axa, I've never ridden mine at anything over 55mph, but I'm pretty sure she hit 80 in the the crate on the way from LA to TX. Some of those long haul trucks go pretty quick on the interstate.

Change in topic. I think I saw our bike on a Chinese website for $800 each in a container of 10 minimum. I would never want to deal with the import and shipping paperwork, but the CCW thing and our interest in a better engine make me wonder if it would be practical to special order some that had what we want in a motor? It seems to have worked for CCW for a while at least. Guess it would be a "Big Dong"

[barnone]

Seems that the subscription notification here has not been working for me so I am behind in keeping up with the news.

Looks to me that CCW is still selling the Heist.

Last year a local Cherokee Indian and I thought about ordering a container load of DFs to sell at his shop but he ran into problems with the tribe with his business so nothing came of it.

[barnone]

8.5:1

9.0:1?

[Roadkill]

Seems that the subscription notification here has not been working for me so I am behind in keeping up with the news.

Looks to me that CCW is still selling the Heist.

Last year a local Cherokee Indian and I thought about ordering a container load of DFs to sell at his shop but he ran into problems with the tribe with his business so nothing came of it.

It would seem that it's a universal thing now for all governments to "protect" us and if it benifits them, why, WIN, WIN!

[barnone]

anyone with a infrared thermometer (and running bike of course) care to get there engine nice and hot and take some readings for me??
Im looking for the following in order to best guess the max CR i can go with.

- Ambient temperature (current temp)
- hottest temperature found on the engine/ where it was found

As i mention we got time as i have to ship these new parts back to have them replaced, so any help is appreciated.

0202141058-01.jpg

I have the 14mm TTO cylinder head temperature gauge (CHT) on my DF and also on my Ural. I see maximum temps of about 400 F on the DF and 425 F on the Ural on high speed () runs and long steep grades where the load on the engine is the greatest. These temps are measured under the spark plug at the head. As an aside the temp drops when either bike is idling at a stop light.

500 F is suppose to be a rule of thumb dangerous cylinder head temperature. I also have a infrared temp meter and the CHT is the highest temp place on my bikes.

http://www.ebay.com/itm/Trail-Tech-T...a6b575&vxp=mtr



IMG_2362.jpg
I get higher CHT on my Ural.

[barnone]

It would seem that it's a universal thing now for all governments to "protect" us and if it benifits them, why, WIN, WIN!

I did not mean to start a discussion on government. There are plenty of sites on the net for that.
It would be nice if we just kept this forum for DF issues and discussion.

[axa]

I have the 14mm TTO cylinder head temperature gauge (CHT) on my DF and also on my Ural. I see maximum temps of about 400 F on the DF and 425 F on the Ural on high speed () runs and long steep grades where the load on the engine is the greatest. These temps are measured under the spark plug at the head. As an aside the temp drops when either bike is idling at a stop light.

.

Thanks this is what i needed to know when as i factor a safe CR, for temp is one factor in detonation...
200°C is indeed what is expected.

more about this in my next post.