Dong Fang DF 250 RTB Bobber Information

**Aboshi** · 03-22-2011, 05:58 PM

barnone:

Can you link me the exact front sprocket you wound up buying. I know you said you need to get more links but if you were to drop the rear sprocket to a 38T you shouldn't need to add any links, plus it would add on about 8-10mph topping out at around 81mph. I saw that Gordo posted that the heist has a 15/41 (seems like a better setup) but they would have to be running a 420 chain if that front chain guide is in tact like on the dong fang, I do however see that CCW left the spindle in tact for the kick start. I really wish they did the same on the dong fang =(
Either way I'm all setup and ready for delivery, I had to get a motorcycle cover because I live directly on the beach and no garage...
I also have some leather laying around and I hope I can cover that seat with it =)
From what it looks like though they didn't use a seat pan, it looks more like a bicycle seat and a bicycle shock for the damping (correct me if I'm wrong).

**barnone** · 03-22-2011, 09:31 PM

Aboshi,
Funny you should ask about sprockets because I just changed out the rear and went with the 33 tooth below. Had to remove three links from the 520 chain but kept the stock 13 front tooth because I decided to not modify the front sprocket cover.

Front Sprocket JTF270.14 14 tooth
Rear Sprocket JTR279.33 33 tooth
They are the ones you gave me in post 185. I got mine from Old Bike Barn but anyone that handles JT sprockets should be able to get them. Rear fit just fine but you need a big pair of o-ring pliers or fight it like I did with a couple of screw drivers.

33/13 = 2.53 my current ratio
45/13 = 3.46 stock DF
38/13 = 2.92
41/15 = 2.73 Heist stock

I only had time for a short ride but it sure was nice to be able to get up to 20 MPH indicated in first gear. It might be too high a ratio but I'm going to try it for a while and report my finding later. Your ratio of 13/38 might be better.

Actually the seat is pretty nice. I adjusted the preload to the max on the spring under the seat to get me sitting up straight with my new bars. The sheep skin or a leather cover like you suggested will help.

EDIT: Stock DF rear sprocket is 45 teeth not 40.!!!!!!!!!

**Aboshi** · 03-22-2011, 09:49 PM

Good to see the sprockets I posted earlier will work =)
Running 33 tooth is crazy!
Do you feel like the bike is a lot slower getting up to speed? Also that is going to put a lot of stress on these tiny motors.
I was going to try to run a 14/38 but if you say its not worth the hassle of running a 14T front I'll stick with the 13 but then run a 38T or 37T in the rear but I'll have to do some math first =(
Also don't forget getting that advanced curve CDI and performance coil will also make a big difference.

**barnone** · 03-23-2011, 12:23 AM

Yes, the 33 might be too extreme.

I'll make a run out to the ranch tomorrow that will give me a better feel. The engine seems to have good low end torque.

I'd say just figure out your rear sprocket size for your desired ratio and leave the front 13 tooth. Normally I like to increase the front which I have done on all my other bikes but a 14 tooth front will be real close to a wire in the area. You will see what I am talking about when you get your DF.

**Aboshi** · 03-23-2011, 02:12 AM

I hope you have fun on your ride tomorrow and get some good feedback on that sprocket setup =)
From what your saying on how close it would be to go with the 14T the only way it would be worth it is to go with a 420 setup, but that would cost around $80 or so.
I think I'll just stick with the 13T front for now and go with a 37T or a 36T in the rear but I will have to work out the math between both. I cant wait to hear your feedback on the current setup you have =)

**redrover** · 03-23-2011, 03:55 AM

Barnone, since you have some miles on your bike now, can you share how well the paint is holding up on the frame and sheet metal? The paint on the fenders and tank look pretty thick in photos, how about the frame?

**jape** · 03-23-2011, 07:52 AM

Originally Posted by Aboshi

I hope you have fun on your ride tomorrow and get some good feedback on that sprocket setup =)
From what your saying on how close it would be to go with the 14T the only way it would be worth it is to go with a 420 setup, but that would cost around $80 or so.
I think I'll just stick with the 13T front for now and go with a 37T or a 36T in the rear but I will have to work out the math between both. I cant wait to hear your feedback on the current setup you have =)

I know it is a different machine but on the Kinlon 200cc, mine is, if i remember, now 13/36, i get true GPS 60mph, cruises at that no probs, 5mph faster if no wind or I wind it right up etc.
thats with knobbies. So with your wheels, so averaging out weight and power differences, you will get 65mph cruise but not a lot more i reckon. if pushed, 70 if you drop a cog and rip it if in trouble.

**barnone** · 03-23-2011, 01:34 PM

Originally Posted by redrover

Barnone, since you have some miles on your bike now, can you share how well the paint is holding up on the frame and sheet metal? The paint on the fenders and tank look pretty thick in photos, how about the frame?

Paint is holding up fine but I keep her in the shop. Frame is flat black so if any problem areas occur it will be an easy touch up.

The more I work on this bike the more I think it is a good job by Dong Fang. Sure is easy to work on.

So far so good but remember it's a 229cc push rod engine. She like to cruise along.

Next project is to move the rear turn signals so I can mount some saddlebags or ammo cans on a rear rack that I need to make. Oh and I would like to rig up a center stand. I find that I do better chain maintenance with a center stand.

**barnone** · 03-23-2011, 01:44 PM

Originally Posted by jape

I know it is a different machine but on the Kinlon 200cc, mine is, if i remember, now 13/36, i get true GPS 60mph, cruises at that no probs, 5mph faster if no wind or I wind it right up etc.
thats with knobbies. So with your wheels, so averaging out weight and power differences, you will get 65mph cruise but not a lot more i reckon. if pushed, 70 if you drop a cog and rip it if in trouble.

I'll be happy with a 60 MPH cruise with lower RPM in fifth gear as a kinda overdrive and don't mind a down shift. Might even end up with a higher top speed in fourth gear which is ok.

**redrover** · 03-23-2011, 04:10 PM

Originally Posted by barnone

Paint is holding up fine but I keep her in the shop. Frame is flat black so if any problem areas occur it will be an easy touch up.

The more I work on this bike the more I think it is a good job by Dong Fang. Sure is easy to work on.

So far so good but remember it's a 229cc push rod engine. She like to cruise along.

Next project is to move the rear turn signals so I can mount some saddlebags or ammo cans on a rear rack that I need to make. Oh and I would like to rig up a center stand. I find that I do better chain maintenance with a center stand.

Thanks for the info, Barnone; I like the simplicity and kinda 'eclectic' look of the DF. That push rod engine has a good reputation, and as you say, everything is right out there, easy to work on. Looking good...