Magician 250 Rear Wheel Upgrade Hawk Owners Help Please

Drak · 04-20-2020, 05:15 PM

Hello,
I've had a magician for the last 2 years and I've put about 1600m on it. Overall I've been very pleased with my purchase. I've done some mods such as changing the main to a 110, removing the cat and opening up the air box as well as adding a 17t front sprocket. I would like to drop my gear ratio a bit more from 2.65. As has been covered in other threads a rear sprocket with fewer teeth than a 45 in a 428 chain is impossible to find. So I've decided I want to do away with the rear wheel, preferably a hawk 18'' rim. I can get one locally for $140 and if I can make it work I'll be very pleased. However I'm willing to change the swing arm if I have too and that's what I need help with.

Can someone please give me the specs one their hawk swing arm? ie dimensions where the spindle secures the arm to the frame and where the shock tower bolts in.

If anyone know of any other rear wheel assemblies that would work as well please let me know.

My goal is get a bigger overall tire, something around 26'' outside diameter (like the hawk) and be able to have options for different rear sprockets.

Drak · 04-20-2020, 11:24 PM

Just trying to determine if the hawk swing arm is compatible with the magician before I start wasting money.

Megadan · 04-21-2020, 05:04 AM

Short of taking my Hawk apart to measure, this thread may be of help to you. The Brozz swing arm is almost identical in terms of measurements to the Hawk, and there are some pictures with a ruler that should give a rough idea of what you might need. https://www.chinariders.net/showthread.php?t=24066

As far as more accurate, unless somebody else can chime in sooner, I will try to get them as soon as I get home.

Drak · 04-21-2020, 09:46 AM

That was very helpful, thanks. I saw in another thread mention that bolt that connects the arm to the frame is 14x1.5x260mm. That should be everything I need for the rear, now about the shock tower...

After some research I discovered that I will have to get the arm to make the hawk rear wheel work on the magician. The two rotors and positions of the calipers are completely different. I will have to get a hawk rear caliper and rotor; which isn't too expensive. All together I'm looking at about 300 bucks.

I keep my bike at my folks place in the country; I'll be going out there to compare measurements in a couple days.

One more question...most of the riding I do on the bike is forestry roads and pipe line. Nothing extreme at all. I do go on a 2 lane highway at 55 to get to these trails. I want a little better road capibility. This thing just screams at 55...will putting this larger tire on and a 40t sprocket give me a better balance between the road and the trails? According to my math, doing this will drop my ratio about 22% from 2.65.

I will continue to update this thread as I go through the he process.

old timer · 04-21-2020, 01:45 PM

Drak, I just added a 40 tooth rear sprocket to my magician two days ago. If any one is interested and responds I'll post all the details.
Old Timer

Drak · 04-21-2020, 03:14 PM

Very very interested. Please let me know where you got it, your process and what kind of difference it made.

Drak · 04-21-2020, 03:17 PM

I saw lots of 40t sprockets for a 520 chain but nothing for a 428.

China Rider 27 · 04-21-2020, 03:31 PM

Quote:

Originally Posted by old timer

Drak, I just added a 40 tooth rear sprocket to my magician two days ago. If any one is interested and responds I'll post all the details.
Old Timer

By all means! Do a write up on how you did it. And post some pictures!

old timer · 04-25-2020, 12:56 PM

I wanted to change my Magician rear sprocket to a 40 tooth. I could not find anybody that sells one, so I ordered one from PBI sprockets in Oregon. I ordered the aluminum as the deal was not available in that size. PBI ass for some measurements, the center hole which is 45 mm, The diameter of the circle which runs through the mounting holes which was 136 mm, and the mounting hole dimensions which were 8 mm. I ordered on Tuesday afternoon and the sprocket was in my mailbox at 11:15 on Friday morning kudos to PBR. I had to use some washers, four per mounting bolt Between the sprocket and the hub mounting tabs. Standard 5/16 washers work just fine. I had to cut off four millimeters off one side of the two washers that were closest to the sprocket. That allowed clearance for the chain. It was fairly easy to do and the total cost was under $45.

China Rider 27 · 04-25-2020, 11:53 PM

My hats off to you for that job! The issue with a 40 tooth on the Magician is the fact that the six mounting holes are 23.5 mm in diameter and border right on the chain at a 45 tooth. So when you got to 40 teeth there simply is not enough room for the chain not to hit the large 23.5 mm round studs that that go through the sprocket and are held by bolts in the center and thus weakening the sprocket. Sounds like you removed the round mounting studs that go through the stock sprocket and used washers to back space the sprocket with an 8 mm retaining bolt to hold it all? I say to be sure I understand how you did it. Here is a diagram for sprocket measurements.

old timer · 04-28-2020, 11:35 PM

The sprocket I had made had no lightening holes, and the 6 mounting holes were 8mm in diameter. So each 8mm mounting bolt went through a lock washer, then through the sprocket, then through the 4 5/16" spacer washers and then screws into the hub. The two 5/16 washers nearest the sprocket had 4mm cut off one side. This clearance allows the chain to go around the sprocket without hitting the spacer washers.

old timer

China Rider 27 · 04-29-2020, 12:06 PM

Quote:

Originally Posted by old timer

The sprocket I had made had no lightening holes, and the 6 mounting holes were 8mm in diameter. So each 8mm mounting bolt went through a lock washer, then through the sprocket, then through the 4 5/16" spacer washers and then screws into the hub. The two 5/16 washers nearest the sprocket had 4mm cut off one side. This clearance allows the chain to go around the sprocket without hitting the spacer washers.

old timer

The discs that mount through the sprocket appear to be some type of cush bearing with a rubber center piece? I have not taken it apart so I am not sure but that would seem to be the only purpose to take up some of the chain force on the sprocket. So how does it run compared to the 45? Have you done any speed testing on it?

old timer · 05-01-2020, 04:51 PM

Yes, those spacers are also dampers. However, as a Yamaha/Honda for 25 years, I've never see another cycle with those type of dampers. I've been inside most of the time sort of sickly the last two weeks, so have been out to ride just around town. No change noted at up to medium speeds. I'll check the higher speeds as soon as i am able.
Thanks for your interest

China Rider 27 · 05-01-2020, 09:48 PM

Rest and take it easy Old Timer, get to it when you feel like it. The only way to realize the speed potential of the 250 cg motor is through proper gearing and for the Magician that is a lower rear ratio. I am thinking the rear wheel swap might give more flexibility.

Drak · 05-03-2020, 04:39 PM

I ended up ditching my original plan; I just can't justify that kind of money to drop my ratio another 10% with a larger wheel. I ended up doing the same thing as old timer and got a 40t sprocket fabricated by PBI. Definitely dropped my rpm. I just went about 50mph and for once the bike wasn't screaming. I couldn't be happier. Thanks so much old timer. You saved me a lot of time and frustration.

I got mine made to the same specs as old timer but for some reason or another I had to change a few things from what he did. My original sprocket was spaced 10mm off the hub. I had to use 6 M8 flat washers to achieve the same spacing as before. I also couldn't use the original flange bolts, they were touching the chain. I could have ground down the flange but I opted to just get new hardware.

04-20-2020, 05:15 PM	#1
Drak Join Date: Jan 2020 Posts: 15	Magician 250 Rear Wheel Upgrade Hawk Owners Help Please Hello, I've had a magician for the last 2 years and I've put about 1600m on it. Overall I've been very pleased with my purchase. I've done some mods such as changing the main to a 110, removing the cat and opening up the air box as well as adding a 17t front sprocket. I would like to drop my gear ratio a bit more from 2.65. As has been covered in other threads a rear sprocket with fewer teeth than a 45 in a 428 chain is impossible to find. So I've decided I want to do away with the rear wheel, preferably a hawk 18'' rim. I can get one locally for $140 and if I can make it work I'll be very pleased. However I'm willing to change the swing arm if I have too and that's what I need help with. Can someone please give me the specs one their hawk swing arm? ie dimensions where the spindle secures the arm to the frame and where the shock tower bolts in. If anyone know of any other rear wheel assemblies that would work as well please let me know. My goal is get a bigger overall tire, something around 26'' outside diameter (like the hawk) and be able to have options for different rear sprockets.
	0

04-21-2020, 05:04 AM	#3
Megadan Join Date: Apr 2017 Location: Omaha, NE Posts: 8,053	Short of taking my Hawk apart to measure, this thread may be of help to you. The Brozz swing arm is almost identical in terms of measurements to the Hawk, and there are some pictures with a ruler that should give a rough idea of what you might need. https://www.chinariders.net/showthread.php?t=24066 As far as more accurate, unless somebody else can chime in sooner, I will try to get them as soon as I get home. __________________ Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124
	1

04-28-2020, 11:35 PM	#11
old timer Join Date: Mar 2020 Posts: 8	Magician 40T rear sprocket The sprocket I had made had no lightening holes, and the 6 mounting holes were 8mm in diameter. So each 8mm mounting bolt went through a lock washer, then through the sprocket, then through the 4 5/16" spacer washers and then screws into the hub. The two 5/16 washers nearest the sprocket had 4mm cut off one side. This clearance allows the chain to go around the sprocket without hitting the spacer washers. old timer
	1

04-20-2020, 11:24 PM	#2
Drak Join Date: Jan 2020 Posts: 15	Just trying to determine if the hawk swing arm is compatible with the magician before I start wasting money.
	0

04-21-2020, 09:46 AM	#4
Drak Join Date: Jan 2020 Posts: 15	That was very helpful, thanks. I saw in another thread mention that bolt that connects the arm to the frame is 14x1.5x260mm. That should be everything I need for the rear, now about the shock tower... After some research I discovered that I will have to get the arm to make the hawk rear wheel work on the magician. The two rotors and positions of the calipers are completely different. I will have to get a hawk rear caliper and rotor; which isn't too expensive. All together I'm looking at about 300 bucks. I keep my bike at my folks place in the country; I'll be going out there to compare measurements in a couple days. One more question...most of the riding I do on the bike is forestry roads and pipe line. Nothing extreme at all. I do go on a 2 lane highway at 55 to get to these trails. I want a little better road capibility. This thing just screams at 55...will putting this larger tire on and a 40t sprocket give me a better balance between the road and the trails? According to my math, doing this will drop my ratio about 22% from 2.65. I will continue to update this thread as I go through the he process.
	0

04-21-2020, 01:45 PM	#5
old timer Join Date: Mar 2020 Posts: 8	Drak, I just added a 40 tooth rear sprocket to my magician two days ago. If any one is interested and responds I'll post all the details. Old Timer
	0

04-21-2020, 03:14 PM	#6
Drak Join Date: Jan 2020 Posts: 15	Very very interested. Please let me know where you got it, your process and what kind of difference it made.
	0

04-21-2020, 03:17 PM	#7
Drak Join Date: Jan 2020 Posts: 15	I saw lots of 40t sprockets for a 520 chain but nothing for a 428.
	0

04-25-2020, 12:56 PM	#9
old timer Join Date: Mar 2020 Posts: 8	I wanted to change my Magician rear sprocket to a 40 tooth. I could not find anybody that sells one, so I ordered one from PBI sprockets in Oregon. I ordered the aluminum as the deal was not available in that size. PBI ass for some measurements, the center hole which is 45 mm, The diameter of the circle which runs through the mounting holes which was 136 mm, and the mounting hole dimensions which were 8 mm. I ordered on Tuesday afternoon and the sprocket was in my mailbox at 11:15 on Friday morning kudos to PBR. I had to use some washers, four per mounting bolt Between the sprocket and the hub mounting tabs. Standard 5/16 washers work just fine. I had to cut off four millimeters off one side of the two washers that were closest to the sprocket. That allowed clearance for the chain. It was fairly easy to do and the total cost was under $45.
	1

05-01-2020, 04:51 PM	#13
old timer Join Date: Mar 2020 Posts: 8	Yes, those spacers are also dampers. However, as a Yamaha/Honda for 25 years, I've never see another cycle with those type of dampers. I've been inside most of the time sort of sickly the last two weeks, so have been out to ride just around town. No change noted at up to medium speeds. I'll check the higher speeds as soon as i am able. Thanks for your interest
	0

05-01-2020, 09:48 PM	#14
China Rider 27 Join Date: Dec 2018 Location: PNW Posts: 982	Rest and take it easy Old Timer, get to it when you feel like it. The only way to realize the speed potential of the 250 cg motor is through proper gearing and for the Magician that is a lower rear ratio. I am thinking the rear wheel swap might give more flexibility.
	0