Another Disc Brake Conversion Thread

[jeffrow68]

The last few days I have been researching a rear disc brake conversion for my 230F. I previously owned a 230F that I was rebuilding and I planned to do this conversion but it was stolen before I could complete it. I found some posts from 5 years ago where I researched this conversion that had some good information. I am planning this conversion again (if my bike doesn't get stolen) but still can't decide on the most economical option. i find that the Honda 250/450 brake systems are very reasonable on eBay so I am leaning towards this, but all the 250/450X wheels are made of gold.  I am really struggling with wheel options. I want an 18" wheel that I could just change out the bearings with 230F bearings to fit the smaller axle but I don't have enough info to know what works. Then, I am not sure about using different parts and compatibility issues. 

So, any of you guys that have done this, what is the best combo that you would recommend?  It seems that I can find a reasonable brake system but not a matching wheel or vice-versa. Any info is appreciated, and if you can give specifics that would be great.

[Chuck.]

Some have converted using L rear wheel and swingarm. I did my XR conversion using a 90-95 XR250R swing arm and brake, and a RM wheel, because the XRs use a 17mm axle like the 230s.
Having said that a 230 drum brake is very good, it uses the same shoes as the XR200 front and rear. IMO a far superior brake than most other drum brakes. And there are work arounds to mitigate most of the drum brake issues.

[ricky racer]

12 hours ago, Chuck. said:

Some have converted using L rear wheel and swingarm. I did my XR conversion using a 90-95 XR250R swing arm and brake, and a RM wheel, because the XRs use a 17mm axle like the 230s.
Having said that a 230 drum brake is very good, it uses the same shoes as the XR200 front and rear. IMO a far superior brake than most other drum brakes. And there are work arounds to mitigate most of the drum brake issues.

Did you have the RM wheel already? Why not use a xr250 wheel that match's the swing arm. Thanks. Linkage the same as the 230? shock length need to be changed at all? doing the swap this winter. Thank you Chuck.

[Chuck.]

I had the RM wheel and it was lighter than the XR250 wheel, just needed to make spacers.

I don't think the linkage is the same because the XRs connect to the linkage above the SA and I believe the 230's connects to the linkage below the swing arm. 

[MetricMuscle]

On 8/10/2017 at 10:16 PM, jeffrow68 said:

The last few days I have been researching a rear disc brake conversion for my 230F. I previously owned a 230F that I was rebuilding and I planned to do this conversion but it was stolen before I could complete it. I found some posts from 5 years ago where I researched this conversion that had some good information. I am planning this conversion again (if my bike doesn't get stolen) but still can't decide on the most economical option. i find that the Honda 250/450 brake systems are very reasonable on eBay so I am leaning towards this, but all the 250/450X wheels are made of gold.  I am really struggling with wheel options. I want an 18" wheel that I could just change out the bearings with 230F bearings to fit the smaller axle but I don't have enough info to know what works. Then, I am not sure about using different parts and compatibility issues. 

So, any of you guys that have done this, what is the best combo that you would recommend?  It seems that I can find a reasonable brake system but not a matching wheel or vice-versa. Any info is appreciated, and if you can give specifics that would be great.

I would want to make the most out of this mod.

- Use the best rear brake assembly.  Best means cost, functionality, common brake pad, etc.  All the upsides with no downsides which are important to me.

- Use the best rear wheel assembly.  Best means cost, size, weight etc.  MX 250/450 wheels are the most plentiful, least expensive and prolly the strongest lightest not to mention the most options aftermarket.

- Many here believe a slightly longer swingarm improves the CRF230F in whoops and at speed.  1-2" longer seems to be the preferred upgrade.  I found this thread,  

 

[jeffrow68]

I eBay purchased a complete rear brake system from a crf250l as a test for a disc brake conversion on my 230. The good news, it fits the 230 axle and aligns with the torque bar on the 230 swing arm. The torque bar will have to be milled down about 3/8" to allow the caliper bracket to sit flush with the swing arm. There is not much adjustment front and back with the axle, so the torque arm will also have to be shortened some to allow the axle to move forward.  Pretty easy mods here, mill the torque bar down some and shorten it. No welding required.

The master cylinder has a remote reservoir that I do not like, I will search for one without the remote. No place to mount the remote reservoir.

The 250L brake pedal mounted directly into the 230 mount, so I was very hopeful, however the pedal is too short. I will have to modify the 230 pedal as others have done. 

Not sure what to do with the return spring on the brake pedal, any suggestions here?

Also still,searching for a rear wheel that is 18", light, and require minimal mods to work.

the wheel cylinder is a single piston design, any concerns here?

[Chuck.]

Single piston is common on rear brakes.

I attached my remote reservoir to the large crankcase vent hose.

Late XR250R wheels could be a candidate.

[MetricMuscle]

11 hours ago, jeffrow68 said:

I eBay purchased a complete rear brake system from a crf250l as a test for a disc brake conversion on my 230. The good news, it fits the 230 axle and aligns with the torque bar on the 230 swing arm. The torque bar will have to be milled down about 3/8" to allow the caliper bracket to sit flush with the swing arm. There is not much adjustment front and back with the axle, so the torque arm will also have to be shortened some to allow the axle to move forward.  Pretty easy mods here, mill the torque bar down some and shorten it. No welding required.

The master cylinder has a remote reservoir that I do not like, I will search for one without the remote. No place to mount the remote reservoir.

The 250L brake pedal mounted directly into the 230 mount, so I was very hopeful, however the pedal is too short. I will have to modify the 230 pedal as others have done. 

Not sure what to do with the return spring on the brake pedal, any suggestions here?

Also still,searching for a rear wheel that is 18", light, and require minimal mods to work.

the wheel cylinder is a single piston design, any concerns here?

The racer trick for holding rear brake fluid is just a clear hose with a plug on the end.  Easy to read, light weight, looks baller!

 

Or like this just a longer hose.

[ricky racer]

Or get a master cyl. with a integrated reservoir. I used on off a late model 2010 yz250f for the conversion on my 89 xr600r.

[jeffrow68]

Thanks for the replies and pics, the tubing idea is a good option. I think the biggest concern was welding on the swing arm, but this caliper bracket is a fairly simple Mod.

what did you guys do for a brake pedal? If you have any more cool pics, please share.

[jeffrow68]

Another question: how do I go about finding a bracket to mount the master cylinder? I don't have any spare parts bikes available to salvage a donor bracket. I can't seem to find anything on eBay that will work either, any suggestions? 

[Chuck.]

I was in a similar situation on my conversion. All of the MCs that I have, integral and remote reservoir,  have the same mount hole spacing. I cut a bracket off a Suzuki frame but needed to fab a triangle piece to mount it to the XR frame.

 

Just need to align the centerline of the MC with the brake pedal arm.  Might not be applicable to the 230 but for the XR I puchased a XR250R disc brake pedal pivot, shown in the picture because it was $30 and ready to go with the MC arm. The XR brake pedal attaches to the barely visible splines.

 

Some more MC bracket pics:

[MetricMuscle]

6 hours ago, jeffrow68 said:

Another question: how do I go about finding a bracket to mount the master cylinder? I don't have any spare parts bikes available to salvage a donor bracket. I can't seem to find anything on eBay that will work either, any suggestions? 

Looks like a MC mount bracket is just flat sheet metal and it would be easier to just make one rather than cutting one off of a donor frame and then modifying it. 

I would figure out the pedal and how it will work with the MC, bolt it all up and then see what my bracket will need to look like and what my mounting options are, probably even tack the new bracket in place with the MC bolted to it.

[bajatrailrider]

96/04 Xr250R works well on my 230 ,not a big deal to fit rear wheel.

[ROD Kerry]

On ‎10‎/‎08‎/‎2017 at 11:07 PM, Chuck. said:

Some have converted using L rear wheel and swingarm. I did my XR conversion using a 90-95 XR250R swing arm and brake, and a RM wheel, because the XRs use a 17mm axle like the 230s.
Having said that a 230 drum brake is very good, it uses the same shoes as the XR200 front and rear. IMO a far superior brake than most other drum brakes. And there are work arounds to mitigate most of the drum brake issues.

What year and model RM wheel did you use and is it a 36 spoke wheel.

[Chuck.]

17 hours ago, MetricMuscle said:

Looks like a MC mount bracket is just flat sheet metal and it would be easier to just make one rather than cutting one off of a donor frame and then modifying it. 

I would figure out the pedal and how it will work with the MC, bolt it all up and then see what my bracket will need to look like and what my mounting options are, probably even tack the new bracket in place with the MC bolted to it.

Look closely at the pics, the bracket for the remote reservoir MC has a "dimple" in it to clear the reservoir fitting.

 

Quote

What year and model RM wheel did you use and is it a 36 spoke wheel.

I used a 89 RM125 wheel as it is 18" 36 spoke, later are 19". The good news is the same hub, with some bearing and rotor variations, was used 88-99.

the 250 and 92+ 125 models doubled up on the sprocket bearing and there was a rotor change in 99.

[Chuck.]

Some rear caliper bracket pics so you can see the differences when shopping. One major difference between rear calipers is the location of the banjo fitting and bleeder and the brackets are different. The other difference on calipers are the pads used on each.

EBC FA346X (ear w/ pin hole  60x44.8x11mm), shorter than FA131w/ squarish pad area,  Caliper pin spacing 65mm.
CRF150R/RB     07-11
CR125/250        02-07
CRF250R/X       04-11
CRF450R/X       05-11

EBC FA131X (ear on end w/ one pin hole, tab on other end   75x36x10.5mm), longer than FA346, Caliper pin spacing 70mm.  Honda pad #s 43105-KZ1-405, 06435-GT4-415

CR80R/RB Expert    92-00      
CR85R/85R Expert  03-07     
CR125/250/500        87-01                    
CRF230L                 08-11                  
CRF230M                09-11
XR250R                  90-04      
XR250L                   91-96   
XR400                    96-04
XR500R                  91-00
XR600                    91-00
XR650L                   93-11
XR650R                  00-07      
RM125/250              96-08

CR85 rear 06

CR125 01

CRF230L

CRF/CR

CRF/CR 05+

XR250R 90-96

Edited August 23, 2017 by Chuck.

[ricky racer]

On ‎8‎/‎18‎/‎2017 at 7:52 AM, bajatrailrider said:

96/04 Xr250R works well on my 230 ,not a big deal to fit rear wheel.

so is the xr250 wheel the same width spacer to spacer as the 230

[bajatrailrider]

6 hours ago, ricky racer said:

so is the xr250 wheel the same width spacer to spacer as the 230

Almost the same here is what I did on the brake caliper holder. The part that spaces the wheel it has about a 1/16 boss on outside. I just ground it off with 7in grinding wheel in hand held grinder.Then after mounting the wheel it is little off set to one side of swing arm. You loosen the spokes on one side tighten the other side 3 turns.Now wheel is centered make sure all spokes tight. that part done. 

[ricky racer]

On 8/16/2017 at 8:30 PM, jeffrow68 said:

I eBay purchased a complete rear brake system from a crf250l as a test for a disc brake conversion on my 230. The good news, it fits the 230 axle and aligns with the torque bar on the 230 swing arm. The torque bar will have to be milled down about 3/8" to allow the caliper bracket to sit flush with the swing arm. There is not much adjustment front and back with the axle, so the torque arm will also have to be shortened some to allow the axle to move forward.  Pretty easy mods here, mill the torque bar down some and shorten it. No welding required.

The master cylinder has a remote reservoir that I do not like, I will search for one without the remote. No place to mount the remote reservoir.

The 250L brake pedal mounted directly into the 230 mount, so I was very hopeful, however the pedal is too short. I will have to modify the 230 pedal as others have done. 

Not sure what to do with the return spring on the brake pedal, any suggestions here?

Also still,searching for a rear wheel that is 18", light, and require minimal mods to work.

the wheel cylinder is a single piston design, any concerns here?

You ever find a wheel to use with the crf250L brake caliper?