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230 Rear Disc Brake Conversion

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Anyone that has changed the rear wheel on a 230 to one with disc brakes, please give me some advice. Which wheels work the best as far as bearings and spacers, etc, and which is readily available on ebay? I find lots of CR125 complete wheels along with brake pedal, mater cylinder, caliper, etc. I am mechanically inclined, but I cant find a clear path as to what works the best. So far, research has suggested to keep the 230 trailing arm, add the caliper brackets, bore the axle slots, and modify the frame to attach the bracket for the master cylinder, then use the complete wheel of your choice. I appreciate any direction to help make this a successful conversion. Before I upgrade anything on this bike to make it handle better or go faster, I want to be able to STOP! The rear brakes are downright scary.

Also, any links to threads where this has been done successfully would be appreciated.

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All of the CRF250/450X rear wheels are easily adapted. Have a bushing made to sleeve the wheel to accept the 230 axle and caliper hanger. Cut the actauting arm portion of the 230 pedal off and weld it to the back of the pedal. Use all CRF 250/450 caliper and master cylinder componants. I actuall have a complete system from an 89 CR250 wheel with brake system hanger. This system has the remote reservoir for the mastercylinder. I also have a complete 89 CR250 front end (USD forks with new seals and wipers) wheel, triple clamps. (theses are one of the few USD fork units that run the same steering stem bearings. I am not allowed to post that these parts are for sale in this forum. So I didn't

ST O.D.

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Those are the steps.

The XRs use a 17mm rear axle so those parts make the conversion easier. Some of the MX bikes use a 20mm axle but sometimes a bearing swap will allow using a 17mm axle.

Caliper brackets can be a problem. The Honda swing arms for drum brakes put the brake torque into the swing arm via a pin on the swing arm centerline, for disc brakes the anchor is on the top edge of the swing arm. Suzuki, and maybe others, anchor drum and discs on the centline of the swing arm.

When you do the conversion post the project on TT. Here are some links:

http://www.thumperta...and-suspension/

http://www.thumperta...ight-reduction/

There are also some threads on this and other forums but I don't have links, you can find them using the search feature.

On edit:

Here is a table of some standard metric bearings used in MC wheels:

#............. ID........ OD..... TH........

6001........ 12........ 28.......... 8........

6201........ 12........ 32........ 10........ CR80/85 f

16101...... 12........ 32.......... 8........

6301........ 12........ 37........ 12........

16002...... 15........ 32.......... 8........

6002........ 15........ 32.......... 9........ CRF150R/RB f

6202........ 15........ 35........ 11........ CRF150/230 XR250 f

6302........ 15........ 42........ 13........ XL185S r

6003........ 17........ 35........ 10........ 89-91 RM125 f, 86 89 CR125

16003...... 17........ 35.......... 8........

6203........ 17........ 40........ 12........ 81-83 XR200R r drum, 90-03 XR250 r disc side

6303........ 17........ 47........ 14........ 81-83 XR200R r sprkt, 90-03 XR250 r sprkt side, CRF230F r

6004........ 20........ 42........ 12........ 315R Front

6204........ 20........ 47........ 14........ 89-91 RM125 r,90-95 XR250 R sprkt side

6904........ 20........ 37.......... 9........ CRF250 f

6304........ 20........ 52........ 15........

6006........ 30........ 55........ 13........

6905........ 25........ 42.......... 9........ CRF250/450/R/X rear

Unlike some other manufacturers Honda list the bearing code in their part fiche making it easy to research bearing and axle sizes.
Edited by chuck4788
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DSC02963.jpg... modified pedal, CR80 master cylinder bracket, CRF250 master cylinder

What did you use for the rear wheel and disk, axle, bearings, and caliper. Also what did you have to do to the swingarm.

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and slipperd 1 each into the oem 250X rear wheel spacers ....

DSC03123.jpg

I actually JB welded them in place so that there would not be so many pieces lying around when I removed the rear wheel for service. I also cut them down to approx the diminsions noted here to center the wheel in the swing arm and line up the

chain/sprockets.

Edited by SacTown Old Dude

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pressed the 230 oem center wheel bushing into the 250X rear wheel (somewhat of an interference fit) and pressed in 1of the modified 230 spacers into either side of the 250X rear wheel. This made a sleeve through the 250 wheel on which the oem 250 bearings would rideand accomodate the 230 axle....

DSC02983.jpg

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slip your modified 250X wheel spacers in the 250X wheel seels just like you normally would and you have a 250X wheel sleeved to accomodate the oem 230 axle.

DSC02987.jpg

Of course you could also spend the money to have a one piece bushing machined to sleeve the 250 wheel. This process was designed to be done by the novice to intermediate DIYer using readily available resources and involving minimal out of pocket expense.

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Re the swing arm..... remove the 230 drum mount....

DSC02975.jpg

1. have a disc receiver machined from a block of alminum

2. remove 1 from a 250X/250R 450X/R swing arm

....have it welded onto your 230 swing arm

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th_DSC02998.jpg?t=1330370826

Cut off this section of the oem 230 brake pedal

And weld it back onto the brake pedal like this...

DSC02979.jpg

I added a pin to attach a return spring....

DSC02980.jpg

Edited by SacTown Old Dude

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Hope this helps. If you have any questions don't hesitate to ask. Like I said I am researching what it will take to sleeve a CR80/85 rear wheel to do the conversion on a 150F 16in rear wheel.

ST O.D.

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Hope this helps. If you have any questions don't hesitate to ask. Like I said I am researching what it will take to sleeve a CR80/85 rear wheel to do the conversion on a 150F 16in rear wheel.

ST O.D.

I thought the 250 wheel were an inch bigger than the stock 230 wheel. any problems with tire clearance. Do you know if the 250x parts are the sme as the 250r parts?

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The different part numbers for the wheel assemblies is because MX bikes (250/450R) use 19" rear wheels. Off-road bikes (250/450X / 230f) use 18" rear wheels. R & X hubs should be the same.

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mdtoney is correct the 250X and R (and for that fact the 450s too) all use the same hub, Rs rims are 19 in and 450 rims are wider. The 230 runs an 18X1.85 rim as does the 250X but the spoke count is different. (230 has 36 the 250, 32)

ST O.D..

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Inquiring minds want to know. How much does the CRF250X F230F wheels weigh? Also what items are included in the weight including tire make/model, axle, spacers, Al or steel sprocket, rotor, etc.

Thanks

Edited by chuck4788

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