Brake shoes for 1979 YZ 250 ? and drum brake arcing

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12/13/2019 12:31 PM

I Put a backing plate with double leading shoes from an 1981 on my 1979 and the braking power is much improved even with the old shoes that came with the Backing plate,I going to buy some new shoes for it and was looking for suggestions on OEM vs after market shoes
What would the Vital vintage gurus suggest?
Has anyone had Race Tech do the Drum Brake Arcing for vintage bikes and what did you think?
It sounds good.
https://www.racetech.com/page/title/Brake%20Arcing
Thanks for any help in advance.

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12/13/2019 8:31 PM

I was wondering the same about the race tech brake arcing.. if they are as good as the emulators sign me up!

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12/13/2019 10:36 PM

The arcing is good. I have another bike that isn't arced and it feels a little bit mushy or feels like the cable is stretched. Take your time to get timing set up properly too for best results.
You need to make sure your wheel is true because you can pull it out of round if you have to adjust your spokes after the arcing.
That's my bike they are arcing the drums in their pics BTW and in the shock development story.
https://racetech.com/html_files/yz465_project.html

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The older I get, the faster I was.

12/14/2019 8:33 AM
Edited Date/Time: 12/14/2019 8:39 AM

As far as shoes go, install the stock Yamaha OEM's, there is nothing better. I've been using the DLS system on a couple of bikes for years.The stopping power is far superior than the metallic and the OEM organic compound does't chew-up the surface of the drum.
Take note: use ONLY Yamaha OEM brake cables. Unlike the cheap aftermarket cables, the wire is larger in diameter and resists stretch and the "mushyness" feel.
It's very important to adjust levers so that the the shoe actuated by the short lever, touches the drum slightly before the shoe from the long lever.
Find a quiet location, spin the wheel and listen closely at the shoes contact and adjust accordingly.
You can also use a flat file and remove the high spots on the shoes until even contact from the drum-to-shoe is achieved. It works well for drums that are slightly irregular.
In all, it's a bit time consuming with repeatedly removing and installing the wheel but the results are great.

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Larry Navarro - Spring,TX. Damm glad to meetcha!

12/14/2019 10:03 AM

wfoyz250 wrote:

As far as shoes go, install the stock Yamaha OEM's, there is nothing better. I've been using the DLS system on a couple of bikes for years.The stopping power is far superior than the metallic and the OEM organic compound does't chew-up the surface of the drum.
Take note: use ONLY Yamaha OEM brake cables. Unlike the cheap aftermarket cables, the wire is larger in diameter and resists stretch and the "mushyness" feel.
It's very important to adjust levers so that the the shoe actuated by the short lever, touches the drum slightly before the shoe from the long lever.
Find a quiet location, spin the wheel and listen closely at the shoes contact and adjust accordingly.
You can also use a flat file and remove the high spots on the shoes until even contact from the drum-to-shoe is achieved. It works well for drums that are slightly irregular.
In all, it's a bit time consuming with repeatedly removing and installing the wheel but the results are great.

Everything he said. ^^^

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The older I get, the faster I was.

12/14/2019 11:01 AM

wfoyz250 wrote:

As far as shoes go, install the stock Yamaha OEM's, there is nothing better. I've been using the DLS system on a couple of bikes for years.The stopping power is far superior than the metallic and the OEM organic compound does't chew-up the surface of the drum.
Take note: use ONLY Yamaha OEM brake cables. Unlike the cheap aftermarket cables, the wire is larger in diameter and resists stretch and the "mushyness" feel.
It's very important to adjust levers so that the the shoe actuated by the short lever, touches the drum slightly before the shoe from the long lever.
Find a quiet location, spin the wheel and listen closely at the shoes contact and adjust accordingly.
You can also use a flat file and remove the high spots on the shoes until even contact from the drum-to-shoe is achieved. It works well for drums that are slightly irregular.
In all, it's a bit time consuming with repeatedly removing and installing the wheel but the results are great.

Yep...
The Yamaha DLS is very good. I have good luck using some adhesive back 150 grit 3" roll sandpaper applied and trimmed to fit inside the drum, then spin the wheel adjusting the brakes slowly till the shoes are sanded round, AKA arched.
Takes some time to do and usually have to remove wheel several times But easiest DIY way if you don't have access to a lathe.
https://www.3m.com/3M/en_US/company-us/all-3m-products/~/3M-Stikit-Blue-Abrasive-Sheet-Rolls-321U/?N=5002385+3291245984&rt=rud

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12/14/2019 2:24 PM

Excellent info guys Thanks so much.
Now to get to work.

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12/16/2019 6:25 AM

There are two types of arching. Arching the drum and Arching the Pads. Arching the drum puts the braking surface on center of the axle and brake plate which is what the lathe is needed for. Yamaha's are half decent on concentricity so it's not an absolute must. Like state above make sure the wheel is true and your happy with the rim/hub as messing with the spokes and pull the hub out of round. The other arching is pad themselves. I use the sand paper taped to the drum method and that works well for 95% of the brakes I've done. I tend to run the EBC groove pads as we deal with mud in the woods racing we do.

I would say unless you are doing expert/pro level vintage racing the arching of the brake pads and roughing up the braking surface is all you need.

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12/17/2019 7:36 PM

450exc115 wrote:

There are two types of arching. Arching the drum and Arching the Pads. Arching the drum puts the braking surface on center of the axle and brake plate which is what the lathe is needed for. Yamaha's are half decent on concentricity so it's not an absolute must. Like state above make sure the wheel is true and your happy with the rim/hub as messing with the spokes and pull the hub out of round. The other arching is pad themselves. I use the sand paper taped to the drum method and that works well for 95% of the brakes I've done. I tend to run the EBC groove pads as we deal with mud in the woods racing we do.

I would say unless you are doing expert/pro level vintage racing the arching of the brake pads and roughing up the braking surface is all you need.

I have a GS3 shock and emulators and I can really feel how weak the brakes are since the suspension can carry you a lot faster. I believe you should do all you can to get the brakes to work better.

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The older I get, the faster I was.

12/19/2019 4:50 PM
Edited Date/Time: 12/19/2019 4:55 PM

wfoyz250 wrote:

As far as shoes go, install the stock Yamaha OEM's, there is nothing better. I've been using the DLS system on a couple of bikes for years.The stopping power is far superior than the metallic and the OEM organic compound does't chew-up the surface of the drum.
Take note: use ONLY Yamaha OEM brake cables. Unlike the cheap aftermarket cables, the wire is larger in diameter and resists stretch and the "mushyness" feel.
It's very important to adjust levers so that the the shoe actuated by the short lever, touches the drum slightly before the shoe from the long lever.
Find a quiet location, spin the wheel and listen closely at the shoes contact and adjust accordingly.
You can also use a flat file and remove the high spots on the shoes until even contact from the drum-to-shoe is achieved. It works well for drums that are slightly irregular.
In all, it's a bit time consuming with repeatedly removing and installing the wheel but the results are great.

This gentleman gave me this exact advice a year or two back when I was having issues with my YZ400 drum brakes. He was spot on! (especially the cables. MUST be OE Yamaha). Follow this advice and take your brakes from "near death experience" to "this bike is fun now". And thanks wfoyz250!

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12/21/2019 6:48 AM
Edited Date/Time: 12/21/2019 6:58 AM

Glad to have helped you with the issue.
Never ever go cheap on cables. That goes for the CLUTCH cable too.
As with brake cables and larger wire diameter, the clutch action with OEM will feel much more positive than aftermarket pieces.
Spend the extra cash on OEM's and never be disappointed.
Just a side note:
Some aftermarket levers, especially the "adjust on the fly" types. They are produced with the smaller hole for the "dowell" and the narrow "slot" that the cable slides through on the levers. Be prepared to modify that type of lever when using the high quality OEM cables.

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Larry Navarro - Spring,TX. Damm glad to meetcha!

12/21/2019 8:17 PM

I am having a hard time finding an OEM front brake cable for my 1979 YZ250 ,anyone know what other years might work?

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12/21/2019 8:29 PM

I have a 1984 RM250 that I've racer restored twice now. When I first restored it for racing I sent the front wheel out for re-lining and arcing of the drum and pads.

I was shocked how good it worked. I actually almost crashed in the driveway testing it because I locked up the front wheel.

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12/22/2019 7:11 AM
Edited Date/Time: 12/22/2019 7:17 AM

"neverwas".......as far as cables go, there should be several models that crossover. Try the IT, YZ models from years 1978-1982, 250-465.
Here's one I found on ebay. There are other sellers with prices ranging all over.

https://www.ebay.com/itm/YAMAHA-NOS-VINTAGE-FT-BRAKE-CABLE-IT-YZ250-425-465-3R8-26341-00/372694313335?hash=item56c64fe977:g:1U0AAOSwke9aSpPt

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Larry Navarro - Spring,TX. Damm glad to meetcha!

12/22/2019 8:02 AM

wfoyz250 wrote:

"neverwas".......as far as cables go, there should be several models that crossover. Try the IT, YZ models from years 1978-1982, 250-465.
Here's one I found on ebay. There are other sellers with prices ranging all over.

https://www.ebay.com/itm/YAMAHA-NOS-VINTAGE-FT-BRAKE-CABLE-IT-YZ250-425-465-3R8-26341-00/372694313335?hash=item56c64fe977:g:1U0AAOSwke9aSpPt

Thanks WFO,Ihave found several 1981 Yz250 on sites like Rockymountainatv,but part numbers were differential from the 79,
I cant imagine them being drastically different.
I am going order one and check it out
Thanks again for all the info,you have been very helpful.

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12/22/2019 8:43 AM
Edited Date/Time: 12/22/2019 8:49 AM

With Yamaha part numbers, the first three digits signify model & year, the middle 5 digits signify what type of part it is. For example, the -26341- is for front brake cable.
The only thing that you'll notice is that the cable used for the ......say, 1980,'81,'82.....will be SLIGHTLY longer given the increase in suspension travel over model years. Nothing to worry about. Just make sure the cable is secured where it needs to be. You don't want it flopping around close to the front wheel.

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Larry Navarro - Spring,TX. Damm glad to meetcha!

12/22/2019 8:27 PM

wfoyz250 wrote:

With Yamaha part numbers, the first three digits signify model & year, the middle 5 digits signify what type of part it is. For example, the -26341- is for front brake cable.
The only thing that you'll notice is that the cable used for the ......say, 1980,'81,'82.....will be SLIGHTLY longer given the increase in suspension travel over model years. Nothing to worry about. Just make sure the cable is secured where it needs to be. You don't want it flopping around close to the front wheel.

Thanks,great info.

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