84 fork schrader valve replacement

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Disco
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84 fork schrader valve replacement

#1 Post by Disco » Tue Sep 06, 2016 12:41 pm

On my '84, the right schrader valve is squashed, and on the other side a screw was put into what appears to be left from the schrader valve (who knows why?).

Anyone have any pics of how they should really look,and can I just go out and purchase pretty much any schrader valve to replace? I've searched this site and others without an answer. I've found stuff for the valve caps, and eliminating the schrader valve, but not replacing it.

Thanks tons.

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Questo vecchio rz
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Re: 84 fork schrader valve replacement

#2 Post by Questo vecchio rz » Tue Sep 06, 2016 9:24 pm

Bike Bandit has it listed in OEM for about $11.00 bucks. Part #10. Couldnt say for certainy if it is compatible w other valves or styles without a side by side viewing.

http://www.bikebandit.com/oem-parts/198 ... #sch224632" onclick="window.open(this.href);return false;

http://www.bikebandit.com/oem-parts/198 ... 7sch224632" onclick="window.open(this.href);return false;
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Disco
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Re: 84 fork schrader valve replacement

#3 Post by Disco » Tue Sep 06, 2016 9:42 pm

And I just sent off an order to bikebandit. Sheesh. Would have been worth ordering one just to see if it's compatible. I guess I can probably access the same type of valve (tire valve) from an auto store and see if it works. Plenty of lookers on this thread, not many answers, so maybe not many people know the answer.

Disco
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Re: 84 fork schrader valve replacement

#4 Post by Disco » Wed Sep 07, 2016 7:46 pm

For anyone looking, the schrader valve at the top of the forks is part no. 5k7-23190-00-00. This valve is discontinued but can be found a few places for about $40-50 each!!!
Surprising that it was discontinued as it was used by many bikes up into the 1990's. Here's a link and a list of bikes.

http://www.onlinecycleparts.com/oempart ... /air-valve" onclick="window.open(this.href);return false;

I'm going to do some searching at a salvage shop and perhaps come up with one for less money. If anyone knows a replacement valve, or additional bikes that used this same valve under a different part # please post.

Bare
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Re: 84 fork schrader valve replacement

#5 Post by Bare » Thu Sep 08, 2016 1:54 pm

Hopefully you are talking about More than the wee Schrader valve insert/stem??
Those are universal.. and Often 4 for 5$ at any parts, Car Or Bicycle shop.

RuZty
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Re: 84 fork schrader valve replacement

#6 Post by RuZty » Thu Sep 08, 2016 2:27 pm

It looks tapered on the back side, and a straight thread going into the fork.

Image

I've never found a need to put air in mine after playing around with them at first, so I don't think there is much downside to plugging them both. It might help if you carry a passenger a lot.

Disco
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Re: 84 fork schrader valve replacement

#7 Post by Disco » Thu Sep 08, 2016 5:01 pm

Bare wrote:Hopefully you are talking about More than the wee Schrader valve insert/stem??
Those are universal.. and Often 4 for 5$ at any parts, Car Or Bicycle shop.
Not these particular ones. They are 8mm with a 1.0 pitch. Just google that and you will see that they are quite difficult to find, and expensive.

I'm thinking about rethreading to a standard size and replacing with a more common version of the same exact :smt021 thing.

I realize that some people don't think they do anything. Though they were on over a dozen models of bikes, including motocross, for a solid 10 years, and similar valves are found on many other bikes, so they might serve a purpose? Many motorcycle engineers (and R&D, test riders) must have thought so.

gpaddict
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Re: 84 fork schrader valve replacement

#8 Post by gpaddict » Thu Sep 08, 2016 9:38 pm

They are probably high pressure valves, and hence the cost.
tuned to Paris Hilton specs............rich and retarded!

evan_calgary
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Re: 84 fork schrader valve replacement

#9 Post by evan_calgary » Fri Sep 09, 2016 4:28 pm

Disco wrote:
Bare wrote:Hopefully you are talking about More than the wee Schrader valve insert/stem??
Those are universal.. and Often 4 for 5$ at any parts, Car Or Bicycle shop.
Not these particular ones. They are 8mm with a 1.0 pitch. Just google that and you will see that they are quite difficult to find, and expensive.

I'm thinking about rethreading to a standard size and replacing with a more common version of the same exact :smt021 thing.

I realize that some people don't think they do anything. Though they were on over a dozen models of bikes, including motocross, for a solid 10 years, and similar valves are found on many other bikes, so they might serve a purpose? Many motorcycle engineers (and R&D, test riders) must have thought so.
Was anyone questioning the effectiveness? Obviously adding pressurized air to the system will have an impact.

Disco
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Re: 84 fork schrader valve replacement

#10 Post by Disco » Fri Sep 09, 2016 5:40 pm

No, not directly. I was more/less referring to the post saying they didn't do much and plugging them would be fine.
It certainly might be, and I don't discredit the poster for his experiences, and it's another option to consider (plug them exactly with what and how so it looks like they belong and serve the needs of the fork? pics?). But while it may have been on other forums, there are people saying the air valves do absolutely nothing to help a bike handle better.

Beyond the handling, which I'm not that concerned about as I'm not out dragging knees, it's more along the lines of the having the bike in a somewhat restored condition and more/less riding/handling as when new(er).

RuZty
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Re: 84 fork schrader valve replacement

#11 Post by RuZty » Fri Sep 09, 2016 7:13 pm

I get that you may want it to look original, or at least not 'bodged', I checked my spare forks to see if I had a set I could give you, but neither my '85 forks (threaded caps) or my later spares (snap ring caps) appear to have removable valve stems as shown above so the US models must be different. My comment was more directed at the fact that if it was a good idea they would still be using it. It also takes a toll on the fork seals, if the forks have older bushings and seals in them they might not hold air long. A better means of adding preload is through a mechanical adjuster such as the one Economy Cycle sells. If you can fix it for cheap by all means go ahead, but I just wanted you to consider the benefit if you decide to spend $50 each on something that might not get you much. IIRC the maximum pressure is around 7 psi, so only ever use a hand pump and a good gauge to make sure you get both legs the same. The pressure climbs faster as the fork compresses (halving the volume doubles the pressure, Boyles law).
Take them off the bike you bought your dad and play with it a bit to help you decide if you need/want them.

Disco
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Re: 84 fork schrader valve replacement

#12 Post by Disco » Fri Sep 09, 2016 9:45 pm

Thanks rusty, it's dad's bike that I'm working on. So that's another part of the equation. The forks on the spec II have both valves intact, looking good, and functional, so I'm not going to mess with them.
I believe one aspect of the valves, at least from what I've learned via motocross/enduro guys, is to be able to release air pressure as shocks heat up. Lots of forum talk and videos about guys tapping their forks on current bikes to add air valves. Anyway, it's more about appearance for my situation, and thanks for checking your forks out. It really seems that guys look out for each other on here, helping out where they can.

Disco
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Re: 84 fork schrader valve replacement

#13 Post by Disco » Sat Sep 10, 2016 9:17 pm

GOOD NEWS!! I went to a motorcycle/snowmobile scrapyard about an hour away after a recommendation from a nearby dealership. The kid working the counter lead me into a shed with a rack of forks and said "poke around and see if you find what you need.". First try was from a Kawasaki, no luck valve was too large, then I spotted a fork kind of wedged and falling down in the back of the rack, I was able to wrestle it out and, bingo. FZ600 fork with a virtually identical valves. The FZ isn't listed as one of the many yamaha bikes to have that particular schrader valve, because visually, there is a very, very slight difference (perhaps 1mm in overall length). I had one of the RZ valves and it screwed into the FZ fork. It went in like butter and the o-ring seated like it belonged there. So I found the matching fork and snagged the other valve. $2.50 each. Better than $40 each for the original part.
I cleaned 'em up and they fit perfect and hold air pressure (I put in 6lbs, went for a short ride, it was still at 6, and I released as much air as I could. I'll leave it at that for right now, other work to be done and not riding this bike right now anyway). Problem solved! Thanks for the suggestions from everyone, and hopefully if anyone in the future is looking for the valves, they will see this thread.

evan_calgary
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Re: 84 fork schrader valve replacement

#14 Post by evan_calgary » Tue Sep 13, 2016 5:29 pm

Good comment on the fork seals Ruzty. We install aftermarket pressure release valves in all of the dirt bikes for transportation to preserve fork seals. There is considerable pressure build-up when compressing the forks for transportation and it will damage fork seals over time.

hablair
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Re: 84 fork schrader valve replacement

#15 Post by hablair » Wed Sep 14, 2016 6:12 am

Interesting on the FZ fork, useful info that

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