R75/5 fork drain problem. yikes!

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Steve in Golden
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Re: Toaster

Post by Steve in Golden » Wed Jan 10, 2018 6:21 pm


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Airbear
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Location: Oz, lower right hand side, in a bit, just over the lumpy part.

Re: R75/5 fork drain problem. yikes!

Post by Airbear » Thu Jan 11, 2018 12:39 am

MikeGeee wrote:
Wed Jan 10, 2018 4:23 pm
It's step 2 of preparing an English muffin
An excellent response. Welcome aboard, Mike.

When my dear old R90 turned up in my life 15 years ago the forks were the first thing to go wrong. Different to yours in that they started to seize on cold mornings. I had no clue on how to get them apart, so ordered a Clymer manual from the US and waited for it to arrive. It didn't turn up for two months (I had chosen the cheapest shipping method and it turned out to be by ship). In the meantime I blundered upon Duane Auscherman's website which gave me some clues. I extracted the stanchions from the tripletree and pulled them apart. The bottom of the sliders each had a good handful of dry crumbs that could be squeezed like silicone. There was no fluid at all. I cleaned everything, put it back together, added some 5W fork oil and suddenly had front suspension that worked in a satisfying manner. Later, when the Clymer manual finally turned up I found that there should be a rubber bumper in each leg, which I eventually replaced. I'm rambling, but the point I want to make is that refurbing your forks isn't a big deal. They come apart easily once you know how, there is a finite number of parts and everything goes back together easily enough. I didn't even replace the stanchion seals, and still haven't - they don't leak. Yet.

So, c'mon, bite the bullet and strip those forks. I promise you won't regret it.**

** Conditions apply.
Charlie
and Brunhilde - 1974 R90/6
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Graduate, Wallace and Gromit School of Engineering and Design (Pending)

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Zombie Master
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Re: R75/5 fork drain problem. yikes!

Post by Zombie Master » Thu Jan 11, 2018 4:31 am

The good thing is that these fork units are much better quality than other bikes of the day. IMO you should resist getting stiff springs. The BMW heavy duty springs are good. When set up right these forks can really eat up the rough stuff. Use OEM parts for best results...IMO
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Wobbly
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Re: R75/5 fork drain problem. yikes!

Post by Wobbly » Thu Jan 11, 2018 4:46 pm

On my '79 /7 forks... the 13mm hex nut is removed completely. Then the 4mm Allen wrench is used to push the bolt up until it rests on an (unseen, but felt) internal step. You must push very hard against the fork spring to accomplish this. Some minor amount of oil will dribble out at this stage. With the bolt up on the step, the front brake can be held and the fork oil pumped out by nose diving the front end. That's the only way all the oil will come out for me.

If your fork oil shows signs of water or is really dirty, you may want to do this procedure again in a week.
After 20 years as a professional bike mechanic and 30 years as an engineer I know just enough to be dangerous !

Roy Gavin
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Re: R75/5 fork drain problem. yikes!

Post by Roy Gavin » Thu Jan 11, 2018 8:50 pm

ATF is cheap ,detergent, and makes a good flushing agent, both for the forks and the drive shaft were the corrugations on the rubber boot can hold a lot of crap.
Works OK in the forks too, but a quality 5 WT Synth suspension fluid will work best.

Fork springs work best if matched to the shocks.
The stiff Progressive brand work fine with the stock springs in Ikons, if you prefer a stiff set up.
I like things a bit softer , and have matched the stock factory soft fork springs with budget priced but fully adjustable TEC shocks , with excellent results, although I did ask for the softest spring TEC have as most of the other bikes they do shocks for are a heavier than my R75/7.
The English guys did this for me, dont know if the US agent is as helpful.
The US guys also have a real cheap TEC shock with limited adjustment which will probably work best with something a little stiffer like the progressives.
Adelaide, Oz. 77 R75/7. 86 R80 G/S PD, 93 R100 GS, 70 BSA B44 VS ,BMW F650 Classic

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jagarra
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Re: R75/5 fork drain problem. yikes!

Post by jagarra » Fri Jan 12, 2018 11:56 am

Taking the forks apart is a snap. Remove the top caps and pull the big springs out. Remove wheel, fender, slide gaiters up, remove nut at bottom of slider and everything should slide off the fork tubes. Clean it all up and reassemble.
1974 R90/6 built 9/73
1994 BMW R1100RS
1964 T100SR Triumph
1986 Kawasaki Concours

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Zombie Master
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Re: R75/5 fork drain problem. yikes!

Post by Zombie Master » Fri Jan 12, 2018 8:18 pm

MikeGeee wrote:
Wed Jan 10, 2018 4:23 pm
It's step 2 of preparing an English muffin
This true!
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Zombie Master
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Re: Toaster

Post by Zombie Master » Tue Jan 16, 2018 7:58 pm

Steve in Golden wrote:
Wed Jan 10, 2018 6:21 pm
https://youtu.be/4HsJ_91YNJ0
Looks like an R75/5 to me.
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Airbear
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Location: Oz, lower right hand side, in a bit, just over the lumpy part.

Re: Toaster

Post by Airbear » Wed Jan 17, 2018 3:24 am

Zombie Master wrote:
Tue Jan 16, 2018 7:58 pm
Steve in Golden wrote:
Wed Jan 10, 2018 6:21 pm
https://youtu.be/4HsJ_91YNJ0
Looks like an R75/5 to me.
Hey, nice Toaster.
Charlie
and Brunhilde - 1974 R90/6
Image

Graduate, Wallace and Gromit School of Engineering and Design (Pending)

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Zombie Master
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Re: R75/5 fork drain problem. yikes!

Post by Zombie Master » Sun Jan 21, 2018 4:01 am

Toaster Shmoaster.
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