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R75/5 fork upgrades
Posted: Sat Dec 06, 2014 2:40 pm
by sprints@pldi.net
I have a 73 r75/5 and want to do some fork upgrades during my complete frame off refurbish this winter. I've heard of many fixes - emulators, heavier top triple clamps, but I understand that BMW may have offered some parts to prevent 'dive' and improve dampening. Can anyone 'steer' me in the right direction. I will need specific parts, brands, or part numbers if you can help - Thanks - Rod
If you want to send them off list my email is
sprints@pldi.net
Re: R75/5 fork upgrades
Posted: Sun Dec 07, 2014 3:53 am
by Duane Ausherman
You wish to reduce the dive? So, you want less fork travel, not more?
Rod, you need to understand that most of the "fork stuff" is done by idiots. Some just want to take your money.
1. You forgot to tell us how you ride, as that is VERY important.
2. What issues do you now have?
3. Do you have stiction?
The most important single thing that you can do is to align your forks. Without aligned forks, all the magic stuff in the world won't make it handle properly. This issue of alignment is highly controversial. That is because it may not be a simple job and people just don't want to do more than a quick fix and go riding.
Just ask anyone who labored over fork problems, often for years, only to finally give up and go through the procedure. They are happy campers.
http://w6rec.com/duane/bmw/forktool/
http://w6rec.com/duane/bmw/fork/title.html
There are a few more things to do, but one needs to get answers from you first.
On Monday, Stephen, of Toaster Tan will be visiting me and we always discuss his fork parts and the fork challenges.
Re: R75/5 fork upgrades
Posted: Sun Dec 07, 2014 7:35 am
by chasbmw
I havent heard of many people who have gone done the emulator route with success. There are very many variables and the racetech base settings are not correct for type 1 BMW forks. People seem to struggle to find settings that will give them supple low speed response AND properly controlled high speed. Ironic given that this is what racetech promise.
And you have to chop your damper rod up in making the change so going back involves more expense.
Stiction is not only due to alighnment, there can also be internal stiction within the forks themselves.
Ill send you some info....
Re: R75/5 fork upgrades
Posted: Sun Dec 07, 2014 1:03 pm
by Duane Ausherman
chasbmw wrote:I havent heard of many people who have gone done the emulator route with success. There are very many variables and the racetech base settings are not correct for type 1 BMW forks. People seem to struggle to find settings that will give them supple low speed response AND properly controlled high speed. Ironic given that this is what racetech promise.
And you have to chop your damper rod up in making the change so going back involves more expense.
Stiction is not only due to alighnment, there can also be internal stiction within the forks themselves.
Ill send you some info....
Chas is right in that there are other factors besides alignment, but in all fixes that I know about it requires the forks to be disassembled to some extent. That alone will require alignment upon reassembly.
sprints, you are to be commended for asking first, before spending your time and money on solutions looking for a problem.
Re: R75/5 fork upgrades
Posted: Mon Dec 08, 2014 1:49 pm
by jtoml
Try a higher viscosity fork oil before doing anything else. I'm using a 10 wt (Belray), and I like the action a lot better.
Re: R75/5 fork upgrades
Posted: Tue Dec 09, 2014 10:21 am
by Duane Ausherman
First do the sticktion test. If it passes, then not only vary the fork oil viscosity, but amount. Putting more oil into the forks reduces the air volume above.
Re: R75/5 fork upgrades
Posted: Tue Dec 09, 2014 10:53 pm
by Duane Ausherman
If you get your forks sorted out as best as can be done and they still don't match your skill, then, only then consider spending some money. Here is one place to start. I just put this message out on the /2 and 5United forums. It is both about socializing with this Motley Crew, but accessory fork stuff.
Stephen (aka Toaster Tan) stayed here one night several weeks ago on his way south to pick up more of his stuff in AZ. We had a very nice visit. This time, on his way back north, he stayed again.
I encourage all of you to invite some of the BMW folks to stop and visit in their travels. You will also save them some of our hard earned dough. It is much better than watching TV. You will be surprised at just how different people are in person from what we see from some typing on a key board.
I got to see some of his products. It is really high quality stuff. I didn’t fit it to anything, but I can’t imagine that it doesn’t fit. The parts were a pleasure to hold in my hands. Were I to look for any of those products, I would highly consider his products. We discussed in detail just how it all works and why it is done this way or that. I can tell you that Stephen understands these forks very well and that is why his parts have a good reputation.
This is not the place to mention his competition, except that he really doesn’t have any, not really.
However, you must be careful of me. I visited Ray Brutti, in AZ, a couple of years ago and he showed me his recently restored /2 and it is beautiful. When I left, it was in pieces and he had an expensive list of parts to get. Now that it is back together again, I think that I am forgiven.
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Ray answered with this;
Duane,
Lest folks get the wrong idea, my entire /2 was not left in pieces when you last visited . . . only one shock absorber. And you did leave me with the know-how to do the other one as well. A few days later Vech sent the new shocks and all was well. Yes, new shocks are expensive. Is anything on these old bikes NOT expensive? There is only one cheap thing on a BMW motorcycle and we all know what that is.
By the way, rode my lovely /2 around town out in the cold today. It seems especially happy to be running around when the temps drop below 30. I’m sure it thinks it’s back home in Bavaria. Started 1st kick several times and ran like a moose on fire. Yowza!
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