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MOTOBRICK.COM => Welcome To Motobrick.Com => Topic started by: -mek- on September 25, 2018, 08:18:34 AM

Title: Hi from Finland
Post by: -mek- on September 25, 2018, 08:18:34 AM
I've allready quite a long time considering to buy a K75. A basic model just for evening rides. For longer trips and more adventurous rides I ride at the moment by -16' Honda CRF 1000 L.

Now I ended up buying a former Swedish Police bike, a -92' K75 RT, 128 kkm. Being a former Police bike it's technikally in good condition, but not a near of being restored, so a perfect base for building the bike to my own taste. I've newer built a bike, so time will tell what I find under the fairings.

https://youtu.be/gPQOwbZyi2s 
Title: Re: Hi from Finland
Post by: Laitch on September 25, 2018, 11:21:38 AM
Now this is a good way to introduce yourself!  :clap: Welcome, MEK. There are a few differences between between model years so put the year of your moto's manufacture in your profile, too, so it will accompany every post.

Good luck with your project.
Title: Re: Hi from Finland
Post by: Skunky on September 25, 2018, 02:08:14 PM
Looks like a good starting point. Welcome  :2thumbup:
Title: Re: Hi from Finland
Post by: natalena on September 25, 2018, 08:02:48 PM
Congratulations on your find, and welcome to the Brickhouse.
Title: Re: Hi from Finland
Post by: Brickler on September 30, 2018, 02:00:49 AM
Mahtava, tervetuloa. I always marvel over how flat Finland is. But I guess it would be hard to place all the lakes in a mountaineous area.
Title: Re: Hi from Finland
Post by: Areshuan on October 17, 2018, 11:05:30 PM
Great video .  And lovely place to ride.  I am also new.  Welcome
Title: Re: Hi from Finland
Post by: Barry in IN on October 18, 2018, 08:36:54 AM
Nice!  It makes me want to go out and buy another one.  As if that takes much. 
Title: Re: Hi from Finland
Post by: -mek- on October 29, 2018, 02:19:07 PM
Should I continue on the projects?

My bike is 1992 K75 RT, former Swedish police bike. I've been told, that at least some of the Police bikes had sport front suspension. My bike is equipped with 41 mm Showa fork. The fork caps do not have S-label and the forks only have one spring, length ca. 380 mm and on top ca 190 mm spacers.  With this setup I only got about 20 mm sag when sitting on bike (75 kg) without fuel and all the fairings uninstalled.  I didn't measure the sag with ful fuel tank and fairings, but I guess it could be around 30-40 mm. When I removed the fork top caps I measured the preload to be around 37 mm. The top edge of the cap is around 7 mm under the fork tube edge and when the circlip was released, it popped up ca. 30 mm above the fork tube edge.

The most confusing thing is, that the fork suspension travel of my bike is only ca. 120 mm. On regular fork it should be 185 mm. Has anyone measured the Showa fork springs and spacers? Are my 380 mm springs and 190 mm spacers standard? Sport forks should have two springs and 135 mm travel, so sport forks this is not. It seems to be so, that someone has made some changes to the fork for decreasing the suspension travel, or installed something wrong?

Hence, the sag with these 380 mm springs and 190 mm spacers was quite ok for the RT. But I'm going to strip my bike down to a Street tracker without the fairings, so quess I should have less preload for increasing the sag to normal for a lighter bike. I got a set of Progressive suspension fork springs on sale. They are about 445 mm long and came with 107 mm long spacers, so that would give me about 17 mm less preload than former setup.

I'm able to test ride my bike just on April, due the Finnish winter, but I hope getting the wheels from powder coating this week, so within a week or so I'm at least wiser about the sag with the new sprigns.

Finally, I flushed the forks today with petroleum and fill them up tomorrow with Motul 7,5 W fork oil to -170 mm before installing the springs. That should(?) be a standard setting, so it's a good starting poing.

Steering head bearings were in good condition, I just washed the old grease and dirt away with petroleum and regreased with CRC heavy duty MO2 grease.
Title: Re: Hi from Finland
Post by: Laitch on October 29, 2018, 03:50:30 PM
Should I continue on the projects?

The most confusing thing is, that the fork suspension travel of my bike is only ca. 120 mm. On regular fork it should be 185 mm. Has anyone measured the Showa fork springs and spacers? 

Finally, I flushed the forks today with petroleum and fill them up tomorrow with Motul 7,5 W fork oil to -170 mm before installing the springs.
Start a thread in the Custom projects section to record the progress of your build. You could then post questions in the Workshop concerning individual situations, or in your project thread.

Showa forks have less travel than the earlier forks. 135mm is the published travel figure for K75 Showa forks. 420cc fork oil per side is the fluid amount used when overhauling a Showa fork. Showa fork travel isn't shown in Phil Hawksley's BM Bikes data—only data from the earlier forks.

Title: Re: Hi from Finland
Post by: The Mighty Gryphon on October 29, 2018, 08:11:31 PM
If your fork travel is 135mm your sag of 20-30mm on an unloaded naked bike is about right. 

I have the longer travel forks on my K75RT, and the front end dive when braking is very annoying.  The shorter travel forks on my other bikes dive much less.  Funny thing, the extra travel doesn't seem to make the ride any smoother.
Title: Re: Hi from Finland
Post by: blackie1 on October 30, 2018, 03:01:39 AM
welcome mek
fantastic color
of course I am completely unbiased