/6 Questions

[Major Softie]

The single disc brake on the 74 seemed a big improvement over the old drums. quote]

ZM, you are about the last person on earth who thinks that the 74 disc was better than the drum on the /5. Even the BMW literature showed it stopped in a longer distance.

Worked better for me. Maybe I just figured out how to set it up. Maybe it was the stainless brake line.

Maybe you had a poorly maintained/adjusted drum.

[KenHawk]

At the risk of a thread hijack (as well as dredging a topic previously well-covered elsewhere), the design fault of the twin Ate caliper setup is the m/c, due its diameter being too big to give a reasonable ratio IMHO. Changing the m/c for a smaller diameter item, or better still, moving to a later handlebar m/c improves the Ate brakes exponentially. My twin 40mm Ate front end with 13mm handlebar m/c is more than capable of locking the front wheel without effort, while most of my braking requires only two fingers at the lever.

Ate: the first radial calipers!

There you go!

Match the ATE calipers with good disks and pads and then install the right Master Cyl and the brakes take on a new life. I set mine up with a 15mm handle bar master cylinder from a late model airhead and the braking is truly impressive and for all intents and purposes completely comparable to the Brembos on my 82RS. When I find a spare master cylinder, I'll have it sleeved down to 13mm and see that the other guys are crowing about!

If things go right, sometime this coming Winter I'm going to be working with the guys at Kosman's Specialities, on a set of replacement calipers and disks that'll swap onto a Brembo front end and deliver some modern style stopping power.

Stay tuned!

[Lasse]

At the risk of a thread hijack (as well as dredging a topic previously well-covered elsewhere), the design fault of the twin Ate caliper setup is the m/c, due its diameter being too big to give a reasonable ratio IMHO. Changing the m/c for a smaller diameter item, or better still, moving to a later handlebar m/c improves the Ate brakes exponentially. My twin 40mm Ate front end with 13mm handlebar m/c is more than capable of locking the front wheel without effort, while most of my braking requires only two fingers at the lever.

Ate: the first radial calipers!

There you go!

Match the ATE calipers with good disks and pads and then install the right Master Cyl and the brakes take on a new life. I set mine up with a 15mm handle bar master cylinder from a late model airhead and the braking is truly impressive and for all intents and purposes completely comparable to the Brembos on my 82RS. When I find a spare master cylinder, I'll have it sleeved down to 13mm and see that the other guys are crowing about!

If things go right, sometime this coming Winter I'm going to be working with the guys at Kosman's Specialities, on a set of replacement calipers and disks that'll swap onto a Brembo front end and deliver some modern style stopping power.

Stay tuned!

http://www.vintagebrake.com/mastercylinder.htm

[Rob Frankham]

What is needed for a dualdisc upgrade?

A fair amount of Rocking Horse Sh1t in the form of a replacement right hand fork slider, second disc , second caliper (technically you 'should' replace the original caliper since the twin disc set up has smaller calipers but most don't bother), additional brake line and either (1) a replacement master cylinder or work to the existing master cylinder to provide a second outlet port (Twin discs 'should' have a bigger master cylinder anyway). There's also a second hose anchorage at the forks If I remember rightly.

Rob

[mattcfish]

Match the ATE calipers with good disks and pads and then install the right Master Cyl and the brakes take on a new life. I set mine up with a 15mm handle bar master cylinder from a late model airhead and the braking is truly impressive and for all intents and purposes completely comparable to the Brembos on my 82RS. When I find a spare master cylinder, I'll have it sleeved down to 13mm and see that the other guys are crowing about!

If things go right, sometime this coming Winter I'm going to be working with the guys at Kosman's Specialities, on a set of replacement calipers and disks that'll swap onto a Brembo front end and deliver some modern style stopping power.

Stay tuned!

My R90 has a 14mm under tank dual MC. The braking is awesome (compared to a single disk or just about any Harley) . It's a vintage bike with vintage brakes. Good brakes for the time. I feel quite comfortable racing down mountain roads with vintage Ducati's and the lot on this heavy obsolete machine. I would love to put a K bike front end on it one day, but that's not at the top of the list.
It's all relative.

[P51j]

Hi everyone. I have been absent for quite sometime as my plumbing needed some attention in my chest. My body is like a 74' R 90/6 but I feel like a Anniversary Boxer Cup machine.

I have both a 76' R 90/6, also made in 9/75', with a single disk and a 74' R 90/6 with a 74 R /90s front end. I have been riding the 76' since 12/75 when I purchased it new. What I am trying to say is that I have ripped up US 129 and its 113 curves several times on both bikes and I am still here to talk about it.

I sure would love to have a high tech newer BMW but my days for accomplishing that dream have dwindled considerably.

I think about all the differences from 74' thru 76' or early 77' have been covered so I am not going to attempt to add anything new. The only problem I have with my R 90/6's is that they are not S's.

[Major Softie]

Welcome P51j. Congratulations on your new plumbing. Nothing wrong with a body like a 74' R 90/6 - properly taken care of, those things can last forever.

[moosehead]

I have a 1974 R75/6 that I purchased last spring to replace my "queen" an 82 R100RS...needless to say the comparison between the two is almost unfair. As Max Headroom pointed out to me on seeing some photos of the /6 the tranny had been upgraded to a "ribbed" newer 5 speed tranny. I was alble to determine that it was a gearbox from 79 model year and it works well. Mechanically it was solid...added a Hannigan fairing and it became a real touring machine but I "go naked" with it during the warmer riding times and its a real hoot.

To make a long story short I was able to re-acquire my beloved RS in July so I have been able to compare each bike...I can't keep both..that's for sure... (be that my wife's "for sure!!!!") but making the choice between the two has been difficult because each has its own strenghths/weaknesses as I came to love riding them both and taking them for what each has to offer...

I think that was the key for me...I hated the brakes on the /6 but got some improvement in stainless steel line, new front brake cable, new pads (ferado) and rebuilt both caliper and m/c...it helped but still not the stopping power of the twin brembos on the RS...BUT...I got to enjoy the "loppiness" of the /6 and, as someone pointed out here or somewhere, I just started "riding within the capabilities of the /6" and, it was wonderful!! Not the crank on power or wheelie stopping ability of the RS but, I slowed down a bit, and loved the /6 for showing me a different way of riding...I loved it!

Recently, my good friend and his wife from BC (Salt Spring Island.. ZM) visited us for the week. Jim was an old K bike afficiando for years but gave up riding motorcycles due to a hip replacement about 5 years ago...he never felt right on the K bike for some reason...during the visit he saw the bikes in the garage and said he had never ridden a "boxer" only K or other Jap bikes...I said "want to try one?" Well, "let me sit on one and see how the hip feels first" said Jim...He found the old /6 perfect. So off for a short days ride we went. Jim loved it! "Christ, what have I been missing these last few years!"...he tried the RS the next day but said he preferred the more "gentlemanly" /6.."won't get me into any trouble with that power band"....Jim and his wife stayed another day so Jim and I could get out for another good days ride...asphalt and gravel he loved that bike!

His hip never bothered him in 250kms we did the next day.

I'm happy to say "ol' Hilda" has a new owner! Jim wants to fly back next spring and ride back out to BC (about 4500kms from our place) or we may do a "hand off" in Winnipeg. We,ve done a few cross Canada runs together over the years...hey...maybe another one!

The last part is a little off thread but my point is.... enjoy and ride them for what they are and ride within their capabilities...it's enjoyable!

[Garnet]

Nice to hear we'll be getting another airhead in the "hood".

They have been gettin a might scarce out here on the Islands.

[moosehead]

Garnet, didn't realize you were in Victoria, BC!

Yep, another airhead will be winding its way westward to the Island, Jim and I did lotsa rides on the Island (Vncuver I)when we visit with them on SS, that's when he had his K's hanging around.

My RS came from Vancouver...after spending most of its life in California (its US model)...bought it off Craigslist years ago, flew out, visited our youngest daughter and other friends, jumped on the bike and rode it back to ON. Never missed a beat.

Once get the /6 out there maybe we could coordinate a meet up with Jim...be great to have a few "airhead" resources out there for him!