No. Not a competition, not a "which is best" but really a personal answer to a question raised elsewhere on the forum and not wishing to hijack an interesting thread.

First I'd best say that I have experience of both, find it impossible to decide which I prefer and in an ideal world would own (at least) one of each.

My first experience of a K75 was an 'S' owned by BMW(GB) that I collected from their UK HQ at Bracknell with under half a mile on the odometer and rode to what was then called the Transport Road Research Laboratory (TRRL) for the demo day of the then new ABS equipped K100LT.

This was one of each current models that BMW(GB) laid on for people to ride while the ABS equipped bike was being demonstrated and tested.

I'd ridden to Bracknell with a group of my colleagues who'd been invited to collect the demo fleet and to have a "play" on the TRRL circuit.

It was interesting to note that this K75S was the bike that was in most demand that day and at lunch-break, a colleague glanced at it as we walked past because it was pinging away as it cooled and gave off a smell that suggested it had been destroyed, I won't use his exact words but he gave me to think that he believed it would go back to Bracknell on a trailer.

It didn't, it was caned around all afternoon too and that was my introduction to the robust nature of the 750 triple.

Some while later, a bean-counter decided that a saving could be made where I worked by buying K75RTs instead of K100RTs. A small batch were purchased and I happened to be due to chop-in my K100 after three years and 80,000 miles. I was disappointed to find that I'd be given a K75 to replace it.

After saying goodbye to the trusty K100, I set off back to my base on the K75RT with every intention of hating it and blowing it up. I found that I could do neither but not for want of trying.

Over the next few months I discovered the delights of the K75 and in due course was sad to see it replaced by a K1100.

So apart from a cylinder missing and either 15 or 25 bhp down (8-Valve or 16-Valve depending), without going into the technical differences, what are the real world effects on use?

Well loss of one cylinder makes a bigger difference in the handling than might be imagined. It isn't just the loss of the pot, it's that the centre of the mass moves more towards the middle of the bike, even though the frame geometry is the same and other weight, such as the radiator, is mounted in the same place.

Nor can the difference be attributed to the forks as the K100s we had alongside the K75s used the same K75 suspension.

The difference in the handling is even more pronounced on the K75S and the lesser faired K75C or completely naked K75. Obviously the lack of that weighty fairing of the K100RT/LT or RS makes a difference but it doesn't explain it entirely. Even the K75RT feels more nimble (a relative term given that no K-Series is really very nimble).

When it comes to the engine and the missing horses, the difference in outright performance is less than the 15 bhp would suggest. It is a different matter with the 100 bhp 16-Valve K100s but still not massively so. This is more to do with the nature of the two engines. The K75 having a combined balancer/output shaft thrives on revs. There's a small step as you hit 6,000 rpm but not a huge one and even though it is rev-happy it still has excellent torque.

Wring its neck and a K75 will do everything short of 10 to 15 mph on the top end that an 8-Valve K100 will do.

It's certainly no drag bike and it needs more revs to pick-up its skirts than a K100 but having owned and ridden 8 and 16-Valve Ks, neither is as happy to be rev'd as a K75 in spite of the 'no flywheel' design being shared by the four and three cylinder engines.

Certainly here in the UK, the K75 suffered from an "entry level" or "poor man's" K-Series image. Sales never matched those of the four cylinder models. This was perhaps true of other markets too but the French in particular as well as the Germans themselves took to the triple. K75 models still sell well in France and Germany is a good source for under-used, high-spec models at reasonable prices.

Had the K75 been allowed to evolve in a similar manner to the four cylinder bike, we'd perhaps have seen a 900cc, 115-120 bhp, Telelever/Paralever machine in the end. I suspect that the reason why that didn't happen is because like with the earlier bikes, the triple was too close to the fours in performance leaving the former to suffer from "cylinder snobbery".

I can say that I certainly agree with what you have said.
I have had and riden all 3 K75, K100 and K1100 and if it came down to having to have only one bike I would choose the K75RT without hesitation and even sell the mighty Z1300 Kawasaki that I bought new in 1979.

Interesting stuff Mike,

I ride a K100 but recently test rode a 75C. Apart from the fact that this was a poorly maintained example, I did in fact find it nimble. Maybe I am used to the heavy big brother but I found I could throw it around a lot more.

Of course this may well be because it was not mine

I have been considering a K75 RT for myself as the one I look after is my wifes and put a paralever rear end with the K1100 frontend with big brakes and adjustable screen and big tyres and wheels from the K1100 RS. I reckon it would be a mighty good bike.

now that explains a lot...when Tackler asked if I could check out a K75RT for sale I thought I would be a little dissappointed when I rode it but oh contrare....it was smooth , nimble , sharp and did not feel like a ton of glass was over the front wheel....I put it down to being a late model well maintained unit with new tyres....but I guess it is what it is and Tackler you lucky bugger did real well...and at a great price.
I imagine a little naked jobber would be real light and perfect for the city.....

Rick G wrote:I have been considering a K75 RT for myself as the one I look after is my wifes and put a paralever rear end with the K1100 frontend with big brakes and adjustable screen and big tyres and wheels from the K1100 RS. I reckon it would be a mighty good bike.

There's a fairly well documented K75S that's been fitted with K1100RS running gear and fairing on AdvRider.

I quite like the idea of a K75 with a Paralever rear so as to fit the 16-Valve 160 tyre and wheel but not all K75 models had the gearbox with the parallelogram lugs. Plus, short of re-shimming the final drive to take the K75 crown wheel, the gearing might be a bit too tall for the triple. It would lengthen the wheel base too and that might not suit the bike either.

My wifes K75 has a 2.91 drive from a K100RT and it is just fine. You need to slip the clutch a tad more on take of but other than that it is good and makes a difference to fuel consumption as well. She gets 66 mpg and only got 58 with the 3.2 drive.

Ok thanks for all that info, so it looks like there are more options for me to consider. I passed on a very nice K75 about a month ago thinking that the K100 would be nicer to ride being more powerful, need to see if I still have that guy's number.

I think all the opinions I've heard from individuals who know their stuff say the K75 is the sweeter bike all round and I believe it to be true. If, however you are a shallow, vacuous sort of character who is driven solely by having the one with the most horses you must ignore this rational debate entirely and buy a K100 16 valve .

Cheers
Dave

MT350Explorer wrote:I think all the opinions I've heard from individuals who know their stuff say the K75 is the sweeter bike all round and I believe it to be true. If, however you are a shallow, vacuous sort of character who is driven solely by having the one with the most horses you must ignore this rational debate entirely and buy a K100 16 valve .

Cheers
Dave

Here, here! I liked the vibe-free ride of my K75C from a coupla years back, but the inherent electric pulse of my K100 puts the vocals down an octave and drops the jewels a notch or two. There's something to be said for horsepower and
displacement. That said, how bout those long-rumoured K75's with K12 throttle bodies... Where dey at? I wanna see one. Anyone got any pics?

MikeP wrote:There's a fairly well documented K75S that's been fitted with K1100RS running gear and fairing on AdvRider.

I quite like the idea of a K75 with a Paralever rear so as to fit the 16-Valve 160 tyre and wheel but not all K75 models had the gearbox with the parallelogram lugs. Plus, short of re-shimming the final drive to take the K75 crown wheel, the gearing might be a bit too tall for the triple. It would lengthen the wheel base too and that might not suit the bike either.

My current project is to transform my K75 into a more retro-looking beast plus change the entire front- and back-ends to improve road handling. I've fitted K1100 forks, 4-pot Brembo brakes, 20mm front MC and 305mm floating disks on the front. I'm fitting "C" style bars as well. In the back, I'm fitting a K1100 transmission, Paralever driveline and 33:12 final drive. Both wheels will be three-spoke K1100LT's (3.5" and not the 4.5" ) and Avon Roadriders for the moment. The final drive is very tall for the K75 but I'll see how it performs before contemplating whether I will change it. The handling should improve markedly. In this guise, the K75 should handle like a modern bike and I'm looking forward to the transformation.

I bought the K75 because I wanted to downsize from my K100RT. I found that I was not travelling distances and so wasn't using the RT features as they were intended. Also, I am a commuter and the large fairing was awkward and heavy in traffic. So, the K75 seemed like the right bike.

I agree that the K75 is light, and nimble yet powerful. As I drive, it compares with the K100 for speed but has the advantage of silky smoothness and light weight.

TWB wrote:That said, how bout those long-rumoured K75's with K12 throttle bodies... Where dey at? I wanna see one. Anyone got any pics?

My K75 will probably have K1100 TBs. Not K1200's but halfway there.

Agreed that the Paralever adds some wheelbase length (I've seen 50mm bandied about), but up the front, you've added K1100 forks which have are set closer to the steering head pivot (I've laid them out together and it's quite obvious), so the wheebase will not be as long as you might expect. Some here have suggested that the standard bikes with no Paralever but with 16V K100/K1100 Marzocchi forks will have a tendency to produce tankslappers in certain conditions. I can't wait to try that out for size on my 8V K100RS when I get back home. Imagine a bike that actually steers as compared to their railroad straight tendency now. If it all goes awry with the experiment, a high quality steering damper might help. Putting it back close to stock if it's shite will mean an experiment for the fun and the learnin' of it. One must try some things for oneself.

robmack wrote:My K75 will probably have K1100 TBs. Not K1200's but halfway there.

Keep in mind that K1200RS have 38mm TBs if non-cruise control and only 34mm if cruise is fitted.

Two Wheels Better wrote:Agreed that the Paralever adds some wheelbase length (I've seen 50mm bandied about)

Bang on.

1516 mm for the non-Paralever bikes and 1565 for the Paralever.

The difference is enough to allow the ABS controller to be mounted behind the battery on the Paralever bikes instead of in the tail unit. The rear mudguard has a much longer leading edge:



The rear wheel is moved back far enough to reveal a problem that never arose with the shorter wheelbase; stones can kick-up and jam the clutch actuating arm. BMW offered an extension piece for the mudguard to prevent this:



I think that the Paralever is an answer to a problem that really didn't need fixing. Yes, I fell for it. I bought an R100GS on the strength of the press release before the first bikes arrived in the UK. It has never seemed worth the added length, weight and weaknesses to me. On the K, the only benefit is that the design has permitted fitting wider rims that allow radial tyres.

On that subject, the first batch of K75RTs that we received at work had radials. They still used the pre-three spoke wheels but the rims were slightly different. The older wheels had a concave outer rim:



The later ones (the same as those that came fitted with radial tyres) have a flat outer rim:



That may just be a design change and nothing more but the rumour at the time was that the later version had a rim designed for radial tyre beads.

I've managed, with a bit of stand and exhaust mount fettling, to fit the three spoke 4.5x18" rear wheel along with a three spoke 18'' front wheel, with Conti Road Attack II radials, to my 8V K100RS without the troublesome 'upgrade' of the Paralever. I reckon she handles and rides beaut!

I was using radials on my solo in the '80's and '90's, with standard wheels; Pirrellis and Dunlops......but the sizes were later discontinued, so I'm now using Bridgestones crossplys. I can't honestly say that I've noticed any difference.

Got radials on the outfit though.

Paul.

[quote="MikeP"][quote="Two Wheels Better"]Agreed that the Paralever adds some wheelbase length (I've seen 50mm bandied about)[/quote]
Bang on.

1516 mm for the non-Paralever bikes and 1565 for the Paralever.

The difference is enough to allow the ABS controller to be mounted behind the battery on the Paralever bikes instead of in the tail unit. The rear mudguard has a much longer leading edge:

[img]http://mikep.smugmug.com/Other/BMW-K1-Red/i-5CLG8Hc/1/L/K1%20BMW%20%2883%29-L.jpg[/img]

The rear wheel is moved back far enough to reveal a problem that never arose with the shorter wheelbase; stones can kick-up and jam the clutch actuating arm. BMW offered an extension piece for the mudguard to prevent this:

[img]http://mikep.smugmug.com/Other/BMW-K1-Red/i-XrbvB2R/1/XL/K1%20BMW%20%2898%29-XL.jpg[/img]

I think that the Paralever is an answer to a problem that really didn't need fixing. Yes, I fell for it. I bought an R100GS on the strength of the press release before the first bikes arrived in the UK. It has never seemed worth the added length, weight and weaknesses to me. On the K, the only benefit is that the design has permitted fitting wider rims that allow radial tyres.

On that subject, the first batch of K75RTs that we received at work had radials. They still used the pre-three spoke wheels but the rims were slightly different. The older wheels had a concave outer rim:

[img]http://mikep.smugmug.com/Other/K75S/i-T5VP4qn/0/L/K75S%20%2852%29-L.jpg[/img]

The later ones (the same as those that came fitted with radial tyres) have a flat outer rim:

[img]http://mikep.smugmug.com/Other/Ryans-K75S/i-bf5LLzx/0/L/BMW%20K75S%20%2857%29-L.jpg[/img]

That may just be a design change and nothing more but the rumour at the time was that the later version had a rim designed for radial tyre beads. [/quote]


No, you can and BMW did in the US, mount a radial tire just fine to the early rim. Look at the rims on the 1988 K100RS ABS, which came with an early Dunlop radial.
BMW went to a different rim design and softer rim material after seeing quite a few Japanese cast wheels, which use a harder aluminum allow, shatter catastrophically on German autobahns with the expected messy outcomes for the riders. They made a deliberat choice to accept some rim bends in normal use to prevent a catastrophic failure and instant death.

Two Wheels Better, a stock K75 with the original triple clamps will go into a diverging wobble at speeds in excess of 100 mph if the Fluidbloc steering damper is not fitted. This was something BMW test riders encountered in early testing and the resultant crashes nearly killed three of their best test riders. A friend of mine was there at the time helping develop the bike. On the 750 the front down tubes are a little further back on the neck and this gives the neck just enough flex to start walking at high speeds where the frame on a K100 does not. This was a real surprise to BMW to say the least, and combined with the clutch problems I described elsewhere the K75 very nearly didn't make it to production.
The solution to the tank slappers was the Fluidbloc steering damper. Never, ever run a K75 without it.
Having said that, I have ridden a couple of K75s with K1100 TB, Paralever, wide wheels, big brakes and R100R triple clamps whos less offset endow the bike with more trail, pretty much how my K100RS in my avatar is set up. Putting K1100 TBs and a K1100 intake snorkel on a K75 along with some air flow meter tuning wakes them right the heck up! They will pull K100RS gearing, but not the taller K1/K1100 gearing. The best clutch is that from an R1100S. It will stand up to the taller gearing where the stock K75 part won't. This is a very fun canyon scratcher. You will never overwhelm radial tires with this engine at any lean angle, so you can get on the power much earlier than you would dare on a sport bike. On tight second gear roads you can just humiliate riders on Ducatis and such who are crouched over narrow bars struggling to keep the rear tire from spinning while you just whack it open and flick it side to side. Whooosh, gone. See-yaa.

Themason wrote:
The solution to the tank slappers was the Fluidbloc steering damper. Never, ever run a K75 without it.

And if a K75 won't stay on a chosen line through a bend, the Fluidbloc damper is rotating with the steering stem.



This one had seized to the stem and the grub screws that keep it from rotating normally have then cut two slashes in the outer body. Later Fluidblocs have an aluminium sleeve:



It wasn't an extreme problem, just unpleasant.

These posts give me the horrors. I can never forget a violent tank slapper I had many years ago on a dual carriageway at 70mph. I managed to stop but the experience is faity horriffic because it usually means an off. Up to that point I had always assumed anything fork mounted such as handlebar fairings, screens etc were likely causes. Needless to say a steering damper was promptly fitted but I have never actually felt completely relaxed aboutt hem. The K100 has always felt rock solid no matter what. The range of movement initially has to be very small, all I can say is make sure that damper is fitted and is in good nick.

I traded a K75RT for a K100RS 16v last year and I would concur that the theoretical 4v/cylinder K75 would have been the best of both with about 90PS. I agree on fluidbloc too, mine was shot and I got some alarming slappers.