The old front has iron sticking out, the rear one tiny holes.
Time for some new rubber



Rear; Roadsmart Sportmax 2, front; Sportmax Qualifier 2

That gets you a heavy fine, points on your licence and an order to get a breakdown truck to take it home in the UK. I ain't seen tyres like that for three decades. How do you get away with it in die Nederland?

Hi There, I see a muffler with round end in the last picture. Is that muffler original or aftermarket one? I have previously seen only squared ends in those mufflers. I am asking because I have that muffler in my K-bike as well?

JiiPee63 wrote:Hi There, I see a muffler with round end in the last picture. Is that muffler original or aftermarket one? I have previously seen only squared ends in those mufflers. I am asking because I have that muffler in my K-bike as well?

Round one on 16v engines, square on 2v engines.

Thanks for a very quick reply .

Dai wrote:That gets you a heavy fine, points on your licence and an order to get a breakdown truck to take it home in the UK. I ain't seen tyres like that for three decades. How do you get away with it in die Nederland?

We don't have MOT or something like that.
If the police sees it, they only can point out the danger.
If the undertaker sees it, he will start baking cake for the family

Since you're obviously no stranger to running tyres down to the limit, can I ask how badly affected a K100RS 16V is by well worn tyres. Handling on mine is truly evil, verging on dangerous. It flops down into slow corners and picks up ruts in the road so badly that I have to stop to check I don't have a flat. Although there's 2mm or so left, hence "legal", tyres (Roadtec Z6) have worn to a triangular profile.

Front:


Rear:


Might be head bearings of course, although they feel fine. And tyres need changing anyway. But I'd be interested to know how sensitive these bikes are to tired tyres.

Since August I'm back working at the local Beemer dealership. The State & some local city coppers ride R1200RT-P & R1250RT-P and they love Michelin Road 5 GT tyres! They're getting punctures constantly so they roll in regularly after repairing their tyre by the side of the road. If the repair/maintenance is under $1000 they don't have to report it to their commander and can use the state issue credit card. Since a set of new tyres is under $600 they buy sets instead of singles. Meanwhile, it costs the shop about $5 or $6 to discard each tyre with the rubber recycler. It's more often fronts that are not fully worn out over rears that are either punctured and repaired, or hardly worn. See where I'm going here? I am steadily growing a handsome selection of not fully worn out Road 5 (not punctured & repaired) tyres in my home garage for future use for myself and others. Thank you Washington state taxpayer, myself included. Please know that your hard-spent tax dollars are getting full use in the local motorbike community.

My 16V K100front tire has a trapezoidal profile like that. Definitely wants to flop into turns at intersections and in parking lots. Dropping the tire pressure from 38psi to 35psi has made it work well enough to get another month or two out of it so I can replace it this winter.

I suspect that as the tire wears, the air pressure tends to accentuate the trapezoid shape by pushing out the center of the tread. Lowering the pressure a little seems to reduce that and lets the tire roll into the turn a little smoother.

Personal experience says my K handles like a dog with worn but legal tyres.Only answer is change them in pairs as soon as you feel uncomfortable.Being a slim bloke 10 stone and a bit,the bikes suspension hardly moves so i feel every bump,grove and ridge.your not alone in this matter and for £230 or so play safe mate

Happy to run a rear down to...whatever. But I like at least a bit of tread on the front for when the rain inevitably arrives.
Dunno why we are so keen on tyre laws here in the UK Four Nations when jolly-faced bus drivers can slosh diesel around all day long like its part of their public duty. I'll take a bald/underinflated/ex-Arlina tyre every time over someone else's diesel incontinence.

92KK 84WW Olaf wrote:Round one on 16v engines, square on 2v engines.

Not to derail the thread or anything, but I see this term (2V, 16V, 4V) thrown around a lot, and no idea what it means. Is it referring to number of valves? Or something else?

You've every right to be mystified. 
You can have a 2v bike (with 2 valves per cylinder)...
and you can call it a 8 valve bike (if it's got 4 cylinders) or a 6 valve bike (if, oh well, you get it by now)
Or, you can have a bike with 4 valves per cylinder...
and if it's got 4 cylinders you can call it a 16 valve bike.
It's be nice if you could have a bike that you could call a  12 valve, 'cept BMW didn't make one 

Cognisenti have this weird habit of talking obliquely. Personally, I think it's a good thing. The alternative is we all speak German.

roach374 wrote:

92KK 84WW Olaf wrote:Round one on 16v engines, square on 2v engines.

Not to derail the thread or anything, but I see this term (2V, 16V, 4V) thrown around a lot, and no idea what it means. Is it referring to number of valves? Or something else?

Yes, all K100 naked, all K100RT, all K100LT, all K75 are 2 valve per cylinder engines so too are K100RS up to 89 including SE models, and looking at the bolts on the cam cover they are zig zag pattern. These have 4 side exhausts and K75 has triangular exhaust. 

K100RS after 89, all K1 and all K1100 are 16 valve or 4 valves per cylinder and all have round exhausts. The valve covers on these have bolts vertically above each other. These have one piece systems and are round and being one piece there are cracking issues. Some of us change them to Remus and so on. K1 owners though like to keep their bikes original. Just saying like.

When a tyre's tread surface begins to match the 'wear bars' and the bike wiggles or wallows passing over highway rain grooves, changing lanes or in warm weather's slithering tar snakes, that's when I ditch the worn rubber for new, or as in the most recent post, near new. I don't enjoy riding on a worn tyre...too, there's often water on the road here in the Pacific North Wet so I like large channels in the tyre to let that potentially slippery wet escape.

moriarti wrote:Personal experience says my K handles like a dog with worn but legal tyres.Only answer is change them in pairs as soon as you feel uncomfortable.Being a slim bloke 10 stone and a bit,the bikes suspension hardly moves so i feel every bump,grove and ridge.your not alone in this matter and for £230 or so play safe mate

It may also be age related. As in the tyres. 

I rode my RS home on 17 year old new tyres on a cold damp evening on a smooth road and it is the scariest bike ride I have ever done. Changed them to nice new BT45 for €245 fitted. 11 stone rider, I run 38/42 psi.

My OZ K100RS-8V has a nice round exhaust outlet made in the UK by Motad...I've never really liked the look of that square K100-8V thang, better the triangle of a K75-6V.

Those Continental Road Attack II radials were the sh*t! Great, nimble handlers, more sport than touring, tho', to bring it back to tyres.

My tyres are shown the bin as soon as they start tracking asphalt joints and white lines i.e. at about 2mm left on the tread.

- Dai 'my middle name ain't Scrooge'

Found out in the tyre swap that the frontwheel bearings yelling for the bin.
Ordered new ones at the dealer. Cost me a leg I guess. Time for a Honda DCT. Only 1 leg needed....

It's always the front tyre that goes first.
I'm the one who doesn't know where the rear brake is  
Also, left my front suspension wek, and rear strong. Love the bike that way.
Take the corners stepping on the throttle while the frontbrake is still in my hand.

Thanks for the comments; it's reassuring (in a way) to know that very worn tyres do ruin the handling. I have some nice new Metzeler Roadtecs waiting to go on and I'll hold off on the steering bearings for now.

I take my R100RS as the benchmark, narrower x-ply tyres of course, but it can be run down to UK legal "...visible tread over the remaining third" without threatening to fire me into the nearest hedge.

Arlina - I thought I'd put a standard 6205-2RS bearing on the RHS with a spacer. 7.81 versus 30.60 (UKP) for 3205. Can't see any justification for the angular contact bearing on a solo.

Never knew what's special about the RHS bearing, will check it out.
Last time they weren't that expensive.....

Bring My Wallet

Dai wrote:My tyres are shown the bin as soon as they start tracking asphalt joints and white lines i.e. at about 2mm left on the tread.

- Dai 'my middle name ain't Scrooge'

I am well aware of that, Ebenezer. 

This, the K1300GT's 190/50ZR17, constitutes a worn-out tyre in my estimation...

...and I try my best to wear them to the edge - I dislike leaving so much rubber to be worn down - but in reality 90% of my riding is commuting (this year, at least) with gentle leans on highway offramps with only the occasional blast up over the Cascade mountains behind Winnebagos or two-up. I'm always amazed that fellow riders decide to ride 'til their tyres are showing wire strands through flattened off rubber.

I've put a new tyre on the front (Metzeler Roadtec 01) and I'm happy to report that the bike seems no longer to want to kill me. Also the old tyre was 40g out of balance which explains something else. All in all a major improvement.

Handling's not great yet, still wants to drop into slows turns a bit (e.g. at junctions) but tolerable now. And the long wheelbase is very noticeable. I expect a new rear will improve it some more followed by a change to 15w fork oil and maybe replace the head bearings.


'91 K100RS 16V

stanthomas wrote:I've put a new tyre on the front (Metzeler Roadtec 01) and I'm happy to report that the bike seems no longer to want to kill me. Also the old tyre was 40g out of balance which explains something else. All in all a major improvement.

Handling's not great yet, still wants to drop into slows turns a bit (e.g. at junctions) but tolerable now. And the long wheelbase is very noticeable. I expect a new rear will improve it some more followed by a change to 15w fork oil and maybe replace the head bearings.


'91 K100RS 16V

Ah, the venerable Metzeler Roadtec 01, a truly wonderful wet weather tyre, and the undersung round rubber roller when it has to go up against the storied Michie Pilot Road series! If only the 01 price was a bit lower...

Recent advice from the Metzeler rep...."Go 42 psi minimum in back and keep the front close to 40 psi or above for longer life on heavier bikes."

I have Roadtec 01s on my R100RS, different construction of course but I'm very happy with them. Unfortunately no 160/60 18 so it's a Z8 in the back for the K.
I did debate putting the HWM (heavy weight motorcycle) Roadtec 01 on the K but decided it wasn't that heavy by modern standards.

stanthomas wrote:I have Roadtec 01s on my R100RS, different construction of course but I'm very happy with them. Unfortunately no 160/60 18 so it's a Z8 in the back for the K.
I did debate putting the HWM (heavy weight motorcycle) Roadtec 01 on the K but decided it wasn't that heavy by modern standards.

Metzeler suggests bike's over 500 Lbs wet or kerb (curb for 'Mericans) weight should use the HWM version. It qualifies, I reckon.

I figure my 16V, minus ABS and with an empty tank should weigh in at about 510 lbs. So borderline heavy.

I've not found any specific weight recommendation from Metzeler online, but perhaps you have a trade bulletin.
I did find this on the R1200R forum where someone has specifically asked Metzeler for advice. Seems very much a matter of rider choice based on riding style - which in my case is solo and unladen. So far, on cold, wet, dirty and potentially icy roads, I'm happy with the Roadtec 01 / Z8 non-HWM choice.

Can say much about my new rubber yet, except got good grip while brake at front.
Cold and wet here lately, and changed work, wich made me get my car too much.
Sofar the new rubber works well, grip on wet and good rolling
Added new bearings to the frontwheel as well, would help keep the front tyre in shape a bit longer.
Bike done 208000km

stanthomas wrote:I figure my 16V, minus ABS and with an empty tank should weigh in at about 510 lbs. So borderline heavy.

I've not found any specific weight recommendation from Metzeler online, but perhaps you have a trade bulletin.
I did find this on the R1200R forum where someone has specifically asked Metzeler for advice. Seems very much a matter of rider choice based on riding style - which in my case is solo and unladen. So far, on cold, wet, dirty and potentially icy roads, I'm happy with the Roadtec 01 / Z8 non-HWM choice.

Your tyre combo is a fine one for you, obviously. The first time I noticed that a lack of the use of GT or HWM spec tyres can be an issue was when a customer came back in after us fitting a set of standard Metzeler Z6 to his K1200RS. He was a Boeing engineer and rode every day to work in Seattle's typical wet and wetter weather. He stated that at near 70 mph or so he could feel a slight weave that increased with velocity from the front end. I requested the tech take the bike for a ride at that speed but he refused as the interstate highway speed was just 60 mph and he didn't want a prize from the state constabulary for exceeding his licence's limits , so I did it myself as parts manager Yep, bike weaved. The Telelever, swingarm, shocks, bearings and tyre pressures, were checked over for anything out of spec. Meantime we had discovered a BMW spec Z6 version and ordered them in after speaking to the West coast Metzeler rep about it and asking for the part number(s) which the distributor/supplier had not listed in their printed catalogue yet.

This was all of fifteen-plus years ago during my first stint in the Pacific North West. At that time there were not a lot of tyre manufacturers making 'heavy' spec tyres for bikes, despite BMW having had the Telelever front on the market out since 1993, and the sturdier Duolever version since '04 on the K1200S, then K12R & GT versions.

When the HD spec Z6 tyre arrived we fitted it and I took the bike to 100 mph for several miles on a relatively empty stretch of I-5. Weave gone, bike stable and railway track straight. Since then nearly every manufacturer bar Dunlop have an HD spec rubber for more portly BMW and other heavy tendency front end motorbikes. I reckon most K100 & K1100 can get away without using the HD version but if a more stable, planted feeling and better tyre life is desired then it's recommended by the manufacturers. And me from my own experience.

That standard front Z6 from his K1200RS with just a few miles on it went onto my R1150R and covered just shy of 13,000 miles for me with no dramas.

I hoped we'd left the problem of a bike that works well with one tyre and is terrible with another, behind in the '70s with the Commando 

The K1200RS is heavier again of course and has different front suspension, but Metzeler won't be offering variants of the same tyre just for fun so the point is taken.

It's probably just coincidence that the tyres I was complaining about were Z6s, well worn but well over 2mm everywhere (no idea whether they were a HWM variant). Perhaps the 01s and Z8s are an improvement.

These sport-touring radials are new to me with their two-compound construction and side wear that puts them seriously out of shape even when there's plenty of tread left. Since replacing the front changed my 16V from frightening to ok, I'm hoping the Roadtec 01 will wear more evenly and keep its profile, even if it wears faster. Maybe I replace it 'cos it's worn out rather than scary but get a similar mileage.

I'll report back in when I have ridden them some more (which could be Easter now ).