bias tire

[41107]

My 1985 k 100 rs became very goofy in the front ,wobbel with front brake and hard to turn at slow speed without using body lean.Looking at the front tire (me 33) it had plenty of life on it but it was the age that made me change it.Over the internet i ordered a new front tire,cheap!Once it came i discoverd it was a me 88 front bias (thats why so cheap) and not what i wanted.Mounted and balanced the tire,took for a nice drive to get rid of moldrelease. Then laid into it a little bid.Every thing seemed just fine me wondering about this mix of tires(Me 55 radial in rear,me 88 bias front) I am sure a no no.But it worked.The sluggish steering and wobble with front brakeing was gone.Then the waterpump seal went the bike sat there till today.Last i had driven it was in nice warm weather.Today at 32 degrees I went out for my sunday morning spin and guess what that sluggishness in the frontend is there again.I done checked head bearings,tire pressure,cable routing etc. Could it be the tire combo that I am running? The only thing different today was the weather and a new water pump seal.:confused:

[manicmechanic]

Not intending to insult, but did you check the tire pressure recently? I'm no expert, but I can detect a noticeable difference in the handling qualities when the pressure is not where it belongs. Also, I've always been told that mixing bias and radials is a no-no, and that's what we advise our customers. Since the weather is changing and getting cooler, you may want to ensure your tire pressures are correct.

[YB in IN]

Originally posted by karlheinz
My 1985 k 100 rs became very goofy in the front ,wobbel with front brake and hard to turn at slow speed without using body lean.Looking at the front tire (me 33) it had plenty of life on it but it was the age that made me change it.Over the internet i ordered a new front tire,cheap!Once it came i discoverd it was a me 88 front bias (thats why so cheap) and not what i wanted.Mounted and balanced the tire,took for a nice drive to get rid of moldrelease. Then laid into it a little bid.Every thing seemed just fine me wondering about this mix of tires(Me 55 radial in rear,me 88 bias front) I am sure a no no.But it worked.The sluggish steering and wobble with front brakeing was gone.Then the waterpump seal went the bike sat there till today.Last i had driven it was in nice warm weather.Today at 32 degrees I went out for my sunday morning spin and guess what that sluggishness in the frontend is there again.I done checked head bearings,tire pressure,cable routing etc. Could it be the tire combo that I am running? The only thing different today was the weather and a new water pump seal.:confused:

How long were you out? Maybe your tires were just cold.

[kbasa]

low pressure = hard to turn.

Also, worn steering head bearings in really heavy and thick grease can mean "hard to turn".

[deilenberger]

Originally posted by karlheinz
My 1985 k 100 rs became very goofy in the front ,wobbel with front brake and hard to turn at slow speed without using body lean.Looking at the front tire (me 33) it had plenty of life on it but it was the age that made me change it.Over the internet i ordered a new front tire,cheap!Once it came i discoverd it was a me 88 front bias (thats why so cheap) and not what i wanted.Mounted and balanced the tire,took for a nice drive to get rid of moldrelease. Then laid into it a little bid.Every thing seemed just fine me wondering about this mix of tires(Me 55 radial in rear,me 88 bias front) I am sure a no no.But it worked.The sluggish steering and wobble with front brakeing was gone.Then the waterpump seal went the bike sat there till today.Last i had driven it was in nice warm weather.Today at 32 degrees I went out for my sunday morning spin and guess what that sluggishness in the frontend is there again.I done checked head bearings,tire pressure,cable routing etc. Could it be the tire combo that I am running? The only thing different today was the weather and a new water pump seal.:confused:

Karl - one request.. please use some breaks for paragraphs. It is very hard to read one continuous message like this.

OK - the ME55 is not a radial tire - it is a belted tire.

Here is a link to the info on the tire: http://www.us.metzelermoto.com/product_info/catalogo/scheda.asp?ID=162&idCat=12&nome=ME_55_A_Metronic

Note that Metzeler doesn't list a front ME88 tire in any size anymore: http://www.us.metzelermoto.com/product_info/catalogo/scheda.asp?ID=148&idCat=12&nome=ME_88_Marathon

If it was me - I'd be asking for a refund for this tire - it is undoubtably old stock (did you check the date code?)

But - I don't think this is causing your problem.

How did you check the steering-head bearings?

This isn't that easy to do. At a minimum the front wheel has to be off the ground, and ideally - all cables/brake-lines/etc removed so they don't cause drag. Most people don't remove all the lines, so it takes an educated touch to really check the bearings.

The relationship to temperture that you indicate makes me think it's time to re-grease the bearings, or perhaps replace and regrease them. As Dave S pointed out - the grease can get very stiff as it gets old, and this condition is made worse by cold. Did you check the steering head bearings in the same conditions (ie - 32F that you're experiencing the problem at? If not.. well, it's obvious.

If you're not confident in doing this - I'd suggest taking the bike to a dealer or independent BMW mechanic.

Best,

[spikethebike]

Mixing bias and radial is permitted by the European safety nazis.
Also. I believe the F650 was delivered with bias front radial rear. The cold grease in the head bearings will definately make the bike steer heavy.

[41107]

thank you guys for all the come back on this subject.
again went out to the garage and jacked up the front end of the bike to check again.Oh made a mistake the front is a M330 and not M88.But anyway i rotated the handlebars thru its swing again and again and then suddenly there it was. I could feel the the bearing notching.Moved it again from full left to right and it was ok.Third time there it was again.Must be one of the rollers in the bearing having a flat spot.Certainly has to come apart to see what is going on.In regard to tire pressure as some one mentioned, I strongly believe in checking before going on a ride.
THANKS AGAIN!

[deilenberger]

Originally posted by karlheinz
thank you guys for all the come back on this subject.
again went out to the garage and jacked up the front end of the bike to check again.Oh made a mistake the front is a M330 and not M88.But anyway i rotated the handlebars thru its swing again and again and then suddenly there it was. I could feel the the bearing notching.Moved it again from full left to right and it was ok.Third time there it was again.Must be one of the rollers in the bearing having a flat spot.Certainly has to come apart to see what is going on.In regard to tire pressure as some one mentioned, I strongly believe in checking before going on a ride.
THANKS AGAIN!

Yup - definately new bearing time. The M330 should work fine with your rear tire. FWIW - there are no radial tires in a size to fit the early K bike rims.

Best,

[manicmechanic]

Last year about this time I was replacing the steering head bearings on my K1100LT, and decided to go the "as long as you're here" route. Since the fork legs had to come off, I disassembled them, cleaned and flushed, new seals, checked the bushings, new fluid. Just a thought.

[FRubio]

Hello Manic,
What would be the pros and cons of going to radials from bias on my 93-K1100LT?
Fernando:dunno

[manicmechanic]

Good question, Fernando. The owner's manual for my old K1100LT included the K1100RS, and the tire sizes and types were different recommendations. Anybody please correct me as necessary. Radial tires generally have shorter sidewalls, therefore give a stiffer ride, but handle a bit better because the shorter sidewall gives more tread area. The radial is supposed to have less rolling resistance than the bias tire, and because of the radial construction may be less prone to "wandering" on rain grooves. This last I'm not sure of, I think it may be more a factor of the tread pattern. I don't claim to be an expert, but I do read a lot, and try to keep up on these subjects. A lot of the things I try to say are my opinion, and we all know what is said about opinions. Somebody more knowledgeable than me may have more and better info.

[SirFer]

Hey Manic,
Do the radials require a different wheel, or can you mount either radial or bias on the same wheel?
Sorry for the long delay in my response but for some reason I had to re-register into the BMWMOA forum.
Thanks
Fernando:dunno

[manicmechanic]

I believe the bead areas are the same on all tubeless rims, so it shouldn't matter.