21" Rim for 1200gs?
 

Anyone know where I can get a 21" wheel made up for a 1200gs. I'd like to keep the standard wheel, so wouldn't be able to utilise the standard hub.

Bob.

VERY few people in the world would even attempt that. See the links page for those who do work on the BMW tubeless spoked wheels - but USA only. (Search on "Bondo", and the other guy is just below him.)

There WAS a guy in the UK who did it but he told me a couple of years ago it was no longer worth doing. Cheaper to replace the wheel - but your needs are different - you may be able to get him to do it for you, but I can't remember his name! Check around in the UK - he's just a one-man band as I recall, but he's been at it for a long time, should be findable.


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Grant Johnson

Seek, and ye shall find.
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One world, Two wheels.
www.HorizonsUnlimited.com

Just noticed you "wouldn't be able to use the standard hub" - you're going to have to buy one, as adapting anything isn't worth the effort in most cases, assuming you want to keep the dual disks in order to make swapping easier.

Getting expensive...

I went through this exercise recently adapting a R100 fork/ hubb onto a R80. I had to have the wheel built on the stock hubb, and choose not to go tubeless/ rim spoked because of cost and hassle. Still expensive, and still have to run tubes. Is a 21" front going to make that much difference? Not sure it's worth it but let us know how it goes if you proceed!

Thanks guys. I now realise that I'm going to have to use the original hubb if I want go ahead with this plan as BMW want the best part of £500 for a front wheel and all I need is the hubb, the rest will be junked. I will try and find a wheel-builder but, in the mean time, will see if the tyre choice for a 19" wheel has grown in the last few years. Obviously it would be alot simpler to go this route but, when I tried to find a decent off-road tyre available for a 19" wheel a few years ago there was nothing available.

Just a small point here to be taken with the appropriate grain of salt, and not withstanding the technical interest of such a mod, but if you are anticipating needing a 21 inch front wheeel for lots of dirt riding, is the 1200 GS the right bike? If BMW is the desired brand would an f650 dakar be more approprite as they are much easier to handle in the rough stuff.

Hi Bob

Zwerver on the UKGSER site did this mod for his 1150. He used an R100GS rim with the 1150 hub. He also fitted an adjustable swingarm to get the ride height even. There are some pictures too. I'm feeling idle so I'll let you do your own search.

Regards, Mick

p.s. The Dri-Bag has proved mega useful already!

simmo, I agree the Dakar would be a better bike, certainly if I were travelling one-up with minimal luggage but (and it's a big butt, if you get my drift..ouch!) my wife and her wardrobe are comming as well. In all honesty she's not that big (about 9 stone) but the Dakar is not an option as I have the 12 and can't afford another bike just for a three week or so trip.

Mick, that sounds exactly what I'm looking for, I'll have a look on the gser site today. Glad the bag is getting some use.

I have checked with the tyres manufacturers and tyre choice for a 19" wheel is still very poor, as I expected.

Just a thought or two...

With your wife and a full load of luggage, what's wrong with a pair of TKC80's? They work well, certified for the Adventure so should be just fine on your 1200, and they're as close to a knobby as you could possibly need.

I can't imagine conditions that you would WANT to get into fully loaded that you would actually NEED a 21" wheel. It MIGHT be nice, but it's incomprehensible to me that it would be worth spending the money and time and effort given two-up fully loaded.

The bike is nicely designed to work with the 19, and you can be sure they tested it two up loaded in all sorts of conditions, and it worked plenty good enough. Granted the 19 is more on-road oriented, but the 19 is good enough off-pavement. There's thousands of GS11xx's out there that have been everywhere to attest to that.

The only advantage to a 21 is in really gnarly off-road conditions, where it's longer footprint is smoother over the potholes, and narrower profile allows you to place it more accurately.

I've even considered putting a 19 on my R80G/S, since I ride almost exclusively two-up on it, and the stickier, fatter road and dual purpose rubber available for it is a big attraction. But it's not worth the effort...

Remember that a 21 is very skinny - no such thing as a fat 21 - and your powerful dual disks could easily overpower it, especially off-pavement. With ABS on-road you might be ok, otherwise I can see you locking it too easily. (One reason I DON'T have dual disks on mine)

If I were you, I wouldn't even consider it for two up. For the real heavy duty off-pavement solo adventure traveller a 21 has some benefit, (and then you should be on a 650) but I do not it see otherwise.

ymmv and your opinion certainly may, but there's mine for what it's worth!



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Grant Johnson

Seek, and ye shall find.
------------------------

One world, Two wheels.
www.HorizonsUnlimited.com

Grant,

The idea was that a mate and I would ride the two fully loaded bikes, two up from the UK to Morroco then base ourselves at one location and explore that area on the un-laden bikes. It's highly likely that the pillions will want a few days off the bikes allowing my mate and I to do a couple of small trips off on our own. We intend to ride down to Southern Spain on the standard tyres then change them for something more suitable there and thought that it would be easier to find something to fit the bikes with a 21" wheel. My mates bike already has a 21" wheel.

If you think the TKC80's would be up to the job I could take a set down with me fit them when we arrive.

imho...

Go with the TKC80's!

Don't know what your mates riding, if it's a KTM950S or some other serious off-road bike he WILL be better off on the off-pavement stuff, but not enough to really matter for the purpose.

I think you will do fine with the 1200 and TKC80's. And that leaves you with a pile of dosh to spend on other stuff...

If you really find you hate the 19 after this trip, by all means go to a 21 - but try it out as is first, you could be very pleasantly surprised.

Best of luck and keep us posted on your experiences.



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Grant Johnson

Seek, and ye shall find.
------------------------

One world, Two wheels.
www.HorizonsUnlimited.com

I've found few sites showing road tests on the TKC80's (all 1150 adv's) and they all rave about them so I will go this route and see how it goes.

My mate is riding a heavily mdified 100GSPD.

Many thanks to all for the info, Ill let you know how it goes. Bob.

Sorry to revive such an old thread but, I'm off to Morocco next week and have just had the TKC80's fitted. They feel absolutely fine on the road. I thought they would be squrming all over the place but, they feel planted and seem to offer a decent level of grip. I don't know ho long they would last if used entirely on the road but, I can't say I'm particularly bothered about that. As long as they last for the duration of the trip that will be fine. A friends parents live in the South of Spain and we are taking the bikes down to their place in a truck then onward on two wheels, so the tyres won't be subjected to lots of motorway miles.

Bob.

Although tire availability would be better for a 21", as well as tire selection, the TKC80 and other similar tires, (Karoo etc.) are not only very capable tires, but are much safer on road than many other tires designed for a 650 sized bike.

The gains converting to 21" will be minimal. Compare a 21" tire to your current 19" tire. Overall size difference is very small. (not 2") in fact, depending on exact tires used, it is less than 1" difference in diameter.

Woody's makes a conversion kit for the GS.