1200GS wheel options

[eri]

hi all, am not asking a question in this thread, just sharing some options/ideas

i have two 1200GS, a 2013 wethead, with spoke wheels and 152,000km.......multiple wheel sets, with a full range of tyres
and a 2008 hexhead, with cast wheels and 181,000km...............mainly used as a city bike with 70road/30gravel tyres

i find myself doing more and more gravel road riding and after losing the front and buggering my knee(ACL?) with combination road/gravel tyres, on thick gravel, i now want proper knobbys as much as possible on at least the front for gravel..............and ideally that front knobbly is on a 21" cross-spoke wheel

but i also ride year-round in a lot of wet, oil slicked city roads, where a fully knobbly doesn't grip well

so have been looking for 2 sets of wheels

unfortunately many, many GS riders are also looking for spare wheels for similar reasons, so even used they are expensive and snapped up quick

so thinking outside the box, are there other wheels we can use?

yes - we can use cast 17" rear wheels from the R/RS/RT bikes.......same bolt pattern and as they are not is much demand so are available and affordable, but mufflers need to be spaced out etc

on the front the wetheads can use 1150GS wheels.....same axle size, bearings and brake disc mounts/spacing.....and the narrower 2.5" rim is better for narrow knobblys to cut through thick gravel, (just need to make 5 little extension arms for the ABS disc)

so the wethead now has a 2nd set of wheels that were easy to find and cheaper than wethead wheels

....

but we can do more!

the best front wheel for an adventure bike on thick gravel is a 21", so in a couple of months a 2nd hand R80GS cross-spoke 1.85x21 front wheel will arrive from germany and can hopefully be easily laced on to a spare wethead front hub from the wrecker...............the R80GS hub has a different brake disc mounting and no mounts for ABS ring


and recently a local wrecker has been flogging off bits from bmw's first cruiser, the R1200C

largely an over-bored? 1150 many of the parts were common with the 1150GS and the parts fiche showed the axle, brakes, abs were the same

which means, like the 1150GS, the 1200C front wheel should fit a wethead with just a couple of axle simple spacers and the same ABS disc arms

picked up the R1200C wheel today and have started cleaning it up.............part of the reason it was cheap is that it looks a mess with the thin chrome over the alloy rim bubbling off


we know some GS riders super-motard their bikes by going down 2" to 17" front wheels, so hopefully dropping down 1" to 18 won't change handling characteristics too much

 

[Bikerboy108]

Depending on where you are at and size of bank acct, there’s woody’s wheels in the us https://woodyswheelworks.com/ and equivalents in other countries

 

[eri]

yeah, and that's a good option for those in the first world with more money than time

but for the rest of us

as a famous kiwi said about the challenges faced in splitting the atom

"gentlemen we have run out of money, it is time to start thinking"

so, dry fitted the 18" wheel this morning and found that the spacers made for the 1150GS 19" front wheel were, as hoped, also suitable to get the R1200C wheel nicely fitting the R1200GSW axle with the brake disc mounts lined up with the brake pads

so fitted a just arrived tps sender, found a suitable 100/80-18 tyre, put everything together, used motoscan to the load the new tps ID# and went for a ride


the questions that needed to be answered were;

- how does it feel?

- are the side and centre-stands ok?

- would there be no ABS until the system learned the new front wheel diameter over 20 minutes?

- is the ID printed on these new tps senders the actual ID number needed?

the answers were

- it feels a little different, but only as much as fitting a new front feels.... maybe a tiny bow down perception, like when you alter the front of the seat height?

- 1 inch wheel size change only means 1/2" height change so the stands seem fine

- perhaps because this in the most basic of the wethead ABS programs (pre cornering abs-pro) there were no abs warnings and after the ride motoscan showed no abs fault or trouble codes

- the ID printed on the new banana tps senders was the ID code needed for immediate tyre pressure display


4 of the 5 wheels currently running, not shown is the oem rear

 

[eri]

today the used 1.85 x 21" R80GS cross-spoke wheel bought on german ebay arrived, (bead-blasted clean), shipping time was quoted as 2 months but has taken only 1

the plan is to spoke it on to the R1200GS front hub on the right, and use on gravel roads etc wherever a little more stability is wanted
extra hub came from a wrecked bike where the rim got totalled hitting a curb at speed

new stainless spokes and nipples would be best but are quite expensive so will first try with the old steel R80GS spokes and nipples, though they may need a few mm trimmed off for the bigger hub..................as the ends of the spokes will be semi-seized in the rim with dirt and fine powder of dis-similar metal corrosion will try to swap hubs without fully removing spokes

wanted to stay with a cross-spoke rim for 3 reasons.....easy tps as the sensor is protected in the empty centre of the rim, easy tubeless, they're very strong rims

clean but rough surfaced rim might get some clear-coat, and spokes and nipples some silver paint

wheel was true and spokes had about 5Nm tension and needed up to 10Nm to crack free after 35? years

 

[eri]

unspoking the R80GS hub went pretty well with only 1 of the nipple grub screws rounding out in the 5mm hex nipple, but that didn't stop the nipple coming off
(nipple soaking in wd40 now, need to find a new 2mm allen and try again)


unlike the 1150GS rear wheel disassembled recently the spokes on this wheel were easy to knock back 50mm, (much less alloy corrosion in the hub's spoke holes) so it was easy to get the bigger hub in


bmw cross-spoke rim spokes appear to come with 15mm of thread. when this wheel arrived they was about 3?mm of thread below the nipple...the thread in the nipple doesn't start until about 2?mm in.....so only about 10mm of spoke thread is gripped by the nipple

this is important because as i tighten up the spokes they are proving to be about 5mm too long, (as expected), and are taking the space the locking grub screw needs, however it looks like 5mm of thread can safely be chopped of each spoke, for the grub screws, and there will still be 10mm of thread gripping inside the nipple

have slowly torqued up all the nipples slowly and evenly to 3Nm but the rim is all wonky so it looks like this will still take awhile

 

[JimVonBaden]

Nice. BMW cross spoke wheels are a bear to get straight. Good luck.

 

[FLrider]

Quite the job for sure! Great job!👍

 

[eri]

yes, there's a lot to do

40 nipples needed a tap run down both directions to remove 30 years of dirt and rust, the external rust was then filed off, the nipples anti-rust treated and sprayed silver


40 spokes needed to be knocked back, threaded with a couple of nuts to reform the thread, then chopped + filed before running the nuts off and knocking back into the hub and the newly spray nipples threaded back on


but that's all done now

and tomorrow it's time to start tighten everything up while keeping the wheel true

when that's done, the spokes will get a spray of silver to replace the bubbled chrome that was bead-blasted off, the 40 grub screws will go back in the nipples, the nipple heads will get a spray of silver, the rim will be cleaned for a spray of clear coat, the valve hole drilled to accept the larger tps valve

then it'll be ready for; brake discs, an abs disc, tyre and testing

 

[eri]

phew, has taken about 6? hours but now seem to have a 21" 'good-enough' front wheel

because the the double box section cross-spoke rim is so stiff the spokes need to be considered in groups of 3 to 16

for a minor swing to the side, 3-5 spokes on that side need tweaking

for large 'hops' in the diameter, 16 spokes in 4 groups of 4 may need adjustment

once some spokes are at max of 5Nm they don't get tightened any more, opposing spokes need to be let back to 2-3Nm

if 1 spoke in a group is tight it stops loosening of the other spokes from having much effect, so it was useful to occasionally 'ring' a group of spokes to work out which was holding the rim back and adjusting that first

still waiting for new tps sensors to arrive so have time to keep tweaking to something better than 'good-enough'

 

[eri]

close enough is good enough for testing

waiting on delivery of new TPS sensors then will pop a tyre on

 

[eri]

the tps senders arrived and after drilling out the rim valve hole to 11mm, the 10mm TPS valve stem on the new TPS sender was installed
but there is very little room for it in the these narrow, pre-tps rims..............perhaps that's partly why the more modern F850GS 21" is 2.5" wide?

a smaller 2nd gen tps sender may fit better but as this is what we have now will move forward with trying to fit a 21" tyre over the top

 

[eri]

'project 21' has been stalled a bit but is now progressing along nicely

on a bmw rally a couple of years ago i was going a fair clip a gravel road when a bridge appeared

unfortunately i focused too much on the bridge and didn't 'see' that the other side had been freshly laid with thick gravel

flying into it a could feel the front 'compromise' tyre, motoz trantionator gps, squirming around and looking for an excuse to wash-out, unfortunately the road was curving off and my line was taking my toward the drain...........maybe if i had stood on the pegs and weighted the bike i could have gotten back to the centre of the road and given the front tyre more time to find grip in the thick gravel or find somewhere with less gravel, but i didn't, i tried to 'tweak' the bars a bit.....WHOOSH, we went down, and i got thrown off............several days later 1 of the tendons in my knee, acl/mcl 'popped' and it's taken 2 years to get it back to almost 100%

that spill led me to a few realisations

1 - i was going faster than my; skillset/bike/tyres could manage
2 - if i wanted to keep adventure riding into my 60s i couldn't afford to wreck my body........ but i could afford to improve at least the bike and tyres and get some 4 strap knee braces
3 - in thick gravel a compromise tyre isn't as good as a full knobbly............ideally on a 21' wheel

back as a group for dinner someone pointed out that one side of me was covered in dust and i was asked if a i had taken a 'roll down the road' recounting the story to everyone, who had managed the same bridge crossing without dumping their bikes, led to me 'winning' a new mitas tyre of my choice

i chose their E10 knobbly in 120/70 x 19"
https://external-content.duckduckgo.com/iu/?u=http://www.overlanders.ie/wp-content/uploads/2015/10/mitas.jpg&f=1&nofb=1

2 years later as i hadn't gotten around to fitting it i asked a friend of the mitas importer if he thought i could swap the 19" for a 21" for the new wheel

he arranged for me to get a mitas E13 90/90 x 21", perfect for the narrow 1.85" rim

https://www.wheelhousetyres.co.uk/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/m/i/mitasrallystarpairdeal.png

but getting it on the rim has been an absolute nightmare as the bead would just not seat.........after a few days of trying with various different air pumps, straps, watching videos etc i located and bought a bucket of thick tyre mounting compound........basically the murphys tire compound seen here
.

but even lathered up with that wasn't enough to keep the air in long enough to 'pop' the beads

after a few days stewing on it i finally realised that the problem was probably that both beads on the last section of tyre must have dropped into the 1.85" cross-spoke rim's narrow centre groove and the air was escaping too fast from 4 gaps deep in the rim to swell the the tyre and lift those beads out and over the 'tubeless" lip of the rim


back to work with 2 thin short levers, to get down to the hidden bead, and then heavy levering with 2 long thick levers FINALLY lifted 1 bead into the sealing position and then the air pump was able to pop the other side

next to fit discs, modify mudguard and reposition brake lines

 

[eri]

am riding with the 21" front it now and working through the issues on my 2013GS


1 - traction control, even after several 20min rides the computers have not accepted the bigger front wheel, flash the traction control triangle at any speed over 30kph and retards the ignition which prevents acceleration..............makes sense, the bigger diameter of the front wheel coupled means the front wheel is turning slower than the rear as sensed by the 48 slot abs ring....the computer reads this as the rear wheel spinning faster than the front wheel...thinks the rear has lost traction and triggers traction control

as i want to change between 3 different front wheel diameters without waiting for the bike to 'accept' the size change, i was always going to need a custom abs ring

the current work-around is turning off traction control, long press on abs button while riding, then acceleration etc goes back to normal

probably linked to traction control being turned off is cruose control no longer turns on:o(...............solution - make/buy a abs disc with 52 or 53 slots

2 - the new tps sensor is not being detected by the bike - seems either the new sensor is defective or i recorded the wrong number when installing.........on theory if the snsoe was good even with the wrong number the bike would learn it during the 20 min ride...this isn't happening...instead, after 25min of riding with a blank front tyre pressure the air pressure warning icon comes on and alert starts flashing.......this is a bit of a problem because the tyre swap from 19' knobbly to 21" knobbly somehow ended up with the 21 being tybed-typed, apparently construction is the same but tubeless tyres get an extra fine spray? of rubber on the inside to help prevent air leakage...........was expecting a working tps system to help me monitor this..............solution - remove tyre and try another sensor

3 - front guard clearance - after cutting out the plastic bulge in the guard that protects the brake-line junction,


the guard is still to low at the front...


stuffing a stick between the tyre and guard over-night has opened the gap to a few mm so it no longer rubs while riding but that's not really enough..............solution - a friend has suggested squeezing the top of the guard with a g-clamp while heating the top to increase the guard upper's arch

4. at highway speeds bars have a little shimmy, so need to balance the wheel with a lead spoke weight

 

[eri]

have taken the 21 wheel off and put the 1150GS front wheel back on while the 21" issues above get addressed

with the wheel off, got to see that not only had the front been rubbing but the back too

plan to remove guard at some stage, clamp the sides, increase the distance between front the rear tips and then heat, to hopefully reform to a slightly better shape for the 21


and this morning bought a hexhead rear spoked wheel, need to go down country in a few weeks to collect

it seems that the rear mount on the final drive of the R1200GS 2005-2012 and the R1200/1250GS 2013-2022 is the same

so both bikes can run each other's rear wheels...but due to the mufflers being on the opposite sides the wheels bolt on opposite sides and so rotate in the opposite direction

will put a full knobbly on the coming rear wheel and in theory it will then be able to be used as the serious dirt rear wheel for both bikes......something like tkc80...... front knobbly in 19" and 21" sizes

the 1200GSW oem wheels will then get a pair of compromise adventure tyres......something like tkc70s...............for typical gravel touring

and for city riding the 1200RS rear wheel will stay with its 100% road tyre and the 18" front wheel from the R1200C will stay with it's current 100% road tyre

 

[eri]

have been thinking about the 21" front wheel not being 'learned' by the bike over a 30?min ride, resulting in ASC traction control always being on and retarding acceleration
meaning asc has to be turned off, which then seems to lock out cruise control

the bike's computers have various adaptations that can be reset and relearned via motoscan/gs911/dealer computer...ie throttle idle synchronisation, gear lever position, throttle position etc

1 of the adaptations found in the engine electronics, DME BMS-X, is listed as being for ASC

seemingly meaning rear? wheel size can be learned to match front wheel size

so have just cautiously deleted the current value and will soon go for a ride to see if/what value it relearns, bike currently has the 1150's 110/80 x19" on front and a 160/70 x17


will try various wheel configurations and see if the bike records differing 'radius corrections'

hoping that manually triggering a new 'radius correction' when 21" front fitted will keep the ASC functioning.
and hence avoid the need of making a new 53/54 slot ABS ring

 

[eri]

ok, so clearing the existing 'radius correction', swapping wheels and going for a 5?min ride starts the recalculation of the radius offset correction

this correction is continually calculated by monitoring and comparing the speed of each wheel and stored for use in determining traction control and abs? trigger points

it can be seen with motoscan by following the path - engine electronics/adaptations/asc-dsc/continue

currently have 3 different rear wheels and 4 different front wheels giving 12? different combinations

R1200C 18" front wheel + new 100/90 tyre - 2000mm circumference - radius 318mm
R1200GS 19" front wheel + badly worn 120/70 tyre - 2020mm - radius 321mm
R1150GS 19" front wheel + worn 110/80 tyre - 2065mm - 329mm

R1200RS 17" rear wheel + good 160/70 tyre - 2022mm - 322mm
R1200GS 17" rear worn 170/60 ........tba

21" front wheel + new 90/90 tyre - 2190mm - 349mm

 

[eri]

hexhead wire wheel on back of wethead


the mounting face of the hexhead differs from the wethead but it seems to bolt on and ride ok



possibly not mounted as well as the wethead though

 

[neil w]

F850gs front wheel is a straight swap with 1200/1250 gs/gsa lc and it is a 21" rim (hub is the same )

 

[fatherwes]

F850gs front wheel is a straight swap with 1200/1250 gs/gsa lc and it is a 21" rim (hub is the same )

So the F850GS front wheel is a direct swap for the LC bikes only? Or would it fit on my ‘07 R1200GS Hex head? I think I know the answer, but hoping I’m wrong….

Is anybody running this front wheel/tire on a 1200GS?

Like the OP, eri, I can’t help thinking a 21” front would make a huge difference in mud and loose sand/gravel, and there’s no traction control on my hex head, so the computer might not be as much of an issue…

 

[neil w]

Not sure I do know it is a straight swap onto a R1200GSA LC as I tried the front wheel off my brother in laws 850 on my 1200