The front axle of the R1150r has a flange bolt in the left hand end. The internally threaded end of the axle is approximately 5mm short of the outside face of the fork leg. (At least it is on my bike.)
I assume this is to allow the bolt to tension the fork legs against the axle /hub assembly.
Short version, I was told by a mechanic that the axle was too short because it didn't go all the way through. (Test mounting a wheel set.). This "assertion" does not seem entirely based on fact but before I dismiss the comment it seemed worthwhile checking.
Is this gap (approx 5mm) common/normal on this model.
Soliton wrote:The front axle of the R1150r has a flange bolt in the left hand end. The internally threaded end of the axle is approximately 5mm short of the outside face of the fork leg. (At least it is on my bike.)
I assume this is to allow the bolt to tension the fork legs against the axle /hub assembly.
Short version, I was told by a mechanic that the axle was too short because it didn't go all the way through. (Test mounting a wheel set.). This "assertion" does not seem entirely based on fact but before I dismiss the comment it seemed worthwhile checking.
Is this gap (approx 5mm) common/normal on this model.
Yes - that's correct. (at least that is MY understanding).
The bolt is plenty long enough to engage sufficiently. Remember to loosen the pinch bolts until AFTER the axle bolt is done up to it's full torque setting (I can't remember, but it's not huge.... 20Nm? 30Nm??)
The axle does NOT rotate in the forks (the wheel rotates on the bearings, and the inner shell of the bearings 'might' rotate on the axle, but it's unlikely - the grease that it's recommended to put on the axle is to stop the bearings rusting to the axle!
At least - I think so....... damn it - I'm second guessing myself now - I haven't had the front off the Rockster for ages so I can't remember exactly how it is on it - but I am pretty sure that it's that way.
I had a set of spoked wheels built by Woody's wheels to fit an R1150r. GS hubs mounted to 17" Excel Takesago dimpled rims. The mechanic had the from wheel mounted (disks installed everything fitting nicely) and advised me that the wheel wouldn't fit because of that gap. There is a collar that fits in the oversized bearings and he believed that was the problem. I had already checked the BMW parts fiche about 17,000 times before I had the wheels built and knew the axle part numbers are exactly the same for the R1150r and the GS ie same length axle on both models. I was not however going to gainsay the mechanic when my front wheel is involved. Especially after the rear wheel debacle. The whole thing got pulled off and the cast wheel re-installed (and I was charged for the pleasure)
I am now at the point of refitting the wheels myself. When I looked and thought about it.... I was a tad cross. There was nothing wrong and all of the calculations were correct. Oh well, live and learn. Nonetheless I decided to err on the side of caution and check the combined wisdom of the group. I had re-checked it, my son had checked it (apprentice BMW mechanic) but another sanity check can't hurt where retaining a front wheel at speed is concerned.
I am at this point waiting on a machinist to shorten the collar on my speedometer drive and it will be ready to go. I'm tossing up about have the rear wheel electronically tested for micro fractures or damage following the accident. The rim was scraped but it still seems to be running true (massively oversized super laced stainless spokes.)
It will look good when it's done and I'm in no hurry.
Today I reinstalled Rockster wheels after new tires were fitted by Cycle Gear.
I had trouble getting the front axle into the left hand side (LHS) fork bottom due to fork twist. Will revisit fork alignment in the future, but the front wheel spins fine with brakes installed. Bike was crashed by original owner and fork/forks replaced...
The gap you see inside the LHS fork lower is normal. I'm on my 3rd R1150R and the gap is normal. Cannot recall the spacing for R850R/1100R/1200C I've owned. Note the differences for front axle setup between Roadster and Rockster: axle + right side dust cap + left side speedo drive or Rockster spacer + outside flanged screw.
I have a 2nd set of R1150R wheels (pre-owned front & rear purchased separately) and have used that spare rear wheel/tire when primary tire gets a flat. Had both front and rear installed for a season but had trouble with the front wheel's brake rotor spacing, and am guessing that I bought wheel incompatible with Rockster. Today I reread the wheels section on Largiader's site and was reminded about need to do my homework. You should check out the info as applicable to your use of GS hubs on R1150R. ABS/non-ABS, speedo or not, type of ABS tone/trigger ring, placement of rear brake disc all matter.
02R1100S,05R1100S(BCR), 
(2)-S1000XR 
