seized front sprocket.

Useles, tried it yesterday again. Went to burrow a pulley from a mate mechanic, tried everything with the result that I nearly wrecked the original bolt. Bent it, didn't want to put the pulley centerpiece straight on the axle.
The more I'm trying, the further away I'm getting to fitting my shiny new 17 tooth sprocket :blast

Called up my dealer, asked him iff I could pop over and if they could fix it. Sure, no prob, c'mon in. They said.

Did so today, fixed up the GS again, using the bent bolt. Hey, the sprocket wasn't going anywhere anyway, could've driven to them without the bolt.

Anyhow, about an hour later, two mechanics working on it, first time they had to use the "three teeth" clamp on the pulley, stoking it up with a weld torche and lot af hammering and even some swearing, it came of :bounce1

To make a long story short, no way in hell I could've pulled it of myself, even with the right equipment.
Glad I went tot the dealer 'cause the 17 tooth sprocket is working wel. Bike is reacting much more smoother on the catchy throttle, and the revs have gone down about 500Rpm at 120km/u. Meaning my fifth gear is now running on the same revs as my sixth used to run, only I've got a sixth left for the motorway :D

Grtz, Philip!

(Pardon for the typographical errors, I'm just typing what comes to mind :P)
 
Guess what ...

same fookin problem here now :eek


I've already changed the rear sprocket - piece of cake - but my puller will need some re-modelling after the strain I put it under trying to get this fooker off.

Now I'm going to try the short length of chain trick...

G
 
Screwfix do a cheap slide hammer with a three legged puller so it just comes straight off.

Happy to do it for anyone who is local if they are struggling.

Regards

Mark
 
Fook ...

My bank balance is £53.00 lighter, my toolbox is 5kg heavier.

Having shagged my old faithful 3 leg puller I thought I'd invest in the slide hammer combo and found one at MachineMart.

So, I thought with a nice shiny new tool it would fly off. It didn't.

I tried heating the sprocket - then tried again. Despite lots of smoke from the burning chain lube nothing moved. Bollocks.

I was naturally worried about the heat being a problem, so I dug out my plumbing heatproof mat and cut a slit in it so I could wrap it around the output shaft. More heat - sprocket teeth cherry red type heat. Still nothing moved. More Ballooks.

Being more than a little p!ssed off I upped the ante and really whacked the hammer - ten minutes hard whacking (I knew that the whacking practice would pay off...:toungincheek ) yielded about 1mm movement ...

Eventually the sprocket gave up its resolve - but only after an hour of increasingly sweaty whacking - which gave me bruised palms and aching fingers.

Thankfully the seal appears to have survived the heat, but only time will tell if I've done any damage to the output shaft bearing...

Ironically, the new sprocket just slipped on - albeit with a little help from a cocktail of Halfords copper grease (brilliant stuff - more of a paste really) and CV Moly grease. Hopefully this will last long enough to ease the next removal.

So - this is what I found....

IMG_0674.jpg


If you look at it compared with the new sprocket you can see the teeth are just starting to hook so its replacement was justified.

IMG_0679.jpg


The rear sprocket however was a bit of a surprise. It's done 13k miles, and is in surprisingly good shape.

IMG_0667.jpg

IMG_0664.jpg

IMG_0670.jpg


There's no real sign of wear until you start looking really closely - in the oblique pic you can see just a little 'smearing' on the driven face of the gear tooth, but other than that it looks fine to me and will be kept in the spares box for the next time.

The new Izumi 'x' ring chain is going on tomorrow - with a spring link. Once it's back on the tarmac I'll post a report on the new TR91's as well...!

G
 
Glad you have resolved your sprocket problem. I found it one of the most frustrating episodes in my long experience of motorcycling. Iv done it dozens of times on other bikes with no trouble, yet BMW make a real challenge of it.
 
This is becoming a bit of a recurring issue. Most of us had chain and sprockets replaced under recall, yet the front sprocket is proving to be a right bitch to remove. Did the dealers have the same issues?

Surely if this was done properly at the recall, then these sprockets wouldn't be so hard to remove.

I'm not normally keen on conspirasy theories, but I'm starting to wonder if there are dealers up and down the country with a pile of unused and new front sprockets.
 
I'd agree with that ...

The work involved in removing what should be a simple item has turned out to be ridiculous - I'd be really pissed off to have to pay £80 quid for a mechanic to do the job, and BMW must be irritated that they have to commit such time under warranty claims - that is indeed if the fronts are actually changed.

I'm pretty sure that if the shaft is lubed or mollied then this wouldn't happen. There was a fair puff of red dust as the sprocket finally gave up - guessing a little rust goes a long way when it's a tight fit.

G
 
I didn't struggle at all with mine, so I wonder if it's a quality control issue with the front sprocket - terrible tolerance margins perhaps?
 
Tolerances these days will be pretty much consistent I'd imagine ...

Dave - had yours ever been off before? I can only guess that if it had been, then it might have been reassembled with a little lube - mine was as dry as a nun's ... ooops! no no - as dry as a bone... as was evidenced by the puff of rust powder when it finally let go...

We all know that a little lubrication goes a long way!

G
 
I learned a new word though I will be googling the meaning of mollied. Okay,..you invented that word just to catch me out.

Greg this could of been a prime opportunity for another maintenance day you tart :P
 
My chain and sprockets will be due for renewal soon as I can see that the front sprocket is getting slightly hooked so reading this thread filled me with dread!:eek: I went out to the garage tonight just to check things out and after removing the cover and taking the retaining bolt out I tried pulling on the sprocket, obviously it would not have come right off as the chain is still in place. Well, the sprocket moves quite easily on the shaft, phew, no worries there then.:) Seems that not all sprockets are so tight as to need special tools.
While I remember I am sure I read somewhere that you need to renew the rear sprocket bolts when fitting a sprocket, is this the case? the Haynes manual makes no mention of this, just telling you to clean the bolt threads, apply Locktite and refit. :confused:


Andy.
 
@ Gunz ... Mollied ... hmmm as in moly (molybdenum) paste which is a super thick very heavy duty lube generally applied to high pressure applications like final drive splines etc.

@ outrunner ... well, I just refitted the bolts, they should be fine as long as they aren't over tensioned.

HeyHo ...

Tomorrow will tell!!


Greg
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
You must log in or register to reply here.

Similar threads

Lee Frost
DROPPING A TOOTH ON THE FRONT SPROCKET
Replies
17
Views
4,571
steadysteve
Anthony Byrne
800GS front sprocket change
Replies
13
Views
3,451
grahn
Sgt Bilco
17 tooth front sprocket
2
Replies
29
Views
7,319
RadioFlyer
  • Locked
Front sprocket nut won't come undone.
2 3
Replies
40
Views
13,733
steadysteve
King Rat
Front sprocket nut
Replies
19
Views
5,880
Wardy


Back
Top Bottom