Front Sprocket Bolt Removal

[swm]

Hi,
Having just spent a couple of enjoyable hrs trying (and failing) to remove the front sprocket retaining bolt, I would like to ask for advice before I get serious with it in case I am missing something. .
I have removed an outer allen-key bolt OK, but the sprocket retaining bolt is putting up a really good fight.
On previous bikes there was always a tab-washer locking this bolt in position, I presume that the allen-key bolt performs this function as I cannot see anything else stopping the bolt from coming out.
So before I get really serious and chance breaking something could anyone advise me if I am missing something in my approach.

[shebee]

I have given away my manual so can’t confirm but i don’t remember a lock washer... and no mention of it on this post. viewtopic.php?f=11&t=5203&p=39371&hilit=Sprocket#p39371.

[swm]

Hi,
Thank you for your response.

I have a manual. Mine helpfully says 'Remove the bolt' with an arrow pointing too the bolt holding the sprocket .
I have replaced a few sockets on various bikes in the past and not had one this tight before.
Just wanted some confirmation that I haven't missed the bleeding obvious before I upped the stakes and broke something (been there before now).

Ah well, time to give it some welly.

Thank you again
Ciao

[nickst4]

I think you'll need a hammer gun for this. I have a cheapish electric one that has saved the day on similar jobs. Just using a long breaker bar won't get it to unstick.

Good luck,

Nick

[swm]

Hi,
Thank you for your reply.

I have a large socket connected to a very thick ¾” T bar, with a 6'+ piece of scaffold pole used as an extension. If I apply more pressure than I have already then something is definitely going to give, I’m just not sure it will be the bolt coming undone.

I am going to take your advice and invest in an impact wrench (hammer gun).
I’ve walked away from it for a day so’s I’m in a cool frame of mind before round 2 (less chance of me just busting it off) (and less expensive).

Thanks again for the advice
Ciao

[nickst4]

Very wise, I think. Tight fixings often resist a progressive load, but the impact wrench seems to frighten them into coming undone. Plus you don't need to put a lot of torque through all the other bits in the chain of resistance. Before you go at that nut, please do check that it doesn't have little notches in the points of the hex. My local garage mechanic struggled with taking a wheel nut off an MV Agusta until I pointed out that the notches meant it was a left-hand thread!!

Nick

PS The MV was nothing to do with me, more's the pity...

[swm]

Hi Nick,

I will check the thread again on the bike, but I did think about it being LH Thread.
Fortunately there are a couple of turns of thread visible on the end of the retaining bolt when the outer allen bolt was removed.

You can just about see this in picture1. But I’ll still check again, easy enough to do.

I’m always open to suggestions on something I may have missed.

Thanks again
Ciao

[andybaggies]

I second Nick, an impact driver will biff that off in a second. I bought a mains one from the Aldi/Lidl middle aisle for 20 sovs and it's proved invaluable.

Don't try to lock it in gear mind, use a metal bar wrapped in a towel through the back wheel and locked against the swingarm. Might need an impact socket also.

Andy B

Btw I did this at the weekend and it's a normal rh thread with no lock washer. If you look it's one of those nuts with locking tab gubbins on it's inside.

[HiFi]

Hello Raptor Gods As part of my ongoing plan to get the "X" back on the road before the spring runs out I need to change the chain and sprockets on my bike. I'm reasonable mechanically sympathetic but have never done this job before. Is it something you think an enthusiastic amateur could realistically do? I'm kind of worried about the damage an incorrectly fit chain could do if it snaps or otherwise comes off because I've done something wrong, but on the other hand I'm also worried about what a bike shop might do when it's out of my sight (eg. the thing mentioned up thread about locking the rear wheel with a bar wrapped in a towel rather than locking it in gear). I have the chain and sprockets already, I'll need to get a chain link separator but for the sake of an hour in the garage it's probably worth a go surely? Any advice / horror stories welcomed please!

[nickst4]

HiFi,

Replacing the chain and sprockets isn't science of the rocket kind, but there can be pitfalls.

First, you need to be able to take the sprockets off. As we said, an impact gun with a proper socket to suit may be vital to shift the front one. Some manufacturers used to fit rear sprockets with red Loctite on the bolt threads, and that can be very difficult to move without heat. Someone here who has done that job can advise as to whether that applies, as I've not been there on my Raptors.

Joining chain links is a job I'm always very cautious about. Not my favourite job by any means! Needs to be tight but not too tight. First you have to get your head around the bits in the chain-link tool. That usually confuses me!

You may find re-fitting the rear wheel is tricky, especially if the little supporting lug has been snapped off the top of the caliper mount. Both my 1K and 650 needed a bit of steel screwed on to replace that bit, otherwise the caliper mount drops out of sight very easily, just as you thought it was lined up.

Lining the chain up is crucial. I use a laser pointer to ensure the sprockets line up, but you can get close-ish using the marks on the swingarm ends. Some people claim the marks are way out, but I've generally found them pretty close. It doesn't guarantee the sprockets are perfectly in line but you can set the front and back wheels inline with each other, but you need to account for the different tyre widths to use a straight edge alongside the tyres.

Once you have the chain line close, make sure the chain slack is right. Too loose and the transmission will be jerky, too tight and you can kiss your gearbox bearings goodbye!

Is the above helpful, or has it put you off completely? Let's see what other opinions come in...

Nick

[swm]

Hi,

Impact wrench on order

To stop the sprocket turning when undoing the bolt, this ytube vid shows what looks like a good way to lock a stubborn sprocket while the bolt is attacked:
Hope this may help, not tried it yet myself.

Big thank you everyone for the helpful suggestions

Ciao

[andybaggies]

Swm,

Yeah I have used that method of locking the chain but only when I'd forgot to undo the bolt and had already removed the wheel. If you're replacing the the clutch pushrod seal (again ) and are not replacing the chain then I would still chock the wheel.

As with most job the right tools make it so much easier. Taking the chain apart is just a case of grinding the rivet head off and using the tool to push it out. However I've found the tools not up to the job of riveting and have actually broke a couple when trying to do it with the thread just snapping See the Sealey one here https://www.demon-tweeks.com/uk/motorcy ... ain-tools/

Notice how much the best one is...

I have managed to do it with freebie one that was some sort of vice type thing (similar to the AFAM one above) but you will be amazed at the pressure required to round the rivet heads over and even then aren't too sure it's enough...

Take your time, stop & have a cup of tea and think it through.

Andy B.

[HiFi]

Thank you very much for the replies nickst4 and andybaggies, I must admit I hadn't considered that lining up the chain would be so crucial as I naively assumed the sprockets would line up the same as the ones that came off. Certainly food for thought. The YouTube video in swm's link made it all look so easy, I'm guessing that is a scenario whereby the job goes well or badly with little in between! All things considered I think I'll leave it for the professionals. I can do all the other stuff and if a bike shop has just that last job to do that'll be okay.

[swm]

Hi,
Cheap Silverline impact wrench failed to loosen sprocket retaining nut (I think this would have worked with a better product, but this tool would have trouble loosening a milk bottle top).
Used a T bar with an extension on the extension while also tapping with a hammer.
Retaining nut came loose but there was far more pressure needed than when changing sprockets on previous bikes.
Still, onwards and upwards, another job done, onto the next.
Ciao