re my Pegaso.

It's a 652cc Pegaso ie 2004 and it needs a new chain etc.
That 'etc' I presume means at least a front sprocket.
Should I assume it also means the rear sprocket too?

Sourcing? Googling turned this place up;
http://www.wemoto.com/bikes/Aprilia/Pegaso_650_ie/01-04/

I'm happy to be advised, oh FOAK.

 

I would nearly always change chain & sprockets together, unless for
example, the chain went AWOL extremely prematurely for some reason.

 

I got right royally fed up over the years with some dealers insisting
that you should always replace sprockets at the same time as the
chain, and even refusing to stock chain other than in a set with said
sprockets. I recall on one occasion even getting the head mechanic out
to check, who agreed that, given no visible wear whatsoever, the
sprockets were absolutely fine.

They still couldn't get me a chain soon enough though, so I popped
over the border to Germany (the previous event being in France) where
they just stocked the stuff on a roll and cut of the required length
to order.

So don't take it for granted, nor take the dealer's word for it - the
sprockets _may_ need replacing, but then again, they may not.

 

+1. And go for quality every time, low priced chain is no bargain.

 

DID ZVM chain every time. It's just stupid to buy anything else if you have
choice, except for racing or dirt bikes.

I use it on all my BMW's

 

On the other hand, it's 80 quid for a chain and 100 quid for the same
chain with a sprocket set, so not much of a cost difference.

More labour though, I suppose.

 

And on that note, I fitted a new C&S set to the Peg before leaving, after
21500 miles the chain was replaced, but not the front sprocket as none in
stock.

Over the last 3k miles the chain has stretched more than normal, probably
due to front sprocket. I have fitted a new one (front sprocket).
The rear is still looking fine and dandy.

So to the OP, just do the front sprocket.

 

Although you of course have a lot of experience of this, that doesn't
make sense to me.

AIUI a chain doesn't really stretch, the rollers etc. wear out due to
grit and/or lack of lube. Hence when you fit a scottoiler chains rarely
need adjusting. When the sprockets wear, the valleys get deeper and the
teeth tend to hook. I don't see how that can make a chain 'stretch' more
quickly. ICBW of course.

 

As a chain/sprocket wear together the teeth become narrower and the chain
link lengths longer. If you put a brand new chain on a worn sprocket it
will wear quite quickly - it has to jump slightly every time a link comes
off a tooth.

 

Bad form, I know, but Sheldon Brown (who else) has a lovely page which
explains all this much better than I just tried to:

http://sheldonbrown.com/chains.html

 

Nope. Don't buy that. I think the rollers, do what they say, and roll.
All provided there is sufficient lube of course.

 

To be absolutely correct, I ought to say the rivets get worn, so the play
increases, so that chain can "stretch" longer over a certain number of
links. It's only a couple of percent at most, though.

There are tools to measure this:
http://www.parktool.com/product/chain-wear-indicator-CC-3

 

£100+ spent on DID chain and both sprockets.
This should be fun, I've not had anything to do with chains since that
old BSA I used to have in my sig, about 20 years ago.

Hats off to all.

 

Dave's got a snotoiller on (I know, coz I put it there) and if he asks me to
replace his chain I'll recommend he changes the sprockets too, if only
because they certainly won't do the new chain any good.

For the cost a pair of sprox, it's not worth leaving the originals in place.
IMO, of course.

 

Cheers

 

Haha... ****.

--
Lozzo
Versys 650 Inter-Continental Hyperbolistic Missile , CBR600F-W racebike
in the making, TS250C, RD400F (somewhere)
BMW E46 318iSE (it's a car, not one of those 2-wheeled pieces of shite
they churn out)

 

<g>

It was known as bastard for a lot of the trip, but then I started to like
it once I had sorted all the electrical gremlins.