Q: (If I can get the crank off) can _I_ replace chain ring



P

Peter Fox

Guest
Chain was worn (slipping again under pressure)...
I replaced it...
But it 'sucked' on 1st-front...
So I removed 4 links...
It still sucked...
So I removed 2 more links...
It still 'sucks'...
So it looks like new front ring required (s)...
No trustworthy LBS...
Q: Is it worth trying to replace front rings myself?
(I Have had the cranks off before to twiddle the front bracket)
Q: I don't even know if rings and crank are separable?

[Marin hybrid. 8 or 9 yo. Approx(ish could be twice) 10k miles. Never
had front rings replaced.]

PS Paranoia is beginning to set in. I'm hearing creaks at every push
and etc. [Not ME!] and beginning to wonder if this [wonderful and
trustworthy bike] is due for retirement. Should I [shudder] 'chuck it
away' and buy another on the basis that the rims will be worn, the
bearings will be worn, the headset will be unrepairable, the BB can't be
adjusted [broken adjuster nut], the everything is too, too near the end
of it's life...
.... or are these real/imaginary ailments easily fixed?

--
PETER FOX Not the same since the submarine business went under
[email protected]
www.eminent.demon.co.uk - Lots for cyclists
 
"Peter Fox" <[email protected]> wrote in
message news:[email protected]...

> Q: Is it worth trying to replace front rings myself?
> (I Have had the cranks off before to twiddle the front bracket)


Yes

> Q: I don't even know if rings and crank are separable?


Post a photo and we'll tell you. Chainrings are normally held on with little
5mm allen bolt thingys - the bit at the back has a slot and it's well worth
getting the little peg spanner thingy to hold it at the same time as you get
a new chainring.

> [Marin hybrid. 8 or 9 yo. Approx(ish could be twice) 10k miles. Never had
> front rings replaced.]
>
> PS Paranoia is beginning to set in. I'm hearing creaks at every push and
> etc. [Not ME!] and beginning to wonder if this [wonderful and trustworthy
> bike] is due for retirement. Should I [shudder] 'chuck it away' and buy
> another on the basis that the rims will be worn, the bearings will be
> worn, the headset will be unrepairable, the BB can't be adjusted [broken
> adjuster nut], the everything is too, too near the end of it's life...
> ... or are these real/imaginary ailments easily fixed?


BB should be easily replacable - adjustable? Headset can be replaced. Wheels
can be replaced. But.. how much did it cost in the first place? If an
equivalent model new is a similar price to all the spares, then it's an
easier choice. OTOH if it was a posh bike in the first place, it's probably
worth keeping going.

cheers,
clive
 
Just a thought - If it's an old bike with a new chain, have you bought
a chain that's too narrow? i.e. an 8/9speed chain on a 7speed setup.
The side plates may be 'gripping' the least worn chainring.
 
Response to Peter Fox:

When you replaced the chain, did you replace the cassette?

I had to replace the middle ring on the trike a few months ago, and
found it was possible to take the large & middle rings off without
taking the crank off; you may not be so lucky, but have a look.


--
Mark, UK
"It does me no injury for my neighbor to say there are twenty gods or no
God."
 
in message <[email protected]>, Peter Fox
('[email protected]') wrote:

> Chain was worn (slipping again under pressure)...
> I replaced it...
> But it 'sucked' on 1st-front...
> So I removed 4 links...
> It still sucked...
> So I removed 2 more links...
> It still 'sucks'...
> So it looks like new front ring required (s)...
> No trustworthy LBS...
> Q: Is it worth trying to replace front rings myself?


Depends on the crankset, but if it's a reasonably good one then yes.

> Q: I don't even know if rings and crank are separable?


Decent quality cranksets have the rings bolted to the cranks. Cheap ones
have rivets. The key questions to get new rings to fit are

(i) how many arms there are on the 'spider' which holds the rings
(ii) what the pitch circle diameter of the bolts which hold the rings

The 'pitch circle' is an imaginary circle drawn through the centre of the
bolt holes.

> PS Paranoia is beginning to set in. I'm hearing creaks at every push
> and etc. [Not ME!] and beginning to wonder if this [wonderful and
> trustworthy bike] is due for retirement. Should I [shudder] 'chuck it
> away' and buy another on the basis that the rims will be worn, the
> bearings will be worn, the headset will be unrepairable, the BB can't
> be adjusted [broken adjuster nut], the everything is too, too near the
> end of it's life...
> ... or are these real/imaginary ailments easily fixed?


Everything on a bike is fixable. Forty years ago you wouldn't have
dreamed of chucking a bike away just because some bearings were
knackered. But, economically, there comes a point where the cost of
fettling exceeds the cost of a new bike. New bikes are nice, of course,
but old favourite bikes which you have fettled yourself are also nice.

--
[email protected] (Simon Brooke) http://www.jasmine.org.uk/~simon/

my other car is #<Subr-Car: #5d480>
;; This joke is not funny in emacs.
 
In article <[email protected]>
Simon Brooke <[email protected]> wrote:
<snip>
> Everything on a bike is fixable. Forty years ago you wouldn't have
> dreamed of chucking a bike away just because some bearings were
> knackered. But, economically, there comes a point where the cost of
> fettling exceeds the cost of a new bike. New bikes are nice, of course,
> but old favourite bikes which you have fettled yourself are also nice.
>
>

I still ride the bike I bought in 1979. Of course it's had two new
frames, several sets of wheels, bars, saddles, gears, brakes ... the toe
clips might be original.
:)
 
Following on from Peter Fox's message. . .
>Chain was worn (slipping again under pressure)...
>I replaced it...
>But it 'sucked' on 1st-front...
>So I removed 4 links...

[etc.]
Thanks for various bits of advice.

I removed the crank. The bit I was dreading worked OK. (So it /was/
worth putting a bit of lubricant on the squares before reassembly.)

The rings were solid with the crank. No way to dismantle whatsoever. :(

With a couple of links removed from the new chain I tried them out on
the bench[1] to see why they should stick. Lo and behold! Although the
chain clearly says for 5/6/7 gears it was narrower internal dimensions
than the old one. A few teeth have worn and burred and were a tight fit
in the 'narrow' links. File these burrs and problem solved.

But the rear gears are still slipping so I haven't been able to get away
with just a chain replacement. :( However before I write the rear gears
off I'll have a look for burring and see if 'not wanting to go on' is
the problem.

[1] Shhh! Kitchen table


--
PETER FOX Not the same since the bolt company screwed up
[email protected]
2 Tees Close, Witham, Essex.
Gravity beer in Essex <http://www.eminent.demon.co.uk>
 

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