Confused about cranks....

"Doesnotcompute" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

As you may have read, I think my crank is knackered.

During the ride yesterday, my LHS pedal came a little loose. At a stop one of the mech's used a
torque wrench to tighten it back up but warned riding with it slack had probably cause damaged to
the crank.

Cest la vie thinks I, nowt I can do about it in the middle of no-where, soldier on and deal with
it afterwards.

Sure enough not more than a mile from leaving the mech, the creaking/clicking returned, by the
time I finished, people were double taking due to the amount of noice coming from my bottom
bracket area!

I haven't stripped it down yet, but what exactly am I looking at and looking to replace? having a
look on wiggle, it seems that whole chainsets are their option of choice, is it really necessary
to replace 3 chain rings, arms and spider?

A cheap repair is to remove crank (you won't need a puller now it's worked loose); wrap a thin strip
of aluminium drink can (say 0.25 inch wide) around the taper; replace crank and tighten screw. The
aluminium seems to act as an adequate shim, though its worth checking the screw tightness
periodically afterwards.

Saves money on chain rings etc!

Doesnotcompute said:

Okay, now I'm home and although faded I reckon the markings suggest Shimano Deore LX.

Would that suggest I can directly replace with this:

wiggle.co.ukv2 product detail.aspOpen ↗

Whoa! That looks like an Octalink crankset. It will NOT fit the axle on your current bottom bracket.
Also, its not the cheapest place to get it.

Quoted message said:

If so I reckon that's an acceptable price to sort the cranks and the bent toothed chainring.

You can get the above crankset with ES70 bottom bracket for less than Wiggle are charging just for
the crankset from www.bonthronebikes.co.uk.

--
Jim Price

jimprice.dsl.pipex.comjimprice.dsl.pipex.comOpen ↗

Conscientious objection is hard work in an economic war.

Jim Price said:

Doesnotcompute said:

Shimano Deore LX.

Would that suggest I can directly replace with this:

wiggle.co.ukv2 product detail.aspOpen ↗

Whoa! That looks like an Octalink crankset. It will NOT fit the axle on your current bottom
bracket. Also, its not the cheapest place to get it.

I fired that reply off as quickly as possible, just in case you were sitting in front of your
computer with credit card in hand.

A more measured response would go something like this:

You need to buy a square tapered crankset to fit your existing bottom bracket. The best value in
town is probably the Shimano Deore, which you should be able to get from around 40 UKP discounted.
Wiggle do them for just over 52 UKP. They don't sell an LX square taper at the moment it would
seem, but the difference would only really amount to a chainring or two made of steel rather than
alloy. The steel may last longer. If you buy a bottom bracket which says anything like "Octalink",
splined or ISIS anywhere in the description, it will not fit your existing bottom bracket. Not
even slightly.

One more detail - your existing crankset is probably a compact drive model. This means it will have
around 44 teeth around the biggest chainwheel. If you get a standard drive replacement, it may
scrape against the chainstays, and you might need a longer chain. Best to replace like with like.

Quoted message said:

Quoted message said:

If so I reckon that's an acceptable price to sort the cranks and the bent toothed chainring.

You can get the above crankset with ES70 bottom bracket for less than Wiggle are charging just for
the crankset from www.bonthronebikes.co.uk.

If you did go for splined and replacing the bottom bracket aswell, you would also need the bottom
bracket extraction tool, which would be probably about a tenner. The proper one to have will have
enough clearance to do tapered and splined bottom brackets. Shimano claim the splined design is
stronger. I have one, and it is very good so far (although I never suffered problems with square
tapered cranks, as I take great care and a torque wrench to them).

--
Jim Price

jimprice.dsl.pipex.comjimprice.dsl.pipex.comOpen ↗

Conscientious objection is hard work in an economic war.

Richard said:

Doesnotcompute said:

I've just had a horrible thought - is it possible it's not the crank that's worn, but the bottom
bracket "end" where the crank slides on? Or is it most likely to be the crank itself?

FWIW, in my callow youth I had a loose left crank on my 10-speed. It would get loose, I would ride
around for yonks with it flapping and being tightened by fingers every mile, then get around to
borrowing the correct tool and overtighten it badly, it would get loose, I would ride around for
yonks with it flapping, etc. When I was finally shown the error of my ways, I had a good look at
it. The "axle" was still (tapered) square but the crank was horribly rounded inside.

R.

That sounds similar to a problem I had 2 or 3 years ago. Eventually found a large crack in the crank
where it went on the bottom bracket.

I got a replacement for just the left crank at Halfords.
--
Mark Road bike, Mountain bike and I'm getting something special built for me (I hope it will
arrive soon).

zerling said:

A cheap repair is to remove crank (you won't need a puller now it's worked loose); wrap a
thin strip of aluminium drink can (say 0.25 inch wide) around the taper; replace crank and
tighten screw.

That is a get-you-home repair - it won't last. Unless you are terminally skint I recommend doing the
job properly - but if the bike is recent (which I think it is) the LBS may well have a left-hand
crank on the shelf.

Guy
===
** WARNING ** This posting may contain traces of irony. chapmancentral.comchapmancentral.comOpen ↗ [currently
offline awaiting ADSL transfer to new ISP]

In article <[email hidden]>, Dave Larrington

Quoted message said:

Way back when, you could - I once had to repace the left crank of a Stronglight 99 after falling
on black ice and bending it to the extent that it could no longer trace a complete circle, as the
chainstay prevented it from so doing. St John St Cycles still sell odd cranks from time to time,
but the chances of their having the one you want are probably slim. This is all part of the
Conspiracy to make bicycles in bigger and bigger lumps, with labels on them saying "No
user-serviceable parts inside", grrr, chiz.

It sounds as if he only needs a left hand crank - pretty standard as long as the cosmetic appearance
doesn't matter too much. UKP 2-00 plus postage and I'll loan him the tools to do it - provided they
are returned!

--
A T (Sandy) Morton on the Bicycle Island In the Global Village sandymillport.fsnet.co.uksandymillport.fsnet.co.ukOpen ↗

In article <[email hidden]>,

Doesnotcompute said:

I've just had a horrible thought - is it possible it's not the crank that's worn, but the bottom
bracket "end" where the crank slides on?

Nope.

Quoted message said:

Or is it most likely to be the crank itself?

Yep.

--
A T (Sandy) Morton on the Bicycle Island In the Global Village sandymillport.fsnet.co.uksandymillport.fsnet.co.ukOpen ↗

Jim Price said:

Jim Price said:

Doesnotcompute said:

Shimano Deore LX.

Would that suggest I can directly replace with this:

wiggle.co.ukv2 product detail.aspOpen ↗

Whoa! That looks like an Octalink crankset. It will NOT fit the axle on your current bottom
bracket. Also, its not the cheapest place to get it.

I fired that reply off as quickly as possible, just in case you were sitting in front of your
computer with credit card in hand.

Heh - no chance - I know life to well to do that!

Quoted message said:

A more measured response would go something like this:

You need to buy a square tapered crankset to fit your existing bottom bracket. The best value in
town is probably the Shimano Deore, which you should be able to get from around 40 UKP discounted.
Wiggle do them for just over 52 UKP.

Okay - "tapered" refers to what? the shape of the hole in the arm that fits over the axel?

Quoted message said:

They don't sell an LX square taper at the moment it

The difference? I'm guessing "Deore" is bottome range, "lx" is next up and so on and so forth?

Quoted message said:

would seem, but the difference would only really amount to a chainring or two made of steel rather
than alloy.

And on a full sus MTB, this is hardly an issue right?

Quoted message said:

The steel may last longer. If you buy a bottom bracket which says anything like "Octalink",
splined or ISIS anywhere in the description, it will not fit your existing bottom bracket. Not
even slightly.

I'm a bit [censored], but I guess you mean and octalink/isis/splined CHAINSET won't fit my current
bottom bracket?

Quoted message said:

One more detail - your existing crankset is probably a compact drive model. This means it will
have around 44 teeth around the biggest chainwheel. If you get a standard drive replacement,
it may scrape against the chainstays, and you might need a longer chain. Best to replace like
with like.

Heh - idiot time - what's a chain stay?

Quoted message said:

Quoted message said:

Quoted message said:

If so I reckon that's an acceptable price to sort the cranks and the bent toothed chainring.

You can get the above crankset with ES70 bottom bracket for less than Wiggle are charging just
for the crankset from www.bonthronebikes.co.uk.

Okay, if I did that, I'd then remove current chainset and BB, replace new BB and Chainset and robert
is the brother of my father?

Quoted message said:

If you did go for splined

Which means? and what's the benefit?

Quoted message said:

and replacing the bottom bracket aswell, you would also need the bottom bracket extraction tool,
which would be probably about a tenner.

Okay - I can do that. Does that suggest your recommended crankset and BB will need this gizmo too?

Quoted message said:

The proper one to have will have enough clearance to do tapered and splined bottom brackets.
Shimano claim the splined design is stronger. I have one, and it is very good so far (although
I never suffered problems with square tapered cranks, as I take great care and a torque wrench
to them).

Hmm - is it worth investing in a torque? thinking about it, we might have one at work that I
can borrow.

Thanks fro your post - most helpful...

--
Dnc

Doesnotcompute said:

Quoted message said:

I hope I'm not confusing the issue even more, but if it's just the BOLT coming "a little loose"
and the crank itself seems to be holding itself on ok, there may not be a problem at all.........

The bolt was coming loose, therefore the crank had play

No, not "therefore". It is possible for the bolt to appear loose even when the crank has no
play......

Quoted message said:

, therefore it seems it's knackered. Even with the bolt torqued correctly, there is still much
noise, creaking and groaning of the cranks. How is this "not a problem at all" ?

I said: ...AND if the crank is holding itself on ok. But you have now made it clear that this does
not apply. I was giving you some more info in case the crank was now staying on ok (since the last
tightening since your last post) but just the bolt still seemed to work loose.

Quoted message said:

Quoted message said:

Please read: draco.acs.uci.edu8f.11.htmlOpen ↗

Excellent. I read it.

All of it? The most relevant bit is half way down......

Quoted message said:

I'm still not sure what point you're trying to make? Or was it just for interesting reading?

I was trying to help you - but didn't have time to explain in full and thought the full explanation
included the article would do. The point is that the bolt can seem to work loose even when there's
no problem because cranks can naturally squirm further onto the axle: bolt should not be repeatedly
tightened.

~PB

I am particularly taken by the cut-'n'-paste job on the Wiggle site:

"The new LX crank features "see through" hollow bottom bracket bolts to initiate discussion at the
sales floor about the Hollowtech design."

Marketroids, eh? Tch!

Dave Larrington - legslarry.beerdrinkers.co.uklegslarry.beerdrinkers.co.ukOpen ↗
===========================================================
Editor - British Human Power Club Newsletter
bhpc.org.ukbhpc.org.ukOpen ↗
===========================================================

Doesnotcompute said:

Okay - "tapered" refers to what? the shape of the hole in the arm that fits over the axel?

Yes.

Quoted message said:

The difference? I'm guessing "Deore" is bottome range, "lx" is next up and so on and so forth?

Yes, sort of. Deore is the point in the range where the good stuff starts in the view of a lot of
people. In my view, it is the price point above which the law of diminishing returns cuts in, i.e.
such good value for money that its not worth paying more (or less).

Quoted message said:

Quoted message said:

would seem, but the difference would only really amount to a chainring or two made of steel
rather than alloy.

And on a full sus MTB, this is hardly an issue right?

In my opinion, yes. You need to be pretty damned good to actually need the difference.

Quoted message said:

I'm a bit [censored], but I guess you mean and octalink/isis/splined CHAINSET won't fit my current
bottom bracket?

Yes.

Quoted message said:

Quoted message said:

One more detail - your existing crankset is probably a compact drive model. This means it will
have around 44 teeth around the biggest chainwheel. If you get a standard drive replacement,
it may scrape against the chainstays, and you might need a longer chain. Best to replace like
with like.

Heh - idiot time - what's a chain stay?

The chain stays are the two tubes which go from behind the bottom bracket to each side of the
rear axle.

Quoted message said:

Quoted message said:

Quoted message said:

You can get the above crankset with ES70 bottom bracket for less than Wiggle are charging just
for the crankset from www.bonthronebikes.co.uk.

Okay, if I did that, I'd then remove current chainset and BB, replace new BB and Chainset and
robert is the brother of my father?

Yes, Your geneology is exemplary.

Quoted message said:

Quoted message said:

If you did go for splined

Which means? and what's the benefit?

Splined means the Octalink/ISIS type of pedal fitting, where you have 8 or 10 teeth on the axle
which engage with similar holes on the crank. The benefit is nominally that you will get a
stiffer/stronger joint here, and would be an advantage to someone who regularly breaks cranks at
this joint. You have only broken this joint once, so its not yet clear whether you would get the
full benefit. It may be a worthwhile solution if you wants belt and braces.

Quoted message said:

Quoted message said:

and replacing the bottom bracket aswell, you would also need the bottom bracket extraction tool,
which would be probably about a tenner.

Okay - I can do that. Does that suggest your recommended crankset and BB will need this gizmo too?

If you want to fit it yourself without bodging, yes.

Quoted message said:

Hmm - is it worth investing in a torque? thinking about it, we might have one at work that I
can borrow.

For one use, borrow it.

Quoted message said:

Thanks fro your post - most helpful...

Thankyou.

--
Jim Price

jimprice.dsl.pipex.comjimprice.dsl.pipex.comOpen ↗

Conscientious objection is hard work in an economic war.

Pete Biggs said:

Doesnotcompute said:

Quoted message said:

I hope I'm not confusing the issue even more, but if it's just the BOLT coming "a little loose"
and the crank itself seems to be holding itself on ok, there may not be a problem at all.........

The bolt was coming loose, therefore the crank had play

No, not "therefore". It is possible for the bolt to appear loose even when the crank has no
play......

I understand that, and if it was just a loose bolt, I'd agree. But given the unbearable racket
coming from the area, I think we can assume some degree of play/knackeredness.

Quoted message said:

Quoted message said:

Quoted message said:

Please read: draco.acs.uci.edu8f.11.htmlOpen ↗

Excellent. I read it.

All of it? The most relevant bit is half way down......

Yes but to be honest I think it was a case of not seeing the wood for the trees.

Quoted message said:

Quoted message said:

I'm still not sure what point you're trying to make? Or was it just for interesting reading?

I was trying to help you

I understand that and thankyou wholeheartedly

Quoted message said:

- but didn't have time to explain in full and thought the full explanation included the article
would do. The point is that the bolt can seem to work loose even when there's no problem because
cranks can naturally squirm further onto the axle: bolt should not be repeatedly tightened.

Understood, but it's not the bolt that concerns me - it's the noise!

--
Dnc

Jim Price wrote:

<snip everything except>

Quoted message said:

Thankyou.

No, thank *you* I think we've probably reached a conclusion to my question. I knew I'd get there in
the ended - I just needed to find the patient soul to guide me firmly in the right direction.

Thanks again

--
Dnc