Crank bolts - how tight?

On 11/4/05 8:10 am, in article [email hidden],

John Hearns said:

Two questions:
a) how tight should crank bolts be done up?
Standard alloy crank

Tighter than Simon had his ;-)

Quoted message said:

b) are hex-headed crank bolts, which you can undo with an
allen key, available? Might be useful, as my Specialized EMT
tool is very nice, but I don't carry anything that fits crank bolts.

Yes, from TA amongst others. They are very good. I now have them on two
chainsets.

...d

Quoted message said:

Two questions: a) how tight should crank bolts be done up? Standard
alloy crank

I use a 10" ratchet and lean on it as hard as i can

Quoted message said:

b) are hex-headed crank bolts, which you can undo with an allen
key, available? Might be useful, as my Specialized EMT tool is
very nice, but I don't carry anything that fits crank bolts.

Standard item so shouldn't be a problem.

--
A T (Sandy) Morton
on the Bicycle Island
In the Global Village
http://www.millport.net

John Hearns composed the following;:

Quoted message said:

I was doing a bit of work on the bike last night,
using the Lidl toolkit.

I took the cranks off using my own crank tool.
The Lidl one doesn't have the socket to fit my crank bolts.

Two questions:
a) how tight should crank bolts be done up?
Standard alloy crank

Depends on manufacturer and type of crank. I've seen Torque numbers for
cranks between 20 and 140 lbf ft

Quoted message said:

b) are hex-headed crank bolts, which you can undo with an
allen key, available? Might be useful, as my Specialized EMT
tool is very nice, but I don't carry anything that fits crank bolts.

Yes. With 8mm or 10mm hex sockets, usually. A good LBS should have them
for sale.

--
Paul ...
(8(|) Homer Rules ..... Doh !!!

John Hearns <[email hidden]> wrote:

: Two questions:
: a) how tight should crank bolts be done up?
: Standard alloy crank

Damm tight.

If tightening allen-key based cranks (usually a 10mm ISTR), then
"as tight as you can manage" will do fine (*)

If tightening old-school crank bolts using a big spanner, then
tight but don't completely welly it down if the spanner if big.

Snug down after the first ride, then leave well alone.

Arthur

(*) Remember that I have no upper body strength here. Adjust if
you are a gorilla.

--
Arthur Clune PGP/GPG Key: http://www.clune.org/pubkey.txt
Don't get me wrong, perl is an OK operating system, but it lacks a
lightweight scripting language -- Walter Dnes

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

Quoted message said:

On 11/4/05 8:10 am, in article [email hidden],

John Hearns said:

Two questions:
a) how tight should crank bolts be done up?
Standard alloy crank

Tighter than Simon had his ;-)

and mine!
http://www.simonmason.karoo.net/zcrank.htm

Simon Mason <[email hidden]> wrote:

: and mine!
: http://www.simonmason.karoo.net/zcrank.htm

Cranks cracking like that is often caused by over tightened cranks. Usually
it's

a) do cranks up tightly
b) go for ride
c) tighten cranks

So far, so good.

But if you keep tighening the cranks down, at some point the expanding tape
splits the crank.

Arthur

--
Arthur Clune PGP/GPG Key: http://www.clune.org/pubkey.txt
Don't get me wrong, perl is an OK operating system, but it lacks a
lightweight scripting language -- Walter Dnes

in message <[email hidden]>, John Hearns

(') said:

I was doing a bit of work on the bike last night,
using the Lidl toolkit.

I took the cranks off using my own crank tool.
The Lidl one doesn't have the socket to fit my crank bolts.

Two questions:
a) how tight should crank bolts be done up?

Tight. See the 'A plague of fairies' thread, in a newsfroup near you
now.

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

[ This .sig subject to change without notice ]

On 11/4/05 11:08 am, in article
[email hidden], "Simon Brooke"

Quoted message said:

in message <[email hidden]>, John Hearns

(') said:

I was doing a bit of work on the bike last night,
using the Lidl toolkit.

I took the cranks off using my own crank tool.
The Lidl one doesn't have the socket to fit my crank bolts.

Two questions:
a) how tight should crank bolts be done up?

Tight. See the 'A plague of fairies' thread, in a newsfroup near you
now.

The problem with crank bolts is that you don't notice they have gone till
well after the event. Your cranks suddenly start feeling strange and you end
up without a bolt to replace,not being sure where to start looking in the
last 5km.

Self extracting bolts are the answer. Can be done up tight and you will
notice them working loose before the crank finally parts company. Mine have
6mm allen key heads.

...d

David Martin <[email hidden]> wrote:

: The problem with crank bolts is that you don't notice they have gone till
: well after the event.

I've only ever had this problem with lightweight al replacement crank bolts.

Once replaced with standard campag allen-key headed bolts I've had no problems.

Arthur

--
Arthur Clune PGP/GPG Key: http://www.clune.org/pubkey.txt
Don't get me wrong, perl is an OK operating system, but it lacks a
lightweight scripting language -- Walter Dnes

John Hearns said:

Two questions:
a) how tight should crank bolts be done up?
Standard alloy crank

The most apt description is attributable to Brant Richards with "[censored]
tight"

Tony

Arthur Clune said:

David Martin <[email hidden]> wrote:

: The problem with crank bolts is that you don't notice they have gone till
: well after the event.

I've only ever had this problem with lightweight al replacement crank bolts.

And I only had this problem with a set where I thought "I'll ust have a cup
of tea then tighten everything up". Guess what got forgotten.

...d

John Hearns said:

a) how tight should crank bolts be done up?
Standard alloy crank

I recommend looking up the recommendation from manufacturer or Park Tools
and using a torque wrench. With square taper types, remember that you're
not only tightening a bolt, you're wedging the crank up the spindle (the
crank will actually expand on the way), and that takes a great deal of
force. Under-tightening is more of a common problem than over-tightening.

~PB

David Martin said:

The problem with crank bolts is that you don't notice they have gone
till well after the event. Your cranks suddenly start feeling strange
and you end up without a bolt to replace,not being sure where to
start looking in the last 5km.

Self extracting bolts are the answer.

Or dustcaps :-)

....Or (with steel bolts) just do them properly tight in the first place
then they'll never come loose.

~PB

Pete Biggs said:

David Martin said:

The problem with crank bolts is that you don't notice they have gone
till well after the event. Your cranks suddenly start feeling strange
and you end up without a bolt to replace,not being sure where to
start looking in the last 5km.

Self extracting bolts are the answer.

Or dustcaps :-)

A while ago, a young lad we know stopped outside our door with a crank
in one hand an the rest of the bike in the other. "Can you fix this
back on?" he asked. Well, I thought that wouldn't be a problem, 'cos
the dustcap was still attached. I removed the dustcap to retrieve the
nut (it was one of those nasty BB axles with a thread stamped on the end
and those very silly [1] nuts to hold the crank on) and there was
nothing in there! It turned out that the BB had just been overhauled at
the LBS - looked as if they just forgot to put a nut on. Unfortunately,
it was after closing time and I didn't have any of those silly nuts
(only spare bolts for proper axles), so he had to walk home.

[1] Why do they put a ratchet profile on the base of these nuts? Grind
them flat and they fit much better and are more likely to stay done up.

--
Andrew

Tony Raven said:

The most apt description is attributable to Brant Richards with
"[censored] tight"

Tight enough that if it slips, you'll see the bone in your knuckles.

--
Andy Morris

AndyAtJinkasDotFreeserve.Co.UK

Love this:
Put an end to Outlook Express's messy quotes
http://home.in.tum.de/~jain/software/oe-quotefix/

Quoted message said:

The problem with crank bolts is that you don't notice they have gone till
well after the event.

So that's why I keep finding old crank bolts in the road! I now have a
collection of five.

Where do you get self extracting bolts and what do you ask for?
I have a campag crankset with them fitted, can they be removed from
that and put on another set?
TerryJ

Terry said:

Where do you get self extracting bolts and what do you
ask for?

Ask for self-extracting (or auto-extracting) crank bolts. Your LBS should
be able to get them. TA is one manufacturer:

http://www.chickencycles.co.uk/products/chains/pg_chainsets.html

Try to get some with an 8mm head if possible: 6mm is on the small side for
the torque you need to apply. There are different versions for square taper
and splined axles.

Quoted message said:

I have a campag crankset with them fitted, can they be removed
from that and put on another set?

Some Campag cranks used left-hand threaded auto-extractors. Most other
modern cranks use a standard 22x1mm right hand thread.

James Thomson

On 13/4/05 12:12 am, in article
[email hidden], "James Thomson"

Quoted message said:

Terry said:

Where do you get self extracting bolts and what do you
ask for?

Ask for self-extracting (or auto-extracting) crank bolts. Your LBS should
be able to get them. TA is one manufacturer:

http://www.chickencycles.co.uk/products/chains/pg_chainsets.html

They would be the ones marked 'Self extracting crank dust cap set'. I have a
pair on my MTB and a pair on the road bike, both with 6mm head which seems
fine (with a quality allen key). The trick is to put gob loads of grease on
them when you install them.

...d

Quoted message said:

Try to get some with an 8mm head if possible: 6mm is on the small side for
the torque you need to apply. There are different versions for square taper
and splined axles.

Quoted message said:

I have a campag crankset with them fitted, can they be removed
from that and put on another set?

Some Campag cranks used left-hand threaded auto-extractors. Most other
modern cranks use a standard 22x1mm right hand thread.

James Thomson

Naqerj said:

It turned out that the BB had just been overhauled at the LBS -
looked as if they just forgot to put a nut on. Unfortunately,
it was after closing time and I didn't have any of those silly
nuts (only spare bolts for proper axles), so he had to walk home.

Presumably the LBS will put the crank back on for him. What they
probably won't tell him is that the crank is now ruined and will keep
on working off.

--
Dave...