Hammering in new crank arms

I am replacing my Nexave crankset with an Alivio one. I managed to remove the old cranks, but now I
have trouble with the new ones which don't seem to want to go in. I applied some copper paste on the
axle and smoothened it to as thin a layer as I could. Should I apply something more slippery
instead? I tried heating the crank arms with a hair dryer and hammering them in using a solid hammer
and a block of wood as a cushion... no apparent progress, even with pretty heavy hammering...

How do you do it?

--
Risto Varanka | http://www.helsinki.fi/~rvaranka/hpv/hpv.html varis at no spam please iki fi

 

[email protected] writes:

> I am replacing my Nexave crankset with an Alivio one. I managed to remove the old cranks, but now
> I have trouble with the new ones which don't seem to want to go in. I applied some copper paste on
> the axle and smoothened it to as thin a layer as I could. Should I apply something more slippery
> instead? I tried heating the crank arms with a hair dryer and hammering them in using a solid
> hammer and a block of wood as a cushion... no apparent progress, even with pretty heavy
> hammering...
>
> How do you do it?

I would try a 4 lb--or even 20 lb--sledge hammer.

 

>I am replacing my Nexave crankset with an Alivio one. I managed to remove the old cranks, but now I
>have trouble with the new ones which don't seem to want to go in.

It's likely that the new Alivio crank has a different chainline requirement than the Nexave crank,
so you need to change the sealed cartridge bottom bracket to a shorter axle in order to correct the
chainline. I believe you can check Shimano's website to determine which cartridge you will need.

 

>I am replacing my Nexave crankset with an Alivio one. I managed to remove the old cranks, but now I
>have trouble with the new ones which don't seem to want to go in.

It's likely that the new Alivio crank has a different chainline requirement than the Nexave crank,
so you need to change the sealed cartridge bottom bracket to a shorter axle in order to correct the
chainline. I believe you can check Shimano's website to determine which cartridge you will need.

 

Russell Yim <[email protected]> wrote:

: It's likely that the new Alivio crank has a different chainline requirement than the Nexave
: crank, so you need to change the sealed cartridge bottom bracket to a shorter axle in order to
: correct the chainline. I believe you can check Shimano's website to determine which cartridge you
: will need.

According to Sheldon, Alivio MC16 is 110-113 while Nexave (T400 something maybe) is 117.5 mm spindle
lenght. So... unless I change, my chainline will be screwed and not even my front derailleur will
work? Didn't occur to my LBS, though, I specced the Alivio... :-(

--
Risto Varanka | http://www.helsinki.fi/~rvaranka/hpv/hpv.html varis at no spam please iki fi

 

Richard Ney <[email protected]> wrote:

: I would try a 4 lb--or even 20 lb--sledge hammer.

And that does nothing to the threading of the bottom bracket? :-/

--
Risto Varanka | http://www.helsinki.fi/~rvaranka/hpv/hpv.html varis at no spam please iki fi

 

Threading isn't a problem for very long...

> : I would try a 4 lb--or even 20 lb--sledge hammer.
>

> And that does nothing to the threading of the bottom bracket? :-/

 

<[email protected]> wrote in message
news:[email protected]...
> I am replacing my Nexave crankset with an Alivio one. I managed to remove the old cranks, but now
> I have trouble with the new ones which don't seem to want to go in. I applied some copper paste on
> the axle and smoothened it to as thin a layer as I could. Should I apply something more slippery
> instead? I tried heating the crank arms with a hair dryer and hammering them in using a solid
> hammer and a block of wood as a cushion... no apparent progress, even with pretty heavy
> hammering...
>
> How do you do it?
>
> --
> Risto Varanka | http://www.helsinki.fi/~rvaranka/hpv/hpv.html varis at no spam please iki fi

I'm not sure why you're hammering so much. Something is not quite right. The heating with a hair
dryer and greasing of the spindle are fruitless, the pressure from tightening the crank bolt makes
all that grease disappear immediately. They're not going to affect the engagement of the crank that
much. Step back and consider why you're hammering. If it's chainline problems, measure the BB axle.
If the cranks simply aren't going onto the taper far enough, perhaps the taper angle is different. A
hammer has its place, but I'm not sure this is it. You can hammer once or twice with a block of wood
to seat the crank and tighten the crank bolt to it's correct torque, but to lay on the sledgehammer
is not right.

Cheers,

Scott..

 

In article <[email protected]>,
[email protected] writes:

>I am replacing my Nexave crankset with an Alivio one. I managed to remove the old cranks, but now I
>have trouble with the new ones which don't seem to want to go in. I applied some copper paste on
>the axle and smoothened it to as thin a layer as I could. Should I apply something more slippery
>instead? I tried heating the crank arms with a hair dryer and hammering them in using a solid
>hammer and a block of wood as a cushion... no apparent progress, even with pretty heavy
>hammering...

You cannot get the new cranks to seat on the old spindle? Do I read that correctly? If so I wonder
if you aren't trying to put a splined crank set onto a tapered BB axle (or the other way around).

Tom Gibb <[email protected]

 

TBGibb <[email protected]> wrote:

: You cannot get the new cranks to seat on the old spindle? Do I read that correctly? If so I wonder
: if you aren't trying to put a splined crank set onto a tapered BB axle (or the other way around).

According to http://www.sheldonbrown.com/bbsize.html both should be square taper. Other than that,
the symptoms sound just like that... Maybe I should make a few photos? :-.

Splined BB shells seem to be only used on high-end stuff by Shimano. The BB spindle looks quite
square, with tapered edges so it's sort of an octagon shape...

--
Risto Varanka | http://www.helsinki.fi/~rvaranka/hpv/hpv.html varis at no spam please iki fi

 

On 24 May 2003 18:24:37 GMT, [email protected] wrote:

>I am replacing my Nexave crankset with an Alivio one. I managed to remove the old cranks, but now I
>have trouble with the new ones which don't seem to want to go in.

How much do they go on ? Do they fit on the square at all ? Do they fit completely, but the
chainline is wrong ? It's normal for some of the taper to be visible behind the crank, so long as
they're on far enough for the bolts to go in. If they go on far enough for the axle to protrude
through the crank socket, then you'd never be able to tighten them !

 

Lol... I think I'm getting the picture...

TBGibb <[email protected]> wrote:

: I just measured the widest part of the taper inside a Shimano SGX crank. I got (with a moderately
: good measuring device) 13.6 mm. I also measured a Shimano spindle on the outer end (I measured at
: the point of initial contact between both parts) and it measured 13.0 mm. They oughta go togther
: without a hammer, mine always have.

Of course, the cranks slide in several millimeters! There is just this recess inside the crank... I
mean, the axle doesn't come all the way up on the hole, and there's some millimeters space between
the crank and the bike frame (amount depends heavily on which side is it). The old cranks actually
seem to behave similarly... So this is actually normal? The crank tightening bolts need some
space, and it's them that keeps the crank in place all the time?

By the way, I measured my old bottom bracket spindle, and it seems to be 111mm, instead of the 117mm
that Sheldon lists for different kinds of Nexave. That's weird, what gives? Could Nishiki have some
kind of weird measurements on their hybrids, does some Nexave stuff use a narrower bottom bracket,
or is it just not so critical after all? :-/

Anyways, I'll just try putting it together now...

--
Risto Varanka | http://www.helsinki.fi/~rvaranka/hpv/hpv.html varis at no spam please iki fi

 

TBGibb <[email protected]> wrote:
: In article <[email protected]>,
: [email protected] writes:

:>Of course, the cranks slide in several millimeters! There is just this recess inside the crank...
:>I mean, the axle doesn't come all the way up on the hole, and there's some millimeters space
:>between the crank and the bike frame (amount depends heavily on which side is it). The old cranks
:>actually seem to behave similarly... So this is actually normal? The crank tightening bolts
:>need some space, and it's them that keeps the crank in place all the time?

: I'm going to have a real name for asking dumb questions here, but here goes:

: How tight are you making the crank bolt?

I'm not a real crank expert, but I tightened them as tight as I could. I mean, I could tighten them
even more, but the tool slipped once and now the bolt doesn't look quite right any more. I'll just
tighten them more after 100 km

Cranks seemed all ok now, 35 km of riding. Though I was underpacing myself... gotta train harder
in June =)

--
Risto Varanka | http://www.helsinki.fi/~rvaranka/hpv/hpv.html varis at no spam please iki fi

 

On 26 May 2003 01:34:46 GMT, [email protected] wrote:

>I'm not a real crank expert, but I tightened them as tight as I could. I mean, I could tighten them
>even more, but the tool slipped once and now the bolt doesn't look quite right any more. I'll just
>tighten them more after 100 km

Really, you don't want to be chasing the cranks up the taper. If they were installed with adequate
torque (around 30 lbs-ft) then they be fine. Unfortunately, from what I have seen, inexperienced
people tend to undertighten crank bolts, especially with the allen head bolts that seem to be
common now.

Read the FAQ:

http://www.faqs.org/faqs/bicycles-faq/part4/section-6.html

Chris Bird