Diamondback MTB rebuild...

N8N wrote:

:Last night I started in on this again. I'd previously got the DS crank
off the spindle but the NDS was stuck tight. Well I rigged up a way
to apply Excessive Force (tm) to my crank arm puller, with less than
successful results. Rather than pulling the crank arm off the taper, the
puller ripped the threads right out of the crank arm. So that will have
to be cut off with an angle grinder.

I've used a jacobs chuck puller wedges to get a crank off a square
taper spindle. Worked great. They are two wedges, you put one in one
side, the other 180 degrees away, and tap them into place. Some bikes
might need a spacer between the bottom bracket shell and the wedges,
so the wedges bear on the crnak.

I'd get a est before getting an angle grinder.

--
sig 8

On Tuesday, July 21, 2015 at 11:15:57 PM UTC-4, Sir Ridesalot wrote:
On Tuesday, July 21, 2015 at 1:41:21 PM UTC-4, N8N wrote:
On Sunday, July 5, 2015 at 1:37:35 PM UTC-4, N8N wrote:
Hi all,

friend of mine was given a "free" bike and asked me if it was worth salvaging... still not sure yet but here goes.

Needs new bottom bracket and probably crankset as it looks like the gears are permanently welded to the spiders (Shimano stuff, assume low end?), and they've been mangled a little by bad shifting. Obviously chain as well and possibly cassette too.

I can't get anything apart yet as it's been sitting outside (so a bunch of stuff is soaking in penetrating oil) and also I need a few tools that I don't have to really tear into it.

does anyone know how I can determine the BB size without disassembly? I couldn't find an email link on Diamondback's web site. It is a Diamondback Response, year unknown. I haven't even got the cranks off yet as it looks like I need to find a temporary bolt to thread into the spindle to pull the arms off and I don't have anything in my stash that thread. It's a standard square taper, I can tell that much.

Does anyone know what tool I need to remove the BB? I can't try the few that I have as I don't have the crank arms off yet.

Also needs new shifters and cables. Condition of hubs unknown but they definitely need at least new balls/repack; they feel awful.

Finally is it possible that 7mm bolts were used in some places? I took the handlebars off and find that the 6mm bolts in my parts bin don't thread into the stem. however the original very rusty ones thread in fine and probably will be reused at least temporarily until I can source some new hardware.

Additionally I pulled the seatpost just to make sure it was free (because that would be a deal killer) the seat angle adjuster I don't have a single allen wrench that will fit it, is it possible it is 5.5mm?

I'm not a MTB guy but I'm kind of trying to save this one because a) it's a lot lighter than most MTBs being non-suspended and I think she's more looking for something for road and light trail riding; also she is very short so finding something "better" that fits her will be hard.

So do you think I can resurrect this for less than $200 or so? Then, is it worth it?

Update again.

Last night I started in on this again. I'd previously got the DS crank off the spindle but the NDS was stuck tight. Well I rigged up a way to apply Excessive Force (tm) to my crank arm puller, with less than successful results. Rather than pulling the crank arm off the taper, the puller ripped the threads right out of the crank arm. So that will have to be cut off with an angle grinder.

I tried to get the one BB cup off that I could get to with also limited success. I think I will strip the frame down after cutting off the crank arm and throw it in the back of my car one day and stop by my friend's auto repair shop after work with my impact gun (I don't have a compressor at home.)

Before I hork this up beyond all recognition, is this a good plan? (will the Park tool hold up to mild impact use? I was impressed with the crank arm puller, I have to say, as I was using it well outside of design parameters and other than some marks on the blue handle, it is just fine.)

Also, please confirm for me that the DS cup is RH threaded but the NDS is LH threaded? (I think that's right, isn't it?) I can't see threads on the cups. Just trying to save this frame before throwing in the towel and giving it to the scrap man... would hate to do it as it was given to the owner by her son even if it was a bit of a bad buy on his part. Also if I can get the BB out and friend decides the Trek I found for her is too big, I can just transfer the crank, arms, wheels, etc. over from that bike and it won't cost me anything to put her on a one size smaller frame.

thanks

Nate

I removed a non-drive side crankarm for a guy who'd also ripped out the threads. I placed a wide piece of metal with a slot that slipped over the bb spindle, behind the crankarm and then drove an old wood working chisel between the crankarm and the piece of metal on either side of the crank arm. He was quite surprised at how that crankarm just popped off.

If you're going to removethe fixed cup on the drive side then take alook at Sheldon Brown's homemade tool for doing that. i made one and it works a treat. here's the link to Sheldon's instructions.
http://sheldonbrown.com/tooltips/bbcups.html

Cheers

are we playing light jazz when using these tools ?

On 7/21/2015 11:33 PM, David Scheidt wrote:
N8N wrote:

:Last night I started in on this again. I'd previously got the DS crank
off the spindle but the NDS was stuck tight. Well I rigged up a way
to apply Excessive Force (tm) to my crank arm puller, with less than
successful results. Rather than pulling the crank arm off the taper, the
puller ripped the threads right out of the crank arm. So that will have
to be cut off with an angle grinder.

I've used a jacobs chuck puller wedges to get a crank off a square
taper spindle. Worked great. They are two wedges, you put one in one
side, the other 180 degrees away, and tap them into place. Some bikes
might need a spacer between the bottom bracket shell and the wedges,
so the wedges bear on the crnak.

I'd get a est before getting an angle grinder.


Yes, or a ball joint remover:

http://www.northerntool.com/images/p..._2000x2000.jpg

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Wednesday, July 22, 2015 at 8:38:44 AM UTC-4, AMuzi wrote:
On 7/21/2015 11:33 PM, David Scheidt wrote:
N8N wrote:

:Last night I started in on this again. I'd previously got the DS crank
off the spindle but the NDS was stuck tight. Well I rigged up a way
to apply Excessive Force (tm) to my crank arm puller, with less than
successful results. Rather than pulling the crank arm off the taper, the
puller ripped the threads right out of the crank arm. So that will have
to be cut off with an angle grinder.

I've used a jacobs chuck puller wedges to get a crank off a square
taper spindle. Worked great. They are two wedges, you put one in one
side, the other 180 degrees away, and tap them into place. Some bikes
might need a spacer between the bottom bracket shell and the wedges,
so the wedges bear on the crnak.

I'd get a est before getting an angle grinder.


Yes, or a ball joint remover:

http://www.northerntool.com/images/p..._2000x2000.jpg

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

mmm, good idea. I have those, as well as the screw type tie rod/ball joint/pitman arm puller set.

it doesn't really matter though as the crankset was already trash which was the whole point of this exercise, as is the bottom bracket. At this point I need to get the bad parts off the frame without damaging the frame, everything else is irrelevant. Oddly I was able to get the seatpost, handlebars, and all bolts that go into braze-ons (yeah, I know, it's an aluminum frame, so they're not really brazed on) out and lubed/replaced as appropriate without damage. It's just the BB that is well and truly fighting me.

This is kind of a back burner exercise now as she has a bike to ride, but I either need to get this "useful" (even if that just means stripped to a rebuildable frame) or else trash it as I can't abide useless stuff taking up space.

nate

On Tuesday, July 21, 2015 at 11:15:57 PM UTC-4, Sir Ridesalot wrote:
On Tuesday, July 21, 2015 at 1:41:21 PM UTC-4, N8N wrote:
On Sunday, July 5, 2015 at 1:37:35 PM UTC-4, N8N wrote:
Hi all,

friend of mine was given a "free" bike and asked me if it was worth salvaging... still not sure yet but here goes.

Needs new bottom bracket and probably crankset as it looks like the gears are permanently welded to the spiders (Shimano stuff, assume low end?), and they've been mangled a little by bad shifting. Obviously chain as well and possibly cassette too.

I can't get anything apart yet as it's been sitting outside (so a bunch of stuff is soaking in penetrating oil) and also I need a few tools that I don't have to really tear into it.

does anyone know how I can determine the BB size without disassembly? I couldn't find an email link on Diamondback's web site. It is a Diamondback Response, year unknown. I haven't even got the cranks off yet as it looks like I need to find a temporary bolt to thread into the spindle to pull the arms off and I don't have anything in my stash that thread. It's a standard square taper, I can tell that much.

Does anyone know what tool I need to remove the BB? I can't try the few that I have as I don't have the crank arms off yet.

Also needs new shifters and cables. Condition of hubs unknown but they definitely need at least new balls/repack; they feel awful.

Finally is it possible that 7mm bolts were used in some places? I took the handlebars off and find that the 6mm bolts in my parts bin don't thread into the stem. however the original very rusty ones thread in fine and probably will be reused at least temporarily until I can source some new hardware.

Additionally I pulled the seatpost just to make sure it was free (because that would be a deal killer) the seat angle adjuster I don't have a single allen wrench that will fit it, is it possible it is 5.5mm?

I'm not a MTB guy but I'm kind of trying to save this one because a) it's a lot lighter than most MTBs being non-suspended and I think she's more looking for something for road and light trail riding; also she is very short so finding something "better" that fits her will be hard.

So do you think I can resurrect this for less than $200 or so? Then, is it worth it?

Update again.

Last night I started in on this again. I'd previously got the DS crank off the spindle but the NDS was stuck tight. Well I rigged up a way to apply Excessive Force (tm) to my crank arm puller, with less than successful results. Rather than pulling the crank arm off the taper, the puller ripped the threads right out of the crank arm. So that will have to be cut off with an angle grinder.

I tried to get the one BB cup off that I could get to with also limited success. I think I will strip the frame down after cutting off the crank arm and throw it in the back of my car one day and stop by my friend's auto repair shop after work with my impact gun (I don't have a compressor at home.)

Before I hork this up beyond all recognition, is this a good plan? (will the Park tool hold up to mild impact use? I was impressed with the crank arm puller, I have to say, as I was using it well outside of design parameters and other than some marks on the blue handle, it is just fine.)

Also, please confirm for me that the DS cup is RH threaded but the NDS is LH threaded? (I think that's right, isn't it?) I can't see threads on the cups. Just trying to save this frame before throwing in the towel and giving it to the scrap man... would hate to do it as it was given to the owner by her son even if it was a bit of a bad buy on his part. Also if I can get the BB out and friend decides the Trek I found for her is too big, I can just transfer the crank, arms, wheels, etc. over from that bike and it won't cost me anything to put her on a one size smaller frame.

thanks

Nate

I removed a non-drive side crankarm for a guy who'd also ripped out the threads. I placed a wide piece of metal with a slot that slipped over the bb spindle, behind the crankarm and then drove an old wood working chisel between the crankarm and the piece of metal on either side of the crank arm. He was quite surprised at how that crankarm just popped off.

If you're going to removethe fixed cup on the drive side then take alook at Sheldon Brown's homemade tool for doing that. i made one and it works a treat. here's the link to Sheldon's instructions.
http://sheldonbrown.com/tooltips/bbcups.html

Cheers

Not that kind of BB. I have that on my own ride but this one appears to be square taper but a unitized Shimano thing e.g. UN55 or similar. I do have the tool for those cups, they're just In There But Good.

Upon reflection, some light heat on the frame followed by some freeze spray on the cups might get it, as the frame is aluminum but the cups are steel (I assume?)

nate