Bent steering stem replacement

[texasmoto]

A friend doing some vapor blasting noted that the steering stem was bent.





I looked for a part number but it doesn't look like Guzzi differentiated this part from the lower part of the yoke





Digging around on ebay I found this, but want to make sure that it is an appropriate replacement before ordering:
https://www.ebay.com/itm/202182148260?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=rbcbQrIITFy&sssrc=2047675&ssuid=&widget_ver=artemis&media=COPY

[RinkRat II]

   I'd put it in a set of v-blocks, with a dial indicator see how much it's out and put it in a press and GENTLY apply pressure 'til it's within a few thousands.  If you're not comfortable doing that, a decent machine shop can do it.  My $.02

   Paul B

[texasmoto]

I'd be open to that, if that kind of machine shop existed in Austin!

[n3303j]

Curious where and how it's bent.
Folded a fork on the Ural in a T-Bone.
Folded the fork on my T3 in a high side.

Both times the steering tube came out straight.

The fork tubes between the two clamps would have to bend for the steering tube to bend.

Three tubes bending is really rare considering that the unsupported section of the fork bends and absorbs the impact first.

[RinkRat II]

   Sometimes you gotta get creative, an electric motor shop, pump repair shop and even a bicycle repair should be able to do it for a case of beer. I've seen parts houses with those capabilities (NAPA)

   Paul B

   

[texasmoto]

Curious where and how it's bent.
Folded a fork on the Ural in a T-Bone.
Folded the fork on my T3 in a high side.

Both times the steering tube came out straight.

The fork tubes between the two clamps would have to bend for the steering tube to bend.

Three tubes bending is really rare considering that the unsupported section of the fork bends and absorbs the impact first.

Well, there is also this unusual dent on the front fender.



The damage is odd. And I bought the bike in complete condition. It hadn't been crashed.

But, I wasn't the one to remove the steering stem. Apparently the lower bearing can really get stuck? Who knows.

[n3303j]

Had that same dent on my T3 front fender after the "high side". Bent both fork tubes and the rim.

Don't have to pull the stem to remove lower bearing race as long as you are willing to bend the lower dust shield. A Carpenders wood chisel tapped into the junction between the lower clamp and the dust shield will act as a wedge and lift the inner race enough to get a puller in place.

[moto-uno]

  If you're from Austin , Texas , you have an excellent machine shop , owned by a Joe Pie ( his shortened YouTube channel name ) , check him out . Peter

[SIR REAL ED]

I'd be open to that, if that kind of machine shop existed in Austin!

RinkRat II is correct. Piece of cake repair.

I would be amazed if a machine shop existed that could not do that type of repair.  I would not expect them to stay in business for more than a week.

[Mike Tashjian]

I have a ten ton press in the garage I made years ago.  Funny that I just used it yesterday to press in some bushings and ball joints on a old Mopar my friend owns.  I also straightened a bar that goes to the lower control arm.  Almost too easy.  Seems the shop working on the car has no torches or press. I bet they could program the computer though, wait that 60's Chrysler doesn't have one. 

[John A]

Check the yokes for being flat with the stem out. Check also the lower bearing mount on the frame for deformation.

[n3303j]

Check the yokes for being flat with the stem out. Check also the lower bearing mount on the frame for deformation.

And the upper too. BMW /2 I bought had two oval bearing mounts and a wheelbase that was 3/4" shorter than published. Frame Guy fixed the forks. Ball Peen hammer fixed the frame bearing mounts. Then the wheelbase matched published specifications.

[Moparnut72]

A hydraulic cylinder repair shop could do this also. They do it all the time.
kk

[texasmoto]

RinkRat II is correct. Piece of cake repair.

I would be amazed if a machine shop existed that could not do that type of repair.  I would not expect them to stay in business for more than a week.

It's not that they can't, it's that they don't want to. I tried to get some machine work done a while ago and every shop I found in Austin was for commercial fabrication, they just were not interested in doing something small scale. I contacted a local shop that does good work but they don't have a press. I wasn't kidding when I said it's difficult to find around here ;)

[n3303j]

Not sure how much or where your steering tube is bent.

In the good old days when I was a kid (22 ish) I managed to a actually bend the front swing arm on the brake side of my BMW R27 in a panic stop. It was enough that the wheel was crooked and the axle holes didn't align. Was sort of living on the road at that time so my shop wasn't available.

I had a SERIOUS welded link chain that I secured the bike with parked on the streets of Boston. I put a hydraulic jack on the high spot of the swing arm leg and wrapped the chain over the low sides and across the top of the jack. Then pump the jack, release and check; several times until the axle inserted correctly and both wheels were parallel.

I've straightened a number of shafts. It seems they have a bit of memory. They will go back to straight with a bit less effort than will be required to "overbend" them. You can almost feel when the shaft (or tube) is back home. Then you feel it trying to resist the over correction.

Find someone with a hydraulic log splitter and get yourself three hard wood blocks. That should get it done.

[ital4me]

Has it been welded together? If so have the machine shop just make a new one.

[n3303j]

Try straightening it yourself.
Chances are you won't make it any worse.
Reasonable chance you'll make it better.

Had a "potato chip" shaped steel rim on my BMW /2 (disassembled wheel).
Took it down the basement and put the rim on two blocks at the low side.
Put a 4X4 across the high side and placed a hydraulic jack in the middle.
Put another 4X4 from the top of the jack to the main beam in the basement.
Then proceeded to try and jack up the house.
Needless to say the rim unbent before the house lifted.
Rim did another 50K miles with me before I sold the bike.

[SIR REAL ED]

It's not that they can't, it's that they don't want to. I tried to get some machine work done a while ago and every shop I found in Austin was for commercial fabrication, they just were not interested in doing something small scale. I contacted a local shop that does good work but they don't have a press. I wasn't kidding when I said it's difficult to find around here ;)

wow!  That is amazing.  I guess they have all the business they want.

Since the bend is a long way away from the bearing surfaces, a big hammer would probably work just fine.  Or a bit of heat and a small hammer.

[SIR REAL ED]

Try straightening it yourself.
Chances are you won't make it any worse.
Reasonable chance you'll make it better.

Had a "potato chip" shaped steel rim on my BMW /2 (disassembled wheel).
Took it down the basement and put the rim on two blocks at the low side.
Put a 4X4 across the high side and placed a hydraulic jack in the middle.
Put another 4X4 from the top of the jack to the main beam in the basement.
Then proceeded to try and jack up the house.
Needless to say the rim unbent before the house lifted.
Rim did another 50K miles with me before I sold the bike.

That is brilliant.  I'm gonna steal that idea.  Thanks.

[Moparnut72]

You could do it yourself with a hydraulic press. You could get one from Harbor Freight for about $175. Expensive for one job but probably not a whole lot more than what you would have to give a shop to do it for you. Then you would have it for miscellaneous other jobs that WILL come up. I have one in my shop, I hardly ever use it but when I do need one it is standing ready.
kk

[SIR REAL ED]

A friend doing some vapor blasting noted that the steering stem was bent.





I looked for a part number but it doesn't look like Guzzi differentiated this part from the lower part of the yoke





Digging around on ebay I found this, but want to make sure that it is an appropriate replacement before ordering:
https://www.ebay.com/itm/202182148260?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=rbcbQrIITFy&sssrc=2047675&ssuid=&widget_ver=artemis&media=COPY

Texasmoto,

Thinking about this while walking the dogs, I'll bet the steering stem was bent like this when it was brand new.

I'm a mechanical engineer with 3+ decades of machine/tool design experience, and looking at the bend, I can't imagine how that got bent while in service.  Even if the bike was in an accident, the steering stem is supported at both ends by the bearings.  How the middle of the shaft could get loaded to produce a bend there is beyond me.

I am comfortable imagining a machinist at the Guzzi factory thinking: "Wow!  This steering stem blank is bent, but since I am machining the bearing surfaces and threads, as long as the bearing centers are collinear, it does not matter!  No point in worrying about things that are not important and will not be inspected.  So, in to the lathe it goes!"

If you want to straighten it, no big deal, easy job.  Just make sure is it support at the bearing surface so you don't make it worse by bending it where it matters.

If it is a headache to so so, I'd leave it.  From your orginal post, it doesn't sound like a handling problem tipped you off to finding this.  Sounds like a non-existent problem that does not require a solution.

The manufacturing world is a fascinating place!!!  Please keep us informed.

[John A]

I’d be looking for a good used one.

[Antietam Classic Cycle]

I’d be looking for a good used one.

I agree - complete good used lower "yoke" with stem. Mark @ Moto Guzzi Classics likely has some 562-986-0070.

[Mike Tashjian]

I would probably go with plan B if you can't find anyone with a press.  Take a 2 x 4 longer than the stem and a large rawhide hammer. I think the one I have is close to three lbs?  Lay the part on the 2 x 4 with the high spot up and solidly hit it. You should be able to get most if not all of that bend out.  The rawhide will not damage the shaft and the 2 x 4 will not damage the threads.