Lovegasoline

Gah!

My main means of transportation in NYC is benched!
It's a mid 1980's Motobecane Grand Touring w/Vitus tubing.

The frame has broken: the seat tube has sheared completely through at the bottom bracket.

Here's all I know
My front derailleur needs a new cable and I've not been using it for most of this year (no need in NYC) ... I bought all new cabling for the entire bike ($50+!) but haven't had the time to install it. Earlier this week I noticed my front derailleur cage was rubbing on the chain, so I stoped and moved it slightly by pushing at the linkages with the end of a tool. Yesterday, I noticed it rubbing slightly again so I stopped figuring there was some tension on the frayed cable or it had somehow shifted over slightly by bumping the levers. It moved rather easily to clear the chain but would return to touching the chain. I was scratching my head when I noticed the entire seat tube would move when I moved the derailleur! Oh dear.
I walked the bike home.

The pics tell the story.

Any idea on the feasibility of repair?
What proceedure would be necessary?
What else would need to be inspected for damage?
Any idea of the cost?

Even thought the bike is a little bit big for me, I've been riding it for about 7 years and it's perfect for my needs. It was a gift from a friend who's brother bought it to ride cross country, one way, in the 1980's and it had been garaged ever after. As mentioned, I have $50+ worth of new cables, I also have some new interrupter levers and aero levers I've been meaning to install but haven't gotten around to. The bike is a great beater for the city as no one ever bothers with it. It's my only wheels (other than Citibike).

One concern is the French(?) bottom bracket and removing all of that for welding. I have a rollcab with a good selection of mechanics tools, but I have very few specialized bike tools.

It's possible I could hit up the metal shop from my alma mater which is only a few blocks away and see if the tech could repair it for a six pack or something. I could also likely locate a friend who has access to a metal shop ... and I'm friends with two guys who work as technicians running another wood and metal shop (which is the premier art school shop in NYC) ... they are both into bikes and if I recall correctly one of them has built his own bike frames from scratch (he has a rad rack he's built that he runs on his current ride).

Anyway, there it is.
Thanks a bunch for any ideas.

fietsbob

strip it and recycle the steel..

shelbyfv

Not worth any further effort. Look at it as an opportunity to upgrade.

02Giant 

Time to source a replacement, or duct tape.

TimothyH

That's gonna take at least a 12 pack to fix.

Or it could be replaced for $265.

https://newyork.craigslist.org/brk/b...275124000.html


-Tim-

maddog34

lots of nice frames on your local CL... find one that fits, swap you parts onto it, and then fit up those new cables... i find quality frames for 20 to 100 dollars all the time.

Lovegasoline

Isn't my mid '80s Motobecane packing some obscure French and/or fairly obscure size components to be able to just bolt onto a Craigslist frame?

Lovegasoline

Thanks ...
However that's the same size as mine, I'd be better with a 54-56. Seems sorta pricey as well.
I need an el cheapo reliable beater that rides well but that does not inspire covetousness, fir daily use locked in public in NYC.

Lovegasoline

I'm all ears...

Lovegasoline

There's no way to repair it for a reasonable cost?

maddog34

the repair will be more than the bike is worth... unless you want to spend a bunch of cash on a bike that doesn't fit you, get a frame... like this one, in your area's CL right now... https://newyork.craigslist.org/que/b...240902884.html

there are a few others listed right now, also... start shopping.

seriously... get a frame that fits... you'll be glad you did.

Lovegasoline

That 22" would be too small.

I'm 5.10.5" but with a long inseam (wear 34" inseam pants). Long arms, short torso.

Also, the old mid '80s Motobecane from what I understand (?) use all different sized hardware from contemporary bikes.

maddog34

oh look... a better bike, for about what fixing your too big bike will cost, and you end up with a lot better, lighter bike!
https://newyork.craigslist.org/mnh/b...280003886.html

do some shopping... if you insist on riding a heavy, old french bike, look around at some local community bike shops... they usually have a few that might fit your taste/size.... or they've scrapped them long ago.

HillRider

Among all of those friends I hope one owns a bike shop. Go see him. Past time to upgrade.

dedhed

I had a co worker with the same break on a Lotus. We talked to a COMPETENT welder I knew and he tigged it up with some splices (tube halves) and created a gusset between the DT & ST all for I think $50. Still riding it to this day as far as I know. Wish I had pictures of it.

https://www.facebook.com/pages/Compe...19249231458389

3alarmer 

TimothyH

I understand. Born in Flushing, grew up in Bayside, moved to Nassau, then Suffolk, then Georgia.

The link was just an example. You could look at bikesdirect. Again, a new bike will draw attention but it won't look new for long in NYC. There is always electrical tape.

If your friends will do it for a 6 pack then go for it. Even if you get a year out of it, that's a win. My father had the local service station weld a broken bike frame when I was a kid. They guy didn't want to do it, said it would break. My father gave him a 10 spot and he did it. Frame lasted another six months.


-Tim-

Lovegasoline

I'm curious about why folks are saying the frame is irreparable? What is is about the material and form that will repel attempts to repair it, or metastasize into a bigger job than it's worth tackling?

---

I'm just used to this bike. One thing I dislike is it ghost shifts from time to time ... pretty freaky especially if it's when blasting through an intersection.
Ideally, I'd like to have a lightweight compliant steel frame that can carry me (135lbs) and 40lbs of groceries with a rack and panniers, that handles well, is stable and responsive, reliable, and is finished with a urban camo paint job that resembles a beat-out rust bucket. The great thing about this bike is nobody is interested in it. In 7 years the only time it was screwed with was once someone let the air out of a tire when it was parked overnight in a weird area (you can count on one hand the times I've locked it up outside overnight).

hokiefyd 

I imagine the ghost shifting may be due to the frame flexing under torque -- the frame that was nearly broken. I bet some of the fracture has been there for a long time.

To those who write this off -- can someone just strip the paint and run a weld bead around the fracture? I certainly don't think that desoldering the tubes and re-tubing it would be cost effective, but I'd think a bead of weld wouldn't be too expensive -- are lugged frames just not conducive to that due to incompatible materials?

maddog34

when steel is welded, it gets REALLY HOT... this imparts hardening of the steel to either side of the weld...

butt welding(what we are talking about) makes the weakest type of welded joint of materials...

the area involved sees both tension, and compression loading... tension loaded welds are notorious weak points... the area also sees high side loading, and twisting... this is why it failed.

do the math... almost every stress mentioned will cause a failure... on a frame that doesn't fit the owner... one must also consider the very real possibility of another, as yet unseen, crack, just waiting to show itself... the bike is OLD, and has already cracked, eh?

get a different frame, or a newer bike.... then make it ugly... gray is the least noticed "color", btw.... many folks in/around Portland cover their beautiful new bikes with stickers... seems to also work as urban camoflage.... and there's the ever popular flat black... or a "Goodwill paint job", one color, and lots of over-spray!

Lovegasoline

The ghost shifting has been there for the entire time I've had the bike.

Lovegasoline

Time for a duct tape repair?

Sorta just kidding.


Can anyone who has a familiarity with this vintage of Motobecane speak to the incompatibilities regarding trying to move the component set and parts to another frame?
For some reason (unless I get a similar frame) I imagine it's going to be an endlessly frustrating mismatched parts headache.

??

maddog34

the bottom bracket MAY be a french thread... the headset MAY be french... and your seat post MAY not fit a different frame.

search this forum for more info.... or find a frame that has those parts already on it. Search: "motobecane bottom bracket" and: "motobecane head set"... then realize
your bike might be late enough that the french oddness has been eliminated from it already.

or get a better bike that doesn't have the chance of odd, outdated, parts on it.

Richard8655

My friend's 25 year old Schwinn cross bike (which he loves and for some reason is strongly attached to) had a similar frame break in similar location. He took it to a welding shop and they expertly welded it from what I can tell. He's been riding for a few years since with no problems and is very satisfied. It was not expensive.

I think checking with a couple welding shops is worth a shot. Especially those who might have dealt with bikes or smaller metal components.

3alarmer 

...I have this one, and it's still mostly French in nature. Motobecane was one of the more progressive makers in terms of using Asian components, and they had better fit and finish than the other guys. I like the ride of it, and see why you're attached to it. But your imagination is pretty much the reality in terms of tubing diameters and threading (IIRC...it's been a while since I had it apart).

You can figure it out pretty quickly as you start to take off the components, and French (metric) tubing diameters will show up in stuff like the seatpost size, and you can measure them with a Vernier caliper pretty quickly.

But at the point in time your bike was made it was still mostly French in the sorts of things you're worried about.


On the Craigslist world of adventure, complete bikes are always a better deal than frames anyway.


By all means, strip and save what you can, but even nice old steel bicycles do have a useful lifespan. Yours just happened to hit it while you were riding it.