Walmart Mongoose, Unreal!! I thought I had seen it all

[AL_BUNDY]

A friend who often stops over to go for a ride showed up tonight with another guy I hadn't seen in years who just bought a new bike. It was a full suspension Mongoose from Walmart. They asked me to adjust the derailleurs and brakes. It had V-brakes and the arms were stamped steel. They flexed so much I couldn't get them to skid the wheels without rubbing the out of true wheels. I finally found a compromise where they kind of worked but did not rub. The derailleurs were also stamped steel and the front one was rotated about 20 degrees. I did get it shifting good. I knew these bikes were cheap crap but I had no idea they were this cheap. On top of being cheap junk it looked to have been assembled/set up by a 10 year old. nothing was lubed. I guess the 1st clue should have been the price tag of $139 for a full suspension MTB. I am in aw that this stuff actually works.

[nfmisso]

so you are saying that with $100- to $150- of additional labor, it will be a sort of okay bike.....

And if you replace the brakes, (another $40- or so discount, plus labor) it should be able to stop well.

So; my as well go to the LBS and spend $330-.....

[AL_BUNDY]

If I was walking through a Walmart and the manager walked up and offered me one for free I wouldnt push it to my car.

[JohnV]

Like the new Schwinn, Mongoose makes some cheap stuff that you can get at department stores that may or may not be a good buy at the time. My son-in-law has a bike he bought at Target (Magna something-or-the-other model MTB) and he has had it for over 10 years and still rides it. He actually needs to have the back wheel trued, but for his weekly family rides in the park, it is still a very good bike. And like anything else, I'll bet that there is someone out here that can tell you horror stories about a 3 to 5 thousand dollar bike as well. Now-a-days, there are lemons in everything you buy. And, you get what you pay for (lemons excluded).

[Bill]

Good point in all comments. I did however luck out with a Mongoose XR-75. Most of the parts were pure CRAP, so being the person I was at the time I put a little more money into it. It does "ok" offroad but constant adjustment is necessary at times. So if you have the money to put towards better parts, then you should just get a better quality bike. Schwinn does make some mid range bikes not found in department stores. Just go to their website.

[steve66oh]

I found an old Wal-Mart Mongoose MTB next to the dumpster. Cables froze, front wheel bent, tires flat. Went to W-M to see about parts - and there I saw a brand new Mongoose XR-75 with a return ticket that said "Chain slips when you pedal it, something is wrong with the chain". I pushed the pedal, and saw that the freewheel was spinning freely on the rear hub.

I called the manager over, explained that I was here to find a front wheel, but I would pay $50 for the whole bike, as-is. He agreed, I took it home.

The freewheel is a Taiwanese Falcon, either FW-70 or FW-710, in perfect condition. The hub is a "DACHANG", and the threads on it appear to be cut about 0.040" undersize. So, my dumpster 'goose donated its rear wheel and I'm back on the road.

My point in posting this is to find out if anyone else has discovered undersize threads on their Asian wheel hubs? Fortunately, mine were SO undersize that the freewheel immediately stripped off the crests of the hub threads, disabling the bike and making it available to me at $85 off. But if the thread deviation had been half as much, say 0.020" under, the bike would have worked for a while but could have stripped at any time - most likely when I needed it most and was pushing hardest...

These department store bikes are hazardous - I encourage every bike mechanic working on one - even if only changing a flat - to remove the freewheel and mic the hub threads, to confirm the standard 1.375" x 24TPI thread. You might sell a new wheel... or you might save a life!

Original sources for my parts:
Freewheel: http://www.falconcycle.com/en/product.asp?id=3
Hub: http://www.cndachang.com/ecp.asp?id=31 (as far as I can tell)

[WeThePeople]

(10-10-2011, 12:40 PM)steve66oh Wrote:  ...confirm the standard 1.375" x 24TPI thread...

You meant to say 1.370" x 24-TPI, right ?

1.375" is for the (older) 26-TPI threadset.

an old Falcon I have is dead-on,
as a sister Sunway was too BTW.

I think that threadset was cut
at ~4:45-PM on a Friday, lol...

[steve66oh]

No, I meant 1.375" x 24TPI, as reported as the U.S.A. standard, here: http://www.sheldonbrown.com/freewheels.html

You may be right about 1.370" x 24 being a new standard, but the only info I have is from Sheldon Brown - who lists that as the British standard. If there's a new standard and an old one, that further complicates the issue and suggests a need for thread inspection gauges of both types in bike shops... and in ANY case, MUCH better documentation by manufacturers as to what threads are specified for particular bikes at the freewheel/hub interface.

[WeThePeople]

I've known the 24-TPI ones to be 0.370" for well over a decade at the least,
only old 26-TPI "Raleigh" and so forth had the 3/8" thread to my knowledge.

The Falcon and Sunray freewheel's I measured are as old as dirt,
so I think (maybe to save money...) they started using 3/8" tooling.

But then again, Falcon had so many spline tools over the years,
it was like they couldn't keep a tool tolerance model to model...

But the price was right for you on this one, and at least it was the
"GO" parts, not the "STOP" parts that failed in this case,
imagine this screwup on brake parts instead ?!

EDIT:
Nice page you referenced, I saved it to read later,
but your right forty thousandths off is a huge flub.

[WeThePeople]

Subscribe Button IS NOW MISSING At Bottom,
had to make a fake post, to subscribe to thread...

[ReapThaWhirlwind]

I have had great experiences with the steel Mongoose bikes.

Sure the stock components are cheap, but replace them with even the entry-level series groupset and you're good to go.

I had a Mongoose Spectra that lasted me almost 3 years and saw 3 winters using Acera M360 mechs, ST-EF500 lever/shifter, and Alivio M430 crankset.

Only issue I had was the bottom bracket shell was a little warped, and didn't allow the non-drive side plastic cup to screw in all the way.

[Cooldood]

(05-23-2011, 11:34 PM)AL_BUNDY Wrote:  A friend who often stops over to go for a ride showed up tonight with another guy I hadn't seen in years who just bought a new bike. It was a full suspension Mongoose from Walmart. They asked me to adjust the derailleurs and brakes. It had V-brakes and the arms were stamped steel. They flexed so much I couldn't get them to skid the wheels without rubbing the out of true wheels. I finally found a compromise where they kind of worked but did not rub. The derailleurs were also stamped steel and the front one was rotated about 20 degrees. I did get it shifting good. I knew these bikes were cheap crap but I had no idea they were this cheap. On top of being cheap junk it looked to have been assembled/set up by a 10 year old. nothing was lubed. I guess the 1st clue should have been the price tag of $139 for a full suspension MTB. I am in aw that this stuff actually works.

Most of the time these bikes are built by people who dont know how to build them, id recommend going used if you can, id rather find a decent specialized hardtail or marin or whatever bike that has better components used. Walmart and target bikes usually have below minimum expectations. A new bike isnt always great but hope things are well and he enjoys it because anything that gets you out there riding is okay in my book :p