juntjoo

So can I use this style derailleur without drilling a hole in the frame there at the dropout? Yes I know I have to bend the frame back a bit where the previous derailleur mounted but after must I drill a hole and tap threads in it? Or will it sandwich in with the wheel just fine and when putting the wheel back in just manually reposition it? I don't know how these work obviously.

I pick up random bike parts up off the street and found this and thought I'd try to use it

Davet

Nope, won’t work.

veganbikes

I don't know if you are real or not, that derailleur belongs back on the streets. It is junk. As usual there is no information about your bike. However in the end get a derailleur that will work for your shifters.

juntjoo

It's a mongoose "snare". Didn't know it needed a special derailleur. You don't know if I'm real? What do you mean? And how is this derailleur "junk"?

dedhed

It needs a direct mount derailleur, not a claw mount.
that is absolutely the worst POS RD Shimano makes.

Do yourself a favor and at least step up to a tourney

juntjoo

Well if that's the case I don't mind discovering on my own as I'm also just trying to get more familiar with bike parts and how they work.

And is it because it doesn't have a hole to secure it to the frame that it would require a "direct mount"? That's all I see as the difference in which case I'm all ready to start drilling

squirtdad

No, claw mount would only work with a horizontal drop out not a vertical drop out.

Claw mounts currently are only on low end cheap bikes (40 years ago they were more common and higher quality could be found)

here are some good sources for education

https://www.parktool.com/en-us/blog/repair-help

https://www.amazon.com/Zinn-Art-Road...3237715&sr=8-3

https://www.amazon.com/Zinn-Art-Moun...3237755&sr=8-2

it always helps to 1) have a more descriptive title 2) more details

juntjoo

Thanks. I think you mean they're for vertical dropouts? Mine looks "horizontal"
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dedhed

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urbanknight

Horizontal means the wheel loads from the front or back. Vertical dropout means the wheel loads from the bottom. Your picture shows a vertical dropout.

Jeff Wills

And it's hard to tell from the photo, but it looks like it's been spread open, likely by a derailleur getting caught in the spokes. It's fixable but not easily. I'd try to fix it, but then I'm not working in a shop.

juntjoo

Ah, I see this. Thanks

squirtdad

this is not a winning plan

juntjoo

Sure it is. What are you talking about? How am I losing?

veganbikes

Not a special derailleur, a pretty standard derailleur that everyone else is using aside from really bottom end bikes typically older low end which your shown derailleur is built for.

I didn't know if you are real with the whole picking up parts on the street, it didn't feel like a real post. I am sorry to confuse on that front.

In terms of the bike looking it up on the internet it is certainly not one I would put any money towards. If you must and are desperate the derailleur it shows in the poor picture I found is a Shimano Altus RD-M310 but I would just use the bottom end Tourney that fits which is a non-claw style, just a standard mount. If you are looking for a really initially cheap bike try and find a single speed, no suspension with rim brakes and avoid going to walmart or similar type places. A single speed has fewer parts to go wrong, a faux full suspension bike like the Mongoose you have listed is just poor at everything aside from maybe a boat anchor though I am sure many captains would disagree. It is overly heavy with the absolute cheapest parts they could find so it has the look of a 90s full suspension bike with the performance of a rotted potato. It is the nature of those bikes, Huffy, Magna, Mongoose (from department stores they do some slightly nicer stuff outside of those venues into some OK stuff)...are all built to only hit a price point and they are put together by people who are paid by the bike and aren't bicycle mechanics with tools you might get from Ikea it just has to look like a bike, safety is barely on the list if at all, generally after a bunch of blank pages.

If your finding stuff on the street mantra was put towards the bike I would put it back out there. I am all for rescuing bikes and keeping them going but this was designed as scrap metal from the factory unfortunately. It was never a product designed to last and putting good money towards it, would be a waste of your money and that money could be much better served for other needs in life or towards actual useable bicycle parts.

juntjoo

Okay, thanks. Yeah, I have low standards and budget and just enjoy riding my bikes and learning how to work in them. Not looking for much more than that for now. And I like my suspension and gears and working on these basic components

veganbikes

Get higher standards you will be happier with yourself and your riding. You will also have an easier time working on bikes.

juntjoo

Just to update in my parts bin found this more appropriate one, "direct mount" type a bit smaller from a smaller bike but it works. Prolly not perfect but it's working so I'm happy for now. I gave it and the chain a good coat of chain lube.

veganbikes

I would try and clean up that rust it is not good nor safe and it will make a poorly performing bike even worse. Lubricate your bikes and they have a potential to last longer

JohnDThompson 

No, there are a couple issues that make it problematic. First, your frame has an integral derailleur hanger that will interfere with any claw-mount; you'd need to chop off the integral hanger. Second, the claw mount on your proposed derailleur is designed for a forward-facing dropout slot; your frame has a vertical slot. Even if you were to castrate the frame by chopping off the integral hanger, the orientation of the slot would position the derailleur in a far-from-ideal orientation with the gear cluster, and shifting would suffer.

N.B. even on a frame with forward-facing dropout slot, you wouldn't drill a hole to secure the claw. That hole in the claw is for a special bolt and nut that fits in the slot to secure the claw, like this:

juntjoo

Thanks. I'm all set for now. I did try the derailleur and discovered the incompatibility. Found direct mount one that is working

Iride01 

Chain looks like it might be too long or maybe too short. Depends on what size ring or rings you have on the crankset. A pic from the side showing both the rear along with the crank might help. One with the chain in the largest cog and largest ring along with a pic of the chain in the smallest cog and smallest ring.

Also not certain if the b-screw is correct. It adjusts the jockey wheel on the DR cage so it sits close to but not letting the chain or it touch the cogs.

And the sharp bend in the cable where it goes into the barrel adjuster seems destined to contribute to some poor shifting.

smd4

And the quick release is on backwards…

Mr. 66

Definitely adjust the dropout, align the dropout, and align the hanger.

And gosh, oil your chain and derailleur, it will shift better.

juntjoo

Does it make a difference? I put it that way to it easier to attach this trailer. Maybe I could just as easilly have it the other way around... but the trailer hooks on on the left side only