thinkOfaNumber

Hi all,

My specific question is at the end, but here is some information that may help you understand what I'm doing

The main two points I guess I want to say here are that:

1. I'm in a small city so local bike shops are very expensive. Parts are usually 2-3 times the online price. I would be happy to spend 10-20% more to support local business but not 2-300%! I tried to get some work done on my old giant mountain bike, and they just told me to throw it out. I replaced the rear sprocket and chain myself around 8 years ago and it's still going great.
2. I don't learn anything by paying someone else, and my son and I are looking forward to a project together, even if my time spent isn't economical, the time together is.

So I picked up this bike from the tip shop for $30. I expect it to have some problems, but the freewheel was very smooth and frictionless, plus it had discs and click shifters so I thought I'd give it a go for my son (new bikes for 3 kids is expensive, so I usually try and find good seconds).

It's a Diamondback Axis(?) mountain bike with:

• Shimano running gear - not everything has part numbers but the rear cassette says CS-HG30-8i and the front derailleur says C101
• Tektro 0H or OH on the brakes
• 6061-16 frame
• GILA RST forks (they were stuck but I cleaned them up so might put off replacing these till later)

The front (chainwheel?) teeth are pointy little sticks so that's definitely going, as well as the chain, and I'm guessing the back cassette teeth are probably not far behind so I'll replace those as well.

My son will probably use it like I did when I was a kid - ride over every curb, driveway, park, or whatever he finds on the way to and from his friends house, so I think similar "low end" shimano parts will be fine.

Now my question: I can't find the HG30-8i cassettes anywhere for sale. Are these not made anymore? Are they obsolete and replaced by something? What can I get that is compatible with the interactive glide? I'm finding it hard to answer this just by reading, hence why coming to this forum

Any other advice appreciated too

thanks
Iain

daverup 

thinkOfaNumber , is this it?

thinkOfaNumber

It is a flat bar, and the wheels are bigger than my mountain bike so I'm guessing that's 27.5... The top bar of the frame has a "knee" in it though.

That's my point, what is a "compatible 8 speed cassette"? Are you saying any Shimano 8 speed cassette is compatible? Or only the compatible ones?

Is this the front cassette? Yes that's definitely worn and being replaced.

thinkOfaNumber

Dave, it definitely has Diamond Back Axis on the frame, but (apart from being blue) the main frame is a bit thicker with the top bar having a slight knee or bend in it. It's got front shocks but I guess they could be aftermarket.

thinkOfaNumber

How so? I have "simply searched" but nothing says "this is compatible with hg-30-8i". Hence my question, "are all shimano 8 speed cassettes compatible?" However I think they're not, as some are thinner cogs, some are spaced differently, some are interactive, some are older and it looks like you can't mix and match everything.

daverup 

Could be a 92, but I'm not sure that bend is original,

Bill Kapaun

You're just being obtuse.
ignore list.

thinkOfaNumber

Hi Dave,

yeah that's strange. I can't post links but it looks more like the "mason". Definitely has Axis on the top bar though. Maybe it was some Australian model variation? There are a few similar looking Axis' on AU second hand sites. And it doesn't look like a 90's bike either, Looks more like ~2010.

Do you happen to know what chain rings and sprocket would be compatible with the ones I posted?

thanks

katsup

Diamondback is using the Axis name on newer bikes like this one


An 8sp cassette is an 8sp cassette. You are probably just looking for a hyperglide (HG) cassette.

Do the gears skip? If no, since you are already planning to replace the chainrings and cassette, I'd run those components as is for awhile.

daverup 

I really don't know what you are dealing with here. You can't post pics or links until you get to 10 posts, but you could upload pics of this bike into your gallery. Then a regular member could post a link to your pics.
Maybe after you post pics of what you have, someone would be able to offer more specific help.
When the bike has badly worn cassette or chainrings, usually it is better to replace all of it. That can get pricey if you can't find good used parts.
Regular bike shops are rarely able to help with older bikes, you would be lucky to find one willing.

bboy314

This seems like what you have, from your description. Any shimano (or Sram, microshift, etc) 8 speed cassette will work as long as the lowest gear doesn’t have more teeth than what you have now. But this advice to run it as is, as long as it’s not skipping under load, is sound.

Check out Sheldon Brown’s bicycle website for help with the basics.

Darth Lefty 

It's very much more likely to be a 2010's bike than one of those old 90's steelies from those catalog scans. Pretty average bike store quality but not high end MTB. Any SRAM, Shimano, Sunrace, or off-brand 8 speed cassette with the same bottom gear (biggest) tooth count should work. You will also need a cassette socket tool and a chain whip. The crankset is very likely square taper but might be Octalink or Isis. At this price level it's usually more economical to replace the entire crank because the rings might be riveted on or would cost more than just the whole set. For that you will need a crank puller.

Price for parts and tools in this post would be probably be around $100 US, I guess.

thinkOfaNumber

Thanks for all the replies.

The reason I wasn't identifying the bike too well is because I thought I could just get parts that are the same as the ones on it and ignore the bike model. I hope this doesn't sound ungrateful (or obtuse, again) but I'm being told both "everything is compatible" and then it appears I need to know the exact bike, year, and model which implies parts are very specific. I really do appreciate the help from everyone. If my questions annoy you, please ignore me and I won't be offended.

As I mentioned it is skipping and worn, so I'm going to replace the cassette, chain, and crank or rings or whatever the front is called. I have the socket tool and whip already.

A low-end bike with discs and click shifters goes for around $700 here so if I can spend around $100 then that's worth it. Plus have a bit of fun learning on the way.

I guess I'll just have to buy something as close as I can find and take my chances. I'll post back once I get it going in case anyone is interested.

thanks again

dedhed

You keep showing steel frame rigid fork ones. His is aluminium with a suspension fork

daverup 

Sorry to offend you and possibly the OP by trying to identify the bike. My mistake.

thinkOfaNumber

For the record I'm not offended at all. It's good to know there were older Axis models in case someone asks when I'm buying parts.

thinkOfaNumber

A quick follow-up question if I may,

when I look at chainrings, is this just one "cog" or is this a set of the front three? The pic looks like one, but it also says 3x7/3x8:
https://www.pushys.com.au/shimano-ali...42t-black.html

If it's just one, now I see the "whole crankset" vs "just the rings" angle, I would have to buy 3!

Darth Lefty 

Bike standards do change but for bikes like this one they change slowly. This is an English-standard which became Japan-standard which became Taiwan-standard which became China-standard bike shop bike. So I can guess it has 135mm rear spacing, QR rear hub with a Shimano compatible freehub, square taper cranks, post mount brakes with an IS adapter on the rear, a straight 1-1/8 steerer, coil spring forks with probably no damper, etc. That will all be true of any bike from the mid 2010's in the $400-1000 range. Shimano frequently replaces their parts at this level with new ones that are functionally the same but with updated styling, so you might not be able to buy exactly the parts you have, but there will be something, and there will be other options too from other companies because that freehub has been the same for thirty years since 8 speed came out, and it works with 8 to now up to 12 speed cassettes, and square taper cranks have been standard for even longer.

The more expensive it gets the less true this is because the top end changes faster. The parts change faster and are more different between manufacturers, while the frame interfaces do change but more slowly. So a nicer bike will still most likely have an English standard bottom bracket shell on the frame (if it's a metal frame) but the crank in it might be SRAM GXP or Dub or Powerspline, or Shimano Hollowtech II or Octalink, or FSA Mega Exo or Race Face or whatever, which are not compatible with one another but nevertheless still go in the same English threaded frame and take the same 9/16 thread pedals. And it will take tapered steerer forks, and thru axles which got a little wider spaced about 2017. But that's probably not true of the bike you have today, which more likely fits the first paragraph.

https://productinfo.shimano.com/#/com