Help with Gears/Sprockets...

[Shinobi]

Hi, New to the forum... and not used forums in a while, so hopefully these pic's will work.... anyway, I'll give you a brief outline of what the situation is, and any advice/opinions would be appreciated, anyway... a few of you have already said hello on the new members area, hello to the rest of you!

firstly, I havent been biking for a while and have been thinking about doing it for the last few months, anyway, me and the missus went to a car boot sale today and i came across a few bikes, on a total impulse i thought i would get a cheapo to make sure i would use it enough before putting real money into it.

The bike in question is a Giant Rock here is a pic for a rough idea;

It is a "bit" on the small side for me, but i hadn't thought that when i got it, (& thought i could re-sell it at a higher price anyway)
After getting it home (trying to fit it in the back of my corsa was fun!) and having a proper look at it, i located all the issues.... now this is when your gunna relise actually how much of an impulse the buy was!

• The V-brakes were very loose and squeaky... they could not stop me when i jamp on it for a test run,
• The brakes were also miss-aligned and rubbing/not allowing the wheel to move freely,
• There was cable ties tightly pulled round the open gear/break cables on the frame,
• The derailleur cage was not changing gear on the front sprockets, and the rear gears would come of and get jammed between the sprockets and frame if i took the gears to high, or low for that matter,
• The front gears plastic cover was snapped,
• The bar grips are foam ones, covered in electrical tape (and feel ripped under the tape)

Now, all these issues, although very annoying, seemed easily fixable, so, I've spent all day fixing what i could, adjusting brakes, cables, calibrating the derailleurs, removing the broke/naff bits, generally getting it to a state where i could ride it.... theres a few things i'm still to do (i dont have a bike pump - and the tyres are inflated, but nowhere near the PSI i will need to get it to - and i also need to pick up some cheap bar grips and a spoke tool for the rear wheel)


I was actually starting to get pretty proud of myself (after the initial "F"ing and "C"ing), considering my lack of bike maintenance knowledge...


anyway.... to the main point of the post.


I've come to the rear gears.... so firstly - i set the derailleur in the same fashion i did the front, the chain does not fall off anymore.... success! (or so i thought at least!) now to indexing the gears.... so, i had a read on how to do it properly and got started.... everything seemed fine, jumping from 1st to 2nd just fine, but then not to 3rd until i got a few more clicks up... so.... after some more "f"ing i started to calibrate it from scratch again.... this is when i notices something pretty wrong looking....


Here's the gear leaver......

The gear changer (if thats what its called)......

and the gears themselves.....

notice anything?
its a 7 speed changer, but it only has 5 gears!!!!!


needless to say i was pretty stumped/felt even more ripped off than before....


I guess the advice/opinions i want to get are.... is a bike like this worth trying to fix... is it the whole wheel that needs replacing, or just the gears themselves.... I'm guessing by the fact the changer says "7 sis" on it, that it is correctly matched to the levers, just not the actual gears.
Is this something that is affordable/worthwhile doing, and more to the point, will I be able to do this myself?, im not too keen on paying for expensive parts or for someone to fix a bike that i have bought for the pure reason of how cheap it was...


Will i need to know particular sizes if i go ahead with buying a part as i have no reference to go by as the gears are currently wrong anyway?
Is there anyone here from scotland know of any second hand parts places (I guess the main online auction sites may be a shout) but i hate waiting for stuff to be delivered! - I've heard about "recycle-a-bike" places that take donations/abandoned bikes from the city you see without wheels ect... i probably should check them out, but don't know if they do parts or keep them for fixing the other bikes they get in...


I'm kinda taking this as a life lesson in bike buying and will know exactly what to look for in the future when i decide to upgrade and spend a bit more cash!


anyway.... I know i said i was going to give you a "brief outline" but i can go on a bit! As you may have noticed! lol any comments will be very much appreciated!

Thanks,
Ross

 

[sabian92]

Wow... some people really don't take good care of their bikes, do they? foam and electrical tape for grips? Tramp alert!

As for a new cassette, I think they're reasonably cheap unless you're into 105 territory, and considering it's only got a tourney set on it then the cheapest will be fine, as long as it will fit. I'm not that good with bikes so I'll let somebody else advise you on that.

 

[Red Light]

You have a problem. The spacing of 5 and 6 speed cassettes is 3.65mm while a 7 speed is 3.15mm. So over 5 gears you'll be close to one gear out. The sprockets look pretty worn as well and I would check the chain - it should measure no more than 12 1/16th inch over 12 links. If it is you will need to replace both together. You might also check the chain width to make sure its not too wide for a 7 speed.

I am assuming its a cassette, not a screw on freewheel, but either way you will need a chain whip, removal tool and big spanner to get it off and if its a freewheel it can be a real grunt job to remove it best done with a good bench vice. If you don't have those tools you can either buy them on the basis you will need them again in future or it may turn out cheaper to get the local bike shop to sell you a new cassette and replace it. It'll also save you the problem of working out whether you need a Uniglide or Hyperglide cassette. A new cassette should cost you £10-20 plus fitting.

Good luck

 

[Shinobi]

Ahh, thankyou very much for the speedy reply.... i guess it serves me right for buying a bike of a dodgey geeza at a car boot sale lol

I'm in the office till late today, so cant take mesurements ect just now, but will be free the rest of the week, so i'll go for a rummage in my dads tool trolly and see what he has lying about.... im sure he has a spoke tool somewhere, and i remember seeing a chain whip many years ago, and i don't think he would conciously chuck a tool out being the way he is (even if he hasnt cycled in around 15yrs haha).

I think i'll try and true the rear wheel before getting into this as im not sure if it is in a good state, and it is a different wheel to the front, it looks like someones maybe buckled the wheel somewhere along the line and whithout researching just shoved another scrap or 2nd hand full wheel/cassette combination from another bike, whithout regard to the gears...

 

[Globalti]

That would be exactly what they have done. You might need a new back wheel.

 

[smithy92]

If its 5 speed then its a screw on freewheel not a casette. A new 7speed freewheel should be about 15£.

 

[Shinobi]

If its 5 speed then its a screw on freewheel not a casette. A new 7speed freewheel should be about 15£.

Thanks for all your advice, I've been looking on the bay, and providing the wheel ain't gubbed this may be affordable, my dad just txt me there saying he has a spoke tool and is searching for the chain whip just now... He's got a work bench too so I may be onto a winner here...

Another question at this point, with regards to the screw on freewheel... Is the tooth-count just personal preference, or will I need to match this to the gear selection system it already has on the bike?

Will the space the 5 gear freewheel be the same as a 7 gear one, but with less space between the gears, or will I expect to have to remove a spacer on the hub or similar? (if I were home I'd prolly have it apart myself looking by now, but stuck in work till 7.30 just now...) Itching to strip it down now and see what this wheel looks like once adjusted right

Also, is there any recommendations on anything else to do when I have the wheel off? (self servicing-wise ect... while it's off anyway)

 

[Red Light]

If its 5 speed then its a screw on freewheel not a casette. A new 7speed freewheel should be about 15£.

Whichever it is, Sheldon Brown can help you tell the difference.

 

[RecordAceFromNew]

Thanks for all your advice, I've been looking on the bay, and providing the wheel ain't gubbed this may be affordable, my dad just txt me there saying he has a spoke tool and is searching for the chain whip just now... He's got a work bench too so I may be onto a winner here...

There is no such thing as a 5 speed cassette (although one can make one if one wants to but I can't think why anyone would want to do that), only freewheel. Don't forget you will need a freewheel removal tool (that matches the particular freewheel you have, see Sheldon on subject).

Another question at this point, with regards to the screw on freewheel... Is the tooth-count just personal preference, or will I need to match this to the gear selection system it already has on the bike?

Yes you can choose, except that the largest cog's size influences the chain length and can potentially exceed the rear mech's capacity. If I were you I would first check the chain to see if it should be replaced (also see Sheldon). A chain length calculator is handy in figuring out what the existing chain can take if resueable, or how many links need to be taken out (you will need a chain tool) if you need a new chain. Just looking at your rear mech I am pretty sure you can go to 28T without exceeding capacity.

Will the space the 5 gear freewheel be the same as a 7 gear one, but with less space between the gears, or will I expect to have to remove a spacer on the hub or similar? (if I were home I'd prolly have it apart myself looking by now, but stuck in work till 7.30 just now...) Itching to strip it down now and see what this wheel looks like once adjusted right

In your case, you can check if the frame/rear hub both have a distance between dropouts/locknuts of 135mm, which should be the case. Unless your rear wheel is ancient or someone has been redishing it I would expect it to be able to take a 7 speed freewheel without modification, but you can check to see if there will be enough clearance between the smallest cog and the frame before committing - 7mm is roughly how much a 7 speed freewheel is wider than a 5 speed one.

Also, is there any recommendations on anything else to do when I have the wheel off? (self servicing-wise ect... while it's off anyway)

I find many, actually I might even say MOST low cost wheels, which invariably have cup and cone bearings, poorly set up and/or greased even when new. Since you seem to be so inclined it is worth check/fixing. You will need suitably sized cone spanners.

 

[Shinobi]

Whichever it is, Sheldon Brown can help you tell the difference.

Thankyou, thats the website i initially came accross while tinkering with the front gears actually, he seems to know his stuff, but I had not seen this particular page.... guess i wont know for sure till i get the wheel off and compare it to those pics, was about to bid on one earlier on as well, just as well i didn't!

 

[RecordAceFromNew]

Moderator: This thread should probably be moved to Knowhow?

 

[Red Light]

There is no such thing as a 5 speed cassette

I thought my memory must be going since two of you said that but Google was my friend.

5 Speed Shimano Uniglide Cassette.

 

[Red Light]

Moderator: This thread should probably be moved to Knowhow?

Don't Knowhow surely?

 

[Shinobi]

There is no such thing as a 5 speed cassette (although one can make one if one wants to but I can't think why anyone would want to do that), only freewheel. Don't forget you will need a freewheel removal tool (that matches the particular freewheel you have, see Sheldon on subject).



Yes you can choose, except that the largest cog's size influences the chain length and can potentially exceed the rear mech's capacity. If I were you I would first check the chain to see if it should be replaced (also see Sheldon). A chain length calculator is handy in figuring out what the existing chain can take if resueable, or how many links need to be taken out (you will need a chain tool) if you need a new chain. Just looking at your rear mech I am pretty sure you can go to 28T without exceeding capacity.



In your case, you can check if the frame/rear hub both have a distance between dropouts/locknuts of 135mm, which should be the case. Unless your rear wheel is ancient or someone has been redishing it I would expect it to be able to take a 7 speed freewheel without modification, but you can check to see if there will be enough clearance between the smallest cog and the frame before committing - 7mm is roughly how much a 7 speed freewheel is wider than a 5 speed one.



I find many, actually I might even say MOST low cost wheels, which invariably have cup and cone bearings, poorly set up and/or greased even when new. Since you seem to be so inclined it is worth check/fixing. You will need suitably sized cone spanners.

wow.... a lot of info there, i think you may have just answered everything I've asked in a oner! looks like i'm fully armed with info for the next few days... thanks a bunch everyone!


RecordAceFromNew, I dunnno how to move posts and guess its prolly a 'mod-thang' --- feel free to move it if you feel it better suited to there, i actually hadn't seen that part of the forum yet (my bad). Also I'm on a work PC, so can only see very basic info just now, not sure if you're a mod or not -

{edit - spelling and i actually can see your a mod, sorry!}

 

[RecordAceFromNew]

Don't Knowhow surely?

In case you did not know, hubs that use the 5 speed cassette you linked to not only haven't been made for around 25 years, they were also only made for only a very short period at the time. They are, for all intent and purpose, imho obsolete.

I see from your link one shop in USA is selling it. How many places did you find in the world that is selling one?

But of course you are right that technically they do exist, if you think that info is somehow helpful to the OP.