Old Shimano cassette..how dismantle ?

[RogerJ]

]Hello.. First post ! In trouble already.. It's years since I last did bike maintenance and then it all seemed to easy.. I've just bought an old Dawes Shuniah mountain bike (£5) that's been very neglected.
The rear hub bearing are dry and I need to repack with grease. Looks like the axle is slightly bent as well. First hurdle is the cassette removal (without special tools ) The lock nut is different from any I've found on tinternet and has an external female "spline" (photo) Does it undo anti-clockwise ? It's tight up against an 11 tooth sprocket and didn't move after a careful tap with a punch.
Thought I'd ask advice b4 trying again.. Roger
   

[Jesper]

(07-01-2022, 12:19 PM)RogerJ Wrote:  ]Hello.. First post ! In trouble already.. It's years since I last did bike maintenance and then it all seemed to easy.. I've just bought an old Dawes Shuniah mountain bike (£5) that's been very neglected.
The rear hub bearing are dry and I need to repack with grease. Looks like the axle is slightly bent as well. First hurdle is the cassette removal (without special tools ) The lock nut is different from any I've found on tinternet and has an external female "spline" (photo) Does it undo anti-clockwise ? It's tight up against an 11 tooth sprocket and didn't move after a careful tap with a punch.
Thought I'd ask advice b4 trying again.. Roger

Hi Roger, and welcome to the site.
I myself am not specifically familiar with that Shimano cassette other than that I believe it to be one of their "economy" components used on lower end bikes.
I would assume that it is a standard thread locknut. If you can see any exposed threads you might be able to determine the thread style (righthand/normal, or lefthand/reverse thread). You might try pretreating it with some penetrating oil and let it sit overnight and then apply some medium heat carefully with a heat gun or torch to see if it will weaken the corrosive bond.
A hook spanner would be required to do it properly with that style locknut, and a chain whip to secure the cassette while cranking on the spanner. If you have a pipe wrench (or 2) you could use one on the locknut without tearing it up too much. You might be able fit another pipe wrench on one of the smaller cogs to act as a chain whip, but you stand a chance of chewing up the cog's teeth which, although it probably won't cause enough damage to the cog to affect the shifting, could cause noise during pedalling (file off any burrs to avoid this). It's just a little more difficult to hold those 2 pipe wrenches in place unless you have a helper. Unless you are deadset on doing the work yourself it may be best to bring the wheel to a shop where they should (in most cases) be able to remove it in a couple of minutes at a minimal cost. It helps that the bike only cost 5 quid since it allows you to spend a little more on maintenance/parts if done by others.
Checking for a bent axle should be fairly easy especially if the hub uses a cup/cone/loose ball bearing design since you should feel some binding when the wheel is spun. If the bearings are loosely adjusted you may not notice binding on a slightly bent axle due to excessive end play. Just tighten up the cone to remove some play and see if it causes binding. A sealed bearing design may not be quite as obvious, but in either case you should still be able visually see the eccentric movement of one end of the axle when it is turned by hand. It might be cheapest and easiest to replace the whole rear wheel if the axle is bent and the bearings are bad (loose or sealed). I would carefully inspect the hub bearing race surfaces for any wear/pitting. If it is just going to be a beater bike then you may be able to still use for some time with some minor pitting with the understanding that it will continue to get worse, and could be in a bad way fairly quickly if you plan to put a lot of mileage on it and/or if you're a heavier rider. Riding on rougher surfaces will also tear it up quicker.
Also, assume that the front bearings will require cleaning/inspection/repacking since they experienced the same use/abuse/elemental exposure as the rear bearings. I would assume that the bike needs a top to bottom service (clean/repack all bearings, probably new cables/housings, maybe new chain and brake pads) to ensure proper and safe operation.
I kind of assume that if you bought the bike cheap you probably don't want to spend 100s to bring it back to proper function. At that point you could find another used bike that although it may cost more to purchase, it won't cost as much to put it right. Hopefully the tires are still serviceable. I just spent about $90/£70 on some gravel tires (Bontrager) for a friend's bike as a birthday gift. Those things keep going up in cost, and even on the economical end I would have spent a minimum of about $60 a pair.

Good luck!

[RogerJ]

Hi Jesper... Thanks for that informative answer.. I should explain the reason for bothering with an old banger at all.. By my standards, I already have a nice 25 year old Raleigh hybrid that I bought to ride to work.. Then I retired..and the bike has seen little use since then.. I got it out a couple weeks ago and went for an 8 mile ride. I found that at my now advanced years I had great difficulty throwing my leg over the cross bar :-(
It's also hilly here in Cornwall and other things I've noticed that I hadn't in the past..
So I set out to find something really cheap to see if bike riding is indeed my (occasional ) thing. ! I also like fixing things up..
So..the old Shuniah came along on FB marketplace.
So far..front tyre gone on the back and a Hybrid tyre gone on the front.
I have tried heat and driving with a punch on that lock ring without success. BUT .. for some reason I thought I need to get it off to get the spindle out and re-grease the loose balls.. I didn't ! The spindle is now straightend by judicious tapping/rotating while held in a lathe chuck.
I had quite a few old cone spanners from by teen years..but they are all too thick.. Cheap ones coming via Amazon.
brake cables replaced.. New chain will be bought later this week.
I also got FOC a 1980's vintage ladies bike (Raleigh Granada I think) with a reynolds 531 frame.. Have decided to do that up next as well :-)
You are quite right of course..There are litterally hundreds of cheap bikes on Marketplace/Gumtree etc many ready to ride away (at the level I'm concerned with) and parts can soon run away with plenty of £s/$s.. if you go too cheap...But I'm learning new stuff at the same time..

[Jesper]

(07-06-2022, 12:00 PM)RogerJ Wrote:  Hi Jesper... Thanks for that informative answer.. I should explain the reason for bothering with an old banger at all.. By my standards, I already have a nice 25 year old Raleigh hybrid that I bought to ride to work.. Then I retired..and the bike has seen little use since then.. I got it out a couple weeks ago and went for an 8 mile ride. I found that at my now advanced years I had great difficulty throwing my leg over the cross bar :-(
It's also hilly here in Cornwall and other things I've noticed that I hadn't in the past..
So I set out to find something really cheap to see if bike riding is indeed my (occasional ) thing. ! I also like fixing things up..
So..the old Shuniah came along on FB marketplace.
So far..front tyre gone on the back and a Hybrid tyre gone on the front.
I have tried heat and driving with a punch on that lock ring without success. BUT .. for some reason I thought I need to get it off to get the spindle out and re-grease the loose balls.. I didn't ! The spindle is now straightend by judicious tapping/rotating while held in a lathe chuck.
I had quite a few old cone spanners from by teen years..but they are all too thick.. Cheap ones coming via Amazon.
brake cables replaced.. New chain will be bought later this week.
I also got FOC a 1980's vintage ladies bike (Raleigh Granada I think) with a reynolds 531 frame.. Have decided to do that up next as well :-)
You are quite right of course..There are litterally hundreds of cheap bikes on Marketplace/Gumtree etc many ready to ride away (at the level I'm concerned with) and parts can soon run away with plenty of £s/$s.. if you go too cheap...But I'm learning new stuff at the same time..

Good to hear. Yes, if just repacking the hub axle bearings you can leave the cassette in place.
Looking at that lock ring again makes me think it might have needed a proprietary Shimano spanner that either surrounds the nut entirely or at least enough to engage it properly without it wanting to slip off.

[RogerJ]

Still working on this old bike. Got the locking ring off (taping with a punch) and removed 4 sprockets But can't see what to do with the "spacer" (see pic) Is this also screwed.. Have tried anti-clock with a punch but no luck.
I have actually now bought a secondhand rear wheel with a standard 12>28 cassette which will suit the new meach I've also bought. So further dismantling of the original cassette is only part of the learning experience. Google searches haven't helped..    



Good to hear. Yes, if just repacking the hub axle bearings you can leave the cassette in place.
Looking at that lock ring again makes me think it might have needed a proprietary Shimano spanner that either surrounds the nut entirely or at least enough to engage it properly without it wanting to slip off.
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[ichitan]

I am not familiar with that model of freewheel, and I can't say for sure, but to remove it you probably need a tool that goes down the inside, around the axle. Remove any nuts and spacers from the axle, and look down the inside. Are there splines, or something which a tool would slot into? You can photograph it, and post the photo if you want.

Freewheels always undo in an anticlockwise direction.

It is likely, but I can't say for sure, that if you removed that freewheel, the thread it screws onto would be standard, and you could replace the freewheel with a modern one.

If the axle has been bent, it may break in the future. You could replace the axle. Or you could just wait, and replace it if it bends or breaks in the future.

You can also make an adapter to prevent the axle bending or breaking in the future.

https://forums.bikeride.com/thread-8031.html

[ichitan]

In case what I am saying is not clear, here is a picture of a modern freewheel. Notice the splines in the center. They are there for the removal tool to lock into when removing the freewheel. Check if your older freewheel has the same, or something similar.

   

[RogerJ]

Hi agian.. Thank you for all the info. I ve learned a lot including the fact that that gear cluster is probably a freewheel and not a cassette. In that case locking the big sprocket with the old chain was never going to work I think. I should have restrained the whole wheel if the whole thing was meant to unscrew ?
Howvever, I'll never know now as I've just returned from a charity bike recycling/repair place and donated all the bits I've bought and don't need, together with that back wheel.
I baulked at sizing and fitting a new chain due to not having the right tools for derailleur chains - and needing an experienced eye to say that the new wheel and the mech I fitted are compatable. Apparently they are and I've left it with them for fitting the new chain. I've also asked about raising the handlebars a couple of inches and the've looked out a S/H adjustable stem riser.
I hope it will at last be ridable when I get it back... and just a few minor improvement (like new handle bar grips and brake blocks) to finish of the job.
I'll post again with the result.. Roger