Rear cassette replacement problem

Breezer

I wore out my chain, which subsequently damaged my rear cassette and front chainset. In my wisdom, I decided replacing them would be a great project to learn about bike maintenance. A week of frustration and walking to work later, I've mainly learned that I don't know my arse from my elbow, although I've managed to get the new chainset and chain on.

I've a problem with the rear cassette. The old one was a Shimano 105 5800, which I couldn't find available anywhere. The new one is the replacement 7000 model. When I put this on the old freehub, I can't get the lockring to tighten. The new cassette seems fractionally too wide, and the threads are unable to grip. If I remove one of the spacers between the sprockets, the lockring can tighten, but presumably that will completely muck up my shifting?

At this stage I'm nearly ready to give up and bring it to a shop, but I'm wondering does anyone here have any ideas. Is it a compatibility problem or could it be something else?

crosstownk

I'll ask the obvious question....

Have you an extra spacer installed on the new cassette by mistake? There should be five in total. The smallest two sprockets have the spacer built in.

Mercian Pro

Sounds very much like the inner spacer is the problem. This is one that is separate from the cassette but fits between it and the hub. With some combinations of cassette and hub, you may need no spacer, a narrow spacer or a thicker one. Sounds like you either have one that is too thick or you don't need one at all. Another possibility is that the old spacer wasn't removed and you added a new one. Don't remove any of the intermediate spacers between the sprockets as that will mess up the changing.

Breezer

crosstownk wrote: »

I'll ask the obvious question....

Have you an extra spacer installed on the new cassette by mistake? There should be five in total. The smallest two sprockets have the spacer built in.

Thanks, but nope, I have them right.

The smallest sprocket doesn't seem to be clicking into place the way the others did. It's sitting on top of the second smallest one and rotating freely. Is this normal?

Breezer

Mercian Pro wrote: »

Sounds very much like the inner spacer is the problem. This is one that is separate from the cassette but fits between it and the hub. With some combinations of cassette and hub, you may need no spacer, a narrow spacer or a thicker one. Sounds like you either have one that is too thick or you don't need one at all. Another possibility is that the old spacer wasn't removed and you added a new one. Don't remove any of the intermediate spacers between the sprockets as that will mess up the changing.

Thanks, but there is none!

crosstownk

There is no difference between 5800 and 7000 from a fitting perspective. If you refit the old 5800 will the lockring tighten?

Breezer

crosstownk wrote: »

There is no difference between 5800 and 7000 from a fitting perspective. If you refit the old 5800 will the lockring tighten?

I'll have a go in the morning. I want to bathe it in degreaser first, it's minging. Cheers.

Edit: OK I went ahead and did it. The old one tightens

Dark sun

Breezer wrote: »

I'll have a go in the morning. I want to bathe it in degreaser first, it's minging. Cheers.

Put up a pic of them side by side looking down on them must be something simple like one of the smaller sprocket wrong way or spacer inserted wrong, should be a straight swap.

crosstownk

Breezer wrote: »

Edit: OK I went ahead and did it. The old one tightens

It's something simple so.

100% it's 5800 and not 5700?

ted1

Deffo not 10 speed to 11?

Breezer

crosstownk wrote: »

It's something simple so.

100% it's 5800 and not 5700?

I don't believe it! It's a HG-700. It should be a 5800 according to the spec on the manufacturer's website, but it's not.

And according to https://productinfo.shimano.com/#/com?acid=C-544&cid=C-544 this, the HG-700 is a different width to other 11 speed Shimano cassettes.

Guess that'll teach me to actually look at my bike, rather than websites, before I buy replacement products

I assume the only thing I can do here is buy a new cassette? I can't actually find a HG-700 online now.

Edit: Actually, I've found a place in Mayo selling them. I'll give them a buzz in the morning, assuming it's my only option?

crosstownk

So many bike manufacturers claim a certain groupset but in reality only some components are of the stated groupset. Chain sets are the most common.

You’ll need the correct cassette by the sound of things.

At least you got the problem identified. That’s more than half the battle.

Breezer

crosstownk wrote: »

So many bike manufacturers claim a certain groupset but in reality only some components are of the stated groupset. Chain sets are the most common.

You’ll need the correct cassette by the sound if things.

Cheers for all that. There's a decent bike mechanic near me, I'll try him in the morning and see if he happens to have one. Failing that I'll try the crowd in Mayo. Thanks again! I'm embarrassed now but you live and you learn!

magicbastarder

if you had the HG700 on the bike, it looks like that was shipped with a spacer which went on first - have you also removed this?
i.e. if i understand correctly, you're taking off a 700 (not the CS-5800 you'd expected), but this fits a spacer first?

or is your wheel configured in such a way that the spacer is 'built in'?

from what i can see, the HG700 is the 34 tooth version of the standard R7000 lineup.

Breezer

magicbastarder wrote: »

if you had the HG700 on the bike, it looks like that was shipped with a spacer which went on first - have you also removed this?
i.e. if i understand correctly, you're taking off a 700 (not the CS-5800 you'd expected), but this fits a spacer first?

or is your wheel configured in such a way that the spacer is 'built in'?

from what i can see, the HG700 is the 34 tooth version of the standard R7000 lineup.

There was no spacer. It's a hybrid bike, so perhaps I've an MTB hub, which seems to not require a spacer for the HG700? How would I tell the difference between that and a road one?

magicbastarder

aha - that would make sense. i assumed it was a road hub.

Breezer

magicbastarder wrote: »

aha - that would make sense. i assumed it was a road hub.

So did I :rolleyes: