Goodbye indexed gears?

[sebinho]

Hi, This is a similar post to @Biker2772's about slipping gears. I suppose all cases are different, so I'm posting my own thread and I'll paste below some detailed images. The gears Ultegra with this code embossed: "RD-6500 VIA". The bike, a Principia Rex, is 20 years old and I bought it recently. The gears were almost perfect when I received it, it just skipped a gear on the smaller cogs of the cassette when dropping down to lower gears from top gear. Took it to a shop for adjustment but it came back worse. Returned to the shop and it turned out even worse again. I took it to another shop where they suggested I should change the chain and cassette. This was done. They also suggested putting the rear derailleur into friction mode (on the shifter I suppose?) because the gears have too much "play" in them (i think that's what he said but i didn't speak to the mechanic). This also was done. I went for a ride this morning and the gears are much better but the occasions hiccup occurred while dropping down the gears. Too me, the rear derailleur seems pretty solid with no slack or movement when handled.

I hope someone can offer an opinion with these photos. Buying a new derailleur is out of the question for me because the prices are eye wateringly high here. But might it be the case that the gears can be serviced (where I wouldn't know) with a change of parts where necessary? The bike has bar end shifters but I'd like to put STI's on it in the future if the indexing/slipping problem can be fixed.

Front derailleur works perfectly.

Cheers,

 

[fossyant]

Looks fine to me. Have you changed the cables (inners and outers) as they have a big impact on shifting.

You also need to check the hanger alignment as the mech looks quite scuffed - i.e dropped at some point - can bend the hanger on the frame (in your case the black metal bit where the mech is fixed).

Cables first though - get new.

 

[Ian H]

Yup, I'll second checking the hanger alignment.

 

[sebinho]

Thanks, will change the cables. Can the hanger be straightened? It's an aluminium frame.

 

[fossyant]

Thanks, will change the cables. Can the hanger be straightened? It's an aluminium frame.

If careful - easy way to check is does the mech cage hang down straight - i.e. level with the wheel. That's a quick check. TBH, new cables first, inners and outers as the shift soon deteriorates if they are not clean, and as a 'second user' just change them.

 

[sebinho]

If careful - easy way to check is does the mech cage hang down straight - i.e. level with the wheel. That's a quick check. TBH, new cables first, inners and outers as the shift soon deteriorates if they are not clean, and as a 'second user' just change them.

No, the mech (mechanism?) cage does indeed seem to be bent inward a little. The frame however looks very sound, I can't see any bend in the tab, so that must be a good thing. There doesn't seem to an adjustment for varying the angle of the hang. I wonder if some sort washer with a slight slope could be used to correct? Batteries are flat in the camera. Will post a photo when charged enough.

 

[fossyant]

No, the mech (mechanism?) cage does indeed seem to be bent inward a little. The frame however looks very sound, I can't see any bend in the tab, so that must be a good thing. There doesn't seem to an adjustment for varying the angle of the hang. I wonder if some sort washer with a slight slope could be used to correct? Batteries are flat in the camera. Will post a photo when charged enough.

This is where you have to be careful - do you know any other cyclists ? You can 'bend' the hanger out slightly with an adjustable spanner, but modern bikes use alloy hangers so really don't like being bent again - usually you buy a new hanger. You have to take off the mech first.

 

[sebinho]

This is where you have to be careful - do you know any other cyclists ? You can 'bend' the hanger out slightly with an adjustable spanner, but modern bikes use alloy hangers so really don't like being bent again - usually you buy a new hanger. You have to take off the mech first.

This shows, I think, that it's bent inward towards the wheel and more at the front. Fixable? The cables, by the way, look brand new.

 

[DCLane]

@sebinho - it's absolutely fixable and an LBS should have picked this up.

It'll have a separate derailleur hanger (the little silver bolt by the skewer, probably two) and it's a case of matching it to the correct one. Principia's are rare, which is why I like them, but the hanger should be available.

 

[Andy in Germany]

If careful - easy way to check is does the mech cage hang down straight - i.e. level with the wheel. That's a quick check. TBH, new cables first, inners and outers as the shift soon deteriorates if they are not clean, and as a 'second user' just change them.

I second this. It's amazing what can get stuck down a cable, especially if the outer is damaged: Last time I changed my cables because of unresponsive rear gears I squirted lubricant down the outer cable and found a fair bit of Germany was in there...

 

[Ajax Bay]

Don't change cables straight away. I don't think this RD has seen much use, for age, but has been put down on its right side.
Sort RD hanger first. Then see if improved.

 

[DRM]

I think you've nailed it with the last picture, it should be a simple fix with a new hanger

 

[sebinho]

@sebinho - it's absolutely fixable and an LBS should have picked this up. It'll have a separate derailleur hanger (the little silver bolt by the skewer, probably two) and it's a case of matching it to the correct one. Principia's are rare, which is why I like them, but the hanger should be available.

I think you've nailed it with the last picture, it should be a simple fix with a new hanger

Well that's brilliant. I've not been able to find the hanger itself for sale but have see a few complete used rear-derailleurs on Ebay and one overpriced one locally. If anyone has any tips on finding the part, please let me know. Thanks everyone for your help!

edit:

This one looks nice and the freight is affordable but things can take months to arrive and may get heavily taxed:
https://www.ebay.com/p/1100634705

This one looks much rougher but is local:
https://produto.mercadolivre.com.br...cking_id=fa2ba792-5c4f-4cd3-bcf5-ec56eb110f6c

More photos with together with front derailleur here:
https://produto.mercadolivre.com.br...cking_id=a552c9c1-64a6-4c44-9208-5351044a0faa

I can try and get the price down on the local one and the platform gives free returns.

 

[si_c]

The hanger can be bent back into place using the right tools. That looks to me like it's also twisted a bit so that'll be the problem with the gears.

Your LBS should fix that for free really given you've had it in twice and they've missed it.

 

[sebinho]

The hanger can be bent back into place using the right tools. That looks to me like it's also twisted a bit so that'll be the problem with the gears.

Your LBS should fix that for free really given you've had it in twice and they've missed it.

That's a point. I'll send them the photos and see what they say.