Absolute black subcompact oval chainring / tiagra crank issues

[bluebus200]

So it says on their website that the 46/30 absolute black chainrings can be fitted to tiagra 4700 cranks.... With a little adjustment....

After I brutalized the cranks for a while with a file I just about got them together with the rings. But for the love of all things Holy I cannot get them to shift properly. The chain always drops between the two.

Has anyone else tried this combo... If so did you manage to get it to work? It's feeling like an expensive mistake at the moment.. Wish I'd just bought the grx 46/30 instead.

 

[Cycleops]

Oh dear, sorry about that. Is there any way of closing the gap between the gap between the rings? Perhaps you could post a pic of the installation?

 

[Ajax Bay]

Links to the rings, please. Number of sprockets? Link to chain you're using. Put in the effort to make it easier for 'us'.

 

[bluebus200]

These are the rings...

https://absoluteblack.cc/oval-road-chainrings-30-46-and-32-48-for-110-4bcd/

The cassette is a Suntour Mx3 11-40 http://www.sunrace.com/en/products/detail/csmx3

Chain is kmc X10 (I'm not sure if the exact type.

I will post some pictures of he set up asap..

 

[Ajax Bay]

Maybe someone on here will have experience.
"Tiagra 4700* (requires modification -contact us)"

I just about got them together with the rings.

Just a suggestion:
Since the small chainring has integrated spacers on the crank side, I wonder if those spacers need a big enough space to 'enter' the crank mounting holes and your 'just about' modification to the FC-4700s has not quite achieved that, meaning that the inner ring is just a tad further inwards than it should be, thus creating a gap (just) big enough for the chain to drop into?

 

[bluebus200]

Maybe someone on here will have experience.
"Tiagra 4700* (requires modification -contact us)"

Just a suggestion:
Since the small chainring has integrated spacers on the crank side, I wonder if those spacers need a big enough space to 'enter' the crank mounting holes and your 'just about' modification to the FC-4700s has not quite achieved that, meaning that the inner ring is just a tad further inwards than it should be, thus creating a gap (just) big enough for the chain to drop into?

Yes, I think you are right. I have been measuring the difference between the original tiagra rings and the new absolute blacks. There is for sure a few mm in it. It’s annoying because they state on the website that they are compatible with a small adjustment, which is patently not true. Having already filed down the tabs on the cranks quite a bit I’m reluctant to take any more off them.... I could try some of the other supposedly compatible cranks but that’s more£££ and it might not work!

ah well I suppose that’s what I get for tinkering in the dark arts 😂😂

 

[bluebus200]

Here's some pics...

 

[topcat1]

It does state "contact us if you are using Tiagra "
once that is sorted you will need to keep the chainrings clean to last longer

 

[bluebus200]

I did contact them, I followed their advice. all they said was ummm we don't know. I'm pretty sure it's not the rings And that they fit the 105, ultegra etc. It's just that they seem not to work very well on a model that they say are compatible..... Anyways I am going to try a 105 crank and see if that works. Will update

 

[PpPete]

I run AB 46/30 on 105 (R7000) cranks and not had any difficulty - although at the time I bought them, the compatibility list said only DA and Ultegra would fit.