I have, twice. Once the company involved didn't turn up on the day so it was found in my favour and I got a fair settlement, which the company honoured; the other time they did turn up, I argued my case, and again it was found in my favour. It actually works pretty well, IME.
Assuming nothing's changed in the interim (which I think unlikely) your 'exposure' is limited to the cost of making the claim - probably peanuts, v the cost of a frame. If it was me, I'd go ahead. And FWIW, as a barrack room lawyer I'd suggest you ignore/reject any attempts to involve you in anything between the manufacturer, importer, distributor or Paddy Maloney's cat. Your contract was with the retailer, period. And as I understand it, they seem to have sold you something which is 'not of merchantable quality':
As with the Sale of Goods Act, under the Consumer Rights Act all products must be of satisfactory quality, fit for purpose and as described. The rules also include digital content in this definition. So all products - whether physical or digital - must meet the following standards:
- Satisfactory quality Goods shouldn't be faulty or damaged when you receive them. You should ask what a reasonable person would consider satisfactory for the goods in question.
If the frame of a really-not-that-old bike is cracking, I think a magistrate would agree that you have not received what you paid for, and had every right to expect: a bicycle frame that would last a decade or more. And if you haven't, the retailer has to put things right. It's up to them whether & to what extent they want to pursue the matter with the maker, distributor or whoever - that has no bearing on the contract they had with you: you give us £x, and we will supply a bike 'of merchantable quality'.
Personally I'd go ahead. Good luck.