Mechanics and Fixing Any Questions Answered

Ta, will get them ordered.

The only thing is with the press tool, it's good if it has steps of different sizes to sit inside the bearing rather than flat plates that sit over the whole cups. Just guides the cups in straighter.

Yep, the ones I looked at had steps on them.

Proper cups as many had already said makes the difference.

Potentially very dumb question exposing my lack of knowledge...

I've cobbled together a budget 1 x 12 TT setup with bits that shouldn't (officially) work together. The good news is that the shifting actually seems to work fine, apart from when I shift to the big cog on the cassette and it drops the chain. Now I hope not to have to use this too often, but it would be nice to know I have the option if there's ever a half reasonable hill.

It turns out I completely ignored the whole chainline thing, and the chainring is now sitting too far away from the frame, causing too great an angle when in the big cog, pulling the chain off. As it's a GXP setup and there are no spacers being used on the BB, I saw no way of bringing the chainring in at all. I figure I have some options:

1) As pictured - I put the chainring on the other side of the spider, then gradually move it away from the frame with GXP spacers. this is what I have done in the images below and I don't feel confident about it for some reason. Apart from the aesthetic impact, if the chainring isn't sat in the 'lip' of the spider, will there be too much force on the bolts? I guess that's what happens with inner rings anyway? It seems to work, but am I setting myself up for disaster? (I know the bolts are backwards).

2) Get a chain guide (would prefer not to do this re buying more things).

3) Get a chainring with offset (would prefer not to do this re buying more things).

4) Give up and go 2x.

looks like a "normal" toothed ring to me, they tend to drop the chain when you ride them very cross-chained. most folks would use a narrow-wide chainring for 1x12 that "holds" the chain a bit better at agressive angles, bc the teeth are shaped more sophistically. I don't think your bolts will shear off.

Yep, it's not a narrow-wide (I was trying to avoid the spend if possible, but may have to bike the bullet). Thanks.

Go for narrow wide on the inside and check your bolts after the first ride

In my experience you'll drop the chain if you ride over a mid-sized bump. When I rode big ring 1x, I bought a Sram X-Sync narrow wide chainring which offsets the chainring in-board from the regular big ring position (teeth sit in line with the crank spider). I still dropped a couple of chains on bigger, avoidable bumps. The Rotor ring look sooo good though! Aerocoach made some nice sleek looking chain guides at one point which could be an alternative

GXP spacers are for using MTB cranks in a 68mm shell. You can't space out a road crank in a road frame with spacers.
You probably know this but just FYI in case

don't know how big you need the ring but this is pretty reasonable https://www.ebay.co.uk/itm/155400374057

Stick the FD back on and use it as a chain catcher?

Happy days - must admit I was sceptical but solid as a rock now. Cheers!

You spaced out a road GXP BB? I mean....talk about asking for trouble.

You've answered your own question really. New NW chainring or a chain catcher. How you'll fit it to that without a DIY mod, no ideal. Just get a narrow wide chainring.
You can get direct mount ones to work on that chainset with 3mm or 6mm offsets depending on frame.
It's what I did. Worked a charm and never dropped a chain.

@Arnomatic - thanks, I'm just going to have to suck it up and buy an offset NW I guess.

@PhilDAS - I didn't know that and now I do, thanks.

@fredtc - I started watching that before you posted! Good deal but not black enough...

@Chak - See above. Didn't know, luckily haven't used it...

Currently looking at a Garbaruk NW direct mount version. Any experiences with them?

Is this do-able and safe (assuming the narrower section of the nut can enter the fork from the rear)?

The fork wants a nutted caliper I don't have. The caliper's bolt will get threaded by 15mm of nut so more than it would have had with a nylock nut on the outside, and the 2 washers fit snuggish and are decent i.e. they shouldn't get pulled through.

Any thoughts? Thanks in advance.

The sleeve nut won’t fit into the hole in the fork if it’s drilled for nutted callipers though surely?

You say “frame” but looking at that it looks more like a front set up so I’d this going on the fork?

What material?

If you need a nutted rear caliper but don’t have one, a modern front caliper will have a long enough axle that you can get a nut on it (usually).

I would ride it, but I'm not an engineer. Is the surface/back of the crown the washers will sit against flat or convex?

Yes, sorry, forks not frame there, I'll change it now.

The forks are original on a steel Raleigh Stowaway. The drilling probably isn't wide enough, I'll try and check today. Wondering really if it's a non-starter from a safety perspective...

Good point, need to check this too...

Would appreciate guidance on converting post mount fork to take flat mount callipers. Can I use https://www.sjscycles.co.uk/brakes/trp-disc-brake-flat-mount-front-flat-to-post-160-mm/ ? Says it’s for flat brake mount to post calliper, so I expect it’s a possible no? 🤔

If not, what mount do I use? Wolf Tooth have one that adds 20mm to the rotor, and I want to keep the 160mm currently running.

No, traditionally you couldn't use that brake and mount combination but now there are some adapters but you will need to +20mm
There isn't physically enough space between the posts on a post mount to fit a flat mount caliper and adapter without adding the extra 20

Thanks all for your comments.
A few options to think about!

Thanks. Seems a fork swap is necessary.

Sorry, this is @adamdenw

You can buy the convertor bolt (and anything else you need from Spa Cycles to make the most of the postage cost).

https://spacycles.co.uk/m7b17s100p2341/SPA-CYCLES-Allen-Key-to-Nut-fit-Converter-Bolt

If it needs a nut-fitting brake front and rear then the rear allen-sleeve-bolt brake with the really short bolt gets converted and goes on the front and the old front brake goes on the rear.