Reading the review of the narrow wide rings “£40 odd?, i could make one for that”

So some measureing and CADing and off cuts of ali here we are. A 28 tooth ring on a 104 pcd fitting. Kind of in between where the middle and inner rings would be.

chain ring assembled by Dean-B1, on Flickr

chain ring assembled by Dean-B1, on Flickr

chain ring assembled by Dean-B1, on Flickr

bit of fine tuning and it should be good to go on the bike.

ooh, that’s nice. If you dont like it send it my way.

doffs cap

Who’s a clever boy then?

If you need an 80bcd 28 tooth testing I’m your man 😆

Haven’t you got a kid to breast feed Gee? 😉

Just doing it!, he’s just dozed off too!. A man can dream can’t he!. Need a thick thin ring for the raceface double. Sram do an 80 bcd double too so surely its gotta be worth someone doing one 😀

Nice idea using a carrier/bash to mount to the 104 BCD. What’s the actual BCD of the 28 ring (I’m assuming they’re 2 separate parts- the carrier and the ring?)

Any way to reduce the offset – it’s going to make your chain line a bit off – but hopefully ok in small-small.

Good work that man.
I used to program stuff like that for fun when I was a setter.

Nice work fella.
Don’t want to wee wee on your firework but what about hardening?

Looks good to me – well done mate!

good work!!

whats the cost price 😉

Can you do me a 32t please? #seriousquestion

Can you do me a 32t34t please? #seriousquestion

+1

28 tooth?! (Well someone had to say it 🙂 ) Nice work though.

Can you make Mint Sauce Key rings?

Can you do me a 34t please?

Missing the point? Every man and his dog does 104mm 32t/34t chainrings. It’s the 28t on 104mm that’s individual.

Thanks for the comments.

An evening in the garage paying with the dirty words in the bike industry (standards and tolerances).

So not all chain ring bolts have the same thread (or diameter) and arm thickness between the outer and middle ring can vary up to 1mm?

Anyway some work with the file to get the carrier to clear the crank and it’s on.

Am going to make another chain ring as the inner plates of the chain have a square notch on the outer edges which is catching plus i think some clearance on the tooth profile might be needed.

fitting 28 tooth by Dean-B1, on Flickr

Also thinking you only have to chamfer on side of the teeth as it’s only the top third of the cassette that creates a high chain angle.

Well its survived a peak ride, all the fun of the pootle, chain only came of when we were stood still and i back pedaled. Not bad considering no cain guide or clutch mech. Also managed round on a 11-34 cassette. On the mk2 chain ring that now has some clearence machined into it for the chain.

Fantastic! 😀

Very nice!
I’d be interested to know if you ever find that you’re under-geared.
Occasionally people with a 30t complain about it, but I’m not convinced it would be a big deal to me.

Good work 🙂

Nice bit of CNC work. And quite a neat solution to a 28 tooth on a 104 BCD. Do you think you could make off set machined spacers to fit the crank arms with an M6 bolt hole for the 28 tooth ring on a smaller BCD ?

Very nice!
I’d be interested to know if you ever find that you’re under-geared.
Occasionally people with a 30t complain about it, but I’m not convinced it would be a big deal to me.

Well for normal pottering say 10-15mph its fine, climbing was ok for what we covered.
As for spinning out in the impromptu race for cake at the end of the day 20mph was just managable and i “spun out” at 23mph.

ive a graph somewhere comparing ratios (all other things being equal)