Hi
Advice please tri talkers…
I run a sram 110 bcd etap chain set 52/36.
The small ring has been changed for a 34, it works perfectly, if anything better than the original but that could be in my head?!
My mate has the newest Shimano Ultegra 8000? Chainset 53/39.
110 bcd we think ?
Can he swop his 39 for a 36?
Anyone know how many links the chain will need shortening, we are looking on google but wondered if anyone had actually done or seen this done ?
All new Shimano chainsets only have a standard BCD, and within reason the rings are interchangeable.
But there’s some restrictions, I don’t think a 34 will go with a 53, 52/36 or 50/34 are options, although sometimes it’s cheaper to buy the whole thing than replacement rings.
Edit, I don’t think a 36 will go with a 53 either.
One ring is £26.
He wants to go from 39 to 36?
He’s a much stronger cyclist than me but I left him for dead on two really steep bits just through gearing
IMUK third lap it would help I’m sure ! Cheers
I presume that’s the inner ring, they’re usually a lot cheaper. I think Shimano might say it’s not supported but could just work, might be worth a go for £26.
Probably just be a clunky change.
He has newest 11 speed di2 so should be ok.
Shimano always say it’s not supported
The alternative is a 11/32 rear block ?
That could be a better option, although it might need a new chain as well?
Could keep an eye on eBay etc for a 52 outer ring, some people do downgrade to a compact.
I think there’s very few 53/39’s sold these days?
Thinking about it, a 53/36 might also leave a lot of slack chain when on the smallest gear, depending on how much spring there is on the rear mech?
I told him to go 52/36 when he got it !
He’s a lunatic descender, says he could do with a 54/55 as he spins out at 40 mph down hill … duck that !
It’s just the inner he wants changing.
Yeah, don’t see the point in taking risks on a descent, you aren’t going to gain that much on a descent in this country.
I’d probably give it a go, worse case is poor shifting and you’ll find out before race day hopefully!
He’s going bigger rear block
28 to 32 should see him spinning a bit more freely.
I assume he’s ridden the course, and based his decision on that? (the desire for a smaller granny ring that is). Would he really be spinning out on a 52/12? Surely getting into a tuck would be preferable.
Please don’t flame me 
Flame the leader / icon/ lunchtime legend…?!
I wouldn’t dare.
It’s a standing joke that he runs Grahams tours and has shown 5? Maybe more athletes a guided tour of the new loop.
Some were even Southerners?!
He’s on 53/11 and doesn’t want to go any lower top gear wise, he really does pedal in all but the steepest parts, we’ve had the tucking up discussion.
Just trying to make his cadence a bit higher on the uphills
I’ve got 53/36 on my TT bike and it shifts fine. You just swap the inner ring and I think I picked one up for about £20
A 55/39 is awful.
It “works” but the chain slaps like f!!!
I’ve put my 55/42 on now.
The 50/34 is just too small for round here.
52/34 might work, if you’ve the newer type.
But I’ve got the old five bolt type 53/39 and 55/42, then a newer four bolt type 52/36.
I’m going with 50/34 12-28 for Bolton (short cage rear)
I’m going with 50/34 11/30.
( Shimano tt bike )
30 will help on the last lap.
My etap 52/34 is on a roadie, sram red 11/28 works perfect.
He’s gone for a bigger rear block, 28 to 32 rear should see him spinning a bit easier he’s going to keep his inner 39 ring.
I would have thought a bigger cassette would be of more help.
32 is a monster!
Do you think?
I’ve only got a short cage rear mech, so am limited there, but happy to buy a medium cage from eBay.
Or not too much difference for me?
I’ve got a 12-28, which was fine at Helvellyn, but that only has one hill.
You must have an idea what you need; apparently you’ve done the Bolton loop 5 times now #absledge
Three 
But not really.
All efforts were easy-ish.
Just thinking of that last lap, really.
Personally I’d just ride it with an 53/39 and 11/28 and be done with it.
That’s what I’ll ride at Wales.
But! I’ve never ridden the roads or climbs up there. I’m firmly in chocolate teapot territory