OK, so the gearing doesn’t need to be exact, but i’d ideally like a 40-42 front ring and i don’t want the smaller to be more than say a 28-30.

This is for the road based event in Belgium that i’m likely giving WAY too much thought to but with a couple of the hills, along with some of the flat speed, i’m not sure i have the gearing in the spares box that’s appropriate.

I’ve got for example at home for Zwift rides a 42T that goes on the outside of the spider but won’t allow me to use the largest cogs on the rear due to chainline, which is fine for Zwifting, i don’t need them gears, but outside I’m thinking of things like the Kemmelberg which is an average of 12% and a max of 22%, but more 13% than 22 that’s for sure… I’m thinking even on a 42T/36 i couldn’t get up that.

So i’ve got plenty of variations in rings etc, but not convinced i have an appropriate compromise for both the climbs and the flats…I’ve got a FSA/GPX crank double which is a 36/24 which would be find for the climby bits but may be a bit lacking in top end (unless using a very high cadence) especially if there’s a bunch and some drafting going on in Belgium.

The rest of my rings are NW type, so i could go a 38T/24 but the 38t being an NW may not shift down using the front mech ?

https://www.chainreactioncycles.com/shimano-deore-m6000-10-speed-double-chainset/rp-prod161594

Shimano Deore M6000 10 Speed Double Chainset which is 38.28 which may be the ideal compromise. But i’m also wondering if just running a single ring setup i should just go for a SunRace MX3 10 Speed Shimano which comes in a 11/40 or 11/42 which I should get away with with a long cage mech i have… I’ve got a 38t NW if i went down that route (which works on the back of the spider for a better chainline.

Thoughts, even if “WTF” appreciated. I may be missing something obvious in crank options, but MTBs seem a bit low, roads seem too high.

Its belgium, the hills are very short and very steep, like the chilterns, but with more flat bits. I think if you try and climb in 26-whatever you’ll just be going backwards.

I think we’re about the same level of fitness based on the few times we’ve met and the lowest gear on my cx bike is 36-36 and I dont think ive ever used it. My SSCX is 39-18, just down from 39-16, and even with the 16 I could climb Hattonhill singletrack between pangbourne and gorring which is about as horrible as climbs get on the singlespeed.

Are you using the parkwood or the cx bike? The parkwood probably wont fit a road chainset as the q factor is too narrow, and a 42t chainring probably wont clear the chainstay in the middle position.

Also 26-42 is a mahoosive jump, with a triple mech even shift that far, bear in mind they swing up each shift as well as out so each shift will be limited to about 50-66% of the total capacity. A double might not reach down to a 26. And would the chain be able to reach the shifting ramps?

Youre over thinking it, build up the bike as you plan to ride it, and get some real world miles in. If after doing some long road rides arround the thames valley and chilterns you still think you need such a low gear, fit a tripple which will have 24/34/44 or there abouts.

What about the new Shimano GRX? https://www.chainreactioncycles.com/shimano-grx-600-2×10-speed-chainset/rp-prod189195 gives you 46/30T

I’ve not done much in Belgium but I have done the Kemmelberg and compared to the climbs here in the Dales it’s not that bad, as TINAS says, short(ish) and steep, hell, it’s not even as bad as the lane from our house.

Are you using the parkwood or the cx bike?

Parkwood with fast CX rubber and carbon forks.

Standard MTB tripple is the answer then.

Although I’d put money on the granny not being the quickest way up the hills if its got at least a 11-36 cassette.

I’ll have a look in the shed, im sure ive got several sets of tripple chainrings, shifters and cranks going spare you can borrow.

I’ve not done much in Belgium but I have done the Kemmelberg and compared to the climbs here in the Dales it’s not that bad, as TINAS says, short(ish) and steep, hell, it’s not even as bad as the lane from our house

I guess that’s the issue, i see “Max 23%” and think “sheesh, that’s horrific” but the reality may be very very different. I’m struggling to find anything to compare it to locally though. I think the closest is Streatley Hill which has some 23-24% bits in and averages 13%
https://www.strava.com/segments/729782

Now back on rides i’ve got up that on a 36/36 (may have been a 34/36) so i’m thinking “Is there any reason i can’t do the Kemmelberg on a 38/40 or even a 38/42

Standard MTB tripple is the answer then.

Although I’d put money on the granny not being the quickest way up the hills if its got at least a 11-36 cassette.

I’ll have a look in the shed, im sure ive got several sets of tripple chainrings, shifters and cranks going spare you can borrow.

That’s very kind.. 🙂

maybe that double above from CRC then is the easiest answer as i’ve got a 2X shifter that came with the Parkwood when i bought it… That’s a 38/28 ring which if i can’t get up it on a 28/36 then the odds are, i’m not getting up it anyhow 🙂

Thanks for the thoughts all. I’ve jumped on this for now

https://www.ebay.co.uk/itm/Sunrace-CSMX3-10-Speed-Cassette-11-42-tooth-322-17/283618179001?hash=item4208f5f7b9:g:5hAAAOSwU1tdgkDU

Will see if i can get it to work on my mech etc for a start point and see what it’s like for climbing… It’s cheap enough that even if it doesn’t work out i can flog it for what i’ve paid, so worth the try.

I’d be surprised if you need a gear lower than 1:1

I’d be more worried about too low a too gear making the rest of the ride a bit of a chore.

I’d be more worried about too low a too gear making the rest of the ride a bit of a chore

I think a 38/11 should be fine at that, I’m only seeing our realistic flat speed averaging 27-28kph, possibly 29 if in a group with some stronger guys.
We’re not looking for pro levels of speed by a long long way, just 2 average guys out having a jolly

👍

When the gears are working on my fatbike (yeah, both my bikes have issues at the mo, I think I simply need a new rear mech rd-m310 for the Wazoo which are ~£13 on Amazon), the default 24/38 chainrings and an 11-30 cassette will get me up anything, regardless of how long/hard a ride I’ve done (or simply visited the local “wall” on the way home from work).

On an average day, I’m happy to climb Dell Rd https://www.strava.com/segments/19974352 on the fatbike in something like 24/23, but sometimes I’ll choose to spin up there while seated using 24/26 or even 24/30.

You may have suitable climbs to test your gearing choices for Belgium closer to home, but besides the above in Midanbury SO18 (along with a handful of other short inclines that hit approx 8-15%), other I’m aware of and sometimes tackle are…
Speltham Hill in Hambledon https://www.strava.com/segments/3557886 (the middle bit is way steeper than the ~12% IMO)
Lynch Lane in West Meon https://www.strava.com/segments/1417580 (short and steep, with option to carry on up Old Winchester Hill after a very brief gradient respite)
Upland Lane in Hawkley https://www.strava.com/segments/20828567 (top bit of a cat4 climb)
Hawkley Rd in Hawkley https://www.strava.com/segments/20828499 (the steep bit is at the sharp hairpin)
Windmill Copse in Hawkley https://www.strava.com/segments/7239131 (nasty climb with worse bit near start)
Turkey Island (Hill Lane) in South Harting https://www.strava.com/segments/3105043
Harting Hill B2141 https://www.strava.com/segments/7373817
B2146 in South Harting https://www.strava.com/segments/2724911
Milland Hill in Rake https://www.strava.com/segments/629672 (supposedly ~25% near summit, yet to visit)
West Marden https://www.strava.com/segments/2413253

They’re a bit of a way to cycle to from Bitterne, but I love heading out to Hawkley and South Harting for the hill climbing challenges.

@weeksy I used a sram X9 mtb crankset with 22/38 on my Raleigh winter bike/Audax/bikepacking/trailer tug bike with an 11-28 cassette. All on rival 22. Worked fine.
Now replaced with a rotor 3d+ with 25/40 purely because I liked it more aesthetically.
If the hills are short but steep then charge them rather than twiddle.
That set up hasn’t failed to get me up a climb yet.