Gravel bike gearing

Talk about anything.

Moderators: Bearbonesnorm, Taylor, Chew

User avatar
ScotRoutes
Posts: 5782
Joined: Mon Mar 18, 2013 9:56 am
Location: Cairngorms
Contact:

Re: Gravel bike gearing

Post by ScotRoutes » Tue Nov 06, 2018 12:40 am

Image

Forsinard?

User avatar
BigdummySteve
Posts: 2156
Joined: Sun Nov 20, 2016 9:16 pm
Location: Oxfordshire

Re: Gravel bike gearing

Post by BigdummySteve » Tue Nov 06, 2018 8:45 am

Sheldon brown’s gear calculator may be of use, you can add a cassette then multiple chainrings to compare.
I changed my sunrace 11-46 to a sram 10-42, using the calculator I needed to drop to a 28 from a 32 to regain the low end.

https://www.sheldonbrown.com/gear-calc.html
:-bd

Retiredtester
Posts: 241
Joined: Sun Mar 18, 2018 10:23 am
Location: Sussex

Re: Gravel bike gearing

Post by Retiredtester » Tue Nov 06, 2018 1:20 pm

I've got a sram 1x11 set up with 50t front and 10-42 cassette on 700c wheels. Seems spot on for my mixture of on and off road commuting and the occasional road tour.

User avatar
Bearbonesnorm
Posts: 18345
Joined: Sun Jun 05, 2011 8:53 pm
Location: my own little world

Re: Gravel bike gearing

Post by Bearbonesnorm » Tue Nov 06, 2018 2:37 pm

Reading through all the replies, I think the governing factor is where you ride. I tend to view my 'gravel' bike as a lightweight mountain bike rather than a more robust, heavy duty road bike. I also tend to think that 'gravel' is about exploring and firmly believe that the bike shouldn't become the limiting factor in that pursuit :wink:
#corporate shill for hire

User avatar
PaulB2
Posts: 852
Joined: Fri Mar 10, 2017 8:32 pm
Location: Stafford

Re: Gravel bike gearing

Post by PaulB2 » Tue Nov 06, 2018 3:26 pm

Bearbonesnorm wrote:Reading through all the replies, I think the governing factor is where you ride. I tend to view my 'gravel' bike as a lightweight mountain bike rather than a more robust, heavy duty road bike. I also tend to think that 'gravel' is about exploring and firmly believe that the bike shouldn't become the limiting factor in that pursuit :wink:
The industry seems to be determined to see them the other way round though with gearing that's aimed at the road (or fitter riders to be fair). My gravel bike has quickly become my bike for 90% of my riding I could just do with a lower bottom end for off-road and/or loaded climbing.

User avatar
Bearbonesnorm
Posts: 18345
Joined: Sun Jun 05, 2011 8:53 pm
Location: my own little world

Re: Gravel bike gearing

Post by Bearbonesnorm » Tue Nov 06, 2018 3:44 pm

The industry seems to be determined to see them the other way round though with gearing that's aimed at the road
Yes, that's largely true although some manufacturers do seem to be getting 'better' with the specs. I wonder whether they believe that the market is made up from roadies migrating rather than mountain bikers?
#corporate shill for hire

User avatar
gairym
Posts: 2723
Joined: Tue Jan 10, 2012 11:05 am
Location: Chamonix, France (but a Yorkshire lad).

Re: Gravel bike gearing

Post by gairym » Tue Nov 06, 2018 6:44 pm

Bearbonesnorm wrote:I think the governing factor is where you ride. I tend to view my 'gravel' bike as a lightweight mountain bike rather than a more robust, heavy duty road bike.
Totally agree, the slant on the target terrain depends on which company is pushing which agenda in which day.

Both (Road and MTB) camps seem to have claimed ownership of the genre (at least while it's popular).

Asposium
Posts: 1312
Joined: Fri Jul 01, 2016 5:39 pm
Location: Hull

Re: Gravel bike gearing

Post by Asposium » Tue Nov 06, 2018 6:49 pm

I’m building a second gravel bike; frameset ordered today.

Going to more geared towards off-road (that and a town bike), so 1x chainset; the spec isn’t helped by Shimano having a different pull ratio between road and mountain along with there not being a gravel group set (yet). Shimano really needs to get its finger out.

Going to use XT gearing and Ultegra shifters in Di2 to get round the pull ratio problem.
Do like how with Di2 both shifters mapped to be up and down, could be handy for when cycling one handed or if a crash were to damage a shifter.

New XTR cranks with the spider look interesting; however, the price is shocking, and seemingly not compatible with 11s

User avatar
Mariner
Posts: 1522
Joined: Fri Feb 06, 2015 2:37 pm
Location: East Devon

Re: Gravel bike gearing

Post by Mariner » Tue Nov 06, 2018 6:58 pm

Slightly OT but when is it expedient to changes the front rings rather than the cassette because to be honest I have no idea how to optimise a gear train?
Never seen this before and looks like a good way to spend a wet stormy evening.
http://www.gear-calculator.com/

I have always used Sheldon Brown before but this looks better and it has Sunrace already in it.

Asposium
Posts: 1312
Joined: Fri Jul 01, 2016 5:39 pm
Location: Hull

Re: Gravel bike gearing

Post by Asposium » Tue Nov 06, 2018 7:18 pm

Mariner wrote:Slightly OT but when is it expedient to changes the front rings rather than the cassette because to be honest I have no idea how to optimise a gear train?
Never seen this before and looks like a good way to spend a wet stormy evening.
http://www.gear-calculator.com/

I have always used Sheldon Brown before but this looks better and it has Sunrace already in it.
Slightly?

User avatar
whitestone
Posts: 5829
Joined: Thu Dec 04, 2014 10:20 am
Location: Skipton(ish)
Contact:

Re: Gravel bike gearing

Post by whitestone » Tue Nov 06, 2018 7:46 pm

Mariner wrote:Slightly OT but when is it expedient to changes the front rings rather than the cassette because to be honest I have no idea how to optimise a gear train?
Never seen this before and looks like a good way to spend a wet stormy evening.
http://www.gear-calculator.com/

I have always used Sheldon Brown before but this looks better and it has Sunrace already in it.
That's my go-to gear calculator.

When to change chainrings? When you start to get chain suck - basically the chainring or rings hold on to the chain for longer than it/they should. So instead of the chain leaving the chainring at 6 o'clock the chainring holds on to it until it leaves at 7 o'clock or thereabouts. https://www.youtube.com/watch?v=LlZ1zvVVgcE Generally I'll get two, possibly three cassettes to a chain and two chains to a chainring.
Better weight than wisdom, a traveller cannot carry

User avatar
Mariner
Posts: 1522
Joined: Fri Feb 06, 2015 2:37 pm
Location: East Devon

Re: Gravel bike gearing

Post by Mariner » Tue Nov 06, 2018 10:17 pm

Badly worded question so try again which may or may not be slightly OT.
My first choice to optimise a gear train is the cassette.
Would it be better to change the chain rings on my gravel bike?

User avatar
whitestone
Posts: 5829
Joined: Thu Dec 04, 2014 10:20 am
Location: Skipton(ish)
Contact:

Re: Gravel bike gearing

Post by whitestone » Tue Nov 06, 2018 10:33 pm

My mistake :oops:

Basically, have a guess at what you think will work, whether that's a 2x or 1x drivetrain and see how it goes during your usual rides. Most of your riding should be in the middle of the cassette with little use of the smallest and largest cogs. If you find you are using the largest cog (i.e. lowest gear) a lot then you can either fit a smaller chainring or fit a cassette with a larger cog. Which you do depends on whether you use the other extreme very much or not.

Fitting a different sized chainring shifts the whole effective range of your gears up or down so you might gain at the lower end but lose at the upper end or vice versa. Changing the cassette usually gives you a bigger range but in the case of wide range cassettes intended for 1x drivetrains the gaps between each ratio get bigger.

Alongside all of this are the derailleurs themselves: they have stated capacities so you can't go outside these without getting shifting problems. Rear derailleurs might have a larger capacity when used in a 1x system for example.

Post sleeping on it edit: Here's an example. My hardtail is 1x10, originally I had a 30T front ring with 11-40T which I found tough to begin with here in the Dales. Over the course of a year I got stronger and replaced it with a 32T chainring. That setup is fine for general riding but if the bike is loaded up for a bikepacking trip I'll drop back to the 30T to give me a bit more at the bottom end.
Better weight than wisdom, a traveller cannot carry

JoseMcTavish
Posts: 149
Joined: Wed Oct 18, 2017 7:08 pm
Contact:

Re: Gravel bike gearing

Post by JoseMcTavish » Wed Nov 07, 2018 1:31 pm

ScotRoutes wrote:Forsinard?
Sure is - was my April executive bivy spot. I went for a mix of mountain and road Di2 to get my 1x setup. I don't think a clutch mech is a necessity if you have a narrow wide up front, so a cheaper alternative might be to use 10 speed road shifters with a 9 speed mountain mech and wide range Sunrace MX3 10 speed cassette. I think that would work...

ianpv
Posts: 147
Joined: Mon Apr 27, 2015 4:23 pm

Re: Gravel bike gearing

Post by ianpv » Wed Nov 07, 2018 1:37 pm

On my Arkose, I've got an MTB triple with 24/38 rings, an 11-32 11 speed cassette, and 105 shifters and mechs. Worked fine for loaded riding around the uk, TNR and in a couple of cross races, but may be a little undergeared with road tyres on in fast group rides (but probably fine for most winter riding...)

User avatar
ZeroDarkBivi
Posts: 1252
Joined: Fri Jun 27, 2014 9:18 am
Location: Somerset

Re: Gravel bike gearing

Post by ZeroDarkBivi » Fri Nov 09, 2018 1:17 pm

Read all about it - gravel bike wins XC MTB race (on buff trails):

https://www.velonews.com/2018/11/news/t ... ike_481072

Not strictly about gearing, although it is mentioned.

Love my Open U.P.

Asposium
Posts: 1312
Joined: Fri Jul 01, 2016 5:39 pm
Location: Hull

Re: Gravel bike gearing

Post by Asposium » Fri Nov 09, 2018 4:06 pm

my gravel bike reminds me what mountain biking was like when i want much younger.

on that rigid bike it was about picking lines and riding with trail sense.
many of these enduro bikes are merely blast down the middle and let the suspension do the work.

so, in some respects the gravel bikes are merely filling a void that has opened as mountain bikes progressed upwards in terms of suspension travel.

User avatar
BigdummySteve
Posts: 2156
Joined: Sun Nov 20, 2016 9:16 pm
Location: Oxfordshire

Re: Gravel bike gearing

Post by BigdummySteve » Fri Nov 09, 2018 8:49 pm

Asposium wrote:my gravel bike reminds me what mountain biking was like when i want much younger.
Definitely simpler times, being older than God (according to my Son) my first MTB was a Diamond Back Assent. No suspension,vee brakes and panracer smokes/darts. We used to run 1.9s in the back to cut through the Kent chalk slime and MASSIVE tyres of up to 2.1” in the front!
How we scoffed when trek came out with the ‘Y’ bike, a richer friend bought one, we thought it climbed crap and flexed a lot, suspension no thanks!
A while ago I went out in a little bimble with pickers, as my charger setup was out of action I ran my spare wheel set with WTB 2.1 Nano’s, although the conditions were much wetter than expected with a bit of care grip was found, admittedly I had to work and look for it, but it was FUN. As an added bonus my Fargo felt like it had a turbocharger on it when on the harder ground.
I wish I’d taken this wheelset on The SDW, conditions were dry and most of the trails didn’t warrant 2.4” rubber.
:-bd
:-bd

dnrc
Posts: 25
Joined: Thu May 18, 2017 11:08 pm

Re: Gravel bike gearing

Post by dnrc » Sun Nov 11, 2018 3:35 pm

when i built up my latest bike (a CDF TI) which is my main bike used for road and cross country general riding and also bikepacking I needed lower gears as my last bikepacking trip with a 50/34 compact really stressed my knee and resulted in too much pushing

I wanted to otherwise keep my 2x setup so I read all about sub-compact etc but availability was an issue, then i came across the modular option for the chainset:

So I got a Middleburn R02 crank and one of the 94bcd spiders and went 40/30 up front

Then swapped out the cassette for an 11-30 and job done (my DA 7900 RD just about shifts this ok)

Maybe worth a look, they have all sorts of spiders from full size down to the incy spider which takes a 58bcd inner ring

https://www.mountainbikecomponents.co.u ... urn/cranks

User avatar
Mike
Posts: 2802
Joined: Thu Jun 21, 2012 9:36 am

Re: Gravel bike gearing

Post by Mike » Sun Nov 11, 2018 5:22 pm

9spd mtb set up with 11 32 cass and iv changed the 42 for a 48. Gets me up those big hills and its fast on the roads :0)

User avatar
ZeroDarkBivi
Posts: 1252
Joined: Fri Jun 27, 2014 9:18 am
Location: Somerset

Re: Gravel bike gearing

Post by ZeroDarkBivi » Mon Nov 12, 2018 12:16 am

BigdummySteve wrote:
Asposium wrote:my gravel bike reminds me what mountain biking was like when i want much younger.
Definitely simpler times, being older than God (according to my Son) my first MTB was a Diamond Back Assent. No suspension,vee brakes and panracer smokes/darts. We used to run 1.9s in the back to cut through the Kent chalk slime and MASSIVE tyres of up to 2.1” in the front!
Makes me laugh how the modern 'gravel bike' is just a drop bar version of the early MTBs that we all rode 30 years ago. Nostalgia must be the biggest force in flogging recycled ideas to old folk with money burning a hole in their pocket :lol:

I do like my Open UP, but do not consider it to be a MTB, just a road bike that is capable of tackling unpaved roads or easy trails. For proper mountain single track, I am very glad for the modern evolution of the MTB.

HUX
Posts: 346
Joined: Mon Jan 16, 2012 6:51 pm

Re: Gravel bike gearing

Post by HUX » Mon Nov 12, 2018 3:42 pm

Currently 1x11 36T up front and 11-42 out the back. Feels just about right for when it's hilly and loaded up with enough for some speed on the flat. Kept the 40T it came with that I'll switch for flatter road tours.

Post Reply