Lower gearing on my Merida 29er

jj93

On my Merida 29er is a Shimano HG200-9 11-34 freewheel coupled with a Shimano M4000 octa 40-30-22 CG (BSA) chainwheel.

My regular ride on a Sunday morning is just under 40 miles, on and off road. I hardly get onto the highest gear on the chain wheel, apart from 1 long downhill on the way home.

There are some fairly tough (for me) uphills during the route but one in particular at the end I just can't manage. Always have to get off and walk/push the last 50 meters.

I'd like to get some lower gearing at the expense of the higher gears I don't use, but still keep an eye on the finances.

A friend accompanied me recently (he's much fitter / younger / keener) and was riding a fantastic Trek with 1 x 10 gearing. He went up the last hill with ease, as expected. I grabbed his bike and had a go and got up the hill for the first time. Hard, but got there.

Based on the gearing mentioned above, can anybody advise please?

Thanks.

EDIT... just to add his bike is a 27.5.

robertpb

It's unlikely that his gearing is any lower than yours and his lowest gear is probably higher.

The only way is to get fitter and love the hills.

PhilipPirrip

Ask your friend what gear ratios he has on his bike so you have an idea what gears you're wanting to achieve.

The Shimano HG200-9 appears to be a cassette (of sprockets) rather than a freewheel but a quick look shows that you're limited in how much lower you can go with that chainset and 9 speed set up, 11-36 appearing to be widest range cassette available, so you could be looking at a sizeable upgrade for that small gain.

fenix

40 miles is a fair old distance if its on and off road. I'm sure your bike has a lower gear than his - but riding other peoples bikes are always better.

billycool

My HT is 3x9 and runs 11-34 with 22/32/44.
My FS is 1x11 with 11-42 and 34T up front.

My HT has far more hill climbing gears than my FS. In my 22T granny ring, it will winch up most hills. My FS can't.

My bike is 26" and yours is 29" but I'd be surprised if 1x10 had better gearing for hill climbing than 3x9. I know a 29" takes more effort to get going but I don't know enough about it all to really comnent on the differing wheel sizes.

I'm sure Steve Sordy or someone else can come along and enlighten us about gear ratios.

steve_sordy

I'm going to ignore the impact of wheel diameter as I can't be sure he doesn't have a 26er also, but if it is at least a 27.5. This will worsen his gearing by 27.5/26 = 1.058, ie his gears are 5.8% harder up hills, whatever he does; double that if he has a 29er. I will also ignore the better rolling capability of larger wheels. It is a benefit, but small.

Your best hill climbing gear is the 22t on the front and the 34t on the back, which is 22/34 = 0.647

If your mate's 1x10 is a 34T on the front and an 11-42 on the back, his best climbing gear is 34/42 = 0.809

That is a lot (25%) worse than yours!

So what could he have?

Maybe he has a 32T on the front and up to a 42T on the back, ie 32/42 = 0.762. So he is still worse than you!

Even if he had a 30T on the front and a cassette with a massive 46T on the back, 30/46 = 0.652, he is still 1% wore than you! And that is ignoring the wheel diameter effect, worse if he has a 29er.

So I suspect the reason for his bike being faster for you uphill than your bike is not the gearing. So what else could it be? How about these?

Your bike is heavier.
You have more knobbly tyres.
You have softer compound tyres.
Your tyre pressure is lower.
Your brakes are dragging (do the wheels run and run after a hand spin, or do they stop quite quickly>)
The bottom bracket is knackered and dragging (do the cranks run well after a hand spin?)

Did your mate ride your bike up the hill? If so what did he say. He may have been too polite to say anything if he thought there was something wrong with it, so ask him!

Edit: I've just thought of another important potential reason why you are faster uphill on his bike than yours, despite the gearing being worse, or at least no better. His bike is better set up for you than your bike is for you. Your saddle may be too low, or too far forward, all sorts of stuff. follow the link below for how to set up an mtb:

https://www.bikeradar.com/gear/article/ ... fit-29498/

jj93

Thanks chaps. You've got me wondering. I will have access to his bike later this week so I'll have a suss of his gearing. It will be interesting to measure how far his bike travels for 1 full pedal rotation compared to mine in the lowest gear. One thing I did notice immediately was just how light his bike is. It's a full suspension with a dropper seat added and it's still way lighter than my hardtail. I did also notice that his granny gear is massive. He lives in a town in the Alps and uses it for some serious hill climbing. While he's over here for work he's brought it with him but he's going back for a few weeks and leaving it here so I'll get a good chance to do some comparisons.

steve_sordy

jj93 wrote:

Thanks chaps. You've got me wondering. I will have access to his bike later this week so I'll have a suss of his gearing. It will be interesting to measure how far his bike travels for 1 full pedal rotation compared to mine in the lowest gear. One thing I did notice immediately was just how light his bike is. It's a full suspension with a dropper seat added and it's still way lighter than my hardtail. I did also notice that his granny gear is massive. He lives in a town in the Alps and uses it for some serious hill climbing. While he's over here for work he's brought it with him but he's going back for a few weeks and leaving it here so I'll get a good chance to do some comparisons.

When you say "granny gear" can we be more specific? The context of your post implies the "granny gear" is the largest gear on the cassette. I have always firmly believed that the granny gear was the smallest gear of the three on the front. Then as 2x and then 1x took over it was a term I heard less and less, which made sense. I guess once 1x is everywhere, the term "granny gear" may switch to the largest ring at the back. Or has it always been that one and it's me that has been wrong all this time (much more than ten years)?

Anyone know for sure?

mrbigbiker

A quick google suggests 'granny ring' and 'granny gear' both refer to the smallest chainring

Killerclown

Try an 11-36 cassette to start. The 2 extra teeth on the largest sprocket will almost certainly feel better.

billycool

You may have partly answered your own question.

If your bike is that `heavy` it can take far more effort to get up steep climbs. I once tried a friends DH bike at Cannock Chase - it was great fun going down but at 15.5kg, it was a b!tch pedalling up anything. My FS is 13kg and fairly light and climbs almost as well as my HT.

Gearing may also be part of it but as Steve says, you *should* have better gearing. Sounds like your mate may have Alps orientated gearing so perhaps he has something hill friendly.

As for `granny` ring. In the days of 3x9, the granny ring was the smallest ring at the front - it maximises your hill climbing 'cos even your Granny could get up a hill in that gear. Obviously the smallest cog at the back is the highest gear so that doesn't ring true, it would have to be the biggest sprocket. We always called it `largest` and `smallest` cog at the back so we knew what we were talking about. 1x gearing may have changed that.

Would be interesting to know that gearing set-up your friend has on their bike.

jj93

OK, just checked. He's got a 28 on the front and the largest on the back is a 44. The wheels are 27.5.

PhilipPirrip

jj93 wrote:

OK, just checked. He's got a 28 on the front and the largest on the back is a 44. The wheels are 27.5.

He appears to have the edge on you with lowest gear but, as has been said, it's only one factor.

jj93

PhilipPirrip wrote:

jj93 wrote:

OK, just checked. He's got a 28 on the front and the largest on the back is a 44. The wheels are 27.5.

He appears to have the edge on you with lowest gear but, as has been said, it's only one factor.

Yep. He's also got a smaller wheel with 215cm circ. Mine is 230cm circ. Small difference but it will add to the equation.

Strangely, his tyres are only pumped up soft. (my 29ers are rock hard). This will reduce his diameter and therefore his circumference a little as well which will help his hill climbing, but hold him back a bit on the road. Again, a small difference, but these differences are adding up.

And his bike is so much lighter than mine.

At the end of the day, I just want to get that gearing down a little on my bike. I will look at ways to reduce the weight a bit (I'm already working on my own body weight!!!!.... sober October has seen 1/2 a stone vanish for a start, and a dry Nov and Dec will help as well). I do have a pannier on the back (I hate rucksacks) and tend to pack the kitchen sink for my rides (just in case) so that's going in the bin.

But... the lower gearing is a must. How am I going to achieve that? Will there be an 'off the shelf' smaller gearing I can fit to the front?

jj93

Out of interest, what do you pump up to for a mix of trail and road?

robertpb

The granny ring is as small as it's going to get, see if you can find a cassette that goes to 36, but that is it.

As for psi I run 20-22 front and 23-25 back on 2.4 tyres, but then I only weigh 60kg.

jj93

Thanks for the advice so far.

If I wanted to fit this....

... https://www.bike-discount.de/en/buy/sunrace-mx8-11-speed-cassette-11-46-535478...

.... would it fit? Apart from an 11 speed derailer and chain, is that it? Would my chainwheel be ok with the thinner chain?

jj93

Got a bundle of bits ordered. Will see how they perform and report back.

jj93

Update on this.... I've now fitted a 9-46 in place of the 9-34 with a goat link added to the rear derailer and I've got the low end difference I was looking for. Had the first test ride today and went up the killer hill no problem (still hard but made it). The only change now is to change the 3 speed chainwheel to a 2 speed. Currently fitted is a Shimano M4000 octa 40-30-22 CG. I'd like to get a 32-22 double to replace it. With the bigger freewheel on the rear I cant use the high gear on the front now due to chain length (hardly ever used it anyway), but I would get away with a 32 in place of the 30. I'll then be maxed out in terms of high and low end gearing.

So, the problem now is that I've no idea what spec the new chainwheel needs to be or what to look for apart from 22-32. Can anybody advise what will fit please?

Thanks.

The Rookie

11-46 is into 1x territory, I'm running an 11-40 as 1x on my 29" FS with no issues at all.

As your keeping the front mech and shifter and cable, I don't really see the point in going from 3x to 2X? That said, the easiest way is to just dump the big ring and use either shorter bolts on a metal bash ring in place of the big ring.

Your chainrings are 96mm BCD so you can get a 32 or 34T to replace your 30T although 96 is rarer than 104.
Techdocs
https://si.shimano.com/pdfs/ev/EV-FC-M4000-3659.pdf

JBA

A Shimano SLX 11-speed double would be a good choice.

Which shifters have you got on the bike?
If they are Deore or above the front shifter has a selector switch that changes between 2- or 3-speed.

The Rookie

JBA wrote:

If they are Deore or above the front shifter has a selector switch that changes between 2- or 3-speed.

Not on 9-speed, not that it matters you just limit the mech using the stops, when I did it I set it so the granny was under the second detent so I couldn't overload the cable and risk putting it out of adjustment.

jj93

Thanks for the techdocs. Very handy. You're also right about 11-46, not 9-46 as I wrote. I've had no luck finding the 32T in a 96mm so I'm just sticking with what I've got now. I've got the large ring locked out on the front derailer. I've not looked close enough to see if I can just unbolt the 40T and lose it.

jj93

Sorry, didn't realise there were more posts.

They're Alivio shifters.

N0bodyOfTheGoat

I've been aware of the thread for a while, but only just got around to reading it...

22/30/40 chainrings with an 11-34 cassette ought to get you up pretty much anything and now you've replaced the cassette with an 11-46, you've got something close to 14.0-106.3 gear inches range according to https://www.sheldonbrown.com/gear-calc.html ! :eek:

Like "The Rookie," I don't see the point in locking out use of the 40T chainring on the triple crankset, surely you will want that for at least downhill sections to actively pedal down gradients up to ~7%?

From the info I've read, my hunch is either the tyres are poor for the hill and/or the tyre pressure is horribly wrong.

When I use my 29x2.35" G One Speeds on the Voodoo, I inflate them to ~35/45PSI (front/rear) for tarmac and ~5PSI lower for dry, mixed terrain. Total weight of me plus bike would be ~93/94Kg. With the 24/38 chainrings and 11-30 cassette, the top part of https://www.strava.com/segments/2558982 is very doable on a bad day using 24/30. The only times I've had to put a foot down and then had fun trying to get going again was before it was re-surfaced a few months ago, as the old tarmac was littered in mini potholes; leaf mulch in winter; soil/mud from the workmen and their tools that were there for months; moss growth in the tarmac etc.

On the rare occasion I fit the fat rear wheel with a 26x4 Jumbo Jim, I do appreciate the 11-34 cassette's easiest gear, if I'm going up a boggy incline.