I dont get single chain ring gearing

I dont get single chain ring gearing

Author
Discussion

hantsxlg

Original Poster:

866 posts

238 months

Wednesday 27th May 2020
quotequote all
Hi All
I'm a bit out of touch with mtb tech and confused by the recent trend to single chain ring set ups. I grew up on triple rings and 7 speed cassettes. This used to give close to 1-1 in granny gear (32 ring and 28 or 30 biggest on the back) and 4-1 for top gear (48 and 12).

With single ring set up seem to get way lower gears. 32t ring with 42 biggest cassette and 11 smallest, so about 3-1 top gear.

Doesn't this mean you will run out of gears at about 20 mph? Or do 29er wheels make up for this???

ukbabz

1,589 posts

132 months

Wednesday 27th May 2020
quotequote all
That's one thing that's frustrated me most with the switch to single speed - most bikes seem to come with a 30T (or maybe the odd 32T if you're lucky). Mine came with a 30t and 10-50. 30-10 did limit top end pace somewhat but I managed to switch up to a 34t but I can't get more than that without touching the chainstays.

Even 2x setups don't seem to go very high on MTB's either, I wonder if it's part of the reason that gravel bikes are rising in popularity

Bacon Is Proof

5,740 posts

237 months

Wednesday 27th May 2020
quotequote all
I've gone from 3x9 to 1x11 and yes I do run out of gears and miss the evenly spaced ratios and nice chainline..
1x is necessary to free up bar space so you can be sold a £300 seatpost, I've embraced it!

chris7676

2,685 posts

226 months

Wednesday 27th May 2020
quotequote all
Erm... on my fast road bike - single chain ring is the best modification I have ever done to anything with the wheels.

I'm running 36-11 (11 speed) and 46 chainring it's great both in terms of range of gears and closeness of ratios.

(And 42-11 is almost 4 to 1 but there you would have the gaps you don't get with 36-11).

Edited by chris7676 on Wednesday 27th May 10:27

Simes205

4,618 posts

234 months

Wednesday 27th May 2020
quotequote all
I’ve gone from 3x to a GX 1x12 about 18 months ago.
One less cable, one less thing to clank around.
I thought it wouldn’t work but it’s fab. I don’t miss the overlap.
I love it, I get the granny gear and the top end gets me up to a decent speed. yesterday. Even passed a couple of roadies.
Yes, I’ve a dropper too!

Edited by Simes205 on Wednesday 27th May 10:46

lufbramatt

5,421 posts

140 months

Wednesday 27th May 2020
quotequote all
1 x 12 speed cassettes are more like 10-50 tooth which gives a decent range of gears.

When I replaced all the worn out gears my old 26" MTB with a 2x setup for commuting, it took me a while to find a chainset with suitable sized rings, luckily I found an SLX one on a German site. The smaller rings needed for bigger wheels don't work on a 26" bike, wheel size makes quite a bit of difference to the gear ratios (it's like the final drive ratio on a car).

PomBstard

7,048 posts

248 months

Wednesday 27th May 2020
quotequote all
I switched my old 26er from 2x10 to 1x11 a few years ago - used a 36T chainring for that one. When I bought my 29er last year I specced an 11-46 cassette and 32T chainring. Can get up most things, and have just about enough speed for firetrails, although often run out of top end on the road going to/from the off-road bits. Don't have use for 30T around here.

Chainrings don't cost much and only take a few mins to change, so its worth have a few and experimenting what works for you. Also some bike now don't have the capability of running anything other than 1x

stargazer30

1,637 posts

172 months

Wednesday 27th May 2020
quotequote all
Well I recently got back into biking too.

Bought a cheap GT Aggressor XC3 which is a classic style 3x8 on 26" wheels. The missus then took that one and I bought a new GT Avalanche which is a 1x11 on 29" wheels.

The 1x11 has a 30T front ring and I'd say it pretty much has the same gear range as my old aggressor without using the large front ring (never did anyway), just the granny and middle rings. Its certainly fast enough for my needs for light trail use, paths and occasional minor roads. Max speed spinning in its stiffest gear would be about 25mph.

I prefer the single speed, the bike is about 1kg lighter too, some of that due to not needing a front mech and extra cogs.

hantsxlg

Original Poster:

866 posts

238 months

Wednesday 27th May 2020
quotequote all
Thanks for replies... seems my thoughts match up to others experience. My main mtb trails here have a fair bit of fire trail and no uber steep/ long up hills and plenty of road to link them up. I'd say I spend 80% of time on big ring with my current 2x11 sram 9 setup on my 26" boardman pro xc. So I'd need a 38 or so front ring with a 10-40 cassette or stick with 2x

Justin S

3,656 posts

267 months

Wednesday 27th May 2020
quotequote all
Glad for my 2 x 10 on my Cannondale Jekyll when in Spain. Others with 1 X were struggling both on the climbs and with speed on descents. Probably as not as much an issue on 'most' UK riding though.
For XC riding, my Cannondale 29er has a triple. Mainly because I changed the Sram for XT groupset and , although I dont use the granny that much, some climbs 'can' be ridden by sensible spinning that knee graunching, yet I also have decent top end pace. Comfortable towpaths can be covered at 17 mph without much effort . Decent byways at well over 30mph without running out of legs.
The wifes new bike is a 1 X 10 but electric. Must admit I dont miss her rubbish gear choice and the chain chewing the front mech anymore !

Court_S

13,821 posts

183 months

Wednesday 27th May 2020
quotequote all
Single rings are ace in my opinion but I was trying to run 1x9 yonks ago which was a pain with the chain device and limited gearing. I’m still on 1x11 but it works (don’t ride much fire road so it’s not an issue).

gazza285

10,098 posts

214 months

Wednesday 27th May 2020
quotequote all
We only discussed this the other week.

https://www.pistonheads.com/gassing/topic.asp?h=0&...

milu

2,413 posts

272 months

Wednesday 27th May 2020
quotequote all
I've got 1x11 on both Mtb and gravel. Really like it. Nice easy riding,less to adjust etc.
Works well on the road on the gravel bike