Hi I'm trying to setup a bike that will run 1x, is 42T front 11-34 rear 26er, a good setup? I will mostly bike in the city, with occasional steep roads.
9speed, Deore XT Rd M750.
by baldokosmic
Hi I'm trying to setup a bike that will run 1x, is 42T front 11-34 rear 26er, a good setup? I will mostly bike in the city, with occasional steep roads.
9speed, Deore XT Rd M750.
by baldokosmic
18 Comments
why would you be doomed? 42-34 is a little hard for steep roads but if it’s short city streets it’s fine
If you happen to feel doomed, install a smaller chairing.
It should be fine for everyday use. For the steep roads maybe 38/40 on the biggest cog would be a good idea.
I’ve had 11-42 with 40t on my gravel for a while and I could do most of the hills nearby, except a few in the woods that are over 35°
Is there anything preventing you from putting two chain rings on there? You could always change the chain manually if you have an “emergency” hill or something.
What do you call steep?
42-34 is about
150W @60rpm on 5% – 200W @60rpm on 7.5% – 250W @60rpm on 10%
Grossly calculated for 85 kg system weight and 30W rolling resistance, add about 2.5W/kg on 8.5% grade
Even the short cage M750 has 33T of capacity, so if you’re really feeling ‘doomed’ just buy a [Roadlink](https://www.wolftoothcomponents.com/collections/derailleurlinks/products/roadlink) and a bigger cassette.
There are online calculators where you can compare 1x to 2x gear ratios. Or just use the math you learned in physics class.
You’ll be fine unless you live in a very hilly or mountainous place.
I used to ride a MTB back in the day with a single 46 up front and 11-36 out back. Could make it up most local hills just fine on the road, some were a bit of a struggle, but then I do live in the Cotswolds. Road to the local MTB spot was a bit of a pig, 15% avg gradient, 20% at it’s steepest. I could climb it on the bike, but often chose not to as was knackered by the time I got to the fun MTB bit.
~10 years ago, everyone was riding around on fixed gear bikes with 46/12 gearing. You’ll be fine.
Depends what kind of steep
Not sure what doomed means, but you’ll have from 31 to 95 gear inches on hand, fine for commuting about a city.
https://preview.redd.it/ao1x5swbv1cf1.jpeg?width=981&format=pjpg&auto=webp&s=9ebd9b6dcc5a677fcd0993479e8cc3bcbf54ce79
My childhood tenspeed was 52/42 x 14-28. I think you’ll live.
You’ll be fine. That’s something like a 38×32 on a 29er, totally find for street use.
Just slow
I run a 42T 11-32 on my CX bikes. It’s fine on the low end for short climbs. I wouldn’t want to do a longer climb with that gearing.
There are a lot of 11-40t cassettes now in various speeds. Many offroad derailleurs can handle that easily.
Sunrace makes some cheap one to try it out. CSM990 Quality is actually pretty good, I run their 8s on a 1500W Ebike.
The M750 should be a Rapid Rise derailleur. Nice for urban riding. A matching 9s RR shifter is a rare part. It can downshift when stopped, or not pedaling. The shift will happen next time you pedal. Twist shifters are non existent for that.
A longer B screw (3mm) should get that to work. Ask at MTBR those guys have been running setups like that forever. B screw keeps the guide pulley off of the large cog
The ratings for that derailleur reflects what was offered back in the 3×9 days, In 1x you can get a bit more out of them.
Chain length may need a little adjustment too.
Upgrade path-I’m running a Zee M640 FR derailleur with an SS cage and 11s 11-40t cassette. SRAM NX twist shifter. SS cage keeps the derailleur up off the curbs on 26″. 42t on the front. No plastic parts on the Zee.
No, seems like a reasonable set up unless it’s super hilly