Lower Gear Options

For discussions about bikes and equipment.
Graham O
Posts: 641
Joined: 27 Jan 2007, 7:54am

Lower Gear Options

Postby Graham O » 22 Jun 2020, 9:24pm

I have a cyclo cross bike with the following spec:
Shimano 105 11 speed shifters
Chainrings 46 - 36 bcd 110mm
Sprocket 11-32

While this was okay for the riding I used to do in the UK, it is overgeared for the terrain now that we have moved to Portugal. There are many more gravel trails here, but they can be pretty steep in places and the tarmac road climbs can be very long. I'm not too worried about top speed and the current 112" top gear is more than I normally use. I'd like to get the lowest gear from 31" down to around 22" which my touring bike has. In essence, I'm after a lightweight hill climbing bike.

The problem is that I'd like to make the change without spending too much money and I'm wondering what is the best route? The smallest chainring on 110bcd is a 32 tooth so not much to gain from that. Perhaps changing the whole chainring set will give me lower gears. Alternatively a longer rear mech and a 42 tooth big sprocket? Will the shifters allow this amount of cable pull?

Am I right in thinking that road and MTB Shimano components cannot be mixed?

Or sell the bike and build one from scratch?

Thanks for any help.

Posts: 42978
Joined: 4 Jan 2012, 6:25pm

Re: Lower Gear Options

Postby Brucey » 22 Jun 2020, 9:29pm

two main options;

1) use a GRX rear mech and suitable cassette with much larger sprockets on it.

2) use a supercompact chainset with smaller chainrings.

Or do both.


Graham O
Posts: 641
Joined: 27 Jan 2007, 7:54am

Re: Lower Gear Options

Postby Graham O » 22 Jun 2020, 9:57pm

Thank you Brucey. With the move out here, I've not thought much about cycling tech, just riding and I'd forgotten about a super compact chainset. Spa have a 42/26 which will certainly do the job.