Need a lower gear

[teskow]

The last block to my home is quite steep and could use a lower gearing. I have a RC with a 52 tooth chain ring. I rarely use or need 9th gear so could I swap some of that high end gearing for more power in gear #1?.
My question is, has anybody changed to a lesser tooth chainring to accomplish this? How many less toothed chainring would bring it down like about one gear or so? How many teeth less could can I go down with out having to shorten the chain?

 

[Sierratim]

What is the tooth count for your cassette's smallest and largest cogs?

 

[teskow]

12 &32.

 

[Sierratim]

Dropping your chainring tooth count would help, and get you into the 12t cog more often. My concern would be the 32t cassette cog, it's on the smallish side to help with climbing for just about any practical chain ring you'd want.

You might want to also consider a different cassette. To get better climbing than the 12-32t you'd need to go with something like a 11-42t or 11-50t. ModernBIKE.com has an 11-42t for $30.

Of course, going with an 11-42t cassette justs compounds the issue of not using the smallest cog now. I suspect you're going to need to need to go with a smaller chain ring as well so that should avoid this problem. What chain ring? Sheldon Brown's GEAR CALCULATOR can shed some light on this. Input your small & large cassette cogs, chain ring, preferred cadence, and some bike specifics and see what impact this has on your speed. Lower speeds = less effort of course.

There's also Grin Tech's MOTOR SIMULATOR that models the performance of various motors with variables for route slope, total weight, rider power contribution, etc. Lots of variables, but gearing is a complicated issue.

You mentioned chain length. Good point. It's hard to say if you'll need to make a change. Part of it is knowing how close your current chain is to the 'correct length' and the rest is your choice of final gearing. This PARK TOOL article and video is one of many free tutorials they offer, this one focuses on getting your chain length correct. Frankly, it is likely you'll need to make a change to be sure you can climb that last block home.

Hope this helps.

 

[Bruce Arnold]

There have been posts on the forum from people who switched to a 42T chainring. Maybe the search function would turn some of them up. But if your only question is, can it be done, then the answer is Yes.

 

[Ant~Phan]

There have been posts on the forum from people who switched to a 42T chainring. Maybe the search function would turn some of them up. But if your only question is, can it be done, then the answer is Yes.

teskow: I too have battled with this (and up many a slope ). Considerations as noted above, including chain length but also the size of the rear derailleur cage. Fortunately, that fitted as standard is the longest at some +3" and allows up to 45T rear sprocket (that said I have read of others that have pushed it to 50T with little more trouble than installing a longer B-Screw that wot adjusts the gap between the top jockey wheel and the largest sprocket).

When I have to replace the cassette and chain wheel I will probably go for 50 or 45T chain wheel and 11-45T cassette.

I tried to 'attach; a home brewed MS EXCEL spreadsheet that may have been of use but it seems that one cannot do that through this forum's web site; so I 'attach a PDF snap shot of the sheet just F Y I?