My MTB isn't geared that low. :twitchy:

Wow! Them's some low gears! At some point the bike will just fall over, eh?

I am running a triple with a low of 30 and a 13-30 cassette (9 speed). I have knee issues and this gearing allows me to keep a nice cadence on all but the really steep stuff. I spin out at about 32 mph on the descents but it's not a concern.

5 years ago I was a mountain biker. Good bikes and low gears in 44/32/22 and 11/32 9 speed gears. I did a few road rides and on the steep hills I used that low gear in places. Not the ideal bike for road with front suspension and 22lbs weight so had to get the bike up slopes aswell. First road bike and a sensible Giant OCR3 with 52/42/30 and 12/26 8 Speed. Still had to find the lowest gear uphills but 22/32 is a lot lower than 30/26. Both bikes got up the hills with the difference being that the road bike was faster. Next road bike and a compact 50/34 and 12/27. Those hills that were hard on the OCR were still hard with the compact but NO harder. The bike may have been lighter and a good few grades higher in quality but it still had to be pedaled up the hills.

For me that 34/27 has been fine but after a winters layoff- the hills have got longer and now have steep bits in them. I have lost a lot of fitness and although it will improve- I am now looking to just make things a bit easier.

BUT there is a problem with going to the wider range cassettes with lower gears and that is the distance between the ratios. On the 12/27 I have on the compact the spacing between the lowest 3 gears is a 3t difference. This is compared to 1 or 2t on the higher gears. To keep cadence right- I use the gears a lot and up to the 21t is fine. Then the jump is to 24 and 27. Breaks the rhythm somewhat but if I need those gears I need them and they are there to be used. Just face it-long hill with steepness built into it and I will only use one gear. This is why I got a triple fitted to the hill bike- so I can use a 12/25 cassette- still get gears low enough and not have that jump in ratios.

But it is when I get back to the mountains that I will have a problem. For those I like a 1 to 1 ratio on gearing and used 28/28 with the triple on the OCR. However one of our prominent "Mountain" climbers in jppe had fitted a compact 50/34 along with an 11/34 cassette. It meant changing rear derailleur to a long reach version but as he found out- that 1 to 1 ratio works.

But this post started about my mate Mike. 34/25 was his lowest gear and even for me when I am fit- that gear is too tall for our hills. New cassette was needed and looking around- the lowest gear we found that would not need a rear derailleur change would be an 11/28. Once that was fitted for last Sundays ride he can climb hills and still do distance and more hills.There is a compromise in that the spacing between some of the gears is a bit high but he needs that lower gear.

Moppeddler, Welcome to BF and 50+, stick around. Here is a link explaining gearing, gears, derraileurs, chains, etc., from Sheldon Brown. Bookmark his homepage and use the information as you need.
http://sheldonbrown.com/gearing/index.html

Bill

I must be seeing a different thread than you. Looks to me that most of the people responding to this thread have at least a workable understanding of gearing and shifting.

Your sensitivity to cadence and also wanting to spread out the range in the back to get lower climbing gear is the same problem many of us face with selecting gearing. For me it boiled down to how my body has changed and realizing I no longer (if ever) fall into the center of the bell curve where bike manufactures like to design bikes.

It wasn’t until I bought a touring bike with a triple and started thinking about adding a lot of weight on the bike and trying to climb hills that I began to see I had to somehow like a wider space between gears to get the spread I needed. I messed around making changes front and back and as I ride the bike for other uses besides touring I didn’t like the mountain gearing many put on these bikes as it was way too low for road riding and had my favorite gears split between the center and large rings.

What I ended up with was treating the two large chain rings like a road double 52, 42 the back I setup like a mountain bike with a 12-36 9 speed. That filled in the bigger steps on the center ring with half step gears on the large ring when I need them. Gave me two nice tall road gears above what the center could get and gave a purpose to the rest of the gears as not being duplication (half step). I slowly kept going lower and lower on the granny and found I could go all the way down to a 24t without issues. When loaded with touring gear I can use the 18 gear inch lowest gear but what I found is I love having a range of low gears not just that one bailout gear. I have 6 gears to select off that 24t ranging from 35 GI to 18 GI and on a long rolling climb it’s nice to drop down to that granny and select the right cog to suit the climb and do it spinning not mashing. I personally would just as soon stay in the saddle keep the cadence up and if I have to sacrifice some speed.

Like I said I think a lot of this is assessing where your strengths are and working within them. It’s not about impressing anyone with what gearing your bike has. I get around the comments by saying oh this is my touring bike that’s why I have such crazy small chain ring and such a big wide cassette.

You mentioned your 1 to 1 gear and I hadn’t thought much about where that is on my bike so I took a look out of curiosity and there it is right in the middle of my granny range. In my case its 24/24 and also my normal starting gear when dropping down on the granny. In my case I have 3 steps lower and 3 higher I can safely bounce around on without fear of cross chaining.

What's not in your legs needs to be in your gears.

Your signature says it all.

I have a 175 crank and it makes it a little easier for me to climb a hill than if I had a 172.5 crank. I have a 11-28 cassette. I don't miss the 16 tooth sprocket because I am comfortable with a cadence between 90 and 120. On big hills it may drop to 60.

When I got back into biking and bought the tour bike so much was new with bike repair from my days as a kid when a flat blade screwdriver and an adjustable wrench was all you needed to build a bike. Things like adjusting STI shifters had me a little worried. I wanted to drop the granny from 30t to 26t and went to the LBS to get it done and they wanted $50 including the ring. I figured for 50 bucks I should at least get some free advice from the guy doing the work as I watched. I was asking lots of questions about gear theory and getting no answers just some annoyed looks. When he got the new chain ring on and handed me the old one as a souvenir I got the only free advice I have to date from my LBS. I thought it was good enough advice to quote him in my signature.


I bought every tool I needed from then on and figured out how to do the work myself. In most cases the cost of the tool was less than the labor to have someone use it once. There is a big advantage to being able to do it yourself if you want to experiment.

I am running a 12-32 cassette with my Ultegra derailluer and it works fine. With a 50-34 compact up front this is still within the take-up rating of the derailluer, even if the 32T cog is four teeth bigger than the 28T max tooth rating. Only change was to lengthen my chain a couple links.

Did you run a longer chain than with the 11-28? I am thinking ahead for the Ride the Rockies. I am not a Mountain Goat like jppe; so, I may do better with a 32 sprocket. I think I can make it with 28, but I may get less fatigued with a 32. My bicycle is the same model as yours but a year older. I did upgrade to Di2. I really like the 11-28; so I may take an extra wheel with a Tiagra 12-32 with me.

I did not need a longer chain going from 11-28 to 12-30, but 12-32 might be a different story. I have no idea whether the Di2 derailleur would work with either the 12-30 or 12-32.

I don't think Di2 will work with a 30 cassette. I haven't tried it but I think 28 is the limit.

I think 28 was also the reported limit for the Ultegra 6700 rear derailleur, but BluesDawg found otherwise. The Tiagra cassettes are relatively inexpensive; so, I could experiment.

If it works, let me know.

One word of warning.

When I set up the OCR for Ventoux I had a short reach Tiagra Derailleur fitted and 52/42/28 as the rings. Set up the chain for correct length for 52/30 and that was fine. But when I tried to get 28/30 I had a Rattly noise. It was the derailleur cog hitting the 30t ring. No problem-I had a 26 I could fit on the crank and I could go 11/28. Did that and I still had the same problem. Had to run 28/28 and it ran very close to touching again. used that so watch out for the derailler touching the cassette if you are running a short reach derailleur.

That gearing got me up the hill but at one point I did want just one more gear.

Did you try adjusting the B screw on the rear derailleur to move the roller away from the cog?

My thinking on gearing. I have bad riding technique. I don't pedal if I have a 15 to 20 mph descent speed so I don't worry about spinning my top gear out. I have never had a bike with a gear so low that I could spin it out going up a hill.

I have a 12 28 on the rear and a 38 42 on the front. So far these gears are working well for my riding style. I could probably just ditch the 42 tooth gear but it is there to prevent cross chaining.

I have one bike with a 28 28 and I still don't spin it out going up the hills that I ride. It would be interesting if there is a gear that I would spin out. I might spin out a 20 up front and a 34 in the rear.

My hill riding is limited to maybe a max of 10% grade and that grade would only be for a few feet along the total climb.

The hill that I spend almost all of my time on is .4 mile long with a total rise of 60 feet. My down hill coasting speed is around 28 mph and my normal climb speed is around 5 mph. On a day when I am felling good I can push over the top maintaining around 7 mph and I can also crest the hill at 10 mph spinning like a maniac. So this old engine is not very powerful, overheats and blows oil but it is all fun. But like I said if I tried spinning at 10 mph all the way up the hill I would blow up and not come close to maintaining that speed.

yep--That is why mid to long reech derailleurs are made. I could have got it to work by taking one more link out of the chain- but 52/30 would not have been possible and with a fast descent- that would have been foolhardy.

52/30 = big/big = severe cross-chaining = don't do it.

I always set the chain to be able to Take Large/ Large--- in case brain fade comes in and I use it--Or attempt to use it.

Perhaps this is the place to get an answer to a question that has been bugging me. I have no idea how to determine the % grade of a given hill. I don't have GPS and topo maps don't really help me. So I tried Map My Ride and the values they show for a given hill seem really low. For instance a hill around here that is known (by local long time cyclists....the guys who truly are into the sport) as a 6% hill show up on Map My Ride as barely over 2%. I have no idea how to get an accurate measurement.

FWIW....I use a 39x25 for the start of hills and on the worst of them I'm usually in the 5-6 mph range.