Sharpshin

That's the plan.

Currently I'm running a 44-32-22 crankset on an 11-34 8-speed cassette. Good for 17 gear inches.

Yet, in NY there were a number of hills that whupped me.

Worse, from what I have read the UK/Ireland abounds in 10-20% grades.

I have a 9 speed 12-36 cassette on hand, and a 20 tooth granny inbound.

IF I can operate a nine speed cassette off of my ol' downtube friction shifters I'm looking at 15 gear inches

I'm not sure anyone pedals up 20% grades but I do believe with 15 gear inches, I coulda not walked at all in NY State.

Mike

Darth Lefty 

48 links wrap... better avoid small/small

nfmisso

Is there a question in there somewhere?

Another option is to rebuild the 12-36 9 speed into a 8 speed using the spacers from the 11-34 - you'd have to figure out which cog to lose. The sprockets are only 0.02mm difference in thickness, but the spacers have a 0.44mm difference Sheldon Brown's Bicycle Glossary Sp - Ss

And addition to the above option is a Miche 1st position cog, with 11T to 16T (out of stock at Niagara, but here is a 15T Miche Shimano 15t First Position Cog, 8/9-Speed ) to get more reasonable jumps. I suggest a 14T 1st position, remove the 12 and 14 from the 12-36, change the spacers to 8 speed, and you have a 14-36 8 speed.

12 - 14 - 16 - 18 - 21 - 24 - 28 - 32 - 36

becomes

14 - 16 - 18 - 21 - 24 - 28 - 32 - 36

McBTC

A 1:1 (a little over 26") is about as low a gear as most would ever need on a road bike. There could be some use for a lower gear on an offroad bike but 15 inches... at 90 rpm that would be a lot of furious effort for just ~4 mph.

CliffordK

Why not just go all the way and get 7.5 gear inches... just in case you need to do a greater than a 30% slope.


I guess I'm a bit old-school, when 42-23 was considered "relaxed" gearing.

Most of the steep sections I've found > 15% tend to be quite short, although I did find a hill, Greenhill, here in Eugene that was a bit challenging. I'll have to head back there and try it while "fresh".

But, choose the gearing that works for your riding style. Personally I mash, and pull up. Cleats are toeclips are necessary for my style. But, other riders are different.

One problem with hills is the slower you go, the more time you spend on the hill

I do go 30/30 on my cargo bike, and am looking for a bit lower gearing for those extra heavy loads

gracehowler

Another thing that should be considered is the length of the cranks, is it possible that you have an unusually short crankset? R

GeoKrpan

I'm not sure I would notice the difference between 17 and 15 gear inches.

robow

I've always said you can't go too low on your touring bike's gearing.........and yet you're about to prove me wrong.

CliffordK

A lot will depend on the bike weight, rider weight, and gear weight. Trailer? Miles per day? Age?

In the winter, I tend to have more problems with traction than anything else once I hit about 16%. But, I'm also limited somewhat on the distance I can climb steep slopes.

The jump from 34T to 36T is about a 6% change.

What is your crankset BCD for 22T? 4 bolt or 5 bolt? If you're running 58 BCD, 4 or 5 bolt, then you should be able to get down to 20T, or a 10% difference, and enough that it should be noticeable.

With the Mountain Tamer, you might be able to drop a little further down.
Mountain Tamer Chainring Adapters, Gorilla Brake Beefers, Gorilla Headlocks and more

Advantages?
There have been a few places where I thought that if I could get my gearing right on my cargo bike, it would be a better gear ratio to keep pedalling than to walk and push. But, I also wondered if I needed outriggers.

bikemig 

That's simply not true for a loaded touring bike for many tourists. There are a lot of threads on that topic and there is no consensus that a 26 inch gear is all that is needed. A lot of tourists prefer to have a low gear to spin up a long climb with rather than walk. This is a topic that has been frequently discussed and more than few experienced tourists will disagree with you.


I did a cross country tour when I was pretty fit a few years back. At the time I was doing all the local training races. I had around a 26 inch low gear and I did not think it was low enough for that trip. I sure as heck wouldn't use that high a gear again since I like my knees just fine.

Sharpshin

Holy smoke! What a great idea, thanks Saves me the hassle of buying a nine speed chain just to test a concept.

On my '89 Voyageur the chainstay geometry is too tight to allow access to the smallest cog so its been functionally a seven speed for some time. And of course in real life a seven speed is really a nine speed, with a granny to fall back on at the low end and a big chainring I almost never need at the other.

I have read on this site about guys preferring eight speeds on touring bikes on account of the more widely-spaced gears allow for more positive shifts, makes sense to be and that was a real concern with my friction shifters.

Now on to see if my original derailleurs will handle a 36 tooth cog and a 20 tooth granny. Might have to switch 'em out.

Mike

Sharpshin

There's a thought. I replaced the original before my TX-NY trip with a Nashbar 44-32-22 Mt. Bike crankset (a tremendous value w/ the 170mm cranks which I believe were similar to the originals.

Mike

Sharpshin

I only did one tour so far, 2,000 miles in 30 days of riding, TX - NY....

But this is what I discovered.

There is absolutely no reason to suffer on these things, if you're straining and getting tired you're doing it wrong.

Rt 303 in Cuyahoga National Park OH were the first hills that whupped me, the previous 1,300 miles or so from San Antonio having been no problem, 17 gear inches comfortably had it covered despite the 40lbs of gear I was packing.

To put things in context, if I walked a total of half a mile out of that 2,000 that was a lot, but there were more occasions where I wasn't having a whole lot of fun. And on a 70 mile plus day, mashing ain't fun.

Having the option of spinning along at 3-4mph wouldn't trouble me a bit, those hills I could effortlessly spin up on my 22-tooth granny were enjoyable. I would study the flowers as I crawled past, listen to the bird songs, even looked at the bugs I passed crawling on the pavement (two degrees in Entomology here Yo ).

Mike

chasm54

People do indeed pedal up 20% inclines, but even in Britain they aren't that common, and if you're a tourist they're easily avoided for the most part. Personally I think a 15 inch gear is extreme, though, I'd rather be out of the saddle and labouring a little than giving my imitation of a hamster.

PhilPub

Seems a bit extreme to me. Yes, depending on where you go over here there can be many short, sharp inclines, but if you struggle that much on hills surely it's best just to plan to avoid them? Or just steer clear of Cornwall, the Lake District, and the hillier parts of Yorkshire.

staehpj1

Different strokes. A 15" gear seems pretty extreme to me.

bradtx

Mike, I like Nigel's (post 3) gearing suggestion. You will have reasonably close gear inches in the middle of the rear cassette and there is the possibility that with the 14T top gear, you'll possibly clear the chain/chain stay interference (If I read that correctly.).

Brad

Tourist in MSN

My expedition bike with Rohloff has a 16.5 gear inch low gear with a Schwalbe 559X57 Marathon Extreme tire, 16 tooth rear sprocket and 36 tooth chainring.

I wanted gearing that would be 3.5 mph with a cadence of 72 for my lowest gear, I calculated that I need the 36 tooth chainring based on that goal for cadence and speed. It is too hard to stay upright if I go slower than 3.5 mph (5.63 km/hour), so that is how I selected my desired speed for my lowest gear and if my cadence falls below 72, my pedaling is not as smooth.

I have spun out a few times on gravel with this setup. With that low a gear I have a lot of torque on the rear wheel and when you spin out (lose traction), you come to a halt extremely fast.

rifraf

According to Sheldon Browns Gear Calculator:

Sheldon Brown's Bicycle Gear Calculator

I'm running my Rohloff at approx 16.2 to 85.2gi, with 622 rims and a crank ring of 34.
When my 16T chain ring wears out, I'll be replacing it with a 17T which will lower me down to 15.3 to 80.2.

Thats if I can wait that long as I struggle on some of the hills locally when I'm loaded up.

This is still within warranty spec for an under 100kg rider with a max low ratio of 1.9 which is equivalent to
32:17, 30:16, 28:15 and 26:13 teeth

Sprocket ratios: www.rohloff.de

I like to keep my cadence in the low 90's rpm wise where possible.
I'm happy to coast down hills but prefer to ride up them rather than walk if I'm able.

I'm not a strong rider and my knees are starting to demonstrate the years of abuse I've offered them.
I'm looking forward to adding that extra tooth at the rear.

I never use the top couple of gears in my hub.

I think you'll enjoy the 15 gear inches and will have no difficulty remaining upright if you can spin in the high 80's rpm for the duration of any hill..

My bike is a steel framed 29er Mountain bike of I think 16kg without the panniers.
Maybe a little lighter without the Berthoud fenders which I've just taken off in anticipation of some off road touring.

Sharpshin

If the tour goes as planned I'll be hitting the Lake District, the Cairngorms, Ben Nevis AND Snowdonia, and if I tarry in the pubs of Ireland I'll have to skip Normandy and do Cornwall instead

If I do 2,000 miles, and 1/2 of 1% of that is spent on the granny, that translates to 10 miles. What possibly do I stand to lose by having 15 gear inches available if'n I need it? Heck, I'm not even using all the cogs on the high gear end of the cassette anyhow.

And the whole point is to NOT have to struggle on a hill.

YMMV,
Mike

McBTC

Sure, I agree but when talking about what 'most would ever need,' I was one of the few over the years that rode nothing but triples so most road bikers had nothing close to a 1:1 and for tourists on road bikes, Trek's venerable 520 pretty much sets the standard in my view as far as what 'most would need' when touring. Standard equipment on a new 520 is a 48/36/26 triple teamed up with an 11-32 cluster --e.g., a low of 21.43 gear inches yielding a speed of 5.10 mph at 80 rpm. And, that's with 25c tires; OEM tires on the 520 is 32c which raises the gear inches to ~22.

bikemig 

Yeah, I agree that 15 inches is lower than most will ever need and it may be counterproductive. A 26-27 inch is probably not high enough for most for loaded touring assuming a traditional touring load; here is where lightweight touring will have an impact on gearing selection. I think the trek 520 is a good benchmark as well and that puts you in the low 20s.

Tourist in MSN

Rohloff is switching to a splined sprocket system, you might want to wait a few more months if you want to make that switch.

McBTC

I pedaled up this once on a 2005 Trek Pilot 5.0 with a bigger than OEM rear cluster. My thought is that going slow with a racing heart rate probably isn't the best exercise plan of attack -- more like a heart attack.

Sharpshin

Color me a tad confused.

On the linked video we see a guy riding with 7.5 gear inches. OK, staying upright would be harder on a loaded bike.

But.... 15 gear inches would be twice as fast as that guy is moving, have you never been reduced to that speed (twice as fast as the vid) climbing an incline on a loaded bike?

If you have, why on earth would you grind if you don't have to?

Mike