Had to take a picture
 

For reference, the crank set on the bike has 4 chain rings and there are no modifications to the FD - just adjustments.

I have the FD set so I can drop the chain down on the smallest chain ring when I am in a low gear on the cassette.

In the past Ive tried to get to the largest chain ring, but have never been moving fast enough to have the chain in a real high gear and there wasnt enough throw in the FD to overcome the chainline to get to the big chain ring.

Well I was cruising down a long hill in the country today and spun out in the highest gear I had around 25mph. Thats normally faster than I care to go anyway, but since I was there and still descending I thought I would go for the big chain ring.

It went!

So I kept on keepin' on.

Never done that in the 4-5 years Ive had the 4th chain ring.

To test it I repeated the shifting. It takes a bit of push on the the shifter past its furthest at rest point and there is some hesitation in the chain going up, but if Im in the lowest cog on the cassette I can reliably shift up every time.

Cool beans! Learned something new today.


https://cimg6.ibsrv.net/gimg/bikefor...049247d28a.jpg

Pretty cool. I rather wish Shimano would make something like a 50-35-20 for touring, might even obviate the need for 11-tooth cassette cog which I find is a bit noisy.

To ensure this is said as well - the bike is a pretty much stock complete Surly Disk Trucker, 2014 model year. The Bottom Bracket, however, is NOT stock. It is a Phil Wood that is several mm wider than the original.

The 4th chain ring is on a Mountain Tamer Triple adapter - essentially an adapter that lets you put a cassette cog on the crank. I think the one that is on there now is about 20t. I had a 17t on there originally, however it was stupid low. Ive managed to flip backwards climbing a hill with rear panniers and no front panniers with the ~20t ring so I dont think there is any merit to getting any more torque to the rear wheel anyhow.

With the stock bottom bracket you are supposed to use spacers on the drive side to push the whole mess out a few mm. I did that for a while but wasnt happy with it so I upgraded the bb to a wider one that put the chain rings at the position I wanted with a symmetrical alignment of tje crank arms on the centerline of the bike (not offset to one side as the original spacer set up was when the Mountain Tamer Triple first went on).

As mentioned in my first post - there are 0 mods to the FD. Only adjustments including the stop screw to widen the throw.

I've got one of those mountain tamer adapters on a triple crank that's in my spare parts bin.

Cheers

cool & I like that co2 holder!

I tried a Mountain Tamer several years ago, do not recall why I quit using it, but it is in a parts bin somewhere. I do not recall which sprocket I put on it.

Avid made a similar adapter, that used a smaller chainring, not a freewheel sprocket, I have one of those somewhere in a bin too. If I recall correctly, the smallest you could put on the Avid adapter was a 20T.

After I bought my Rohloff bike, I decided to use that for my super low gearing trips. My derailleur touring bikes have 24T granny gears which is low enough for me for lighter weight touring. If I anticipate super steep hills, I use the Rohloff bike instead.

Bontrager Air Rush Road. I think they have changed designs a bit over the years, but it is a combo hand pump/CO2 inflator like the one below:
https://www.americancycleandfitness....d-154654-1.htm

I've never used the CO2's.

In fact, I've only had 1 flat on a ride in 6 years.

I did learn that the pump housings screw together and if they are not tight/seated you can't build any noteworthy pressure. Of course, that knowledge was gained after sitting on the side of the trail for about 30 minutes trying to get it to work... Now I know. The pump is actually a pretty decent pump for being a compact bike mounted one, though it is a small/low volume pump. You can still get up to 60PSI or so without much trouble. I never put a gauge on it, but it wasn't "low" after I fixed it.

What cassette do you have paired with that quad?

Off the top of my head I don't know. Checked the specs on that MY bike and its a 9 speed 11-32. I would assume that is accurate. Shimano HG-50. 700c wheels with 38mm tires.

I think the small chain ring is a 20t. I will have to check later - its still in the back of my truck at the moment. I did have a 17t on there until last Fall, but it was ridiculously low.

Stock 3x rings are 26, 36, and 48t.

The 64/104 bcd should work? 22 ( 32/34/36) and a 46/48.

Sure, there are MTB/trekking cranksets like that which give a pretty wide range but generally to get the nice low gear one ends up with a top gear where one will quickly spin out on big descents, esp with 559 or 584 wheels. I'm not trying to set speed records but on a long descent it can be nice to pedal at a moderate cadence, if only to keep the blood circulating.

The small ring is 20t. So take that for what it's worth. I haven't run the gear calculations in a few years and, unfortunately, the folder I had that in as well as all my other riding related data was lost a while back. I could set up a gear-inch calculation spreadsheet again but don't have the gumption to tackle it at the moment.

I do know the 17t ring was too small and I can still flip the bike backwards on a steep hill with the 20t so that is all I need to know at the moment. If I run out of steam climbing in the lowest gear with the 20t then I'll be walking anyway, I'd just be pedaling faster and going slower with the 17t - not making any headway on time.


https://cimg7.ibsrv.net/gimg/bikefor...8a0e35d7d9.jpg