QX100 - Adding front chain ring - from 2 to 3. What's needed?

[Scott]

I am planning on starting to bike backing on my Q.

I was wondering about getting some additional lower gear range.

My bike came with a 3 gear shifter for the front derailleur.

What would it take to add an additional smaller chainring?

Does anyone have any experience of how many teeth to go down to?

Open to any wisdom the group can share!

Thank you,

Scott

 

[Frito Bandito]

If I am not mistaken, you would need to buy a 3 ring crankset as I dont think you can simply buy a smaller chainring to install on a 2 ring. You might be able to just buy 2 smaller rings than your current set and replace those to help you on the climbing parts of the ride. Keep in mind chain length though. I am not sure how much you can reduce the chainring sizes before you have to also remove links. At least removing them is cheaper than adding them though.

 

[Doug Burton]

The direct ancestor of the QX100, Quest 1.0 was delivered with a 3-chainring crank. If you were tall enough where the chainstay angle didn't become too open when setting your x-seam, this worked fine. Judging by your profile picture, you should be fine where you have the front tube currently adjusted.

The Bandito is correct above; you'll need a triple crank, chainring bolts for the third chainring, and maybe a triple front derailleur (cage is a little different, but in practice this doesn't seem to matter). I would start with the chain the same length and adjust its length if you can't take up the difference by adjusting the B-tension screw on the lower derailleur.

I would recommend a 30-tooth chainring. Very common value for road triples, and should be within the chainring difference capability of the lower derailleur.

Tinker proudly!

Good luck,

Doug

 

[benphyr]

Agreed with both.

You probably already tested this out but if not, test out how slowly you can ride with your current setup in 1st gear transitioning from unloaded to loaded, flat to uphill, smooth to bumpy/loose, and dry to wet - any conditions you expect to encounter. The more you ride slowly the better your balance and application of power will get and the slower you can go reliably. That might help guide what size to use.

I find that for me I can’t t really push the lower limits of the stock gearing before I struggle with balance. (My typical rides are relatively unloaded, paved, and relatively level and I am light at 62kg=136lbs so I don’t often see the conditions you may encounter.)

 

[Doug Burton]

This was my Quest 1.0 when I was doing drivetrain research. I used a 54-44-24 triple with an 11-25 cassette to help figure out what I wanted.

Didn't work very well; I was always shifting the front derailleur. But the drivetrain will take a lot of variations and still work.

I had to use a special derailleur hanger (-5 degree offset) to get the effective chainstay angle right so the chain wouldn't drag the derailleur in the small chainring. Unfortunately, these hangers are made of the purest unobtainium these days.

I ended up with a 50/34 double with an 11-34 cassette. II found a nifty carbon crankset that Performance was dumping for $70 at the time. This setup works well for me.

So go ahead and try some stuff out. You get get exactly what you want if you do a little tinkering.