Triple crankset on QX100

[DavidJL]

Has anyone ever put a triple crankset on the QX100? When I went with a 12-21 cassette, I realized 34-21 is a bit too high for the lowest gear. I like having close-spaced gears, but maybe I should just put the original cassette and have wider spacing. I am thinking the innermost ring of a triple will not clear the BB pivot.

 

[MrSteve]

Has anyone ever put a triple crankset on the QX100? When I went with a 12-21 cassette, I realized 34-21 is a bit too high for the lowest gear. I like having close-spaced gears, but maybe I should just put the original cassette and have wider spacing. I am thinking the innermost ring of a triple will not clear the BB pivot.

My old Sofrider probably has the same bottom bracket shell that the QX100 uses... and it's been wearing a Bontrager triple for years.
With the original 11-34 cassette, the ultra mega-low low-low gear gets my tired-out bod home after a long day of sprinting up hills.
There's plenty of room for the classic triple (with internal bearings and ISIS splined cranks), especially compared with modern systems that use outboard bearings.

 

[Doug Burton]

I tried the 12-21 cassette on my Quest 1.0 - which in all important ways is identical to the QX100. Found that for me, I spent all my time shifting. Went back to the wider ratio cassette.

I was using a 24-42-54 triple I built especially for this application, and I used an old SunTour derailleur that had a very long cage.

The key to running a triple (it clears the BB shell just fine) is the length of your legs. If the adjustable front tube needs to be short, the chainstay angle will be wide. Triple front derailleurs are looking for a chainstay angle of 63 to 66 degrees, something you can fudge a little if you use a long cage derailleur.

But if the angle is too open, the chain will drag on the bottom of the derailleur cage in the small ring.

If you measure your current chainstay angle and it's 70 degrees or less, you should just about be able to bolt on a triple and go. The derailleur yaw angle and tail position might be a little itchy to set up, but once you have it right it should be no big deal.

Good luck either way.

 

[DavidJL]

I already have an Ultegra triple front derailleur. Evidently, the Q-factor is greater on the QX100 than it is on my road bike. I like close gearing because I often find that the gear I want is right in between. In hillier areas, wider spacing is more appropriate. I will have to see if close spacing is useful on a utility bike. One advantage of closer gearing is that the wear is spread out more evenly among the cogs. Losing 40-50 pounds wouldn't hurt.

 

[1happyreader]

What BB (botttom bracket) width did you change to ???

"For a double chainring, you'll need a 68mm wide English type bottom bracket with a 115mm axle width. For a triple you'll need 113mm axle width,"

?? later,,,,, bye

 

[Charles.Plager]

I used a 123mm bottom bracket.

 

[DavidJL]

Will be taking bike to local shop to try out triple and see what bottom bracket will be needed. Definitely going to need a granny ring.

 

[Charles.Plager]

Will be taking bike to local shop to try out triple and see what bottom bracket will be needed. Definitely going to need a granny ring.

I seem to be in the minority here, but both of my Cruzbikes go down to 17" (or less) and I use that gear a lot. It helps that I can ride at less than 3 mph and not fall over.

 

[Doug Burton]

Will be taking bike to local shop to try out triple and see what bottom bracket will be needed. Definitely going to need a granny ring.

Probably the best approach. "Road" square-taper cranks sit further down on the BB axle (JIS taper) than "trekking" or MTB cranks. It can be itchy getting the BB axle length correct if you're working with different types of cranks. The objective being that for a triple, the center chainring should line up with the center of the cassette.

The chainline dimension for triples (distance between the center of the adjustable front tube and the center chainring) is typically about 45mm. This can vary; I have found 47mm works fine with "trekking" triples. Chainline will be a product of the BB axle width and how far the crank sits down on the BB axle.

Useful reference:

http://sheldonbrown.com/chainline.html

 

[super slim]

I seem to be in the minority here, but both of my Cruzbikes go down to 17" (or less) and I use that gear a lot. It helps that I can ride at less than 3 mph and not fall over.

Charles you have a fellow lover of triples with me, with a Softrider, Quest 559, and a Silvio ALL with 18.5" gear inches as the lowest gear!!!

 

[DavidJL]

Today, I put on a 175 mm Tiagra outboard bearing compact crankset on the QX100. Rode 15 miles on it. The outboard style crank won't clear the boom pivot if it is a triple. The Tiagra is 50-34 double. If I am going to be riding in hilly terrain a lot, will just swap cassette to 11-34. So far as I can tell, I actually liked using a longer crank. Another nice part is that the Q-distance is a little bit less. So I have decided against going triple for the time being.

 

[chrisblessing]

I seem to be in the minority here, but both of my Cruzbikes go down to 17" (or less) and I use that gear a lot. It helps that I can ride at less than 3 mph and not fall over.

You're a better man than me; 5 mph and I'm tipping or walking...

 

[super slim]

Pratice practice practice 3 mph as it better than walking

 

[mzweili]

5 mph and I'm tipping or walking

So do I !!

 

[chrisblessing]

Pratice practice practice 3 mph as it better than walking

I've been practicing for as long as I've been riding my conversion. We'll see if the Quest is easier. Anyhow, I can push the bike at 5 mph.

 

[Rick Youngblood]

Pratice practice practice 3 mph as it better than walking

I'm able to get down to 4.5 mph on the Vendetta up hills, but that's as low as I can go with my current gear. It does take practice however.

 

[super slim]

Rick, I think the 45 degree seat back of the Silvio V1.0 helps with cycling at 3 mph (5 kph), OR is it my low centre of gravity?

 

[Charles.Plager]

Rick, I think the 45 degree seat back of the Silvio V1.0 helps with cycling at 3 mph (5 kph), OR is it my low centre of gravity?

I do think the upright angle helps, but I've had my seat angle well below 45 degrees able to ride under 3 mph. I rode a Silvio v2 a couple hundred feet, so I can't tell if the fast bikes are less stable than my Sofrider or Cruzigami.