Road bike vs. Mountain bike Q-factor

[Ron]

I road ride about 300 miles a week and jump on my mountain bike a
couple of times a month. When I ride my mountain bike my cadence
feels awkward and I get pain in my knees. My road bike has 170 cranks
and my mountain bike 175. In addition I notice my feet are wider
apart on my mountain bike which is annoying. I measured the distances
from the inside of my shoe to the frame center line. On my mountain
bike it was 4 inches and on my road bike 3 inches. So on my mountain
bike my feet are 2 inches farther apart.

My road bike has Shimano Ultegra cranks and my mountain bike Shimano
XTR cranks. Does anyone know how to get the q-factor more narrow on
my mountain bike?

thanks,
Ron

[jim beam]

Ron wrote:
> I road ride about 300 miles a week and jump on my mountain bike a
> couple of times a month. When I ride my mountain bike my cadence
> feels awkward and I get pain in my knees. My road bike has 170 cranks
> and my mountain bike 175. In addition I notice my feet are wider
> apart on my mountain bike which is annoying. I measured the distances
> from the inside of my shoe to the frame center line. On my mountain
> bike it was 4 inches and on my road bike 3 inches. So on my mountain
> bike my feet are 2 inches farther apart.
>
> My road bike has Shimano Ultegra cranks and my mountain bike Shimano
> XTR cranks. Does anyone know how to get the q-factor more narrow on
> my mountain bike?
>
> thanks,
> Ron

you could try something like a 2 ring ritchey compact 'cross crank. it
has very low "q", but the reason most mtb cranks are high "q" is to
allow for the extra width necessary for the chain stays to accomodate
fat tires, so unless your frame is skinny in that department, you're
kinda stuck.

a number of folks in my neighborhood seem to be riding 'cross bikes on
the mountain almost exclusively these days, so a different vehicle is a
thought.

[jim beam]

Ron wrote:
> I road ride about 300 miles a week and jump on my mountain bike a
> couple of times a month. When I ride my mountain bike my cadence
> feels awkward and I get pain in my knees. My road bike has 170 cranks
> and my mountain bike 175. In addition I notice my feet are wider
> apart on my mountain bike which is annoying. I measured the distances
> from the inside of my shoe to the frame center line. On my mountain
> bike it was 4 inches and on my road bike 3 inches. So on my mountain
> bike my feet are 2 inches farther apart.
>
> My road bike has Shimano Ultegra cranks and my mountain bike Shimano
> XTR cranks. Does anyone know how to get the q-factor more narrow on
> my mountain bike?
>
> thanks,
> Ron

you could try something like a 2 ring ritchey compact 'cross crank. it
has very low "q", but the reason most mtb cranks are high "q" is to
allow for the extra width necessary for the chain stays to accomodate
fat tires, so unless your frame is skinny in that department, you're
kinda stuck.

a number of folks in my neighborhood seem to be riding 'cross bikes on
the mountain almost exclusively these days, so a different vehicle is a
thought.

[Rik O'Shea]

(Ron) wrote in message >...
> I road ride about 300 miles a week and jump on my mountain bike a
> couple of times a month. When I ride my mountain bike my cadence
> feels awkward and I get pain in my knees. My road bike has 170 cranks
> and my mountain bike 175. In addition I notice my feet are wider
> apart on my mountain bike which is annoying. I measured the distances
> from the inside of my shoe to the frame center line. On my mountain
> bike it was 4 inches and on my road bike 3 inches. So on my mountain
> bike my feet are 2 inches farther apart.
>
> My road bike has Shimano Ultegra cranks and my mountain bike Shimano
> XTR cranks. Does anyone know how to get the q-factor more narrow on
> my mountain bike?
>
> thanks,
> Ron

I sometimes use an MTB on the road during winter as a diversion from
the normal racing bike and have felt a bit uncomfortable with the
wider Q-factor. Here's what I'd suggest.

(1)You can replace the MTB triple with a road touring triple. Using
something like a customised Stronglight (110 BCD) you can even get the
same gearing. This will reduce the distance "2 inches farther apart"
by more than an inch.

(2) Assuming you use the MTB on the road you can install a double
chainring on the MTB with 170 cranks - then you should have the exact
same Q-factor as the road bike.

If you choose the second option you should make sure that the road
cranks still clear the MTB chainstays (which are wider at the rear
than on a road bike).
You may also need a new bottom bracket for new cranks to maintain
chainline but more often than not you can get away with what you have.

-R

[Rik O'Shea]

(Ron) wrote in message >...
> I road ride about 300 miles a week and jump on my mountain bike a
> couple of times a month. When I ride my mountain bike my cadence
> feels awkward and I get pain in my knees. My road bike has 170 cranks
> and my mountain bike 175. In addition I notice my feet are wider
> apart on my mountain bike which is annoying. I measured the distances
> from the inside of my shoe to the frame center line. On my mountain
> bike it was 4 inches and on my road bike 3 inches. So on my mountain
> bike my feet are 2 inches farther apart.
>
> My road bike has Shimano Ultegra cranks and my mountain bike Shimano
> XTR cranks. Does anyone know how to get the q-factor more narrow on
> my mountain bike?
>
> thanks,
> Ron

I sometimes use an MTB on the road during winter as a diversion from
the normal racing bike and have felt a bit uncomfortable with the
wider Q-factor. Here's what I'd suggest.

(1)You can replace the MTB triple with a road touring triple. Using
something like a customised Stronglight (110 BCD) you can even get the
same gearing. This will reduce the distance "2 inches farther apart"
by more than an inch.

(2) Assuming you use the MTB on the road you can install a double
chainring on the MTB with 170 cranks - then you should have the exact
same Q-factor as the road bike.

If you choose the second option you should make sure that the road
cranks still clear the MTB chainstays (which are wider at the rear
than on a road bike).
You may also need a new bottom bracket for new cranks to maintain
chainline but more often than not you can get away with what you have.

-R

[Tim McNamara]

jim beam > writes:

> Ron wrote:
>> I road ride about 300 miles a week and jump on my mountain bike a
>> couple of times a month. When I ride my mountain bike my cadence
>> feels awkward and I get pain in my knees. My road bike has 170
>> cranks and my mountain bike 175. In addition I notice my feet are
>> wider apart on my mountain bike which is annoying. I measured the
>> distances from the inside of my shoe to the frame center line. On
>> my mountain bike it was 4 inches and on my road bike 3 inches. So
>> on my mountain bike my feet are 2 inches farther apart. My road
>> bike has Shimano Ultegra cranks and my mountain bike Shimano XTR
>> cranks. Does anyone know how to get the q-factor more narrow on my
>> mountain bike? thanks, Ron
>
> you could try something like a 2 ring ritchey compact 'cross crank.
> it has very low "q", but the reason most mtb cranks are high "q" is
> to allow for the extra width necessary for the chain stays to
> accomodate fat tires, so unless your frame is skinny in that
> department, you're kinda stuck.

Good point. Perhaps shorter cranks- 170 since that what he uses on
his road bike- would buy him a little extra clearance? A bigger
problem might be whether the middle and granny rings clear the frame
with a narrower Q crank. With aluminum frames this is more likely to
be a problem than with other materials.

I switched from an LX crank to a Ritchey 110/74 triple on my MTB, oh
10 years ago now, and reduced the Q factor quite a bit. Clearance
wasn't a problem on that bike (1993 Specialized StumpJumer M2),
although it was close (the middle ring was about 2 mm from the
chainstay). Still have the cranks, now on another bike, but sold the
M2 years ago with the original LX crank and BB reinstalled.

> a number of folks in my neighborhood seem to be riding 'cross bikes
> on the mountain almost exclusively these days, so a different
> vehicle is a thought.

That ended up being my personal solution for about 8 years.

[Tim McNamara]

jim beam > writes:

> Ron wrote:
>> I road ride about 300 miles a week and jump on my mountain bike a
>> couple of times a month. When I ride my mountain bike my cadence
>> feels awkward and I get pain in my knees. My road bike has 170
>> cranks and my mountain bike 175. In addition I notice my feet are
>> wider apart on my mountain bike which is annoying. I measured the
>> distances from the inside of my shoe to the frame center line. On
>> my mountain bike it was 4 inches and on my road bike 3 inches. So
>> on my mountain bike my feet are 2 inches farther apart. My road
>> bike has Shimano Ultegra cranks and my mountain bike Shimano XTR
>> cranks. Does anyone know how to get the q-factor more narrow on my
>> mountain bike? thanks, Ron
>
> you could try something like a 2 ring ritchey compact 'cross crank.
> it has very low "q", but the reason most mtb cranks are high "q" is
> to allow for the extra width necessary for the chain stays to
> accomodate fat tires, so unless your frame is skinny in that
> department, you're kinda stuck.

Good point. Perhaps shorter cranks- 170 since that what he uses on
his road bike- would buy him a little extra clearance? A bigger
problem might be whether the middle and granny rings clear the frame
with a narrower Q crank. With aluminum frames this is more likely to
be a problem than with other materials.

I switched from an LX crank to a Ritchey 110/74 triple on my MTB, oh
10 years ago now, and reduced the Q factor quite a bit. Clearance
wasn't a problem on that bike (1993 Specialized StumpJumer M2),
although it was close (the middle ring was about 2 mm from the
chainstay). Still have the cranks, now on another bike, but sold the
M2 years ago with the original LX crank and BB reinstalled.

> a number of folks in my neighborhood seem to be riding 'cross bikes
> on the mountain almost exclusively these days, so a different
> vehicle is a thought.

That ended up being my personal solution for about 8 years.

[Ron]

(Rik O'Shea) wrote in message >...
> (Ron) wrote in message >...
> > I road ride about 300 miles a week and jump on my mountain bike a
> > couple of times a month. When I ride my mountain bike my cadence
> > feels awkward and I get pain in my knees. My road bike has 170 cranks
> > and my mountain bike 175. In addition I notice my feet are wider
> > apart on my mountain bike which is annoying. I measured the distances
> > from the inside of my shoe to the frame center line. On my mountain
> > bike it was 4 inches and on my road bike 3 inches. So on my mountain
> > bike my feet are 2 inches farther apart.
> >
> > My road bike has Shimano Ultegra cranks and my mountain bike Shimano
> > XTR cranks. Does anyone know how to get the q-factor more narrow on
> > my mountain bike?
> >
> > thanks,
> > Ron
>
> I sometimes use an MTB on the road during winter as a diversion from
> the normal racing bike and have felt a bit uncomfortable with the
> wider Q-factor. Here's what I'd suggest.
>
> (1)You can replace the MTB triple with a road touring triple. Using
> something like a customised Stronglight (110 BCD) you can even get the
> same gearing. This will reduce the distance "2 inches farther apart"
> by more than an inch.
>
> (2) Assuming you use the MTB on the road you can install a double
> chainring on the MTB with 170 cranks - then you should have the exact
> same Q-factor as the road bike.
>
> If you choose the second option you should make sure that the road
> cranks still clear the MTB chainstays (which are wider at the rear
> than on a road bike).
> You may also need a new bottom bracket for new cranks to maintain
> chainline but more often than not you can get away with what you have.
>
> -R



Thanks, I'll check the clearance between the cranks and the
chainstays. I think there's quite a bit of clearance.

Ron

[Ron]

(Rik O'Shea) wrote in message >...
> (Ron) wrote in message >...
> > I road ride about 300 miles a week and jump on my mountain bike a
> > couple of times a month. When I ride my mountain bike my cadence
> > feels awkward and I get pain in my knees. My road bike has 170 cranks
> > and my mountain bike 175. In addition I notice my feet are wider
> > apart on my mountain bike which is annoying. I measured the distances
> > from the inside of my shoe to the frame center line. On my mountain
> > bike it was 4 inches and on my road bike 3 inches. So on my mountain
> > bike my feet are 2 inches farther apart.
> >
> > My road bike has Shimano Ultegra cranks and my mountain bike Shimano
> > XTR cranks. Does anyone know how to get the q-factor more narrow on
> > my mountain bike?
> >
> > thanks,
> > Ron
>
> I sometimes use an MTB on the road during winter as a diversion from
> the normal racing bike and have felt a bit uncomfortable with the
> wider Q-factor. Here's what I'd suggest.
>
> (1)You can replace the MTB triple with a road touring triple. Using
> something like a customised Stronglight (110 BCD) you can even get the
> same gearing. This will reduce the distance "2 inches farther apart"
> by more than an inch.
>
> (2) Assuming you use the MTB on the road you can install a double
> chainring on the MTB with 170 cranks - then you should have the exact
> same Q-factor as the road bike.
>
> If you choose the second option you should make sure that the road
> cranks still clear the MTB chainstays (which are wider at the rear
> than on a road bike).
> You may also need a new bottom bracket for new cranks to maintain
> chainline but more often than not you can get away with what you have.
>
> -R



Thanks, I'll check the clearance between the cranks and the
chainstays. I think there's quite a bit of clearance.

Ron