Front dérailleur solution for smaller chainring

[paco1961]

The experts would say that the shorter cranks allow you to spin faster and go faster. May be true for some but I have never found that to be true for me. But as a former runner turned bike nerd I have always been more of a masher than a spinner. Constantly work toward the latter but default setting is the former. Seems clear that in burst efforts like sprints and the steepest climbs the leverage is a plus as long as your strength and fitness can take advantage of it. But that’s a plant doctor dabbling in biophysics. Probably a dangerous thing.

 

[Donald Harter]

The experts would say that the shorter cranks allow you to spin faster and go faster. May be true for some but I have never found that to be true for me. But as a former runner turned bike nerd I have always been more of a masher than a spinner. Constantly work toward the latter but default setting is the former. Seems clear that in burst efforts like sprints and the steepest climbs the leverage is a plus as long as your strength and fitness can take advantage of it. But that’s a plant doctor dabbling in biophysics. Probably a dangerous thing.

Just learning to ride my new Q-45. DF's for 55 years and trying to figure/understand the biomechanics of the Cruzbike. Much may be because I am at the early Learning stage. Does seem like I shift much more than before. Also thinking about the stock low gear of 26 and touring. On my conventional tourer, 20" low gear is more suitable for the short steep hills of Missouri. Adding in more grade to my learning routes. Possible this will all work out and be fine. Do appreciate thoughts from the more experienced cruzbikers!

 

[Frito Bandito]

Proportionally, I think my legs are on the longer than average side so longer strides seemed to produce higher speeds for me in running. My first real bike had 175mm cranks and that was the closest I felt to getting the most power out of each stride. If the chance comes, I will try out some longer cranks on the V20 to see how it feels.

 

[paco1961]

Just learning to ride my new Q-45. DF's for 55 years and trying to figure/understand the biomechanics of the Cruzbike. Much may be because I am at the early Learning stage. Does seem like I shift much more than before. Also thinking about the stock low gear of 26 and touring. On my conventional tourer, 20" low gear is more suitable for the short steep hills of Missouri. Adding in more grade to my learning routes. Possible this will all work out and be fine. Do appreciate thoughts from the more experienced cruzbikers!

You will absolutely shift more often on a CB compared to a DF. The spin rate sweet spot is narrower on the CB. Particularly hard for this masher to get through his thick skull though I am working on it . . .

 

[benphyr]

As you gain skills and experience you will be able to ride slower and slower while maintaining balance and control. If 20” is your lowest on diamond frame then at the learning stages 26 may be too low for control. As you become an expert 20” may be possible. Generally the lowest gearing is bounded by what you can reasonably maintain balance and forward motion without losing traction. You can probably already see there are many variables including road surface, tire size, grip, pressure, gearing, pedal type, bottom bracket location / bike setup, comfort level, seat angle, experience, cadence, endurance, center of gravity/ location of bags, water, balance, etc.

Practice the drills is the quickest way to improve the most important factors.

 

[Donald Harter]

As you gain skills and experience you will be able to ride slower and slower while maintaining balance and control. If 20” is your lowest on diamond frame then at the learning stages 26 may be too low for control. As you become an expert 20” may be possible. Generally the lowest gearing is bounded by what you can reasonably maintain balance and forward motion without losing traction. You can probably already see there are many variables including road surface, tire size, grip, pressure, gearing, pedal type, bottom bracket location / bike setup, comfort level, seat angle, experience, cadence, endurance, center of gravity/ location of bags, water, balance, etc.

Practice the drills is the quickest way to improve the most important factors.

Ben, I appreciate your thoughts on this. Weather clearing tommorow and I will get back in the saddle and onto some hills. The drills on an open parking lot was a great 1st step. I do listen to the experts. I am taking the process with a relaxed attitude.

Don

 

[AWP]

Just learning to ride my new Q-45. DF's for 55 years and trying to figure/understand the biomechanics of the Cruzbike. Much may be because I am at the early Learning stage. Does seem like I shift much more than before. Also thinking about the stock low gear of 26 and touring. On my conventional tourer, 20" low gear is more suitable for the short steep hills of Missouri. Adding in more grade to my learning routes. Possible this will all work out and be fine. Do appreciate thoughts from the more experienced cruzbikers!

I’m in mid-Missouri and I can barely get out of my neighborhood because of the steep hills. I am thinking of putting on a smaller chainring - what size do you think might be good? My mechanic says a 2x won’t play well with the 11 in the back.

 

[Frito Bandito]

An 11 in back is probably too small. I don't have much to climb here, so I have a 52/36 and a 12/28 on the bike I ride when climbing. However, if I did have much to climb, I'd change it to a 50/34 and a 12/30, or maybe even a 12/32.

 

[Donald Harter]

I’m in mid-Missouri and I can barely get out of my neighborhood because of the steep hills. I am thinking of putting on a smaller chainring - what size do you think might be good? My mechanic says a 2x won’t play well with the 11 in the back.

I respect professional opinion, but you might get a second one. The forum brings up what other Cruzbike owners have found that works. The Cruzbike site does have the gearing chart in the Q-45 section. I am considering this issue as I get experience with my new Q. I am in Columbia. Where are you in Central Missouri?

 

[Frito Bandito]

Sorry, it was early in the morning and I was having breakfast before going out to practice golf so I was in a hurry in writing my response. A 2x11 works as long as it is set up properly. You might get a bit of noise if you are on the big ring in front and the big ring in back, or small in front and small in back (called cross-chaining) but it will still work. As demanding as cyclists can be, that noise might be irritating, cause premature wear on the gears and chain and some other things, but again, it will still work. In my case, on the small ring in front (36t) I start spinning out at 37kph when I am in the tallest gear in back. So, any time I am going 35kph or less it is on the small ring on front.

Edit: A 1x12 speed might sound attractive, but before you select that make sure you know what all of the cog differences are. You don't have to worry about a front derailleur on a 1x12, but if the gear range difference is too high (differences in the number of teeth on each gear) you may find yourself spinning too quickly or too slowly, when you upshift or downshift.

 

[Donald Harter]

I have recently converted my Q45 to 2 x 11 as I wanted lower gears for Bike Packing. I am going to ride the Tour of Aotearoa next march which is a 3000 km unsupported ride the length of New Zealand.
My new chainrings are a Shimano 36/26 mountain chain ring.
I used a Shimano E type front derailleur and an E type backplate to mount the front derailleur on.
The E type backplate is clamped between the Bike Frame and an external bottom Bracket.
I cut the front derailleur stalk off. The stalk is hollow and has a hole through to the underside of the bike.
I routed the gear cable around the bottom bracket and up through the hole under the derailleur stalk.
This arrangement shifts very well.View attachment 10248View attachment 10249View attachment 10250View attachment 10251View attachment 10252View attachment 10248

Matt,
What length arms are the new cranks for your 2X system? If different from the original 155's what change do you experience? At 6', I am wondering about the original short crank arms and why their use. If going to a 2X system I would expect to purchase typical 170's.
Thank you,
Don

 

[benphyr]

In addition to the leverage and (inverse effect) higher, smoother cadence changing crank length changes fit.

Let’s take your example of going from 155mm to 170mm. At maximum leg extension the crank lengthens by 15mm which means you need to pull the boom in towards you ~15mm to keep maximum leg extension the same. That means that the bottom bracket moves up slightly which can be more aerodynamic up to a point and is also more twitchy, handling is more difficult as it gets more horizontal. (Small effect).

The minimum leg extension is now 2*15mm= 30mm closer to you so your knees are more bent (less power at minimum extension and not good for bad knees) and sticking up higher which may result in contacting the handlebars especially because to keep the handlebars the same distance from your chest you will need to move them away 30mm.

Factors to consider especially if any of your clearances are small.

 

[Donald Harter]

In addition to the leverage and (inverse effect) higher, smoother cadence changing crank length changes fit.

Let’s take your example of going from 155mm to 170mm. At maximum leg extension the crank lengthens by 15mm which means you need to pull the boom in towards you ~15mm to keep maximum leg extension the same. That means that the bottom bracket moves up slightly which can be more aerodynamic up to a point and is also more twitchy, handling is more difficult as it gets more horizontal. (Small effect).

The minimum leg extension is now 2*15mm= 30mm closer to you so your knees are more bent (less power at minimum extension and not good for bad knees) and sticking up higher which may result in contacting the handlebars especially because to keep the handlebars the same distance from your chest you will need to move them away 30mm.

Factors to consider especially if any of your clearances are small.

Ben,
I have about 3" currently knees to bars. I will pedal slowly while paying attention to knee bend angle. I do need to pay attention that the bio-mechanics is different on a Q than a DF bike. My body is used to 60 years on a DF and need to acclimate to the recumbent MBB design. I think I will need a lower low gear for touring while retaining the current 99" high gear. So a double chainring crank and 170 is a very available choise.
Don

 

[benphyr]

Ben,
I have about 3" currently knees to bars. I will pedal slowly while paying attention to knee bend angle. I do need to pay attention that the bio-mechanics is different on a Q than a DF bike. My body is used to 60 years on a DF and need to acclimate to the recumbent MBB design. I think I will need a lower low gear for touring while retaining the current 99" high gear. So a double chainring crank and 170 is a very available choise.
Don

Hi Don,
Don't count out the 155 if that is what comes standard on the Q model that you have. The smaller cranks do seem to be preferred by a fair number of riders. Not that longer ones can't be done, they absolutely can, but I would first acclimatize myself to the smaller ones and see what feels better when the time comes to switch. You may be surprised. One thing I forgot to mention is that they also aid slightly in tight corners as the difference between leg extension when turning is less exaggerated. Not a big deal and doesn't come into play for faster corners but for my commute I can tell the difference between my two bikes that are set up pretty similar but have different length cranks. (Doesn't stop me from riding either one of them though.) Whatever your preference I would definitely agree on the larger range of gearing and smaller spacing that a double can provide. I might not need it for my commute but I do still like having smaller spacing and would actually wish for even smaller spacing if I were custom building or going to spend 1000s of kms on it. Anyway, share your experiences and if you have any problems let us know.

 

[Donald Harter]

Hi Don,
Don't count out the 155 if that is what comes standard on the Q model that you have. The smaller cranks do seem to be preferred by a fair number of riders. Not that longer ones can't be done, they absolutely can, but I would first acclimatize myself to the smaller ones and see what feels better when the time comes to switch. You may be surprised. One thing I forgot to mention is that they also aid slightly in tight corners as the difference between leg extension when turning is less exaggerated. Not a big deal and doesn't come into play for faster corners but for my commute I can tell the difference between my two bikes that are set up pretty similar but have different length cranks. (Doesn't stop me from riding either one of them though.) Whatever your preference I would definitely agree on the larger range of gearing and smaller spacing that a double can provide. I might not need it for my commute but I do still like having smaller spacing and would actually wish for even smaller spacing if I were custom building or going to spend 1000s of kms on it. Anyway, share your experiences and if you have any problems let us know.

Ben,
Part of the reasoning for buying a Cruzbike was the forum. I knew this would be quite different and knowledgeable folks like you would be a big plus. The tight corner thing is like toe overlap on a DF bike. Just something that occasionally is an issue. I agree with the giving time and not even being aware of all the implications. I will check what the smallest ring that the 110bcd original crank will accept. I would like to do 30 or 28. I am starting to work on my hill skills. It does get better quickly. After 60 years on a DF, I knew this would require patience.

Don

 

[AWP]

I respect professional opinion, but you might get a second one. The forum brings up what other Cruzbike owners have found that works. The Cruzbike site does have the gearing chart in the Q-45 section. I am considering this issue as I get experience with my new Q. I am in Columbia. Where are you in Central Missouri?

I’m in Jefferson City

 

[Donald Harter]

I’m in Jefferson City

Jefferson city is quite hilly. Are you doing okay with the stock gearing or changed it? Needing to get more practice in on steeper grades to decide myself. I have a friend in Jefferson City, Jim Brown. Rides a Rans on the trail. Would like to meet him in Hartsburg for lunch once things dry out. Maybe you could join us.
Don

Don

 

[AWP]

Jefferson city is quite hilly. Are you doing okay with the stock gearing or changed it? Needing to get more practice in on steeper grades to decide myself. I have a friend in Jefferson City, Jim Brown. Rides a Rans on the trail. Would like to meet him in Hartsburg for lunch once things dry out. Maybe you could join us.
Don

Don

I rode to Hartsburg last Saturday and the trail was fine. I’m free to leave JC after 1pm this week. Is there any way to pm someone on this forum?

 

[Donald Harter]

AW,
Folks say to pm me on the forum. Not sure how myself. Email is my usual communication tool other than calling. My email is harterd@missouri.edu
Next Tuesday the 6th may be possible.
Don

 

[Mathew Fy]

Is there any way to pm

Click on the person’s avatar or name, then on “Start a Conversation”. It goes to their email via Cruzbike.