Front dérailleur solution for smaller chainring

mattwall

Member
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.IMG_1096.JPGIMG_1100.JPGIMG_1213.JPGIMG_1214.JPGIMG_1215.JPGIMG_1096.JPG
 
As someone who is in the midst of buying parts to build up an S40... when does this become necessary? I am planning a 46/30 up front. Will I need any special adapters? I had thought I would be fine as long as the front derailleur had the needed "capacity" but I can see there's more to it than that.
 
to build up an S40... when does this become necessary? I am planning a 46/30 up front. Will I need any special adapters?
The current S40 has a chainstay without the stalk, it's a bolt-on accessory. You'll probably want to buy the Wickwerks adapter to bring the front derailleur closer to your smaller rings.

I have the following on my 2020 S40 and don't need the adapter, but had to buy and install the stalk.
Sram cassette: 10-12-14-16-18-21-24-28-32-36-42
Sram chainrings: 42 & 50
Gear Inches 21.05-88.35, 30.92-129.92
34t chainring: 5 - 21 mph @ 80 rpm
50t chainring: 7.8 - 31mph @ 80 rpm
 
The current S40 has a chainstay without the stalk, it's a bolt-on accessory. You'll probably want to buy the [] adapter to bring the front derailleur closer to your smaller rings.

I have the following on my 2020 S40 and don't need the adapter, but had to buy and install the stalk.
Sram cassette: 10-12-14-16-18-21-24-28-32-36-42
Sram chainrings: 42 & 50
Gear Inches 21.05-88.35, 30.92-129.92
34t chainring: 5 - 21 mph @ 80 rpm
50t chainring: 7.8 - 31mph @ 80 rpm

This is helpful. Thank you!
 

dule0911

Active Member
I am building up a 2020 S40 with a 30-46 front and ultegra 8000 fd. I should know in the next week or two if the setup works (and how it shifts if it works). I don't have the adapter, don't mind buying it if it doesn't work like this. The stalk came with the frameset.

@matwall
Really nice setup, didn't even think about these type of fd, this might be a better solution then having a lot of adapters for smaller chainrings. What size/model tires are you using for the brevet? Please follow up after the ride, it sounds really nice, didn't know about it until now! Not sure what the hills are on the brevet, but after my experience with the stock 38T on the Q45 and weak knees, I would go even lower then 26 for the smallest ring up front (with 42 in the back). Something like a 24 or 22, but that is just me.
 
I finally got my front derailleur. Shimano says it should be 1-3 mm above the teeth of the chainring (a 46t) and as you can see from the picture it doesn't quite reach that range. It's more like 4 mm. I don't have a sense of how important this is. Do people think this is close enough for jazz, or should I buy the special extender?
IMG_3599.JPG
 

cpml123

Zen MBB Master
I finally got my front derailleur. Shimano says it should be 1-3 mm above the teeth of the chainring (a 46t) and as you can see from the picture it doesn't quite reach that range. It's more like 4 mm. I don't have a sense of how important this is. Do people think this is close enough for jazz, or should I buy the special extender?
View attachment 10347

You can probably just ride it and see if the chain drops. If not, then it's all good! Make sure you ride it a few times because I found adjusting on the stand doesn't match real world condition sometimes.
 

Frito Bandito

Zen MBB Master
You can probably just ride it and see if the chain drops. If not, then it's all good! Make sure you ride it a few times because I found adjusting on the stand doesn't match real world condition sometimes.
Excellent advice. The front derailleur doesn't get as much use as the rear, so if it works during the test rides then it shouldn't need any adjustment for the duration of the ride (3000km). Good luck on the ride Matt and would love to read about your experiences during it.
 

benphyr

Guru-me-not
I finally got my front derailleur. Shimano says it should be 1-3 mm above the teeth of the chainring (a 46t) and as you can see from the picture it doesn't quite reach that range. It's more like 4 mm. I don't have a sense of how important this is. Do people think this is close enough for jazz, or should I buy the special extender?
View attachment 10347
It kind of looks ( maybe camera angle optical illusion) as though the derailleur would ideally be rotated (around the derailleur) (Image 1: A or B rotate counter clockwise) so that the outside face (large chainring side) of the derailleur is parallel to the teeth of the chainring (Image 1: 1 becomes more like 2 which is parallel to 3) as in Image 2 from cyclist.co.uk.

Image 1:
IMG_3599.JPG

Image 2:
upload_2020-11-1_7-11-53.jpeg

I agree with the others, perfection is not necessary. It will quite likely function great as is. There are other solutions too if it tries to jump off often.
 
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Thanks for the advice everyone! I am still waiting for my wheels to arrive but when they show up I'll give it a shot as is.
 

mattwall

Member
I cut the front derailleur stalk off as the front derailleur that I used occupied the same space as the stalk. FD M8025-E
I an quite happy about this as I view it as replacing a Cruzbike front derailleur mounting system designed for road chainrings and having the mounting system for road front derailleurs with a Shimano system designed for the specific cranks and front derailleur that I installed.
The front derailleur shifting is exceptional. By far the best shifting front derailleur that I have ever used.

I am trialing Compass Rat Trap Pass tires. If the knobbly version of this tyre is released soon, then I will probably run that in the front.

My lowest gear 26 x 42 on 26 inch tyres is 16 gear inches which I think is low enough. Traction on steep gravel hills is probably a bigger issue than low gears. I am expecting to walk my bike on a lot of these hills. I have designed my bike bags so the bags are flush with the seat so that walking the bike is not impeded by bags.

Shimano FD M660-E is a front derailleur with backplate that is a triple 9 speed front derailleur with a maximum tooth capacity of 46.
I am not sure that a triple would be compatible with a 46/30 double chainring. Someone else with more experience could chime in on this.
 

DavidCH

In thought; expanding the paradigm of traversity
I am amazed at this forum's ingenuity!

This probably could be applied to my converted 8 speed track bike to give it 16 gears.... amazing.

Please @mattwall , let us know how you get on.
 
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
What length crank arm did you change to from the 155? I have a Q-45 and have never had crankarms less than 170. So wondering the difference a rider notices. Also thinking about going to a double, 42/30. That gives a range of 18-99.

Thank you,
Don
 

paco1961

Zen MBB Master
I can tell you from my experience going from 172.5 on my S40 (that I rode for years on my DFs) to 155 cranks, it makes all the difference in the world. The longer cranks left me limping around on 2 sore knees. Switch to the 155s and within 2 rides I was back to normal. You do give up some leverage on climbs and sprints but I’ll take that trade off.
 

Frito Bandito

Zen MBB Master
Paco, now you got me thinking of longer cranks. I have 172.5mm on my DF bike, and 165mm on my V20, which rarely encounters any hills. Maybe it is mental, but my pedal stroke feels abbreviated, and I have not been able to match my highest top speed on the DF with my V20 (2kph slower in a max sprint). :confused:
 
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