What crank arms/ should I use?

[Black Hawk Down]

I'm upgrading (downgrading?) my 2016 V20 group from Ultegra DI2 to SRAM Rival GX AXS Mullet Groupset - Rival eTap HRD Shifters, GX AXS Rear Derailleur, Battery/Charger, Chain & Cassette. It's 1X12 with a 10-52 cassette. But it doesn't come with the 1X chainring and crank arms. I believe I'll need a 50t chain ring. I noticed that many people on this forum use very short (155 mm) crank arms and I don't know why. My current cranks are 165 mm and they seem fine to me. Also, many people use Q-rings. Again, I don't know if this is worth it. I'm not a racer. In fact, I'm making mods on the bike to use for credit card touring. I need low gears for hills but want decent speeds for tailwinds and shallow downgrades. Finally, I like the idea of no front shifting as it's always problematic in my experience. Any tips on the cranks/BB/Chainrings that are compatible with the V20 would be appreciated. Thanks.

 

[Frito Bandito]

On my 2018 V20 I have Shimano 105 R7000 165mm cranks with 52/34t chainrings, and they have worked perfectly since day 1. You can also get them in a 50/34t and just remove the 34t ring. My Force AXS FD works perfectly so I don't think you'll have any FD problems if you install it, but if you want to save a few grams of weight by removing the 34t inner ring, and saving even more weight by making it a 1x system without a FD or heavy shifter then that should be fine. Of course Ultegra and Dura Ace are steps up from 105, but in light of crank arm failures under heavy loads with those two I decided to stay with the more robust 105 crank arms. Keep in mind this is me over-estimating my actual power as I haven't seen +800w in a while on any ride.

Back to the FD, and the problems you had... there are many possible issues so I won't try to guess which caused your problems, but the AXS FD works flawlessly on my V20. So, I don't think you should have any fear about it shifting properly between the front 2 rings if you go with a 2x system. Whether you can get the right chain tension with a 2x system with that 10x50 cassette is out of my paygrade.

 

[Henri]

Whether you can get the right chain tension with a 2x system with that 10x50 cassette is out of my paygrade.

The SRAM Eagle rear mechs for 50t cassetes are specifically 1*12, I think. You need to adjust the B-screw for a small changes of chainrings and for bigger changes adjust chain length, if you want to be able to shhift all cogs. (Or have a carefully placed idler to counter the chain length difference.)

 

[Black Hawk Down]

On my 2018 V20 I have Shimano 105 R7000 165mm cranks with 52/34t chainrings, and they have worked perfectly since day 1. You can also get them in a 50/34t and just remove the 34t ring. My Force AXS FD works perfectly so I don't think you'll have any FD problems if you install it, but if you want to save a few grams of weight by removing the 34t inner ring, and saving even more weight by making it a 1x system without a FD or heavy shifter then that should be fine. Of course Ultegra and Dura Ace are steps up from 105, but in light of crank arm failures under heavy loads with those two I decided to stay with the more robust 105 crank arms. Keep in mind this is me over-estimating my actual power as I haven't seen +800w in a while on any ride.

Back to the FD, and the problems you had... there are many possible issues so I won't try to guess which caused your problems, but the AXS FD works flawlessly on my V20. So, I don't think you should have any fear about it shifting properly between the front 2 rings if you go with a 2x system. Whether you can get the right chain tension with a 2x system with that 10x50 cassette is out of my paygrade.

I currently have a working 2X system since I bent the derailleur loop. I took it for a 40 mile ride yesterday and it did work well. But I still don't like how the chain slips when moving from the large chainring to the small one. It's not that bad, but it annoys me. The chain also rattles while switching from the small to large chainring. Also not that bad, but... I also like one less derailleur to worry about with the 1X system. I did have some issues while on my tour with the FD. I don't care at all about weight. My touring bags will be 40-50 lbs. What's another pound or so. I also have seen no issue with crank arm failures on either of my bikes (S40 and V20), both of which have the Ultegra HolllowTech II cranks. Both are 165mm.

I don't think you want to just remove the small chain ring to make it a 1X. The large chainring needs to move to be aligned to the center of the freewheel or you may have cross chain stresses. I wouldn't mind using the cranks I have but I think I have to get cranks that are designed for the 1X drive. I also think (not sure

The SRAM Eagle rear mechs for 50t cassetes are specifically 1*12, I think. You need to adjust the B-screw for a small changes of chainrings and for bigger changes adjust chain length, if you want to be able to shhift all cogs. (Or have a carefully placed idler to counter the chain length difference.)

I just ordered all the components for the conversion last night from Pro Bike Supply.

Includes:

SRAM GX Eagle Chain - 12-Speed, 126 Links, Gray
SRAM GX Eagle XG-1275 Cassette - 12-Speed, 10-52t, Black, For XD Driver Body
SRAM Rival eTap AXS HRD Shift/Brake Lever and Hydraulic Disc Caliper - Right/Rear, Flat Mount 20mm Offset, 1800mm Hose, Black, D1
SRAM Rival eTap AXS HRD Shift/Brake Lever and Hydraulic Disc Caliper - Left/Front, Flat Mount 20mm Offset, 950mm Hose, Black, D1
SRAM GX Eagle AXS Rear Derailleur - 12-Speed, Long Cage, 52t Max, Lunar
SRAM Battery & Charger
$949.00

I purchased from Wolf Tooth:

Set of 4 Chainring Bolts + Nuts for 1X
$24.95
Chainring -- 110 BCD Asymmetric 4-Bolt for Shimano Cranks, Drop-Stop B / 50T
$89.95

I plan to put the Shimano components back on my S40 so it's functional again. I made it into an eBike.

I appreciate the suggestions to help me decide how to go about this.

 

[Mathew Fy]

You may need extra chain. On my V20c with SRAM Eagle 10-52 with 46 tooth chainring and standard chainstay, the 126 link chain was just enough. But when I had on a larger chainring, I had to add a few links. So I made three chains from four and cycled through them, fresh waxing in between.

Also, I expect the hydraulic hose length may be too short. I've had to buy longer hoses and (depending on the brake) adapters.
See the second photo of this post for a Jagwire adapter being used.

V20c disc brake adapter - solved

Does anyone know what disc brake adapter I need on the rear? I have 140 mm disc brake an SRAM Red (road) hydraulic caliper. @Robert Holler , @Jim Parker ?

forum.cruzbike.com

 

[Mathew Fy]

BTW, I think the 50 tooth chainring is a bit steep unless you're going after high speed. I get by with the smaller one. Here I'm able to pedal up to 40+ mph with my set-up.

I would even consider a smaller one if I was to do some loaded touring. I want to be able to pedal at 80 rpm up a long steady climb.

 

[Black Hawk Down]

You may need extra chain. On my V20c with SRAM Eagle 10-52 with 46 tooth chainring and standard chainstay, the 126 link chain was just enough. But when I had on a larger chainring, I had to add a few links. So I made three chains from four and cycled through them, fresh waxing in between.

Also, I expect the hydraulic hose length may be too short. I've had to buy longer hoses and (depending on the brake) adapters.
See the second photo of this post for a Jagwire adapter being used.

V20c disc brake adapter - solved

Does anyone know what disc brake adapter I need on the rear? I have 140 mm disc brake an SRAM Red (road) hydraulic caliper. @Robert Holler , @Jim Parker ?

forum.cruzbike.com

Thanks for the tips. That's saves me the frustration of finding both too short while in the middle of a build. I'm curious, what method did you use to add the extra links? Quick links or did you buy new pins or did you reuse the old pins? I'm unfamiliar with SRAM products.

When looking for the Jagwire adaptors, they didn't have a selection for Rival brakes, but I believe they are the same in function as the Red and Force designs. I ordered adaptors and hose. I'm sure I can return if they don't work.

Yes.. I was wondering what brake adaptor I would need for the V20. Thank you very much for the link to the thread with the appropriate adaptor. I remember going through adaptor hell when putting larger rotors on my S40.

Oh! No! I just realized the mullet group set that I purchased does not include rotors. Guess I'll have to pick some out before I figure out the correct brake adaptors. I tend to go with the largest rotors I can fit with the given brakes. I like stopping especially with a full touring load. I recall going down the 6000 ft grades coming out of CA, fearful that my brakes would turn to liquid.

BTW, I think the 50 tooth chainring is a bit steep unless you're going after high speed. I get by with the smaller one. Here I'm able to pedal up to 40+ mph with my set-up.

I would even consider a smaller one if I was to do some loaded touring. I want to be able to pedal at 80 rpm up a long steady climb.

I hear you on the chainring size. I tried to match the speeds I see with my current setup using the BikeCalc.com calculator:

BikeCalc.com - Bicycle Gear Speed Chart

I don't know what cadence to input as I don't measure it. I find it useless unless I need the info for this calculation. Here's the results when imputing the new setup and assuming 80 rpm:




Which is pretty close to what I get now with the Ultegra setup. I am assuming that I converted to 26 inch wheels from the current 700 mm and 1.5" tires from the current 1". If this is wrong, it would be nice to know so I can order a smaller chainring. I guess I could try it and replace it if it doesn't work.

Thanks!

 

[Black Hawk Down]

BTW, I think the 50 tooth chainring is a bit steep unless you're going after high speed. I get by with the smaller one. Here I'm able to pedal up to 40+ mph with my set-up.

I would even consider a smaller one if I was to do some loaded touring. I want to be able to pedal at 80 rpm up a long steady climb.

Gotta say.. you can move on that V20. I rarely hit 40 mph, and when I do, I'm gripping the handlebars like I'm hanging off a cliff. Peddling isn't an option after 30 mph. Guess I'll have to buy a blue tooth cadence kit as I use my phone (RideWithGPS) for all my metrics. I currently have no Idea what my cadence is.

Edit: I just ordered a Wahoo cadence and speed sensors.

 

[Frito Bandito]

...I appreciate the suggestions to help me decide how to go about this.

Glad to hear you made a good decision about what to go with. I'm not sure how well my input comes across, but what I try to do is include what works for me for my situations. I hope and believe that most readers take into account their situations when deciding what they will use.

 

[Mathew Fy]

My cadence input comes from the power meter.

Another heads up:
The brake adapter thread I shared was specifically aimed at the V20c with its newer brake mounting standard. For older models look here, it may vary with your caliper, though:

The Blue S40 Build

Hi, Not having built a bike before I have just received a lovely Electric ? Blue S40 Frameset in Wales, UK. Can't believe it was delivered in 4 days. I can't that in my own country! I am currently ordering parts. I hope you don't mind what you guys probably think are stupid questions, but...

forum.cruzbike.com

V20 build

Hi Gang, I am planning on buying a V20 and building it up with Di2, my wheels will have hydro disk brakes. My question is what type of disk brake caliper mount does the V20 have? I own a Silvio, was going to upgrade to DI2 but figured I'd just go V20 all new. On the Silvio I would need to use a...

forum.cruzbike.com

Anybody using a disc brake on the front wheel of new V20?

By the way even on the big 6000' decent where I mentioned me wanting to 180 rotor up front, I never felt the 140 in the rear to lack power. I good rider will do 80% of their braking with the front due to weight distribution under braking load.

forum.cruzbike.com

 

[Mathew Fy]

what method did you use to add the extra links?

I think I used a KMC quick link for 12 speed to add the links. I prefer a Wippermann link for the easy on-off.

Bicycle chains made in germany by Connex by Wippermann

High-performance bicycle chains, sprockets and chain wheels from Connex by Wippermann made in Germany.

www.connexchain.com

A caveat: these links can be a source of chain jumping.

Cruzbike 3000 Mile Challenge 2021

Excellent effort guys, and thanks for that suggestion Larry. I tried the refresh and it didn't stick the Top 10 badge on the segments, but my name still appears on the leaderboard with those efforts, which is fine. They will get topped soon anyway so it's not really a big deal.

forum.cruzbike.com

 

[Black Hawk Down]

My cadence input comes from the power meter.

Another heads up:
The brake adapter thread I shared was specifically aimed at the V20c with its newer brake mounting standard. For older models look here, it may vary with your caliper, though:

The Blue S40 Build

Hi, Not having built a bike before I have just received a lovely Electric ? Blue S40 Frameset in Wales, UK. Can't believe it was delivered in 4 days. I can't that in my own country! I am currently ordering parts. I hope you don't mind what you guys probably think are stupid questions, but...

forum.cruzbike.com

V20 build

Hi Gang, I am planning on buying a V20 and building it up with Di2, my wheels will have hydro disk brakes. My question is what type of disk brake caliper mount does the V20 have? I own a Silvio, was going to upgrade to DI2 but figured I'd just go V20 all new. On the Silvio I would need to use a...

forum.cruzbike.com

Anybody using a disc brake on the front wheel of new V20?

By the way even on the big 6000' decent where I mentioned me wanting to 180 rotor up front, I never felt the 140 in the rear to lack power. I good rider will do 80% of their braking with the front due to weight distribution under braking load.

forum.cruzbike.com

I was not aware that there was a change. Thanks for the links. I'll check them out. I have previously purchased brakes and adaptors for my S40 as I put the largest rotors that would fit, on the bike. I'm hoping the brake standard on my 2016 V20 is the same as my 2019 S40, as then I can try them on the V20 before I buying anything. If they work, I'll just reorder the same parts and be done with it. Otherwise, I'll do the research.

As far as cadence, I purchased Wahoo speed and cadence sensors that should work with my RideWithGPS app.

 

[TransAm]

I have been running SRAM Eagle AXS 1x on my V20/V20c. I use the 11-50 cassette and a 50t chainring, so I have 1:1 gearing. That definitely needs more than one chain. I just use two quick links to splice in a few extra links.

I wouldn't worry too much about being able to pedal at high speed downwind/downhill. With bags on the bike, shimmy is going to make pedaling hard at high speed too scary (and dangerous). If you can go fast enough without trying too hard, I would just save it for when you really need to pedal.

I've done CC touring on the V20, but I didn't carry that much. I didn't weigh it, but definitely less than 40lbs (when I did TABR I was under 40 lbs, including winter gear for the rockies and a sleep system). I just used one rear rack-top bag on the V20 (no paniers) and a top-tube bikepacking bag under the slider/boom, plus the Moose Pack. You need to be careful about swaying bags. They can set up a resonance with the bike, and that can cause big problems on any bike, but especially the V20. And if you want to go fast, forget about paniers.

I assume you decided to stick with 700c wheels? Otherwise you are going to need a bigger boat (chainring).

 

[Black Hawk Down]

I have been running SRAM Eagle AXS 1x on my V20/V20c. I use the 11-50 cassette and a 50t chainring, so I have 1:1 gearing. That definitely needs more than one chain. I just use two quick links to splice in a few extra links.

I wouldn't worry too much about being able to pedal at high speed downwind/downhill. With bags on the bike, shimmy is going to make pedaling hard at high speed too scary (and dangerous). If you can go fast enough without trying too hard, I would just save it for when you really need to pedal.

I've done CC touring on the V20, but I didn't carry that much. I didn't weigh it, but definitely less than 40lbs (when I did TABR I was under 40 lbs, including winter gear for the rockies and a sleep system). I just used one rear rack-top bag on the V20 (no paniers) and a top-tube bikepacking bag under the slider/boom, plus the Moose Pack. You need to be careful about swaying bags. They can set up a resonance with the bike, and that can cause big problems on any bike, but especially the V20. And if you want to go fast, forget about paniers.

I assume you decided to stick with 700c wheels? Otherwise you are going to need a bigger boat (chainring).

I did buy 3 chains. I expected to have to do some splicing.

I don't worry about riding at fast speed while touring as I don't do that anyway. In the past, I have loaded up my V20 with a large Radical Design banana panniers and had way too much wobble just riding normally down the road. I tried to move everything to a very lightweight trailer (DOM T2) but had the same problem. I was carrying ~70 lbs and I weighed about 225 at the time. This was way too much for the V20. I'm expecting to lose all my weight for my next tour and not carry camping or cooking equipment. That will put me at around 170 lbs and the gear at around 40 lbs. I'm hoping the V20 will be able to handle the lower weight.

I think I used a KMC quick link for 12 speed to add the links. I prefer a Wippermann link for the easy on-off.

Bicycle chains made in germany by Connex by Wippermann

High-performance bicycle chains, sprockets and chain wheels from Connex by Wippermann made in Germany.

www.connexchain.com

A caveat: these links can be a source of chain jumping.

Cruzbike 3000 Mile Challenge 2021

Excellent effort guys, and thanks for that suggestion Larry. I tried the refresh and it didn't stick the Top 10 badge on the segments, but my name still appears on the leaderboard with those efforts, which is fine. They will get topped soon anyway so it's not really a big deal.

forum.cruzbike.com

I already have a bunch of SRAM quick links. I've had good luck with those.

 

[TransAm]

I already have a bunch of SRAM quick links. I've had good luck with those.

The SRAM are not re-usable. Most of the aftermarket are, which can be handy. CB used to sell a small quick link opening and closing tool, but I don't see it listed any more.

 

[Black Hawk Down]

The SRAM are not re-usable. Most of the aftermarket are, which can be handy. CB used to sell a small quick link opening and closing tool, but I don't see it listed any more.

Well, that's interesting because I've reused them dozens of times without issues.

 

[TransAm]

Well, that's interesting because I've reused them dozens of times without issues.

OK, maybe they have changed. The old ones were one-shot.

 

[Steve Heywood]

Well, that's interesting because I've reused them dozens of times without issues.

Me too. The latest ones I used on my Bacchetta chain last week didn’t seem to have the same snap that they normally do, I used light hand pressure to seat them which was a bit of a worry

 

[Black Hawk Down]

You may need extra chain. On my V20c with SRAM Eagle 10-52 with 46 tooth chainring and standard chainstay, the 126 link chain was just enough. But when I had on a larger chainring, I had to add a few links. So I made three chains from four and cycled through them, fresh waxing in between.

Hi Mathew,

I did finally reduce my front chainring from 50t to 46t, so I have the same setup as you on my V20. I have not been able to get the derailleur micro-adjusted to work properly with the new setup. The worst problem is when shifting from the 12th gear to the 11th, it won't go in. Going the other way is no problem and I can also shift from 11th gear to the 10th with no problem. Most of the gears seem well aligned (except for the 11th gear issue), but when I'm shifting into the lower two gears (1 & 2), I have trouble getting all the rattling out. When in 2nd gear, I can visually see the edge of the chain catching on the 1st gear at times. I can't seem to adjust this out, without wrecking the alignment for the rest of the gears. There is noticeable chain sound that makes me think the chain is too tight. Using the SRAM recommendation of wrapping the chain around the front and largest back cog, there should be 2 links overlapping. When I did this it seemed way too tight, so I added an extra link. I'm currently at 129 links.

After much emailing with the online shop were I purchased the SRAM upgrade package, they think the chain is too tight, probably due to it being a recumbent. My questions are:

1. How do you properly size the chain for a V20 with the current setup that we both appear to have?
2. How many chain links are you using?
3. Are you seeing any chain issues with your setup?

I do know how to properly setup the b-screw. I can set it manually, which matches the setup using the SRAM b-screw tool.

Thanks!

 

[Mathew Fy]

Hi Mathew,

Mine continues to work flawlessly. Except yesterday when the chain was off the upper derailleur pulley, easily fixed.
Here's my set up:


The B-limit or tension screw. I didn't have to adjust mine at all, it worked correctly out of the box. Click here for a guide.


The limit screws on the underside. You may have to back out the left side a bit to allow shifting into the biggest ring. Again, I was lucky in not having to adjust mine.