llavalle's A4X Build

[Robert Holler]

The s

Thanks for following up Robert. I received a package from you guys that included the required shims and washers for the QR skewers and a replacement shock. Haven't had the time to test the new shock but the spacers obviously fix the issue.

I was expecting a bit of an early adopter tax here, especially on a frameset No worries at all! I've also added longer screws for the bottles, I had a bunch lying around.

I just need to see if a new cable housing makes everything better for shifting. My chainline is sitting at exactly 49mm now but I'm wondering if the factory bike is narrower since it uses a "BSA Road BB" with a +6mm offset making it narrower (likely 45.5mm or 47.5mm).

A 49mm chainline should work, I have another bike with a 142 ThruAxle and a 49mm chainline with the exact same groupset (Shimano Deore 11 speed with a 11-51) but perhaps the chainstay is longer on the cruz? I'll do a few tests tonight

View attachment 20105

The stock setup chainline looks to be right around the 46mm mark.

Robert

 

[Robert Holler]

Ok... I feel stupid now. The BiMotal setup clearly fits perfectly fine on the front wheel

View attachment 20102


View attachment 20103


I installed the shifter and started to adjust the derailer but I think something might be up. Chain line looks really extreme to me and can't get the 11 speed to work reliably... I think my cable housing might be wrong (even though it's branded Shimano SIS). I'm getting Jagwire housing delivered tomorrow to see if that fixes the issue!

Might be the derailleur hanger too - looks good to the eye but perhaps it's just slightly bent (in transit). I have a tool to check this somewhere but can't find it right now.

Stay tuned!

Cat is out of the bag with your post - the Bimotal is the system I have been messing with. If you can figure out a mechanical caliper that works let me know. The company has offered to help design a specific mount for us that will work with all our current modes other than the V.

The challenge is the brake for sure.

 

[llavalle]

The stock setup chainline looks to be right around the 46mm mark.

Alright, after measuring another 1x11 bike I had lying around with the exact same chainline (49mm), I fixed my issues with proper JagWire cables and housing. Everything shifts beautifully now! We're good but thanks for checking.

Cat is out of the bag with your post - the Bimotal is the system I have been messing with. If you can figure out a mechanical caliper that works let me know. The company has offered to help design a specific mount for us that will work with all our current modes other than the V.

The challenge is the brake for sure.

Interesting - in the Front I assume? Cause it won't fit on the back of the A4X (180mm rotor doesn't fit). I know that they were working on a 160mm version too but it's not out yet and will limit speed.

I actually asked the BiMotal folks about it and they said "only 1 mechanical brake is compatible and it's more expensive than good quality hydraulic ones".

After a bit of digging, I found those : Growtac Equals. https://growtac.com/eng/products/mdcs/

There's a review on VeloOrange that states "Works with Bimotal"


You can see the caliper mounted on the Bimotal mount



These things.. are... expensive...
https://velo-orange.com/products/growtac-equal-brakes-post-mount $405 USD but they come with high quality compression-less housings

Only come in pairs even if we only need one
Maybe you guys should order a bunch and sell us only one?

I'd be super interested in their system. They told me I could run their regular adapter on top of a flat-mount to post-mount adapter since it's not like traditional "adapter stacking" where you put longer screws and the adapter acts as a "washer". FM to PM mounts are fully screwed in and the caliper has threaded holes to secure it to the adapter. The TRP FF-2 is perfect https://trpcycling.com/products/flat-mount-to-post-mount

What were you guys thinking for battery location?

 

[llavalle]

Installed my TRP Spyre. Still need to do the bedding cause right now they brake like crap




Used the Shimano Tiagra levers. They look almost similar to my old XT levers. SUPER smooth actuation and convertible from Long Pull to Short Pull (picture is short pull)

You can also see the grips - they are a bit on the long side so the push the shifter a bit far but it still fits ok. Used a Deore 11 speed without a display



The Jagwire really makes for a clean install



Bike is usable now! Left plenty of housing to allow for fitting the bike




I still need to trim some of the tie-wraps. Decided to use rubber lined tie wraps, LOVE those. They are also re-usable!







Now I'm just missing lights and reflectors!

 

[Greg S]

I have GrowTac Equals on both my Cruzbikes (V20c and S40). Excellent brakes that come with everything: 2 complete sets of housing (compressionless and regular), brake cables for both road and mountain brakes, ferrules, crimps, …). The only thing “missing” was I needed longer brake cables than supplied on both bikes. I have road shifters (SRAM) on the S40 and mtb shifters on the V. I ended up buying tandem brake cables in both cases.

Excellent brakes ‘tho expensive, as noted.

 

[Robert Holler]

Alright, after measuring another 1x11 bike I had lying around with the exact same chainline (49mm), I fixed my issues with proper JagWire cables and housing. Everything shifts beautifully now! We're good but thanks for checking.


Interesting - in the Front I assume? Cause it won't fit on the back of the A4X (180mm rotor doesn't fit). I know that they were working on a 160mm version too but it's not out yet and will limit speed.

I actually asked the BiMotal folks about it and they said "only 1 mechanical brake is compatible and it's more expensive than good quality hydraulic ones".

After a bit of digging, I found those : Growtac Equals. https://growtac.com/eng/products/mdcs/

There's a review on VeloOrange that states "Works with Bimotal"

View attachment 20106
You can see the caliper mounted on the Bimotal mount

View attachment 20107

These things.. are... expensive...
https://velo-orange.com/products/growtac-equal-brakes-post-mount $405 USD but they come with high quality compression-less housings

Only come in pairs even if we only need one
Maybe you guys should order a bunch and sell us only one?

I'd be super interested in their system. They told me I could run their regular adapter on top of a flat-mount to post-mount adapter since it's not like traditional "adapter stacking" where you put longer screws and the adapter acts as a "washer". FM to PM mounts are fully screwed in and the caliper has threaded holes to secure it to the adapter. The TRP FF-2 is perfect https://trpcycling.com/products/flat-mount-to-post-mount

What were you guys thinking for battery location?

I can confirm with you that the Growtac does NOT fit. I was doing a rear fit attempt on the S40. Indeed our dropouts are not technically designed for rotors that massive - becasue why would they be - though on my A4x there is a few mm clearance for the Bimotal rotor. It's not ideal but would work.

It fit that one time for that one reviewer - but the newer Bimotal adapter has a beefier area around the plug attachment - that blocks the caliper from fitting. That was my experience. It could possibly be modified but thats not something I am willing to deal with. Also the caliper is simply too expensive to be part of a conversion kit option.

The sad news is that a low profile mechanical caliper is a rare find, and at the Taipei Cycle show this year - it became flat obvious that mechanical disc brakes are going to be extinct - or relegated to the cheap bin - in just a few years. Literally ALL of the manufacturing companies had ONLY hydraulics on display.

 

[llavalle]

I can confirm with you that the Growtac does NOT fit.

It fit that one time for that one reviewer - but the newer Bimotal adapter has a beefier area around the plug attachment - that blocks the caliper from fitting. That was my experience.

Oh crap - good catch and good to know for sure!

I've been exchanging emails with Jeremy from BiMotal - he's yet to confirm which caliper he was hinting at.

I guess I might just convert to regular drop bars on my A4X and install a road groupset with hydraulic brakes that are compatible. Flat bar hydraulic levers are really problematic at that angle.

 

[llavalle]

This looks promising too --> https://www.cyplore.com/

It's not out yet but it's a super small hub motor with a small bottle type battery. Total weight is listed at 1.7kg. Seems to use the recess in the thru-axle as a torque arm.



Edit : no throttle, pedal assist only.

 

[kizarmynot]

Decided to use rubber lined tie wraps, LOVE those.

Didn’t know these existed. They may make attaching a bottle cage to the Q45 slider much more secure. Thanks!

 

[Doccus]

Installed my TRP Spyre. Still need to do the bedding cause right now they brake like crap

View attachment 20108


Used the Shimano Tiagra levers. They look almost similar to my old XT levers. SUPER smooth actuation and convertible from Long Pull to Short Pull (picture is short pull)

You can also see the grips - they are a bit on the long side so the push the shifter a bit far but it still fits ok. Used a Deore 11 speed without a display

View attachment 20109

The Jagwire really makes for a clean install

View attachment 20110

Bike is usable now! Left plenty of housing to allow for fitting the bike

View attachment 20111


I still need to trim some of the tie-wraps. Decided to use rubber lined tie wraps, LOVE those. They are also re-usable!

View attachment 20112


View attachment 20113


Now I'm just missing lights and reflectors!

Thanks for heads up on Grip Lock Ties! I haven’t heard of them. I ordered a pack today.

 

[llavalle]

Thanks for heads up on Grip Lock Ties! I haven’t heard of them. I ordered a pack today.

It's an aviation product so if anyone's looking for them outside of the USA, check your aviation supplier. Aircraft Spruce carries them for instance (that's where I ordered them from)

 

[Robert Holler]

Here are some pics of my experience trying to fit the Growtac caliper. As you can see it would not seat properly and the top interfered just a bit. Also in my case the lower part would contact the gear - even if it didn't have the upper interference.

The folks at Bimotal confirmed with me after that there have been changes to their bracket since likely when that review was posted about it on the Velo Orange site.

 

[llavalle]

Here are some pics of my experience trying to fit the Growtac caliper. As you can see it would not seat properly and the top interfered just a bit. Also in my case the lower part would contact the gear - even if it didn't have the upper interference.

The folks at Bimotal confirmed with me after that there have been changes to their bracket since likely when that review was posted about it on the Velo Orange site.

That's a bummer. I really like the idea of this kit easily removed....

But the price is still a bit steep considering the limited life of both the large gear and motor gear (3,000 miles and 1,000 miles respectively)

Straight from their FAQ :

How long will the plastic output gear last?
There will be some variation based on riding conditions much like brake pads, but we expect the output gear to last about 1000 miles.

How long with the Rotor-Gear last?
There will be some variation based on riding conditions, but we expect the Rotor-Gear to last about 3000 miles.

It's clearly plenty for a MTB when climbing a mountain you're about to go down afterwards... but for an road / adventure bike... seems limiting. The motor gear isn't too expensive ($40) but the rotor gear is $195.

 

[llavalle]

Couple of updates today.

First - the bike fits great on my Thule T2 XTR rack, as expected.



Added a Coospo Ant+ & BT Cadence and speed sensor. Those new speed sensor are really convenient - no magnet and pickup. Just a rubber band around the hub.





I started looking at bike computers when I realized that I could just use my Garmin Watch (Instinct 2x). Supports Ant+ and BT sensors, has ton of battery life, solar charging AND a light that can be set to blink! Was about to 3d print something to put it around the handlebar but then found that Garmin has a cheap rubber piece just for this. (still need to trim the tie-wraps)



Created a custom screen with my heartrate (chest strap), cadence, speed, odometer and heart rate zone (not shown)

Received 1 of my 2 lights. a Allty 1200 with the small remote (both USB-C charging).





I would have preferred something hooked up to the ebike battery but until this thing is electrified, I wanted something to be seen. My back, flashing light is on the way as well.

Speaking of electrifying, I redid a 3d print with tighter tolerances and the torque arm actually doesn't touch the frame. VERY CLOSE, but doesn't touch.



So I decided to go with the Grin setup.

• Ordered a WTB Korm Light i25 Rim in 27.5" from FortNine and had it shipped directly to Grin - ETA is around April 17th (coast to coast shipping + they had to get the rim from the supplier)
• Ordered a Grin All Axle Front V3 with :
  • Slow Winding (7.5rpm/v). Should top out at around 32kph with 36V battery which is the legal limit for ebikes around here
  • Super Harness kit
  • Thumb Throttle + Button Thumb Throttle (one for acceleration, the other one for regen since the bi-directional twist throttle doesn't fit my shifters and I didn't feel like added a brake sensor and holding the brake + using throttle for regen)
  • Magura disk brake rotor - it's slimmer around the axle to clear the cabling. Might not be required but I'll have it in case
  • PhaseRunner (instead of base runner) since it won't be shielded in a battery enclosure
  • Mini OLED display and switch - I want a minimal setup
  • Small battery : 36V 10Ah bottle battery <- Started with that, might just use my Ego battery (without regen) - we'll see.
  • Triple Bob : to mount the battery UNDER the A4X's frame.

The torque arm will require some fab work. Same for the battery mount - unsure if I'll put it upside down and just use my heavy zip ties + 3d printed wedge to hold everything in place OR draw a nice bracket in CAD and have it bent by Send Cut Send.

In both cases, I plan to 3d Scan the rear swing arm and the frame and 3d prints a few prototypes to be able to work the kinks. For the torque Arm I could simply 3d print a "feet" for the frame but I might test the CNC capabilities of PCB Ways.

More to come!

 

[llavalle]

Forgot to add. I have just over 5km riding it (~3.1miles).

I'm sorta getting the hang of it I would say. Starting is now a non-issue after watching one of Robert's video where he gave the tip to push the opposite side instead of pulling (which I was doing). Low speed is still weird and I need 3 parking spaces to do a U-Turn

One nagging issue right now : I can't get the rear caliper adjusted properly. It might be the paint interfering but when I tighten it down, it's not perpendicular with the rotor anymore. I swapped rotors and calipers (and flat mount adapters) to no avail.

My best guess : the paint isn't perfectly flat on the caliper mounting surface and it's pushing the caliper out of alignment when torqued down. I guess I'll know more when I 3d scan the rear of the swingarm because it looks good by eye but might be off by a few degrees.. If it's the case, I guess I could carefully shim or file the flat mount plate - better than filing the frame . It might just be a burr on one of the holes or a edge (that was then painted over). I'll do a high resolution blue laser 3d scan, we'll know for sure

 

[llavalle]

Let the fun begin!

Whipped out my 3d Scanner (Einstar RockIt) - had to add a few reflective dots since the matte metallic paint wasn't great with the blue laser lines



First time really using it for real (not just for fun). That thing is SICK.

Did a super quick scan without proper lighting and everything needed :



Then simply added Grin's STEP file to an assembly in Fusion 360



Looks like the TRP Spyre will fit without adding a spacer behind the disk (and also behing the axle endcap



Now the "only" thing needed will be to think of a torque arm foot adapter or perhaps a whole new torque arm?
Then learn CAD to make it work ... 3d print a few prototypes and then have it CNC ?

Fun times ahead!

 

[kizarmynot]

Then simply added Grin's STEP file to an assembly in Fusion 360

 

[Benell]

Hi All,
Great topic llavalle. This is my first Cruzbike and I'm learning a lot.
Why not use the rear grin motor in the front wheel?
Just wondering.

 

[llavalle]

Hi All,
Great topic llavalle. This is my first Cruzbike and I'm learning a lot.
Why not use the rear grin motor in the front wheel?
Just wondering.

Couple of reasons

1. Weight Distribution - with my preferred upright seating position, lots of weight is already on the front wheel on the A4X. It's great for a front-wheel-drive bike so from a design standpoint, I get it.... I still need to put it on a scale with me on it to confirm the actual % but didn't want to make it worse.
2. Steering impact : having already ridden a normal bike with a hub motor in the front, I didn't like the impact of the steering feeling. Sure it's centered and actually "dampens" but requires lots more force to straighten back up too.
3. The front wheel of the Cruz is already trouble enough to fit in : regular cassette & disk fiddling + the 2 forks. Didn't want to add a torque arm to this!
4. The rear motor of the Grin All Axle limits your cassette options. It now uses a Shimano HG Road freehub which is better than a MTB HG but if I want to go Shimano 12 speed or Sram 12 speed with a 10teeth cog, it wouldn't work. I'm also contemplating going with a Rohloff hub drive which is a no go if the hub is up front!
5. And lastly : wiring. The battery is likely to be on the back, under the bike or somewhere around there. The motor controller is almost guaranteed to be between the seat and the seat post. Having the motor itself in the back makes everything easier.

On the plus side, the Front All Axle motor is 4.0kg instead of 4.3kg (10oz difference). On the minus I don't get built-in torque sensing.

 

[Benell]

Couple of reasons

1. Weight Distribution - with my preferred upright seating position, lots of weight is already on the front wheel on the A4X. It's great for a front-wheel-drive bike so from a design standpoint, I get it.... I still need to put it on a scale with me on it to confirm the actual % but didn't want to make it worse.
2. Steering impact : having already ridden a normal bike with a hub motor in the front, I didn't like the impact of the steering feeling. Sure it's centered and actually "dampens" but requires lots more force to straighten back up too.
3. The front wheel of the Cruz is already trouble enough to fit in : regular cassette & disk fiddling + the 2 forks. Didn't want to add a torque arm to this!
4. The rear motor of the Grin All Axle limits your cassette options. It now uses a Shimano HG Road freehub which is better than a MTB HG but if I want to go Shimano 12 speed or Sram 12 speed with a 10teeth cog, it wouldn't work. I'm also contemplating going with a Rohloff hub drive which is a no go if the hub is up front!
5. And lastly : wiring. The battery is likely to be on the back, under the bike or somewhere around there. The motor controller is almost guaranteed to be between the seat and the seat post. Having the motor itself in the back makes everything easier.

On the plus side, the Front All Axle motor is 4.0kg instead of 4.3kg (10oz difference). On the minus I don't get built-in torque sensing.

Thank you so much for answering my question, it's greatly appreciated.