My new Custom GMAC build

stanmiller

Active Member
...and finding 36h rims can be a REAL PITA..I tried)

I rebuilt my wheels with 26" Sun Ringle Rhino XL (36h) rims. And have Maxxis Holy Roller's 2.4 mounted.

These wheels are also compatible with rim brakes should you go that route. I have Shimano BR-T4000 rim brakes on my electric Electra Townie with Clark pads and can lock the wheels.

Though in short supply you can find Rhino XL's online.

Another option is Sun Ringle's MTX-33 (though this one is disc only)

And there are Velocity Ciffhanger's - but expensive.

Good luck with the build!
 

linklemming

Well-Known Member
Thanks for the links, I searched universalcycles quite heavily(they are the ONLY place in the US to have a surly ECR size M frameset) but somehow missed those rims.

Those rims appear to be about 24mm (give or take) inner width so they are about the same as the weinman dm30 that grin built the wheel with.

All my existing 26 wheels are built on 19mm inner width rims so I decided to get a wider front wheel as well. Finding a 26wheel with 9x100 QR and a wider rim took along time to find. I found a front wheel with 30mm inner width rim for $100 from halowheels. Hubs are pretty cheap cup/cone but good enough for now. I should have no issue running up to 2.4 tires on these rims.

Velocity seems to have 26 inch 36h rims with 30mm and 39mm inner width with the Blunt 35 and Dualie respectively.

Supposedly the Troll can take a 26x3 tire so that tire with the Dualie Rim could be in the future.

So many options/ideas.
 

linklemming

Well-Known Member
Initially I planned on reusing alot of parts, in the end I lost control and bought all new parts including frame. I am reusing 1 rear brake rotor, a luna 52V 13ah battery and a set of handlebars, a stem and grips..

So far the total cost is right at $3k(without battery). Building your own bike is never cost effective but you usually get much better parts. I didnt go super high end but parts specced are much better than you get on many $3k stock ebikes. Most bikes I have built up are still running strong on the parts I chose after 5+years (some over 10 years).

I will post a list of parts tomorrow if people are interested.

Wont get all the parts till next thursday.

I put all the bike details into bikecad (fun tool to play with) and now have a good idea of what headset spacers/stem/handlebars will be needed.

Bikecad is highly recommended
https://www.bikecad.ca/
 
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linklemming

Well-Known Member
Here is the total cost breakdown
trollbuild.PNG
 

linklemming

Well-Known Member
Got the frame today. There are lots of diehard Surly Fans and I can see why, the frame is a beauty. I cant imagine a better frame manufacturer for an ebike conversion. I will cover more details later, its been a long day. This frame(troll) while not my first choice, seems like it will exceed my expectations.

Anywho, here is a picture as I mockup and try different things. By no means the final setup
IMG_20201029_220759384_HDR.jpg
 
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Deacon Blues

Well-Known Member
Love your build. 👍
Even though I recently bought a new ebike and I have another new ebike coming in December, but I have a strong urge to do a DIY build. Yours is spot on to what I'd build.
 

linklemming

Well-Known Member
Still prototyping but here is a pic. Again more details once I get it all finalized. Weighs 50lbs at this point just missing rear brake and the left pedal.
IMG_20201030_213435600_HDR.jpg


Had some issues with the crankset (the spider that bolted to the bottom bracket). It wouldnt bolt on square so the crankring wobbled quite a bit, I had to slowly enlarge the mounting holes as they were binding when tightening it all down. Spent 2 hours on this. The left crankarm also wouldnt accept the pedal so I had to order a tap/die top open up the threads so no ride till sunday:(

Also, the rear brakes seems stuck with USPS near chicago. I guessing it was thrown in a ballot harvesting box by accident so I should be seeing it promptly next week. :cool: I really like these shimano deore 6100 brakes so I might just order another pair and have them shipped UPS and if I endup with two pair, I will replace the SRAM brakes on another bike.

Initially hooked up the Phaserunner, Cycle Analyst and throttle and tried some throttle power. Warning to others who might try this, the motor starts up but when the speed gets higher, the motor controller makes the motor stop sporadically and dramatically (like someone threw a wrench in the gears). I thought the motor was damaged. If the torque arm wouldnt have been hooked up, the mtor would have likely damage the power cable by spinning in the dropout. This might not be the issue if you order it all as a kit (I ordered many parts seperately).

The Phaserunner needs to be tuned to the motor using pc software (linux, windows or macos) with a serial to USB cable that need to be bought seperately. Make sure to heed all warnings in the phaserunner manual when autotuning(like motor might initially run backwards so pedals might get stuck on something like kickstand). Initially got a few overcurrent errors but it finally started working/tuning and the motor runs fine now. With the battery at storage voltage(53V), the motor spins up to 31.6mph unloaded and I have not even tuned the FOC(higher top speed due to reduced back emf) yet.

I think Im really going to like this ebike:)
 
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Deacon Blues

Well-Known Member
@Comfortably Numb I test rode a Hilleater last year on Saltspring. The 'good' is the bike is fast and it really is a hill-eater. The 'bad' is the build quality of the bike. The electric components from Grin are top-notch, but the rest of the bike felt cheap.
I recommend, if possible, that you test-ride the bike before you buy one.
 

linklemming

Well-Known Member
Just another quick update today(no pics).

Played around configuring the phaserunner and CA thru my pc. Its quite refreshing to be able to change so many behaviors and setting. The Cycle Analyst is so well designed although big and bulky

Played around with field weakening settings on the phaserunner software with the following results.

Field Weakening Amps PWR (unloaded) Speed(Unloaded)
------------------------- ------------------ -------------------
0 112 watts 31.6mph
5 120 watts 34.7mph
10 147 watts 39.4mph

Note that these are unloaded speeds, my main reason for setting this up is to increase my downhill coasting speed which for this motor gets limited by back emf just like a DD motor.
 
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linklemming

Well-Known Member
Took lots of pics tonight, will post them all tomorrow with build info.

In the meantime, I wanted to discuss why I think surly frames are good for DIY builds.

While I prefer MTBs, most of the surly MTB frames were made for 1x setups and big tires with short chainstays. As such its hard to get a large chainring on the front without spacing the chainring out which could cause chainline issues. There are many workarounds for this...all with limitations (like not using the biggest rear cog).

Im 6ft with a 32inch true inseam. I typically fit a 19" bike perfectly, choosing between an 18inch and 20inch frame is always a crapshoot with me usually going with the 18 for maneuverability.

The flat bar surly bikepacking bikes I was considering for an 27.5x2.6 tire, surly follows the 18inch/20inch frame size:

All surly bikes have welded on inserts for mounts as opposed to rivnuts which a big deal for mounting a battery IMHO.

Bridge Club - a little lower priced frame as it removes several bells/whistles from other frames (dropout style, less reinforcement and likely lighter more flexy tubing). While its touted as a bikepacking bike, I would consider it on the lighter side of that. Vertical dropouts and old style 100mm front hub spacing and 138mm gnot-boost rear spacing(as opposed to 135mm) which is exactly what most hub motors seem to have. Note that its pretty easy to spread or shrink the rear dropouts a few mm. To get a 42t chainring would require the large chainring on a 2x boost spacing. Classic old school mtb geometry. If you wanted a frame for a hub motor with 12mm or 14mm axle with 10mm flats, this would be the best bet IMHO. Can fit a 180mm rear brake rotor. Cant find them in stock anywhere. Surly typically gets the new model year mid-november.

Surly Ogre - Can take a 1x Mtn spaced 42t chainring. I have seen a Bafang BBSHD 42t leekie chainring build using this frame with minimal spacers so its good for that conversion as well. Head angle a little steeper(72 degrees) than I would like but not a deal breaker. Has 145 gnot-boost horizontal dropouts with adapter washers for 10x135 solid axles or 9x135 QR (I will show more details on how this works for my build when I post pics tomorrow). Can fit a 160mm rear rotor. Cant find them in stock anywhere. Using a hub motor with 12mm or 14mm axle with 10mm flat would require a custom piece to work with this frame.

Surly ECR - Appears to be the most robust and heaviest frame(along with the troll) meant for the most extreme bikepacking, I almost bought one of these in a medium but Grin didnt have any rims for the prebuilt wheel option to suit this frame and tire combo (27.5x2.6). In the end, the medium would have been the wrong frame for me(too small). It has the same horizontal dropout design as the Ogre. I could only find a medium in stock, no other sizes available anywhere.

Surly Troll - Pretty much what the ECR is but for 26inch tires for expeditions where 27.5 and 29 tire sizes might not be supported (third world countries). Definately not my first choice. Can support a 1x Mtn spaced 42t chainring just like the Ogre. Same rear dropout design as the Ogre and ECR. I found a frame in Large(20 inch) which isnt typically what I would pick but its PERFECT. It has good standover, reach and enough tire spacing to go to 27.5x2.4 definately and maybe even 27.5x2.6. In the end, I think covid karma made me get this frame and the name matches my avatar :cool:
 
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@Comfortably Numb I test rode a Hilleater last year on Saltspring. The 'good' is the bike is fast and it really is a hill-eater. The 'bad' is the build quality of the bike. The electric components from Grin are top-notch, but the rest of the bike felt cheap.
I recommend, if possible, that you test-ride the bike before you buy one.
The build quality is my issue too. I need to see one in the flesh.
I have several bikes on my short list but the Hilleater's performance got my attention.
I might have to give up some performance for build quality and go with something else. Bummer, 'cause I like the idea of messing with the output. 107 nm torque would be great.
I understand there is an 'in town' rep floating around now where can see, and demo one, so I'll have a look.
Thanks. CN
 

linklemming

Well-Known Member
Well, the bad threads on one of the crankarms appears to be due to the pedal having bad threads. Ran a Tap 9/16-20 LeftHand Tap on the left crankarm, no issues. Luckily I bought a tap and a die so I tried the die on the pedal and just could not get the die to cut threads. Not sure what the hardness of pedal spindles are but I have never encountered that before.

Using pedals from another bike for now, will be doing a test ride tonight
 

linklemming

Well-Known Member
Still need to show alot of detailed build pics but wanted to share a ride report so here is a pic after the ride. Still need to clean up and protect wiring and make the Cycle Analyst sit lower.

No back brake unfortunately, I tried some old avid BB7s in the rear temporarily but the GMAC motor blocks the inner pad adjustment so I couldnt use them . First stop was interesting when your grab the back brake and its not there😀

postride.jpg


So here is the ride report summary: WOW

Seriously, I couldnt be happier with this setup.

Frame: More than stiff enough for the power Im putting thru it. This frame is rated for a 300# rider with 55#gear. I have owned/ridden flexy touring frames and this frame is solid. Maybe too solid.

Tires: Smart Sam 26x2.35. I really like these tires. I dont do alot of pavement riding (just ride pavement to get to more dirt). Better offroad traction than my marathon plus MTB.

GMAC+CA+torquesensor: I am TOTALLY HAPPY with this setup. Not as responsive as my Brose bikes....but really close. While I love the Brose bikes when going really slow and uphill and in technical terrain (eMTB), all of that is less important as you get to higher speeds and gravel rides which I built this bike for. Definately better than my juiced CCX as far as responsiveness. Everything is adjustable thru the CA but I am pretty happy with most of the stock settings. I initially had it setup with up to 4x assist of human power with 4 assist levels. With Just pedaling input, it would top out about 26mph on level ground, With throttle on level ground I got it up to 32mph (1550watts), up to 40mph on a 3% downhill. I think I will go up to 5x human power and 5 levels of assist. Might take off the throttle and leave in my camelback as it just seems like the most boring way to ride an ebike...IMHO. An interesting observation compared to my Juiced CCX. I found that I only like riding the juiced at higher speeds and assist levels. I used it more for my off days or for longer rides due to the battery size. Not so with this setup. Im just as happy slowing it down and enjoying the ride. I suspect its the better torque sensor response as I feel more in tune with the bike.

FWIW, Im running with no ebrake cutouts and love it. This always annoyed me on the CCX. While waiting at a stoplight, the CCX would sometimes jump out from under me if I put pressure on the pedal in just the right way so I always would use the brakes while stopped which would then cause a delay as I wanted to get going again. I can still use the brakes with this setup, just no motor cutout/delay.
 
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linklemming

Well-Known Member
The build quality is my issue too. I need to see one in the flesh.
I have several bikes on my short list but the Hilleater's performance got my attention.
I might have to give up some performance for build quality and go with something else. Bummer, 'cause I like the idea of messing with the output. 107 nm torque would be great.
I understand there is an 'in town' rep floating around now where can see, and demo one, so I'll have a look.
Thanks. CN
The build quality was always an issue with the Juiced CCX as well (at least for me). While it was fast and cost effective for the performance, it just felt cheap
 

JRA

Well-Known Member
"and make the Cycle Analyst sit lower."

I wondered if that wasn't going to bother you....not sure if it would work out but you could flip it 180d and point it to the side of the steerer tube so it sits behind the bar? I made some plates that do that as that aspect bothered me also using the stock mount plus it took up real estate on the bar....

thumbnail_IMG_1982-1.jpg
 

linklemming

Well-Known Member
"and make the Cycle Analyst sit lower."

I wondered if that wasn't going to bother you....not sure if it would work out but you could flip it 180d and point it to the side of the steerer tube so it sits behind the bar? I made some plates that do that as that aspect bothered me also using the stock mount plus it took up real estate on the bar....
Thanks for the pic, I would have never thought of doing that.

Yeah it does bother me being up that high and overall just being so darn big. I had planned on moving an origin8 strongbow bar over to this bike but the cycle analyst will likely keep me from getting on the aero front of the bar.

Waiting on a new 40mm rise handlebar, me thinks with a lower rise stem and this bar, it wont look so bad.

Im using the CA steering bracket from grin, easy enough to bend to get it lower
https://ebikes.ca/shop/electric-bicycle-parts/ca-accessories/ca-steerbracket.html

Rode 30 miles tonight, mostly with 1x assist and 2x assist with some 5x assist at the end. 5x assist is just stupid...fun but stupid

My Juiced CCX is going up for sale very soon
 
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JRA

Well-Known Member
Thanks for the pic, I would have never thought of doing that.

Yeah it does bother me being up that high and overall just being so darn big. I had planned on moving an origin8 strongbow bar over to this bike but the cycle analyst will likely keep me from getting on the aero front of the bar.

Waiting on a new 40mm rise handlebar, me thinks with a lower rise stem and this bar, it wont look so bad.

Im using the CA steering bracket from grin, easy enough to bend to get it lower
https://ebikes.ca/shop/electric-bicycle-parts/ca-accessories/ca-steerbracket.html

Rode 30 miles tonight, mostly with 1x assist and 2x assist with some 5x assist at the end. 5x assist is just stupid...fun but stupid

My Juiced CCX is going up for sale very soon

It looks like you have quite a few spacers and basically that is what the Grin bracket as well as the ones I made are in essence? Don't be afraid to add it to the underside of the stem in other words to get it lower.

I have some fast hub bikes also and it's true that under the right conditions, aka nobody watching, it can stupid fun.