Salsa Blackborow with Grin Max45

[MSF]

Bike has had a QS205 on it for years and decided to give the max45 a try to lighten the bike up a bit. Was 130lbs or so in these first two pictures

 

[MSF]

Down to 70lbs as it sits now. I have some ideas to shave a bunch more weight off.

 

[MSF]

Ran into an issue with the wires not fitting and had to do some filing. Its still not perfect but i may upgrade the phase wires to 10awg and get rid of the PAS wires anyway

 

[MSF]

Hard lesson on what rims will work with this motor being offset as much as it is. Started with a Mulefut 80 and not a chance to get even close to center. Had the brake side fully tensioned and the chain side finger tight and it was still not over far enough. Switched to a Alex Blizerk 70 and its better but still not perfect. After a bunch of searching i found a rim that will work good with almost an even tension on both sides. Bontrager Jackalope with offset spoke bed

 

[MSF]

ASI Bac4000 set to 100 phase amps for testing. I have got the wires slightly warm and the motor connector has stayed cold so far. Next step is to cut the connector off and push 150-180a to see how the motor handles it. If it heats up real fast i will just leave the original phase wires there and turn down the power.

 

[chuyskywalker]

My crazy idea for switches. Power, cruise control and street mode.

Nice. Any concerns over having drilled holes there?

 

[MSF]

Nice. Any concerns over having drilled holes there?

Not at all.

 

[gromike]

The stem is a critical, highly stressed part. A failure would be catastrophic.
It looks like you used a quality stem.
If one is worried and OCD, one might drill holes under size and ream to final OD.
Otherwise: vaya con dios.

 

[uhmwpolyethylene]

I saw GRIN was planning on making a version of this for 135mm dropouts as well

 

[MSF]

The stem is a critical, highly stressed part. A failure would be catastrophic.
It looks like you used a quality stem.
If one is worried and OCD, one might drill holes under size and ream to final OD.
Otherwise: vaya con dios.

This stem is pretty thick so i have no worries about it breaking.

 

[MSF]

Hopefully this weekend I can get time to bypass the motor connector and up the power considerably. Also I noticed that my speed doesn't match what the simulator says. Slow wind with 72v was around 33mph standard wind 39mph. I ordered and received a slow wind and my top speed is 40 with field weakening off.

 

[neptronix]

I saw GRIN was planning on making a version of this for 135mm dropouts as well

Woah, where did you see that?

 

[maiz]

Woah, where did you see that?

I saw it as well. It's a single speed. It was mounted on a cruiser type frame. But I can't find any reference to it on their social media. I must have seen it on the cruiser frame builder's social media but I can't find it.

 

[99t4]

Down to 70lbs as it sits now.

Do you miss the front suspension?

 

[MSF]

Do you miss the front suspension?

I do but really starting to like the lighter bike

 

[MSF]

Waiting on the Molicel m65a to be available so I can build some smaller lighter packs and get rid of the box that weighs over 4lbs empty.

 

[OkinawaJapan]

Hard lesson on what rims will work with this motor being offset as much as it is. Started with a Mulefut 80 and not a chance to get even close to center. Had the brake side fully tensioned and the chain side finger tight and it was still not over far enough. Switched to a Alex Blizerk 70 and its better but still not perfect. After a bunch of searching i found a rim that will work good with almost an even tension on both sides. Bontrager Jackalope with offset spoke bed

Wow, that's some great info! I was researching hard where to order some 32H 80mm 20 inch rims, but came up empty. Ended up having to order a 90mm from grin and let them do the wheel build for me. Probably for the best as I have never done a wheel build yet and don't need the stress right now in getting it wrong on such a high priced hub motor.

I'll google and see if that rm is available in an 80mm 20 incher. Thanks.

Looking forward to your progress this weekend.

 

[MSF]

Wow, that's some great info! I was researching hard where to order some 32H 80mm 20 inch rims, but came up empty. Ended up having to order a 90mm from grin and let them do the wheel build for me. Probably for the best as I have never done a wheel build yet and don't need the stress right now in getting it wrong on such a high priced hub motor.

I'll google and see if that rm is available in an 80mm 20 incher. Thanks.

Looking forward to your progress this weekend.

Are you talking about this rim? Rim20_Fat90_32H

 

[OkinawaJapan]

Are you talking about this rim? Rim20_Fat90_32H

Yes. That's what they're going to build for me over the next few days and send me. They said it would work.

They don't have the 65mm fat 20 inch 32H rim in stock right now. And I've not been able to find anything else online yet as an option.

 

[MSF]

If so i can tell you that there is no way to get it centered between the dropouts unless your frame is offset where it wont matter. If the rear tire is not inline with the front you will have steering wobble

 

[OkinawaJapan]

If so i can tell you that there is no way to get it centered between the dropouts unless your frame is offset where it wont matter. If the rear tire is not inline with the front you will have steering wobble

Hmmm... Interesting info. I'm a complete noobie on this stuff for fat bikes. I was trusting grin that it will work.

Do I need to ask them to offset the wheel build to work or something? I will be using a 7 speed Shimano cassette. Do I need to send them a pic of my rear dropouts with some measurements? Or I just need a completely different sized rim or something?

They don't seem at all concerned about this. Which is why I didn't even know it could be an issue.

I can take a picture of my rear dropouts from the rear if that will help show the design/offset of my bike.

 

[MSF]

Hmmm... Interesting info. I'm a complete noobie on this stuff for fat bikes. I was trusting grin that it will work.

Do I need to ask them to offset the wheel build to work or something? I will be using a 7 speed Shimano cassette. Do I need to send them a pic of my rear dropouts with some measurements? Or I just need a completely different sized rim or something?

They don't seem at all concerned about this. Which is why I didn't even know it could be an issue.

I can take a picture of my rear dropouts from the rear if that will help show the design/offset of my bike.

What frame do you have?

 

[MSF]

I didn't consider that you probably have a 170mm dropout and if so it will work just fine. I apologize for being an idiot.

 

[MSF]

Mine is 197mm so that's where my problem is.

 

[OkinawaJapan]

View attachment 376097I didn't consider that you probably have a 170mm dropout and if so it will work just fine. I apologize for being an idiot.

No worries at all man. All good. I appreciated you were being helpful. Thanks for the clarification and correction.

Info is in my two build threads on my wheel building endeavors. Still very green on it all.