Bafang bbshd on trek marlin 6 2022

[Wojt]

Hi,

In the end I used 2mm spacer and I didn't put on the M33 nut cover.

I also grinded off (using a hand file tool) the weld visible in the photo 6.

I got rid of throttle as it turned out to be not very useful with 250W motor I have.

I set the speed limit in the display to 50 km/h. Using the debug cable I programmed PAS levels as in the attached screenshot.




I'm very happy with the bike!

[Marius]

How did your build go Wojt?

[Wojt]

Hello,

I tried with 2mm spacer and now there are not enough threads on the non drive side to screw on the second M33 nut (or nut cover really). Do you think it would be better to go back to the set up without the spacer to be able to install m33 nut cover?

[73Eldo]

If the stock ring works just go with it. Most of the upgrade rings are a narrow wide design which can sometimes help if you have chain drop issues.

The HD is just a little larger in every dimension. The wider width doesn't solve all fit problems. Sure you can get a wider one and stack a bunch of spacers but the chain line is usually questionable with no spacers. The more spacers you stack in the further out the chain ring will be even if you get something like the Luna Eclipse or Lekkie 40t that has the maximum amount of offset possible.

[Wojt]

I have to park the conversion for now as I'm waiting for couple of items to arrive (my kit arrived without cable harness and without speed sensor).

Pictures 1 and 2: I still can't decide whether I should grind some plastic off the gear case or not. I think I will just try cycling first and I will pay attention if there is anything suspicious going on there.
EDIT: I decided I'll just buy a large file and try to grind some plastic off the case, just to be on the safe side. I'm waiting for missing items anyway.

Picture 6: I'm not going to grind the weld, I think the motor position is not that bad and I prefer not to mess with the frame.

Chainring: I'll try cycling with a stock chainring first. Maybe I'll throw an email to Lekkie asking if they know if 42t/40t will fit Marlin 6. Alternatively I could do some cardboard cutouts. I'm attaching pictures of the chain line in lowest and highest gears.

EDIT: If going with Lekkie won't help with a chain line, do you think it is worth replacing the stock chain ring for better durability etc.?

Isn't BBSHD motor the same size as BBS01?

And I think BBSHD comes with large set of bottom brackets lengths so you could pick the one that gives you better clearance on the chain
stay.

[soonerthebetter]

Hi,

Last week I started building a bicycle based on Trek Marlin 6 2022. I use Bafang BBS01 250W 36V motor.
The build isn't complete yet, but I already installed the motor, a chainring and a chain.

As this is my very first build and I have never worked on bicycles before, therefore I would appreciate your comments and advice.

There are some caveats:
1. The reduction gear case touches the frame. The motor is fully seated into bottom bracket shell though. I placed two transparent M3 stickers between motor case and the frame. See photos 1 and 2.
2. There is a bulge on the frame that prevents motor from being placed fully horizontally. See photo 6.
3. I had to use longer M6 screws (M6 20 mm) and a couple of washers in order to fix Bafang mounting plate to the motor. See photos 5 and 6.
4. There is very little clearance between chainring (stock Bafang 44t 180 mm in diameter) and the frame. See photos 1, 2 and 3.
5. The chain line does not look bad in my opinion. I'm going to take some pictures in the lowest gear and in the highest gear. See photo 4.

Questions:
Q1. Do you think the reduction gear case touching the frame (point 1) may cause issues?
Q2. Do you think very little clearance between chainring and the frame (point 4) may cause issues?
Q3. Do you think the chain line looks OK (point 5)?

BTW, the chain is:
https://www.kmcchain.com/en/product/...turbo-10-speed

Potential modifications:
Adding a spacer between bottom bracket shell and the motor would help with with issue (1) and (4), but would obviously push chain line outside.

To fix the chain line I would have to use different chainring:
My stock Bafang 44t is 180mm in diameter and has an offset of 5/5.5 mm.
Lekkie 42t is 176 mm in diameter and has an offset of 10.5 mm.
I took these numbers from the sources below.

Lekkie 42t is 4 mm shorter in diameter but 5/5.5 mm closer to the frame than stock Bafang 44t I use now.

I have hard time determining if Lekkie would fit. I'll try to make some measurements.

I'm not sure if my calculations are correct, but:
If I'm to use 2 mm spacer, then (if Lekkie fits) I gain 3 mm in offset.
If I'm to use 2 + 1 mm spacer, then (if Lekkie fits) I gain 2 mm in offset.
If I'm to use 2 x 2 mm spacer, then (if Lekkie fits) I only gain 1 mm in offset.

I don't have 1mm spacer at the moment but I could potentially buy it from Lekkie.

I would prefer to avoid buying Lekkie blindly as it's basically too expensive.
I wonder if buying a Lekkie chainring would be a good idea only for its durability and quality, even if it wouldn't help with fixing the chain line.
That would mean going from 44t to 42t though.

Sources:
https://bafangusadirect.com/products...39496023277767
https://fasterbikes.eu/media/pdf/90/...ettenlinie.pdf

Thanks!
Wojciech

Nice post Wojt. If I knew for sure that the BBSHD would get as close to fitting as your kit, I would probably throw down some cash and get started. Yours looks doable. That number 6 picture is hard to figure on how much would be needed to grind a little off the weld to get the motor to rotate up more. Proceed with caution.

[73Eldo]

Gear case to frame my only concern there is that you are not putting pressure on anything there. On my builds I like to see a tiny gap there so I know that all the clamping force is down on the BB and not at all on the case. Doesn't have to be a lot just enough to slide a sheet of paper through or see some light. Looking at how many threads you have on the other side I don't think I would add any spacers. If it was me I would be grinding a little off the gear case to make sure I had that clearance.

Chain ring tooth clearance I think I would try and run with and see what happens. If it rubs it should be minor and not really a big deal.

Chain line looks like it may be OK. I'm not sure that the 42 will help that much since it doesn't look like it would get you far enough into that curve to take advantage of the extra offset. Maybe the 40 would? So if you have chain line issues save up the money for the 40t kit?

[Wojt]

Hi,

Last week I started building a bicycle based on Trek Marlin 6 2022. I use Bafang BBS01 250W 36V motor.
The build isn't complete yet, but I already installed the motor, a chainring and a chain.

As this is my very first build and I have never worked on bicycles before, therefore I would appreciate your comments and advice.

There are some caveats:
1. The reduction gear case touches the frame. The motor is fully seated into bottom bracket shell though. I placed two transparent M3 stickers between motor case and the frame. See photos 1 and 2.
2. There is a bulge on the frame that prevents motor from being placed fully horizontally. See photo 6.
3. I had to use longer M6 screws (M6 20 mm) and a couple of washers in order to fix Bafang mounting plate to the motor. See photos 5 and 6.
4. There is very little clearance between chainring (stock Bafang 44t 180 mm in diameter) and the frame. See photos 1, 2 and 3.
5. The chain line does not look bad in my opinion. I'm going to take some pictures in the lowest gear and in the highest gear. See photo 4.

Questions:
Q1. Do you think the reduction gear case touching the frame (point 1) may cause issues?
Q2. Do you think very little clearance between chainring and the frame (point 4) may cause issues?
Q3. Do you think the chain line looks OK (point 5)?

BTW, the chain is:
https://www.kmcchain.com/en/product/...turbo-10-speed

Potential modifications:
Adding a spacer between bottom bracket shell and the motor would help with with issue (1) and (4), but would obviously push chain line outside.

To fix the chain line I would have to use different chainring:
My stock Bafang 44t is 180mm in diameter and has an offset of 5/5.5 mm.
Lekkie 42t is 176 mm in diameter and has an offset of 10.5 mm.
I took these numbers from the sources below.

Lekkie 42t is 4 mm shorter in diameter but 5/5.5 mm closer to the frame than stock Bafang 44t I use now.

I have hard time determining if Lekkie would fit. I'll try to make some measurements.

I'm not sure if my calculations are correct, but:
If I'm to use 2 mm spacer, then (if Lekkie fits) I gain 3 mm in offset.
If I'm to use 2 + 1 mm spacer, then (if Lekkie fits) I gain 2 mm in offset.
If I'm to use 2 x 2 mm spacer, then (if Lekkie fits) I only gain 1 mm in offset.

I don't have 1mm spacer at the moment but I could potentially buy it from Lekkie.

I would prefer to avoid buying Lekkie blindly as it's basically too expensive.
I wonder if buying a Lekkie chainring would be a good idea only for its durability and quality, even if it wouldn't help with fixing the chain line.
That would mean going from 44t to 42t though.

Sources:
https://bafangusadirect.com/products...39496023277767
https://fasterbikes.eu/media/pdf/90/...ettenlinie.pdf

Thanks!
Wojciech

[73Eldo]

Grinding the BBS housing is an option too that many of us have done. Usually where its hitting is an angle so 1mm of grinding on the housing gains you like 2mm of not needed spacers.

[soonerthebetter]

I didn't use the spacer. Just the standard stuff. Good luck on your build

Thank you for your time. I have been researching the situation a bit and the mid-drive conversion is on hold. To me, the best solution seems to be to alter(press in) the outside of the chain stay tube without altering the stay integrity and alignment to make room for the motor housing and gear. That seems like it would be a pretty dicey project that could destroy the entire bike if I made a wrong move. I would probably be better off just getting another bike for the project.

The good thing about hobbies and projects is that they can take you in directions you don't foresee. And the thing that is making this project not a failure(at least for now) is I really like the Trek. I don't know if I have mentioned it but I am kind of old and haven't ridden a bike in years and have no desire to be a mountain biker.. My ebike project has stalled, but my Trek Marlin 6 project hasn't. I have put some more road friendly tires( American Classic Kimberlite, tan walled 700x 50c) on the Trek and threw a 3 inch riser handle bar and a 35 degree 70mm bike stem on it. I have a rear rack in the mail. I'm cruisin' baby.

Oh well, live and learn. Thanks again.

[Bill B]

Ok, good to know. I know I keep one more questioning you to death, but here goes another one. Did you have to use spacers to avoid the Bufang housing touching the chain stay?

A funny thing happened on my way to buildng an ebike. I started riding the Trek. I hadn't ridden a bike in too many years to mention but I decided while I was studying my options to ride the bike to get used to shifting etc. I couldn't even make it around the block at first because of a big hill. I have conquered that hill and am thinking about venturing further out. LOL.

I am still bound and determined to do this build but at the moment the only thing I have purchased are the special bike tools needed to do the job. I have also decided that I am going to try to find a battery pack that will fit in the frame to keep the weight centered and so the tail don't wag the dog. I have been making cardboard cutouts of the approximate size of batteries online and seeing if they will fit on the Marlin 6. It is a small and odd shaped triangle.

I didn't use the spacer. Just the standard stuff. Good luck on your build

[soonerthebetter]

Ok, good to know. I know I keep one more questioning you to death, but here goes another one. Did you have to use spacers to avoid the Bufang housing touching the chain stay?

A funny thing happened on my way to buildng an ebike. I started riding the Trek. I hadn't ridden a bike in too many years to mention but I decided while I was studying my options to ride the bike to get used to shifting etc. I couldn't even make it around the block at first because of a big hill. I have conquered that hill and am thinking about venturing further out. LOL.

I am still bound and determined to do this build but at the moment the only thing I have purchased are the special bike tools needed to do the job. I have also decided that I am going to try to find a battery pack that will fit in the frame to keep the weight centered and so the tail don't wag the dog. I have been making cardboard cutouts of the approximate size of batteries online and seeing if they will fit on the Marlin 6. It is a small and odd shaped triangle.

[Bill B]

Bill B, if you are still around. Did you have any chainline issues with your build? I noticed that you can't buy an offset chain ring in the 36t size.

The Marlin 8 has a 12 speed sram cassette. I thought the big 50T was too much of a bend so I limited it myself with the stop screw. Now it wouldn't jump off itself. But the next cog up was a 42T. It worked out fine. Now I have the 750 watt where as you're putting on the 1000 watt. Now if you put on the 36T lekkie sprocket like I did, you're going to find you can easily start the bike in a much higher cog that 1st. In fact, unless on a steep up hill, 1st is just too low. I think your Marlin 7 is a deore 10 speed. Which I think will be just fine.

[soonerthebetter]

Bill B, if you are still around. Did you have any chainline issues with your build? I noticed that you can't buy an offset chain ring in the 36t size.

[Bill B]

Wow, that's a ton of info. I picked through it and researched all you wrote until I understood it. I will definitely take this advice. Here is what I am thinking on it.

Except for price, I can't see any disadvantage of going with the BBSHD over the BBS02. So I will probably go with the BBSHD.

I don't want to skimp on the battery or its capacity. I do like the idea of the rear rack battery. Especially the ones that cage the battery and still give you a useful rack to use. One- it gives you a tail light. Two- to the untrained eye, it just looks like a rear rack and less like a gawdy battery pack wedged somewhere. It doesn't look like Lunacycle carries this type, so I do worry that their kit universally connects to some random rear rack battery pack I pick up. I have plenty of time to sort that out.

Everything else seems pretty cut and dry and I will take your advice. Thanks a ton!

What I did is put the Trek rack, their bag on the back and put the big battery in there.