Bafang bbshd on trek marlin 6 2022

[ncmired]

Is there any other build attempts on the trek marlin 6 2021 model? Im sure they are some build attemps on the 2021 version that the 2022 version.

All of the Marlin builds I came across via a forum search use pre 2020 frames. Step up and be the 2022 Marlin build pioneer! It may be a piece 'o cake, just need a looksee at the frame.

[Biker3422]

All of the Marlin builds I came across via a forum search use pre 2020 frames. Step up and be the 2022 Marlin build pioneer! It may be a piece 'o cake, just need a looksee at the frame.

I really want to pull the trigger but again, this would be my very first time building a mid drive motor bike and secondly, im just worried of not enough clearance for the chainstay and chain line issues.

Also what does this mean? 1x/2x: 34T, 3x: 42T

Thanks

[73Eldo]

That is the front chain rings crank setup. How many 'gears' or chain rings are at the crank. So if you have 10 gears in the back and a 1x up front you have 10 speeds. 10 in the back and 2 up front you have 20. 3x you have 30. The classic 1970's 10 speed was a 2x. 5 in the back and 2 up front. When MTB's really caught on in the late 80's they were 7 in the back and 3x up front so 21 speeds.

So the Trek specs are saying if you have 1 or 2 up front the max you can go and have frame clearance is 34t. If you go 3x they are stacked so you can go bigger, 42t for the biggest one so maybe a 22-32-42? My guess is the dent in the frame is there for that 42 to tuck into which we think is good because a 42 is a common size of offset ring and there are 2 different offsets available depending on how much you need to get that ring tucked in where the stock one would have been if the bike came as a 30 speed with a 3x up front.

[Biker3422]

That is the front chain rings crank setup. How many 'gears' or chain rings are at the crank. So if you have 10 gears in the back and a 1x up front you have 10 speeds. 10 in the back and 2 up front you have 20. 3x you have 30. The classic 1970's 10 speed was a 2x. 5 in the back and 2 up front. When MTB's really caught on in the late 80's they were 7 in the back and 3x up front so 21 speeds.

So the Trek specs are saying if you have 1 or 2 up front the max you can go and have frame clearance is 34t. If you go 3x they are stacked so you can go bigger, 42t for the biggest one so maybe a 22-32-42? My guess is the dent in the frame is there for that 42 to tuck into which we think is good because a 42 is a common size of offset ring and there are 2 different offsets available depending on how much you need to get that ring tucked in where the stock one would have been if the bike came as a 30 speed with a 3x up front.

So it should fit a 42t stock bafang ring right as well as a lekkie 42t bling ring?

[73Eldo]

Based on that 42x3 in the specs yes we think IF you can get a 42 ring tucked right tight to the frame that should put the chain in the same position it would be if it had and x3 setup with a 42t ring.

What we don't get many clues on is how tight will the gear case get to the frame and then which offset spacing ring will get that tight to the frame. If there is some interference with the gear case that requires spacers there this is where you could run out of threads on the other side and need a wider unit and also where maybe even with the max offset ring, the Luna Eclipse you could still end up too far out to get a good chain line. Probably won't be an issue but since this bike isn't made for this kit and this kit isn't made for this specific bike ya never know for sure till someone tries it.

Historically the stock ring for a BBSHD was a 46t steel ring that looked kinda cheap. More recently I have seen a 42 aluminum ring that looks to be a copy of the Lekkie except for its not a narrow wide. I'm nut sure about any of the details on that one like the quality or offset.

[ncmired]

Well ... I'm reading Trek's "Max chainring size 1x/2x: 34T, 3x: 42T" as, the ring closest to the frame (not the outest , or third ring of a triple crank) can't be bigger than 34T. You can substitute the Bafang reduction gear case's diameter here. But I've not ever see that spec before, from any bike manufacturer - have you, 73Eldo?

So I'll be the rude bastard PITA and ask, can't you go to the bike shop and looksee? You, know, the DIY up front research part of adding a aftermarket motor to a bicycle. Or do you have to buy / deposit the bike first, then they'll order it up (sad reality here in the states in many shops).

This, as 73Eldo typed - "What we don't get many clues on is how tight will the gear case get to the frame". Treks pictures suck, and that big dimple you can see in the chainstay implies that they've changed the frame design from previous years.

[Biker3422]

Well ... I'm reading Trek's "Max chainring size 1x/2x: 34T, 3x: 42T" as, the ring closest to the frame (not the outest , or third ring of a triple crank) can't be bigger than 34T. You can substitute the Bafang reduction gear case's diameter here. But I've not ever see that spec before, from any bike manufacturer - have you, 73Eldo?

So I'll be the rude bastard PITA and ask, can't you go to the bike shop and looksee? You, know, the DIY up front research part of adding a aftermarket motor to a bicycle. Or do you have to buy / deposit the bike first, then they'll order it up (sad reality here in the states in many shops).

This, as 73Eldo typed - "What we don't get many clues on is how tight will the gear case get to the frame". Treks pictures suck, and that big dimple you can see in the chainstay implies that they've changed the frame design from previous years.

When i went on the website for the detail page for the trek marlin 6 2021 model it says the same thing as the 2022. 1x/2x: 34T, 3x: 42T. Because of this, would i still be able to fit a 42 ring teeth or no? Also, what dimple are you talking about? Could you show me an example? Is it this? Please see image attached. If the image is correct, would that dimple be a problem?

[ncmired]

When i went on the website for the detail page for the trek marlin 6 2021 model it says the same thing as the 2022. 1x/2x: 34T, 3x: 42T. Because of this, would i still be able to fit a 42 ring teeth or no? Also, what dimple are you talking about? Could you show me an example? Is it this? Please see image attached. If the image is correct, would that dimple be a problem?

Yes, that's the dimple, just to the left of the chain ring. And, again, dimple aside, "What we don't get many clues on is how tight will the gear case get to the frame".

The answer to, "would i still be able to fit a 42 ring teeth or no?" is, we don't know / can't tell.

[Biker3422]

I'm doing this right now, through my local bike shop on a 2022, or 2021 Marlin 8. Same frame as your Marlin 6. We're just waiting on a Lekkie 42T for the BB02 motor. Things to note: The frame where the motor fits into, needs ground a little. The motor won't just slide in. Luna and Lekkie have a 30 or 28T sprocket that works. But I have a 12 speed and it has trouble getting in the lower gears. Yours might not with it being the 10x. I first tried the Luna 46T. It fit but it was close to the chain stay. Ordered a Lekkie 28T and 36T. Misshipment and got (2) 28T. But the mechanic said he thinks a 42T would work, and I'm allowed to return pats unused for credt, less shipping, to the online distributor. And the 42T Lekkie, per Luna, will bring the sprocket closer for the lower gears. The brake levers. The hydraulic magnets don't sit easy on them like a regular flat bar. Now the dealer just finished putting the Luna setup on a new Trek Domane AL5, so I'm just letting the same person work his magic on how to put it on the levers then post it in the forums. Last the battery. The Direwolf is too big to fit in the frame. So I'm putting it in a bag on a rack in the rear. We think the smaller worlf battery would fit. Hope that helps.

Hi, thanks for the reply. Could you please confirm whether if its a 2021 or 2022 trek marlin 8? And please update me on your trek marlin 8 buld.

Also when you said that the motor wont just slide in, is there any reason for that?

Thanks

[Bill B]

Definitely 2022. Just checked the receipt. The motor won't slide in due to the bottom bracket. Some of the frame in there, there's a bump that needs ground down. Now the dealer used a form of Dremel tool to get it down. I did find something interesting on youtube of a bike builder that uses a metal hole cutter. I'll post the link. In the video he describes also about this "bump" in there: https://www.youtube.com/watch?v=FlSuerBVXXs

[73Eldo]

The smallest ring you can get that has an offset that may get you close to a stock chainline on most bikes is a 40t. Anything smaller has a pretty minimal offset usually around 9mm. From memory the stock and Lekkie 42 and bigger are around 19mm. Luna Eclipse or Lekkie 40 with its combo spacer is more like 24mm. Rings like a 36 are going to put you further out than stock on most bikes which in most cases gives you a terrible chain line. All this gets worse if you also had to use spacers to get the gear case to clear the frame. Also note that for the most part we are talking about classic BBSHD here. BBS02 and perhaps the latest BBSHD may have different options and slightly different spacing.

[Biker3422]

Yeah it's tough. Trek's spec say a 1x max 34T. But for a BBS02, for the 12X needing an offset is 36T in a Lekkie. But Luna Doesn't sell Lekkie so had to go to another place. But I got mis-shipped 2 28T and the chain line isn't good. The other place doesn't have the 40T so ordered the 42T and we'll see if it fits. Just each time an order is placed, it's 2 days to get it out, and 5 days shipping. That's what I like about Luna Cycle. I can order, and they ship it quick. If I have preorder questions, I can call or write and get answer back. Or come in the forums. So much better here.

Yh, i hope 42t works and doesnt mess up the chain line. Btw, how much gears does it have?

About the bb having the bump so because of this the motor wont fit, i wonder if its the same for the 2021 model.

[Bill B]

It's the 12 speed cassette. 1X sprocket. The beginner SRAM MTB gearing. Now it's my understanding the frames from 2021 to 2022 are the same. But the Marlin 8 is the same frame as all of them. Now I'm putting in, or the bike shop, the 750w vs your 1000w. Noone there at the 10 year old Trek dealer that this "bump" was there and needed cut or ground down. The motor is in now.

[Biker3422]

Id probably get it fitted by a machanic. With the trek marlin 6 2022, its a 1×10.

[73Eldo]

I'm guessing that the bump grinding issue they are talking about is inside the bottom bracket tube. Most bottom brackets shaft and bearing assemblies are only large at the ends where the threads are then are a little smaller diameter in the middle. This means that when building the frame they don't have to worry about weld boogers or maybe a little bit of the down tube sticking out into that space. The BBS's are the same diameter the full length so nothing can be sticking out. Grinding what ever is in there should not cause any structural issues or issues if you wanted to go back to stock.

[Biker3422]

I'm guessing that the bump grinding issue they are talking about is inside the bottom bracket tube. Most bottom brackets shaft and bearing assemblies are only large at the ends where the threads are then are a little smaller diameter in the middle. This means that when building the frame they don't have to worry about weld boogers or maybe a little bit of the down tube sticking out into that space. The BBS's are the same diameter the full length so nothing can be sticking out. Grinding what ever is in there should not cause any structural issues or issues if you wanted to go back to stock.

Yh. I just hope that the installation goes smooth with a 2022 trek marlin 6 and have no issues with chain line etc as I want stealthy bike with a bit of colour instead of having a bright bike.

[Biker3422]

I'm guessing that the bump grinding issue they are talking about is inside the bottom bracket tube. Most bottom brackets shaft and bearing assemblies are only large at the ends where the threads are then are a little smaller diameter in the middle. This means that when building the frame they don't have to worry about weld boogers or maybe a little bit of the down tube sticking out into that space. The BBS's are the same diameter the full length so nothing can be sticking out. Grinding what ever is in there should not cause any structural issues or issues if you wanted to go back to stock.

Would there be a bump for 2021 version of the bike?