Anyone Using Spacers to Fit a 36T Chainring

Voluptua · Aug 31, 2021

For speed and cadence calculations, I prefer this website. BikeCalc

aviserated · Sep 11, 2021

My new spyder has more offset than the steel factory gear. I believe I can fit a 38 tooth sprocket (no spacers needed). I removed plastic chaingurd because my chain was rubbing slightly against. Here is correct part number for the FSA Bosch Gen4 Boost 148x Alloy Spider BCd104 SB black(CL53)

380-0372000050

The new Spyder is a tight fit, but it will slip on eventually...do not give up.

I discovered that my chain ring nut was loose so I used blue loctite to reattach.

Gropec · Jan 2, 2022

Hey guys,

I really want to change my original 34T sprocket by a spider one with more offset to avoid scratches on my frame!
Could you please tell me which one will be good?
Thanks

yatayata · Mar 3, 2022

dixie600mhz said:
Aviserated, I've tried three spiders so far and the best one for the 36T is the FSA 1X Spider Boost 104mm BCD for Bosch Drive Unit Gen4 - W0138. With the FSA W0138, I added two thin washers and now the chain line is as close to stock as I can make it. The 36T is almost rubbing like the 34T was. The washers are thin enough that the chain ring still rests in the spider alignment grooves.

My trick to finding parts is get the part number and spend a while googling. It usually works but I've been looking for a smith mainline helmet in stock now for over 8 months! I feel your pain.
View attachment 70162 View attachment 70163 View attachment 70164 View attachment 70165

Ciao Dixie, thx for your work because maibe i will get the possibility to install the 36 on my focus Thron2 . Could i ask you what you mean for two thin washers? Did you have some pics? What is the final chainline did you achieve? Because i found a 36 chainring from raceface which have 55 chainline, what do you think about it?

dschae1 · Mar 20, 2022

Update: I just placed the order. I'm 99% sure these are the right parts.
Update #2: I ordered the wrong boost spider. I got the 50mm by mistake. My bad.

-----------------------------------------------------------------------------------------------------------------
I want to do this upgrade too. I've read over this thread about 5 times now and since there are so many options to choose from, I think I want to try the last configuration that dixie600mhz did except using the SRAM chainring that Link used. I have listed below what I think will work except for the washers. I figure I'll head to Home Depot / Lowes and find what will work (matching what is shown in the pictures)

I'm hoping either of you have a few minutes to verify that this is what I need. I'd rather not order this stuff twice.

Shopping list:
Spider 1x boost 104mm BCD Bosch: (ships from 4 US states) $26 + $7 shipping

FSA E-Bike Bosch Gen4 104BCD Spider

FSA E-Bike Bosch Gen4 104BCD Spider :: From $26.00 :: FSA Crank Parts

www.universalcycles.com

SRAM Chain Ring: (ships from Colorado) $51.95 + free shipping

SRAM X-Sync 2 11 or 12 Speed Chainring 36T 104mm BCD Black

planetcyclery.com

Yuauy Chain Ring Bolts: $8 + free shipping at Amazon
http s://www.amazon.com/gp/product/B07V7534WY (remove the space between http & s to make this amazon URLwork)

Thanks in Advance!

yatayata · Mar 20, 2022

Hi dude it’s ok

dschae1 · Mar 21, 2022

yatayata said:
Ciao Dixie, thx for your work because maibe i will get the possibility to install the 36 on my focus Thron2 . Could i ask you what you mean for two thin washers? Did you have some pics? What is the final chainline did you achieve? Because i found a 36 chainring from raceface which have 55 chainline, what do you think about it?

The washers are kinda visible in two of his pictures above. There are three washers per lug (I think) 2 on one side and 1 on the inside. His other picture shows this better.

dschae1 · Mar 26, 2022

What about this option? Pretty sure the 36T has a 53mm chainline.
e*thirteen Bosch Gen 4 Aluminum Direct Mount Chainring | Trek Bikes

dschae1 · Mar 26, 2022

Also, I ordered the wrong spider. The 50mm boost version arrived today. I should have gotten the one below it or 53mm boost. I am finding that 53mm FSA spider is out of stock almost everywhere (I did find it in Europe with a 2 week ship back to Texas).

dixie600mhz · Apr 15, 2022

Sorry I didn't answer any questions. Missed the posts!

Here's some better pics of the washers. The 36T is perfect with the FSA 1X Spider Boost 104mm BCD for Bosch Drive Unit Gen4 - W0138 and some really small washers to help tweak to perfect chainline.

I've tried three spiders so far and the best one for the 36T is the FSA 1X Spider Boost 104mm BCD for Bosch Drive Unit Gen4 - W0138

dschae1 · Apr 15, 2022

I am waiting on delivery of the boost spider but it is stuck in Chicago customs for 12 days now ... Ugh! I found black washers, they were ordered the same day and arrived last week. Can't wait to assemble and try this setup. I'll post pics and a review once it is all together!

dixie600mhz I'm curious, was this washer needed? Was the hole in the spider too big for the chain ring bolt?

dixie600mhz · Apr 15, 2022

Thinking back to when I did it, I think the chain ring bolts were slightly long and that's why I added the washer on the back. I remember that the bolts weren't threaded their entire length and the nut would bottom out on the end of the threads unless I added that washer. I'm super happy with the 36T ring. I even went 10-46 on the back and have enough low end grunt to do the black trail rated technical stuff. I think the bike is happier in general after moving away from the tiny 34.

dschae1 · Apr 15, 2022

dixie600mhz said:
Thinking back to when I did it, I think the chain ring bolts were slightly long and that's why I added the washer on the back. I remember that the bolts weren't threaded their entire length and the nut would bottom out on the end of the threads unless I added that washer. I'm super happy with the 36T ring. I even went 10-46 on the back and have enough low end grunt to do the black trail rated technical stuff. I think the bike is happier in general after moving away from the tiny 34.

When you have time, please can you post a link to where you ordered the back sprocket (10-46) I want to look into that.
I wonder if going to a 9 tooth cassette would make sense (for top speed)

dixie600mhz · Apr 17, 2022

A couple of weeks ago I bought a 10-45 SLX from Amazon. I destroy expensive cassettes quite often so moved to the cheaper heavier SLX version. I think they last longer.
SLX CS-M7100

dschae1 · Apr 24, 2022

I have this much clearance with the new 36 tooth chainring. So, I ordered a 38 tooth chainring today. Hope it has clearance too as going from 34 to 36 is not that big of a change.

dschae1 · Apr 24, 2022

Here's the 36 Tooth mounted on my Rail. Turns out, that chain guide above is adjustable and still works after finding the sweet spot.

dschae1 · Apr 28, 2022

Anybody want to use a 38 tooth chainring on your Trek Rail? Yep, it fits! ... ... ... I'll post a write-up in a few days.

I have clearance!!!

Even the chain guide works, but this is the extreme limit for height adjustment.

I used two washers, but it looked like it would work with just one. Each washer is 1mm thick.

I may have to worry about the chain and chainring being too low, Gotta be careful when traversing rocks I guess.

Zaskar20 · Apr 28, 2022

This might be useful to some.

Cannondale Habit & Moterra Ai Offset Update

So I wanted to change to a 36T and decided to go Hope E Chainring. Trouble is, the Cannondale uses its own Ai offset. First, the chainring lock ring tool. I purchased this from Amazon. Did a great job, but needs a 32mm socket. When I had removed the FSA spider (and ring) I placed it on a flat...

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Anyone Using Spacers to Fit a 36T Chainring

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