Experience with 38t RaceFace chainring

[Jeremy McCreary]

Thinking of trying the RaceFace 38t chainring below in lieu of the stock 42t. Have a 1x drivetrain with a 9-speed 11-36 Shimano casette and 9-speed KMC chain. Motor is a 500W hub.

https://www.amazon.com/gp/aw/d/B00D3FG9TA/ref=ox_sc_act_image_7?smid=A2RNBXAVQ4OOHG&psc=1

Somewhat mixed reviews -- including a few reports of catastrophic failures 6-12 months out. Most were on MTBs with 1x drivetrains, some under less than extreme conditions.

Thoughts?

I live in a hilly area with lots of short, steep grades, and my lowest gear could be lower. I prefer to pedal whenever possible, but my legs aren't yet in shape. No desire to ride advanced MTB trails and don't mind losing some top pedaled speed.

 

[m@Robertson]

They are top quality products. Pretty widely respected in analog cycling/MTB circles. I have one on my enduro with a CYC X1 Pro motor and that thing screams so fast its frightening if you let it wind up and stay there (10k rpms max on the motor although that is before the secondary gear reduces it to the chainring). Mine is a 32T. Luna has used these on their Ultra-powered bikes for years.

I'm not sure I would call those 'mixed' reviews. 995 ratings. 86% 5-star. Only a very few bad reviews. 13 are 1-star. Some people screw up and blame the equipment.

 

[fooferdoggie]

I doubt you could ever work it hard enough to cause issues. you can just get a cheap steel one and not worry at all.

 

[m@Robertson]

Surly makes steelies, but they are not narrow-wide. but... waitasec... speaking of narrow-wide and why you use those,

@Jeremy McCreary isn't your bike a hub drive? If so you have minimal wear/tear on the ring you should be fine no matter what with a cheaper ring.

I would not hesitate to buy another Deckas ring for a hub bike. I've got one of them on my twin hub motor bike and they are great. I've heard others who built bikes with them speak highly of them as well. I would not bother with a Raceface on a hub motor.

https://amzn.to/3hqFNVt

And do you know what chain type you have? If you have an IGH are you using a singlespeed chain? If so then you want something different entirely. For that matter, have you confirmed your BCD (Bolt Circle Diameter) type of your chainring so you can get one that matches? Your 42T ring might be a 110 and we've been talking about 104's. You need to cover that base.

 

[Jeremy McCreary]

This is the most helpful forum I've joined in a long time. Thanks for the missing pieces of the puzzle, @m@Robertson and @fooferdoggie!

Relevant equipment:
o Bafang G020 500W rear hub motor
o Unidentified single 42t chainring, 104 mm BCD, prob steel, not narrow wide
o KMC 9-speed chain
o Shimano 9-speed 11-36t casette

With remodeling money flying away at a terrifying rate, cheap and worry-free sounds pretty darn good. (Wife has this crazy idea that homes are more important than bikes. Shoulda blocked all cable home improvement channels when I had the chance. If I hear "Oh, that's so outdated!" one more time, I'm gonna... take a long bike ride!)

Certainly no point in shaving grams off a 63 lb bike, so I'll shop steelies now.

 

[m@Robertson]

Certainly no point in shaving grams off a 63 lb bike, so I'll shop steelies now.

I would just do the $13 Deckas ring. The Surly steel rings are like $35 or more. If you ever have to replace a Deckas, you can buy three of them for the same price as one Surly. Or if you are like me you keep experimenting and if so each experiment is only a $13 throwaway. I literally have a small stack of rings in my shop.

If it turns out you wear the ring out fast (VERY unlikely as hub drivetrains get very light duty) then you can think about blowing more money on a steel ring.

 

[Jeremy McCreary]

I would just do the $13 Deckas ring. The Surly steel rings are like $35 or more. If you ever have to replace a Deckas, you can buy three of them for the same price as one Surly. Or if you are like me you keep experimenting and if so each experiment is only a $13 throwaway. I literally have a small stack of rings in my shop.

If it turns out you wear the ring out fast (VERY unlikely as hub drivetrains get very light duty) then you can think about blowing more money on a steel ring.

Thanks, you just saved my marriage.

 

[Jeremy McCreary]

I would just do the $13 Deckas ring. The Surly steel rings are like $35 or more. If you ever have to replace a Deckas, you can buy three of them for the same price as one Surly. Or if you are like me you keep experimenting and if so each experiment is only a $13 throwaway. I literally have a small stack of rings in my shop.

If it turns out you wear the ring out fast (VERY unlikely as hub drivetrains get very light duty) then you can think about blowing more money on a steel ring.

DECKAS chainring on the way. Fingers crossed it's compatible with the stock bolts.

 

[tomjasz]

(Wife has this crazy idea that homes are more important than bikes.

Imagine for a moment you have 6 with two wheels and 2 trikes.

 

[Jeremy McCreary]

Can't imagine it ever getting that far. My wife's read hundreds if not thousands of murder mysteries. She knows her poisons.

 

[Rás Cnoic]

This is the most helpful forum I've joined in a long time. Thanks for the missing pieces of the puzzle, @m@Robertson and @fooferdoggie!

Relevant equipment:
o Bafang G020 500W rear hub motor
o Unidentified single 42t chainring, 104 mm BCD, prob steel, not narrow wide
o KMC 9-speed chain
o Shimano 9-speed 11-36t casette

With remodeling money flying away at a terrifying rate, cheap and worry-free sounds pretty darn good. (Wife has this crazy idea that homes are more important than bikes. Shoulda blocked all cable home improvement channels when I had the chance. If I hear "Oh, that's so outdated!" one more time, I'm gonna... take a long bike ride!)

Certainly no point in shaving grams off a 63 lb bike, so I'll shop steelies now.

So I have a Raceface 38T Narrow Wide chainring, replaced the Praxis 44T that came on my Vado SL. I have numerous short very steep climbs. The alloy Raceface has worked perfectly on and off road in summer and in muddy winter conditions, for about a year and a half now. It's an MTB chainring and although alloy is fit for purpose. Works perfectly. Highly recommended.

 

[Jeremy McCreary]

Finally got around to swapping the stock 42t chainring on my 2023 Surface 604 V Rook for a DECKAS 38t. Left the 9-speed 12-36t 11-34t cassette alone.

The good news: REALLY like what the 38t does for my gearing -- happier knees on steeper climbs, and the bike's now significantly easier to pedal on PAS 0 or with a dead battery.

The 38t had an interesting effect ratio-wise. Within 5%, old 8th became new 9th, old 7th became new 8th, and so on all the way down. Then it dropped 1st from 32 to 29 34 to 31 gear-inches.

The bad news: With the 42t chainring, the Shimano Alivio derailleur shifted flawlessly through all 9 gears. But now it misses ~30% of the downshifts from 9th to 8th. (All other shifts are still fine.)

So something needs adjustment. Remove a link from the chain? Tweak the derailleur somehow? Suggestions?

 

[m@Robertson]

So something needs adjustment. Remove a link from the chain? Tweak the derailleur somehow? Suggestions?

This is normal. First thing I would do is optimize the chain (it might not be too long). Using these instructions on chain length for a 1x setup, which is what you have, resize accordingly.

Installing A New Chain For Your 1X Drivetrain (How to do it Right!)

The link below covers the whole drivetrain install, which is more than you need, but in it I also included all of the correct chain sizing and derailleur adjustment resources anyone could ever need.

Sizing the chain is something most people get wrong. Especially on a 1x (which translates to a drivetrain with just one chainring in the front). Pay particular attention to how your derailleur cage needs to be pointing straight back (still with some tension on the chain!) at your highest gear / smallest cog. Your derailleur's cage exists to wrap excess chain, and many (shops and manufacturers included) screw this up out of either a misunderstanding of what they should be doing or a desire to save a bit of money on chain links since they buy chains on big drums and not like we do at the local level.

How To Build An Ebike From Scratch: Assembly Day 2

Assembly Day 1 got us a rolling chassis that looks like a bike. If you squint a little. Lets keep up the pace of progress here on Day 2

talesontwowheels.com

As for the derailleur adjustment, The Box Components and Microshift help vids are a little bit amazing in that they show a relatively simple (and each different) method that actually works. Both the Box and Microshift vids also show proper chain length/sizing for a 1x drivetrain that all agree with the article above on how long it should be.

The last linked Park video is the Gold Standard of derailleur adjustment videos and has been that for years. If you want to understand the process and be able to adjust any derailleur you come across in the future - or one of the two shortcut videos don't do it for you - then go to the industry standard source and do it thataway.

EDIT: If you still have problems after this, it is unlikely but possible your derailleur is not up to the task. As noted a derailleur cage exists to wrap chain. Bigger rear clusters require longer cages. Hopefully your manufacturer didn't cheap out and give you something like a short- or mid-length cage when you need the next size up. If your system is an 11-36 in back then you likely have a mid-length. Or iodeally a long cage. But a mid- should be fine. The longer the cage, the more excess chain it can wrap.

 

[Jeremy McCreary]

This is normal. First thing I would do is optimize the chain (it might not be too long). Using these instructions on chain length for a 1x setup, which is what you have, resize accordingly.

Installing A New Chain For Your 1X Drivetrain (How to do it Right!)

The link below covers the whole drivetrain install, which is more than you need, but in it I also included all of the correct chain sizing and derailleur adjustment resources anyone could ever need.

Sizing the chain is something most people get wrong. Especially on a 1x (which translates to a drivetrain with just one chainring in the front). Pay particular attention to how your derailleur cage needs to be pointing straight back (still with some tension on the chain!) at your highest gear / smallest cog. Your derailleur's cage exists to wrap excess chain, and many (shops and manufacturers included) screw this up out of either a misunderstanding of what they should be doing or a desire to save a bit of money on chain links since they buy chains on big drums and not like we do at the local level.

How To Build An Ebike From Scratch: Assembly Day 2

Assembly Day 1 got us a rolling chassis that looks like a bike. If you squint a little. Lets keep up the pace of progress here on Day 2

talesontwowheels.com

As for the derailleur adjustment, The Box Components and Microshift help vids are a little bit amazing in that they show a relatively simple (and each different) method that actually works. Both the Box and Microshift vids also show proper chain length/sizing for a 1x drivetrain that all agree with the article above on how long it should be.

The last linked Park video is the Gold Standard of derailleur adjustment videos and has been that for years. If you want to understand the process and be able to adjust any derailleur you come across in the future - or one of the two shortcut videos don't do it for you - then go to the industry standard source and do it thataway.

EDIT: If you still have problems after this, it is unlikely but possible your derailleur is not up to the task. As noted a derailleur cage exists to wrap chain. Bigger rear clusters require longer cages. Hopefully your manufacturer didn't cheap out and give you something like a short- or mid-length cage when you need the next size up. If your system is an 11-36 in back then you likely have a mid-length. Or iodeally a long cage. But a mid- should be fine. The longer the cage, the more excess chain it can wrap.

Many, many thanks! Just what I needed to get started.

My derailleur cage is 100 mm on center from pulley to pulley (or whatever those 2 little idlers are called). Would you call that short, medium, or long?

May not make a difference, but I counted cassette teeth myself to clear up some online discrepancies, and it's 12-36, not 11-36 as previously stated.

 

[m@Robertson]

My derailleur cage is 100 mm on center from pulley to pulley (or whatever those 2 little idlers are called). Would you call that short, medium, or long?

Thats pretty clearly a long cage. So you are good to go on that front.

May not make a difference, but I counted cassette teeth myself to clear up some online discrepancies, and it's 12-36, not 11-36 as previously stated.

That won't matter. Just get thru the re-optimization process and you should be fine. The Alivio is not what I'd call a quality derailleur, but its a basic one that should be able to go thru the motions.

EDIT: I just checked the Alivio's specs and its max teeth capacity is 36. So don't try and go with a bigger cassette than a 36. But if you re-use what you have you should have no complications with your derailleur. And the Park video will be perfect for this derailleur to adjust step by step. If you'd had a SRAM derailleur it would be a little more complex but not an issue here.

 

[Jeremy McCreary]

Thats pretty clearly a long cage. So you are good to go on that front.

That won't matter. Just get thru the re-optimization process and you should be fine. The Alivio is not what I'd call a quality derailleur, but its a basic one that shoulda be able to go thru the motions.

EDIT: I just checked the Alivio's specs and its max teeth capacity is 36. So don't try and go with a bigger cassette than a 36. But if you re-use what you have you should have no complications with your derailleur. And the Park video will be perfect for this derailleur to adjust step by step. If you'd had a SRAM derailleur it would be a little more complex but not an issue here.

Confession time: Delayed taking your derailleur tuning advice and let my LBS/dealer do it about 2 months and 600 miles later. By then, saw little if any progression in the shifting problems brought on by swapping the stock 42t steel chainring with a 38t aluminum chainring. The main problem was still a matter of downshifts from 9th to 8th jumping from 9th to 7th instead about 30% of the time.

The LBS fixed the skipping but made shifting a little sloppier in general — especially the downshifts. They said the derailleur and chain would eventually need replacement but still had some life in them. Doubt they ever measured the chain for stretch.

Decided to live with the slop for another 2 months — till about 2 weeks ago, when shifting started deteriorating rapidly. So back to the LBS.

Long story short, at 900 miles, my original Shimano Alivio 9-speed derailleur now has way too much side-play to adjust properly due to loosened pantograph bearings. And the original KMC 9-speed chain can now be bent sideways into 2/3 of a circle! Replacing the chain alone didn't help.

Not sure what's to blame here, but riding short, steep hills daily at PAS 1/9 in a sandy, salty, humid coastal enviroment with infrequent chain care probably didn't help.

Anyway, the LBS is now recommending that I upgrade to a 10-speed drivetrain with Shimano XT derailleur and 11-36t cassette. If the upgrade has a reasonable chance of preventing a recurrence of this situation, I'd be fine with it, as I'd then have an even lower 1st gear.*

But I'd love to hear what our drivetrain experts think about this saga at only 900 miles. The bike has a 500W rear hub motor and has never been dropped or hit. The 38t aluminum chainring teeth still look good.

Thanks!

* Miscounted the original cassette's biggest cog. It's 34t, not 36t as previously reported, so the proposed new 11-36t cassette would drop bottom gear from 30 7 to 29.0 inches. Every inch helps around here!

 

[fooferdoggie]

Confession time: Delayed taking your derailleur tuning advice and let my LBS/dealer do it about 2 months and 600 miles later. By then, saw little if any progression in the shifting problems brought on by swapping the stock 42t steel chainring with a 38t aluminum chainring. The main problem was still a matter of downshifts from 9th to 8th jumping from 9th to 7th instead about 30% of the time.

The LBS fixed the skipping but made shifting a little sloppier in general — especially the downshifts. They said the derailleur and chain would eventually need replacement but still had some life in them. Doubt they ever measured the chain for stretch.

Decided to live with the slop for another 2 months — till about 2 weeks ago, when shifting started deteriorating rapidly. So back to the LBS.

Long story short, at 900 miles, my original Shimano Alivio 9-speed derailleur now has way too much side-play to adjust properly due to loosened pantograph bearings. And the original KMC 9-speed chain can now be bent sideways into 2/3 of a circle! Replacing the chain alone didn't help.

Not sure what's to blame here, but riding short, steep hills daily at PAS 1/9 in a sandy, salty, humid coastal enviroment with infrequent chain care probably didn't help.

Anyway, the LBS is now recommending that I upgrade to a 10-speed drivetrain with Shimano XT derailleur and 11-36t cassette. If the upgrade has a reasonable chance of preventing a recurrence of this situation, I'd be fine with it, as I'd then have an even lower 1st gear.*

But I'd love to hear what our drivetrain experts think about this saga at only 900 miles. The bike has a 500W rear hub motor and has never been dropped or hit. The 38t aluminum chainring teeth still look good.

Thanks!

* Miscounted the original cassette's biggest cog. It's 34t, not 36t as previously reported, so the proposed new 11-36t cassette would drop bottom gear from 30 7 to 29.0 inches. Every inch helps around here!

do the upgrade what you have is the s*it grade. you will also get a much better and far more ergonomic shifter. the shifter alone will be worth the effort. so far never wore one out even after 14,000 miles. had to replace the cable once then the housing and cable but the competes are going strong. but can you go to a 10 speed? most hub drives wont support it.

 

[Jeremy McCreary]

do the upgrade what you have is the s*it grade. you will also get a much better and far more ergonomic shifter. the shifter alone will be worth the effort. so far never wore one out even after 14,000 miles. had to replace the cable once then the housing and cable but the competes are going strong. but can you go to a 10 speed? most hub drives wont support it.

Thanks! The LBS sells ebikes exclusively, so I'm assuming for now that they know the 10-speed drivetrain will work.

 

[fooferdoggie]

Thanks! The LBS sells ebikes exclusively, so I"m assume for now that they know the 10-speed drivetrain will work.

depends most hub drives have the feehub How managers do you have now? wait you have 9 so it may work. it would be a huge improvement in shifting quality and ergonomics. I can shut and brake with not moving my hand off the grip without moving my hand at all just my thumb to shift or finger to brake

 

[m@Robertson]

do the upgrade what you have is the s*it grade.

That really does sum up the situation rather well. @Jeremy McCreary your parts suck so your results will too. There's just no fixing that other than replacing it.

Here's an interesting thing: Just yesterday - literally - I replaced my Box2 Xtra Wide derailleur, Box 1 Single shifter and 12-50T Box 2 cluster with... Microshift Advent X. I was having issues with the really steep hills coupled with my short chain- and seatstays here in the Monterey Bay Area... My Box 9 spd system only had 6 usable gears thanks to the chain line limitations that go with a bike with a nimble rear setup. I have been sitting on a complete Advent X setup I got on a clearance sale - all of it was about $100 - and the results have been nothing short of awesome. Shifting is great, I have a range effectively just as wide as before and have access to two more gears, not just one. Microshift has one of the nicest clutches on any derailleur, too.

And its a bargain-priced performer. I have used Microshift Advent 9 spd and have been similarly happy. Their clusters are steel 1-piece that are excellent for mid drive use that is also as kind on your cassette as possible. Also the Advent 9 uses a single-gear shifter which is what you want on an ebike.

If I were redoing your drivetrain, I would first try Microshift because it is a budget brand that punches way above its weight class in terms of quality. If you want to go truly premium, a Box 2 derailleur, Box 1 single shifter and a Microshift cluster (1 pc steel 11-46T and only $39!) would be the next choice. Another excellent avenue would be 9 spd SRAM which since its 9s is cheap. Shimano would be my last choice. Not because its bad but because others are better. No matter what you pick, use the SRAM EX1 chain which is an ebike strong chain and costs only $25.

EDIT: Also you can use this video to tell you everything you need to do step by step.