NBD - Disappointment content.

Totally normal on my bikes. Both 1x12. Just don't back pedal in the biggest sprocket. There's no reason to do it during normal use.

Normal on 12 speed. Look at the angle the chain has to sit at in the big sprocket.

In my experience it becomes less of an issue once the drivetrain is "worn in" a little.

I had this on a SRAM 1x11 setup too. Didn’t affect anything.

Totally norma

I had this on a SRAM 1×11 setup too.

Not something I’ve been aware of on any of my bikes in the past. Would annoy me too tbh.

Sounds like typical online buying a bike in a box issues.
Have you taken it out on the trails and how does it ride?

I'd just ride it for a bit. Once the chain has loosened up, it will probably improve.
I always degrease new chains, dry them thoroughly, then apply my lube of choice. The stuff manufacturers use is very thick and nasty imho.

Both my 12 speed xt and GX eagle do this. Back pedal in the lowest gear and it falls down to the next ring 🤷‍♂️

There’s no reason to do it during normal use.

Sorry but turning the cranks backwards is very normal*!

*says the man who's just been practising trackstands in the confined space of his shed.

You do trackstands in 1st gear? With a 50t sprocket?

No I'm not that abnormal 🤣

I haven’t ridden the bike yet as I am unsure I can live with the chain dropping.
I’m pretty certain it’s not normal as it’s never been mentioned in any reviews of a bike using the sram 1x12 gx.
Unless they can sort it, I think the bikes going back. It shouldn’t happen on a 4k bike.

woteva

@surfpunk It's just how it usually is on 1x12 and most riders don't have an issues with it.

Just don’t back pedal in the biggest sprocket. There’s no reason to do it during normal use.

Ratcheting the pedals on a tricky climb? Only a problem if you ride steep rocky/rooty climbs in bottom gear. imho a drivetrain on an XC bike that does this has a flaw but the advantages of 1x12 outweigh it for most riders.

edit to add, if it's a 55mm chainline you might be able to improve it by putting a 52mm CL front ring on there by dropping down a couple of teeth, 32 to 30 etc. Been a few articles online about the pros and cons of 55mm CL 1x bikes.

Normal, no.... However, as above, not uncommon. Of many reasons to send a bike back, i'm not sure this would top my list.

When you say it drops off, what exactly do you mean?

From the largest cog on the cassette to the second largest - not uncommon. Different bikes seem more prone to it than others, but I don’t think I’ve had a12 speed mtb that is completely immune.

Falling off of the front chainring - shouldn’t do that in normal use (but if you were spinning the cranks backwards to test if it could happen, I wouldn’t be surprised if it did occasionally).

Whyte 120C works from Rutland Cycles.

Despite their bajillion point check over almost nothing was right with the bike.

Still, once I had done their job for them it became the great bike it is.

And yes, the chain falls off the big sprocket when you back pedal, which has never been an issue when out on it.

Perfectly normal IME. If you’re ratcheting the cranks on a technical climb, it’s only going to affect 10 or so teeth on the cassette, but will go straight back on to the original gear as you pedal forward. Non of the reviews will mention it as its normal for it to happen

Totally normal, never had an issue with it in normal life.

@surfpunk It is mentioned in reviews for the kit alone, for example when a new groupset is launched and some bike reviews mention it.

You are a little bit OTT rejecting a bike based on that alone as it really is a non entity when riding.

We have 4 bikes in the household that all drop the chains when backpedalling more than 1 full revolution when in a workshop stand. All of them cost more than £4K and not once has it been a problem when riding any trail or surface.

Correct B-Tension setting is important on them all though, especially Sram 12sp it seems.

As above, its only an issue if you're one of the vanishing breed of dinosaurs who like to pedal your bike on gnadgery tech. The fact that it ****s up pedalling pales into insignificance alongside the numerous huge advantages of 1x drivechains.

Like aesthetics, the reassuringly expensive commitment of paying three figure sum for a new cassette and having an uncluttered left handlebar.

TBH you should me more grateful that it does fall off. Its a sign of progress.

if you’re one of the vanishing breed of dinosaurs who like to pedal your bike on gnadgery tech.

Sheepishly raises hand.

Hi. I'm a dinosaur.

On my Trek fuel ex running deore 12speed it does not drop off but it does try too but if the clutch is off it is fine.

yeah , its normal on some bikes, its not a problem in normal use, not a good reason to reject a bike (IMO), but if its that big a deal then its your choice.

Its certainly not indicative of a fault anyway.

All my 12 speed bikes do it but it takes a good half a turn of the cranks backwards to happen. Never been an issue on the trail and I love a technical climb where ratcheting the cranks is an essential technique. You should never have to ratchet back more than a 1/4 turn if you plan your line anyway. I'd definitely say it's a non-issue for me and not worth sending a bike back for.

This is often much less of an issue when the bike it at sag, and the gears have run in a little.

Same kind of reason why SRAM says to set your b-tension at sag too. You're not optimising it for when its in the stand.

I've had two bikes with SLX 12-speed - with all tension screws adjusted properly, chain length measured etc. and get the same issue.

This is on 2 different frames with a 52mm and 55mm chainline spacing.

It's a bit annoying, but I think it's 'normal'.

I bought a Trek earlier this year that was spec'ed with e13 drivetrain parts in lieu of the Shimano that ought to have been there. As you say, OP, the chain would do down the cassette if you back pedalled in the large sprocket. It went back to the shop and Trek replaced all of the components for the correct stuff and the issue went away.

A chain derailing when back pedalling should in no way be considered 'normal'. It's rather like Sram denying that there's any problem with their front mechs on road bike. Everyone in the trade knows the issue exists but it will always be blamed on set-up if it's raised as a warranty issue.

One way to cure it is with a new, different brand, probably more expensiver, chain. There are a few vids on YT about it.

But I'd ride it, then declare disappointment or joy.

(Send it back? don't be a div 😆 )

This is often much less of an issue when the bike it at sag, and the gears have run in a little.

+1
I've got several bikes with 1x11 and 1x12 systems that i look after, about half of them either exhibited some minor pre shifting noise/chatter or actually dropped down when backpedalling in the stand and brand new.
None of them do it in the real world.
I suspect the standard sticky grease in the chain probably doesn't help either. Couple of cleans and some proper lube works wonders.

I’ve had a look at the bike and taken into account your replies, here’s what I found:

1, it still drops the chain at sag.

2, the chain doesn’t stay on the next gear it happily skips over the teeth until it snags up around the derailleur/ jockey wheels.

3, I’m a dinosaur who needs to back pedal in a low gear occasionally when negotiating a rooty or rocky climb rather just smash into said roots or rocks with my pedals and or crank arms.

4, I’m not sure how accommodating they would be at replacing the bike once it’s been ridden.

Customer service at Rutland cycling has gone quiet.

@mtbfix

It’s rather like Sram denying that there’s any problem with their front mechs on road bike. Everyone in the trade knows the issue exists but it will always be blamed on set-up if it’s raised as a warranty issue.

Whats the SRAM front mech problem? I've got SRAM Force on mine, I haven't ridden it for a while, and the front mech doesn't actually get that much use, but can't remember if there are any issues with it.

The word from Whyte is it’s not normal and is an issue with the chain line.
At least that is good to know that it’s an issue and not a feature.
Hopefully it will be sorted soon and I can get out on it.

as above, it happens on lots of wide range setups, especially with shorter chainstays
of my 4 bikes, I know at least 2 do it, and my nippers bike
it has absolutely zero effect in use, you will never be in a situation when backpedalling will make it drop.. unless you trackstand and spin pedals for show

might not even happen when weighted on a full sus as the cs will likely grow
the only viable solution on your specific bike, is to make the chainline none standard with spacers.

If you consider what is happening, its the chainring acting as the derailleur in reverse, and as above, it lessens as the chain and cassette wear together

IME it happens because of either a. The chain-line isn't centred properly, or the crank-off set is wrong b. the chain's not lubed but has the sticky transit grease on it, or sometimes both. Sometimes it just needs wearing in, sometimes you'll need to degrease and re-lube the chain , sometimes you'll need to check the offset on the cranks. (I think that in order to get bikes off the production lines, sometimes chain rings /cranks with the wrong offset are fitted)  There's no reason why SRAM chains should fall off when backpedalling, although they do (see above) .

One Up did a good article to read to understand crank off-set and chain line. Its mostly about converting your bike to 1x, but the principles still apply. in essence you need to check which off set (normal, 3mm, 6mm you should have)

The word from Whyte is it’s not normal and is an issue with the chain line.

But what do Whyte know eh?! Good job you followed your instinct and didn't listen to people on here.

It isn't normal and shouldn't happen. I've had three brand new SRAM Eagle drivetrains (NX, GX & X01) on the same bike and none of them did this. Full sus bike. Friends have it on their bikes, doesn't happen. Seems like there's a lot of people with a poor set up on here.

I'm like you, its brand new, everything should work flawlessly. Its as simple as that. IF this is a 12-speed chainline issue thats common then its not your problem, thats Whytes problem that'll they need to sort. I certainly wouldn't just accept it, once you've rode the bike they could easily blame you somehow etc.

@ads678

At a former employer we had various issues with Sram groups dropping the chain on the front. To the point that one manufacturer paid for a few bikes to be swapped to Di2 at their cost as Sram denied fault. There's plenty of it on the internet. For less of people it works fine. For others not so much. But when you've spent north of £6k on a bike you are entitled to have working gears.

This thread just reminds me of absolute nightmare customers in bike shops. Especially the "This bike cost XXX, it should do this, this, this and transform into a unicorn"

It isn’t normal and shouldn’t happen. I’ve had three brand new SRAM Eagle drivetrains (NX, GX & X01) on the same bike and none of them did this. Full sus bike. Friends have it on their bikes, doesn’t happen. Seems like there’s a lot of people with a poor set up on here.

I'm calling cobblers on this. I've never seen a bike with a modern drivetrain where you can pedal backwards in the 50t or 52t sprocket without dropping the chain.

I’m like you, its brand new, everything should work flawlessly. Its as simple as that.

Bikes aren't flawless though are they? They're a mess of delicate, fragile components which have to be perfectly set up despite having a really hard life. Usually at the hands of people with no mechanical understanding or sympathy.

Just ride it. Once you've done a few hours of riding and the drivetrain is worn in it will cease to be a problem.

Thanks for your input everyone but Whyte have said it’s not right and it’s an issue that needs addressing.
If the company that make the bike say it’s a problem, I’m going with what they say.

I’m calling cobblers on this. I’ve never seen a bike with a modern drivetrain where you can pedal backwards in the 50t or 52t sprocket without dropping the chain.

I've got 2 Deore 12 speed 10-51, 52mm chainline on a 135QR frame and 52mm chainline on a boost frame, chain has never fallen off pedalling backwards in the 51t cog

I also got 11 speed SLX 11-42 and chain falls every time backpedalling in the 42t cog and the chainring is 2mm from the chainstay

I checked both of my bikes (both Sram Eagle. One 50t. One 52t). Neither does this, and I can't remember the 60+ rental bikes at work doing this either. It used to happen on older systems (like Shimano 11sp as mentioned above).

I've also seen it with daft set-ups like kids bikes with super short chain stays and Boost spacing, which I've fixed by installing a non-boost chain ring and straightening all the teeth on the biggest sprocket that point in towards the spokes. A pain in the butt, but it worked.

I’ve never seen a bike with a modern drivetrain where you can pedal backwards in the 50t or 52t sprocket without dropping the chain.

You're more than welcome to come around to my place and pick either my Scandal or Enduro and watch neither of them drop the chain while they're pedalled backward

@mtbfix

Cheers. Wasn't doubting what you were saying, just wondering if I was covering something up assuming I just wasn't setting it up properly or something. Fortunatley mine seems to be one of the good ones. 🤞