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Discussion Starter #1
Bike was purchased brand new from RM dealer in Greensboro, NC on June 1, 2020 this bike has < 30 miles on it, from day one it has developed an issue with loud pop while chain skipping when
pedaling under load, dealer has replaced the freehub body but that did not solve the problem. Bike was in the shop for total of 5 months waiting for parts and still in the shop (COVID slowed things down a lot, I understand that).
The mechanic at the bike shop has said that an only way is to upgrade the drive train, he is unsure what is causing the skipping, theory super cheap parts bin and they see silvering of gears on the cassette. Second opinion from another LBS also responded that he does not know why it skips, he put brand new cassette and that did not solve the problem.
When I have contacted RM support they responded that Rocky Mountain does not warranty the bike, only frame, but it was Rocky Mountain who built the bike. Dealer does not know who to contact Shimano, Suntour or KMC. Fallacy of the situation is that Rocky Mountain designed, speced and built the bike but does not warranty the final total product. Dealer advised me to buy a Banshee bike for $3000, saying you get what you pay, but $1000 is not a chimp change for many people, if I could I would buy Santa Cruz or Banshee, we are raising 4 boys and even $1000 is a lot of money for us but we wanted something good for our son when he turned 18.

We have a bike that is under warranty <30 miles, mechanics do not know what is wrong with it, and we cannot use the bike for intended purposes. Where do I go from here? Who do I call as the dealer claims that bike was shifted under load as he sees silvering on the cogs a bit. Please advise if you know RM and how to deal with the problem, we are lost, 9 months into a life of a bike and he rode it for total of 30 miles on local greenways.

Loud pop and skipping problem
 

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first, get a new mechanics/shop. If those mechanics were the ones who assembled the bike to begin with, they're not going to figure it out the second time around, and they shouldn't recommend someone upgrade the entire drivetrain/replace cassette on a brand new bike unless it truly is defective.
Sunrace cassettes work just fine, as do all the shimano stuff on that bike. Here's where I would start:
Tune derailleur and re-tension cables. 30 miles seems like the right amount of time for the cables to do that initial stretch thing.
make sure chain is lubed
Check chainring bolts, are the tight?
Check crank and bottom bracket interface, is there any play?
Rear hub, is there any wiggling between cassette and freehub, freehub and hub, axle and hub? (start with wheel on bike, can you feel play when pulling/pushing on rim, remove wheel, check for cassette looseness, check for freehub looseness, check for axle play.)
check rear der hangar (is it tight, is it bent? the shop should have a tool to measure it) If so, replace it)
check if rear der is tight (is the bolt torqued to spec?)
Adjust rear der b-tension screw
possibly remove a link from the chain
check frame for cracks (not likely on brand new frame)
find a new bike shop
 

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Bike was purchased brand new from RM dealer in Greensboro, NC on June 1, 2020 this bike has < 30 miles on it, from day one it has developed an issue with loud pop while chain skipping when
pedaling under load, dealer has replaced the freehub body but that did not solve the problem. Bike was in the shop for total of 5 months waiting for parts and still in the shop (COVID slowed things down a lot, I understand that).
The mechanic at the bike shop has said that an only way is to upgrade the drive train, he is unsure what is causing the skipping, theory super cheap parts bin and they see silvering of gears on the cassette. Second opinion from another LBS also responded that he does not know why it skips, he put brand new cassette and that did not solve the problem.
When I have contacted RM support they responded that Rocky Mountain does not warranty the bike, only frame, but it was Rocky Mountain who built the bike. Dealer does not know who to contact Shimano, Suntour or KMC. Fallacy of the situation is that Rocky Mountain designed, speced and built the bike but does not warranty the final total product. Dealer advised me to buy a Banshee bike for $3000, saying you get what you pay, but $1000 is not a chimp change for many people, if I could I would buy Santa Cruz or Banshee, we are raising 4 boys and even $1000 is a lot of money for us but we wanted something good for our son when he turned 18.

We have a bike that is under warranty <30 miles, mechanics do not know what is wrong with it, and we cannot use the bike for intended purposes. Where do I go from here? Who do I call as the dealer claims that bike was shifted under load as he sees silvering on the cogs a bit. Please advise if you know RM and how to deal with the problem, we are lost, 9 months into a life of a bike and he rode it for total of 30 miles on local greenways.

Loud pop and skipping problem
First off lets correct a few things, this isn't a car. Notice even with a car you get the tire warranty booklet?
Anything that isn't Rocky Mountain's is warrantied by that 3rd party company. It's the same for any bike you buy, Specialized doesn't warranty the Sram or Shimano parts that come with the bike.
Yes you don't shift a bike under load
As advised, find another shop.
 

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Discussion Starter #4
Thank you, I will punch through the checklist @dompedro3 once I pick the bike from the shop, another 2.5 hours and 120 miles trip. I know adjustments were checked and rechecked including b-tension. I installed brand new shift cable, lubed the cable with Shimano lube. I have triple checked the adjustments personally. It shifts superbly well, it is when I apply torque to pedals it immediately skips/pops. I will work through the list above one more time and then it is time for a new drive train. I will take drivetrain of my bike, buy a brand new chain and install it.
I cannot see the flexing of the wheel and a highly trusted mechanic here in Cary, NC he was very very puzzled as he did not see the play/flexing either but brand new cassette installed and bum still skipping.
 

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Murica Man
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does it have a clutch? my shimano 9 speed stuff always skipped and i moved to microshift advent w/ clutch and everything was fine. i am assuming this is the bike?
 

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Discussion Starter #6
Ours is 2020 precisely, so no clutch. They obviously know about this problem and in 2021 they already spec a derailleur with clutch. What Microshift did you end up buying?

does it have a clutch? my shimano 9 speed stuff always skipped and i moved to microshift advent w/ clutch and everything was fine. i am assuming this is the bike?
 

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Murica Man
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Ours is 2020 precisely, so no clutch. They obviously know about this problem and in 2021 they already spec a derailleur with clutch. What Microshift did you end up buying?
this set:
here is a review by @DeoreDX
 

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Discussion Starter #8
Perfect. Thank you.

this set:
here is a review by @DeoreDX
 

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Murica Man
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Perfect. Thank you.
if you have been able to ride it enough to get a feel for the range, you shouldn't have to get a new cassette; you have to buy the shifters and rear mech together tho. another thing to remember is replace the chain and cassette at the same time, so if you do get the new cassette, get the kmc x9 chain. i got it and with this combo it is really good
 

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Cycologist
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I would repost this in the drivetrain thread. That seems like an issue someone will be able to figure out.
 

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Ours is 2020 precisely, so no clutch. They obviously know about this problem and in 2021 they already spec a derailleur with clutch. What Microshift did you end up buying?
It has nothing to do with a clutch or not. They moved to clutch RD because they moved to 10 Spd drive train and Shimano didn't offer a clutched 9 spd RD.

Not to be rude but you're making wild assumptions and you have very little knowledge to back them up.

I rode Shimano 9 spd for years, never had a problem. Find a reputable shop to help you. You say that money is tight, throwing parts at a problem is just going to cost you more.
 

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Murica Man
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It has nothing to do with a clutch or not. They moved to clutch RD because they moved to 10 Spd drive train and Shimano didn't offer a clutched 9 spd RD.

Not to be rude but you're making wild assumptions and you have very little knowledge to back them up.

I rode Shimano 9 spd for years, never had a problem. Find a reputable shop to help you. You say that money is tight, throwing parts at a problem is just going to cost you more.
uuuhh... i had shimano 1x9 system that skipped in the lower gears. when i moved to a derailleur that had a clutch (microshift advent) everything was fixed. it was a chain retention issue.
 

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Are you sure that it is not the freehub slipping?
Another thing would be to check for any kinks in the chain. Your video is kind of short but if it has a pattern to the skip, i.e. every fifth revolution of the crank then something is wrong with the chain.
 

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a proper shop mechanic would be able to isolate exactly why you have a skipping issue. any issue you can recreate means you can identify it precisely. I would not change parts on whims.
 

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Cycologist
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Are you sure that it is not the freehub slipping?
Another thing would be to check for any kinks in the chain. Your video is kind of short but if it has a pattern to the skip, i.e. every fifth revolution of the crank then something is wrong with the chain.
I would suspect a defective freehub.
 

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Discussion Starter #16
Freehub was replaced to an upgraded hub from Shimano by the dealer, exactly same issue with new hub, two LBSes evaluated the new hub again, they do not see hub issues or flexing.

I will work through the checklist myself until I find the problem, my fear was that the wheel hub was the problem like flexing or play in the wheel. Wheel is a quite expensive (for us) to replace.

Are you sure that it is not the freehub slipping?
Another thing would be to check for any kinks in the chain. Your video is kind of short but if it has a pattern to the skip, i.e. every fifth revolution of the crank then something is wrong with the chain.
 

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Discussion Starter #18
Just left a vmail for the dealer since the bike is still there and asked him if he does not mind checking as he has the tools to check the hanger / derailleur. Let's see what he says or if he is willing.
I realize it was pretty far down on my list, but check the chain and the derailleur hangar next.
 

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Discussion Starter #19
BTW, @diamondback1x9 is correct it skips in 1-3 gears only. Because warranty is running out in 2 months, I have decided to take the 1x11 drivetrain off my bike that I know works extremely well, I bought brand new SRAM chain, will put it on a Growler, will adjust precisely and will take it on a run, if my SRAM 1x11 drivetrain skips, then I am down to hangar alignment, wheel, axle, hub issues. He is graduating and I want to get him off to a college with a good bike that he can ride instead of repairing. I will have to wait for my new drivetrain until parts shortage in US recedes, which according to LBS freight ships are in ports, it is customs that is taking a bit longer due to COVID backlog.

uuuhh... i had shimano 1x9 system that skipped in the lower gears. when i moved to a derailleur that had a clutch (microshift advent) everything was fixed. it was a chain retention issue.
 
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