FatSix Top Gear Skipping

[Fitzy]

Hey all,

I started riding my new FatSix 2015 about two weeks back, and have had few issues. Recently, one has been giving me plenty of aggravation. After I oiled up my chain, it has an annoying habit of skipping teeth on the highest-gear of my cassette when under load. It seems to occur regularly when in Tour and above. I made sure the derailleur was properly adjusted to align chain with teeth. The limits are set properly, and there is no visible damage or defect with any components. The derailleur-clutch is "ON", and I've even adjusted the B-tension screw in hopes I could get at least one more tooth covered on the gear: still slips. Any suggestions would be helpful.

BTW: I weigh about 280# if that helps.

Model: Shimano XT RD‑M786 10SPD Rear Derailleur and matching 10-speed cassette.

Thanks,
-Fitz

 

[Jeff Backes]

Do you have at least 5mm between the jockey wheel and the largest sprocket? How much of an angle is there on the chain? Does it ever happen on the second to largest cog?

You might want to point a video camera (phone, GoPro) at your derailleur and see what is actually happening under load.

jeff

 

[Fitzy]

Ha! Thanks Jeff, I was actually going to include a "short of getting a slow-motion video of the problem, I don't know what to do!". I just may end up doing just tat.

Love your avatar BTW. There used to be huge "Reddy Killowatt" sign at a power-plant near where I grew up. Always thought he was pretty cool looking.

 

[Joe Remi]

Ha! Thanks Jeff, I was actually going to include a "short of getting a slow-motion video of the problem, I don't know what to do!". I just may end up doing just tat.

Love your avatar BTW. There used to be huge "Reddy Killowatt" sign at a power-plant near where I grew up. Always thought he was pretty cool looking.

You say it started after lubing the chain, so I assume it's overlubed, a common thing with cyclists. It only needs a very light coating on the the sprocket side, so I would try running your chain through a paper towel to get the excess off. Also, make sure you're using a real chain lube, not something like WD-40.

 

[Fitzy]

Hey Joe,

Thanks for the advice. I think you may be right.

A little back-story: I got the bike about a month back and most of my riding has been on beaches and sandy shoreline. My first experience with chain-suck occurred in about the first week, and I felt embarrassed that I'd actually neglected to lube the chain AT ALL since I'd gotten it. I picked up some "Finish Line Wet" lube, and applied a generous amount. The chain-suck disappeared, and I was back on the road (sand). On a side-note, this lube has a strong scent which alarmingly mimics that of burning electronics! I was worried for a short time that perhaps my Bosch had an electronic defect after applying the lube. Crisis averted.

I made a point of applying he lube regularly, and about a week back, I began getting chain-jump and ultimately chain-suck again. Although I kept the lube up, I'd neglected to periodically clean out the gunk that built up THANKS to the sand/lube mixture. I believe this contributed most to my chain issues. I cleaned up the chain, sprockets, and derailleur on Friday, and was VERY disappointed to find that the chain-suck came back with a vengeance. It turns out that with all the abuse I'd been administering, the chain's master-link had become damaged, and its pin had popped from on of its leafs (right term?). It was a subtle issue...I only found it by carefully looking at the chain...but it was enough for the chain to suck at this link repeatedly.

So, I was fortunate to find a shop with the exact replacement-chain and installed it without issue...the weekend was saved. I will be less liberal with the lube in future...and more active with the toothbrush.

Now...my NEW issue is that my Bosch is creaking. It matches the crank-cadence, so I think it's just the mounting-bolts needing tightening. Also, I broke a pedal on one of this weekend's outings. It's under warranty, so I'm not too worried. Still, I hope it's a defect, and not my weight being too much for the part. I weigh about 270#, and it occurred whilst trail-riding. Nothing out of the ordinary. In fact, I didn't realize it had happened until I was demoing the bike for someone after a ride.

 

[Joe Remi]

Yes, sand is very hard on bike parts, and a thick wet-lube is just going to grind it in. Honestly, I think you were better off with no lube than the stuff you ended up using. My advice would be to use a very light lube, and clean your chain regularly with one of those chain cleaner thingeys.

Is that a plastic pedal? I would think an Xduro-level Haibike would come with metal pedals, but maybe they sell them with "test ride pedals", thinking people who spend that kinda cash on a mountain bike already have their own pedals they like. I would recommend something like VP-001 or VP Vice.

 

[Fitzy]

Hey Joe,

Thanks for the advice. Those pedals look like they'd suit my needs well, and they're not eye-bulgingly expensive.

http://a.co/6KywrB6

Yep...they're plastic

"...thinking people who spend that kinda cash on a mountain bike already have their own pedals they like"

How convenient for HaiBike! Nope...this was a major, thpoughtful purchase for me, and I purposefully chose the more expensive RX package since its hardware was meant to be of higher quality. In the process of replacing under warranty, but will consider getting the VPs. I don't need this kind of failure again.

Got these coming tomorrow in the meantime...whatya think?

http://a.co/1SEpyYF

Thanks again,
-Fitz

 

[Joe Remi]

That looks good to me. The "test ride pedals" policy is very common in non-electric world, especially with high end road and mountain bikes. Most riders at that level feel like they're paying for an expensive pedal they don't want, so manufacturers tend to skip that step.

 

[Fitzy]

Hey all,

Just a follow-up on this issue. I'm embarrassed to admit I didn't think to closely inspect my cassette's chainrings: it turned out that the upper three chaintings were severely shark-toothed which resulted in the insanity-inducing skipping. This bike was only two-weeks old, and it didn't occur to me that this could POSSIBLY be an issue. Unfortunately, with this persistent condition after weeks of fruitless and repeated readjustment of the derailleur, the intermittent chucking resulted in minor damage to the splines on the freehub. I suppose the motor-assisted hammering exacerbated the damage. In any case, I replaced the three rings in question, and I'm back to being happy. The damaged splines aren't perceptible, but I'll be changing that freehub next.

So, I THOUGHT that the FatSix's unique raised drive-sprocket configuration was the main-factor in this skipping problem...it was not, although it MAY have contributed to the extraordinarily rapid wear of the upper-chainrings' teeth. I'll be keeping an eye on them as well as the cleanliness of my chain going forward.

-Fitz

 

[MLB]

I'd assumed it was sprockets, but didn't know it was THAT fast.
I suspect your weight and the dongle and you must be gnashing some nasty shifts?
Argument #2 against dongles.

 

[Fitzy]

I'd assumed it was sprockets, but didn't know it was THAT fast.
I suspect your weight and the dongle and you must be gnashing some nasty shifts?
Argument #2 against dongles.

Thanks for the input. Yep, I'm a newb! Sholda looked there first. I've learned to be a little more gentle on the gear-changing as well. But this IN NO WAY diminishes my proponency of dongling. I'll just try to keep my chain as clean as practical, and replace rings as needed. What I really would like are titanium rings; these'd solve the issue outright.