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8/1/2009
Location
Fletcher, NC
US
Edited Date/Time
5/11/2021 10:46am
So with the injury to Luca Shaw, I wanted to pose that thought. Can we engineer the guide system to prevent that from happening again? There has to be a protective measure that could prevent that from happening.
Where is Dave Weagle when the world needs him?
Where is Dave Weagle when the world needs him?
On a side note, I've have a chain "jam up" in a chain guide during a race run. I pedaled to un jam it. Fortunately for me it worked and it was only on the Kamikaze fireroad. As for Luca, I don't know the exact details his chain guide situation but I know the feeling of trying to work out a mechanical during a race run. It's GO time!! Heal up Luca.
What type of chains do they use in WC DH at the moment? I believe most riders run 7 speed DH specific groups, but is that with a 7, 10, 11, or 12 speed cog spacing in the cassette?
Back in the 9speed and 10speed days I used to snap chains relatively often. I have never snapped an 11sp chain (using x1 i.e. the cheapest sram one) on my enduro and ebike, and I don't replace them that frequently. Especially surprised that it has never blown up on the ebike from mid-climb re-attempts in Boost.
Apparently because the chains are narrower they are more reliable these day.
But in DH, we moved to XC narrow wide rings & minimalist guides. I think we've gone too far.
There ought to be a front guide system that doesn't let chains drop into the cranks/sprocket/bottom bracket.
Whether that is some sort of encasement like the old MRP sandwich or in combination with a wider sprocket base or something. Chains shouldn't be able to jam into the front of a DH bike.
Chain guides are minimalist, have too many openings, sprockets can let the chain drop in between them and the BB. There is a better way, but I lack the engineering or ideas to come up with it.
Regarding e.13 products, I have this to say:
Some 12-13 years ago, living in this corner of the world, I made sure both my DH bike and DJ hardtail had e.13 chainguides: LG1 on my Supreme DH WC-edition and SRS on my Spank Smoke. Until I had an issue. I'd like to add that both were very meticulously set up and working very well. We had this spot where there were 4 smallish stair sets with flats between them and next to the stairs there were banks for wheelchair access. One of the goals was to sprint from the top, bunnyhop and try to gap the flat into the bank/landing of the next set. We were at it and it was hella fun, until I got a random chain jam in the SRS mid sprint. It was one of the scariest spills I ever took and if I wasn't wearing a helmet, I'd probably be some place else now. We laughed it off, but I ditched the SRS immediately and soon the LG1 too and tried to avoid any e.13 guide for years. Of course, it's a stupid attitude, if you ask me now, and I have had decent experiences with e.13 guides since then. I'd have no issue running one right now.
Anyway, I have found chainguide happiness in the Straitline Silent Guide, after experimenting with a Gamut on the big bike. I still have the Silent Guide and find it one simple and amazing product.
I'm currently building a new 29” DH rig and I am tempted to do the no-guide way, as I've had zero issues with dropped chains on my enduro bikes since 4 years now.
I'm very sure most guides on the market right now are pretty reliable and well made.
Cheers,
Mx
Seems like there should be something built into the design that eliminates the gaps chains can lodge into is all I'm suggesting. It would have to be important to a designer, similar to why Leatt was started or why the Lotus Designs/Astral Buoyancy creator made the first lifesaving PFD's. They either lost a friend due to an unaddressed safety issue or witnessed/had a life changing injury.
That's usually the only thing to trigger major design re-innovation. But not much death or drowning going on in the front chainring jam category
a) Chainguide failure ===> causes broken chain ===> chain goes into front wheel and flips Luca OTB?
b) Chainguide failure ===> causes broken chain ===> chain goes into rear wheel and flips Luca OTB?
c) Chain breaks ===> chain gets sucked into chainguide ===> chainguide causes crash?
d) We all know chainguides R dumb ===> Luca gets hurt ===> thus chainguides R dumb?
Mx
If I was a betting man, I'd say it was more than one. Front shifting is horrible for chain endurance as you shift by pulling the chain up by snagging the outer plate, effectively trying to open up the chain. With a 1x drivetrain you don't have that mechanism, which is part of the reason why chains are more durable on 11 and 12 speed drivetrains - because we removed the front derailleur. We added other problems (chain alignment and all), but it's still a net gain when looking at it from a system perspective (narrow-wide rings holding chains better, P-shaped derailleur cages, horizontal paralelogram movement, only one shifter which makes it less complicated to choose the right gear, etc.).
He hit the nail on the head mate, you don't have a case here.
Praise be to our lord and saviour DW!
That guide, the G4 has been around since 2012 (first as the G3, "G4" just signified an upper guide update, we're actually onto the "G5" now) and is by far our least "minimalist" guide. It even predates narrow-wide rings. So have guides gotten too minimalist? Maybe (I certainly have my opinions), but this ain't the one.
Anyway, I don't think the guide design had anything to do with that crash and I don't think Luca or Doug E. Fresh do either. In fact, I just sent them more guides.
Believe me, I watch World Cups with baited breath wanting our athletes to crush it, but also scared shitless something freakish could go wrong with our products. I'm sure everyone that makes stuff raced at the highest levels can relate. You think it's easy watching a live Danny Hart run? But I think it's fair to say they've proven pretty dang reliable.
But, to the point you were trying to make, I LOVED our last "System" style guide (one with plates and rollers), the S4. But it didn't sell very well, as the market was really keen on the guide format of our "G" series guides. I honestly think it had a lot to do with people wanting to show off colorful, anodized rings, as well as other aesthetic reasons more than a preference for one's performance over the other. I ran the S4 Carbon for DH until it was discontinued. I loved how silent and easy to setup it was.
Circa 2011?
That said, there are a lot of advantages to the integrated skid design (G5/G5, SXg, AMg, etc.). The biggest is that they help you maintain momentum over obstacles if you make contact, whereas crank-mounted bashguards tend to get hung up AND give that feedback/force through the cranks.
Would love to get anyones feedback on guide design. We're working on some pretty rad news stuff, but I gotta keep that quiet for awhile.
This one: https://cambriabike.com/products/mrp-system-3-piece-chain-guide
So that guide is more safe in regards to chains than all of the ones on market that have the plastic "box" to encase the chain in a lot of scenarios. The bash ring is a better way to do it in my opinion. Sure, World Cuppers and gram counters want the shark fin underneath and to brag on how "narrow wide" chains have changed the world.
And I'm not blaming MRP for any failure or injury probability. The whole industry tried out the shark fin and like you said, the consumer jumped on it, but to me for the cool factor. Heck, a lot of DH shoes still run exposed laces & shark fin bash guards do nothing to keep a shoe lace or velcro strap from sucking into the chain like it was a 1982 GT bmx bike.
To me, a synthetic bash ring on both sides of a narrow wide chainring is still the most secure & safest way to guide a MTB chain. I feel like the chain should be sandwiched to keep it from being able to wrap around anything.
My Demo 29 Expert has an MRP on it which I've bent the BB ISCG mounted bash on multiple times in a short period of ownership (no fault of MRP). Just seems like a redesign to a more bomber way to trap, guide and protect is needed on DH bikes.
Getting the market to buy into "this guide finishes races" when designing a stouter guide/bash system would be a good thing
But like you said, consumers...consume. They don't win World Cups though.
What it boils down to is if you said to a World Cup pro "Hey, we want you to run this new jam-proof, unbendable, completely bashable chainguide on the circuit", would they say no?
If you bought a Kawasaki,or Honda you wouldn't expect to see the guide being something not in house.
But then again, mountain bike frame manufacturers still think 20 years later it's perfectly acceptable to let the chain smash your alloy chainstay and seatstay with abandon off the factory floor
As for double bash rings to guide a chain, you often don't have the space to do it on the inside on many modern bikes with the packaging and all. Plus direct mount chainrings, etc.
Plus, while the bashring probably is a better solution than a taco bash mounted to the ISCG tabs load bearing wise, putting a high impact load through those bearings also doesn't seem as the best idea.
If you told an engineer in another industry that he had to design a bike from the ground up that you would slam into boulders at 30mph and his goal was to ensure the bike, chain and sprocket took NO performance hampering damage, don't you think we'd see a completely different frame & product design?
Bikes would probably be quite a bit different, yeah. But it is a bit on us consumers not buying better, but "worse looking" products and burying them.
Also.....breaking a chain is not evidence of a chainguide failure.
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