Shimano Prototype Chainguide Debuts at Sea Otter
Shimano's 2013 Saint launch went off at the Sea Otter in front of an enthusiastic crowd, where we noticed a prototype chainguide which breaks a few rules and looks quite promising. The bash guard, which is intended to be an addition to the Saint group is segmented so that riders who favor one foot forward can save some rotating weight and run only one segment on the side of the crankset that faces downwards. Riders who can corner and jump with either foot leading can run two segments. Shimano states the weight of a single-segment guide is 147 grams, which is definitely race worthy.
![New chain guide]()
Where most chainguides use a roller on the lower boomerang. Shimano chose a carefully contoured rubber-like guide shoe that articulates on a spring-loaded arm. The net result of the spring-loaded guide shoe is that the chain is supported closer to the chainring and the guide tucks away to safety when bashed by a root or rock.
![photo]()
The new guard is not a rough prototype, as the molded rubber shoe and the upper guide mechs are produced in molds, as is the spring-loaded articulating arm. The boomerang fits ISCG-05 mounts and is adjustable to fit 34, 36 and 38-tooth chainrings. Not finalized yet is whether or not the bash guard segments will be produced in separate diameters for each of the three chainring sizes Shimano offers for the Saint crankset.
![Lower link is spring loaded]()
While the new guide is definitely a downhill setup, Shimano says that Saint, XTR, and XT share the same bolt circle, so the new guide, when released, can retrofit to a lighter-weight crankset should one want to assemble a sweet enduro style one-by-ten drivetrain. On that subject, the friction created by the sliding surface of the lower guide is reported to be equal to or less than that of a roller-type guide. The explanation is that the deflection of the chain is less with the Saint guide and there is less resistance when the chain is running at the extreme ends of the cassette. Spinning the crankset on the demo bike, while not a conclusive test, lent credibility to Shimano's claims.
Will we be seeing the guide in our LBS anytime soon? Highly unlikely. Shimano's Matt Robertson says that the Saint team wants another year of testing on the World Cup circuit before they give it a thumbs up for production.
Photos by Ian Hylands
The segmented bash guard is novel, but it makes sense - the guard always points down when the pedals are in position. To add a second segment; remove the cosmetic threaded lugs on the two remaining spider ends and replace them with chainring nuts.
Where most chainguides use a roller on the lower boomerang. Shimano chose a carefully contoured rubber-like guide shoe that articulates on a spring-loaded arm. The net result of the spring-loaded guide shoe is that the chain is supported closer to the chainring and the guide tucks away to safety when bashed by a root or rock.
The lower guide is made of a similar rubber-like substance used for cam-chain guides in auto engines, so it should be quite durable.
The new guard is not a rough prototype, as the molded rubber shoe and the upper guide mechs are produced in molds, as is the spring-loaded articulating arm. The boomerang fits ISCG-05 mounts and is adjustable to fit 34, 36 and 38-tooth chainrings. Not finalized yet is whether or not the bash guard segments will be produced in separate diameters for each of the three chainring sizes Shimano offers for the Saint crankset.
The guide's lower shoe pivots on a sturdy, spring-loaded arm.
While the new guide is definitely a downhill setup, Shimano says that Saint, XTR, and XT share the same bolt circle, so the new guide, when released, can retrofit to a lighter-weight crankset should one want to assemble a sweet enduro style one-by-ten drivetrain. On that subject, the friction created by the sliding surface of the lower guide is reported to be equal to or less than that of a roller-type guide. The explanation is that the deflection of the chain is less with the Saint guide and there is less resistance when the chain is running at the extreme ends of the cassette. Spinning the crankset on the demo bike, while not a conclusive test, lent credibility to Shimano's claims.
Will we be seeing the guide in our LBS anytime soon? Highly unlikely. Shimano's Matt Robertson says that the Saint team wants another year of testing on the World Cup circuit before they give it a thumbs up for production.
Photos by Ian Hylands
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They explained this in the description. You can attach the other "half" bash to the upper two bolts...so when your feet are switched or rotated around 180, the other section would then be down. They are just showing that one for someone who primarily rides right foot forward.
half bashguards which favour a pedal forward bias from the rider when grinding (BMX) or hopping (Trials)
It's not like you are spinning your cranks at 1000rpm or more
Other than that, it's a nice PROTOTYPE Chainguide that goes into the right direction..
Let's seee how the final Product looks like..
Keep up the good work Shimano
Anyway, if I was capable of working out rotational weight, I'd be much happier with a 250g balanced bash guard than a 150g offset weight.
Nothing like treating your customers like fools!
Ultimately this may never make it to us consumers but it's this sort of R&D and experimentation that delivers us with better products. Well done Shimano.
Stupid.
A hard hit on this one can actually torn the "star" of your crank ! Tested, so ...
I obviously see no useful innovation in this thing.
www.blackspire.com/DER-Guide
The Beavertail bashguard is designed to absorb the impact and not transfer it to the guide frame and consequently the bike frame. The Beavertail can be replaced for around $35, much less than a frame or a crank spider!
The chainguide itself looks damn good but as mentioned why have only half covered when you can get a full bash ring that weighs the same as one segment, get a bashring and make it lighter by drilling some bleeding holes in it, but honestly how many people would ACTUALLY notice a few grams difference?
blog.derestricted.com/wp-content/uploads/2011/02/carbon_fibre_bashguard_custommade1.jpg
Build one for myself on a SLX 3pcs crankset and made a 2pcs crank of it with segmented chainring. Works like a charm!
What the point in protecting something you will never hit?
www.trial-bikes.com/images/protec_tryall_sy_033.jpg
I would imagine running one segment would mean that it would feel weighted oddly when it is rotating. Not to mention that it would feel heavier than the LG1+ for instance since it would be rotating. Adding also if you need to run two that is 147g + the 2nd segment so that will weigh more than both the LG1+ and the SRS+ which would offer greater protection at all times.
The weight of the E-Thirteen LG1+ is 165g and the SRS+ is 195g total so that really isn't allot of extra weight for the protection advantage of knowing that you don't need to have you feet in the perfect position if you was running a single segment.
The boomerang with the spring loader at the bottom looks good though. That seems like a neat design but would it clog with mud in wet weather? and if you haven't got the segment in the right place would it be able to take a few rough hits over roots and rocks?
Nice try Shimano and all that but for me I will stick with the E-Thirteen and MRP for now thanks.
This has been done before in BMX and trials I think, maybe profile have a bashie like this available, yes different but the same. Maybe even Shimano make one for BMX.
Not a fan, won't save you wheelying into a log or rock.
Don't always dare to be different, got all german on us and solved a problem that doesn't exist.
No way the chain's staying on that thing.
But you could always just stick some other brands bashie on it.
Maybe a centered tacho mounted on each side of the BB would be better, massive center skid plate. Too far from chain ring for protection I guess. I'll stop shooting from the hip.
Just build a gearbox or a narrower axle internal geared hub for gearbox use. You know it's inevitable Shimano.
-When you get a hit at the bash guard you will feel it to the pedals !!!
-The spider is strong enough to accept that hit???
I like the look of the guide and im sure it will work great, i just hate it when they spout crap about it being innovative!
Also, since when do people not still pedal through nasty rock sections?
i know, i also run a half bash guard ... but my one (e13 LG1+) is mounted to the back plate and doesnt rotate with the cranks ... so IMO its more safe than a rotating bash
I've bent multiple Profile spiders on my DH cranks (after I destroyed the boomerangs that is). 50 to replace them. BUT Saint cranks is the entire crank arm/spindle. IE a little tad bit more than 50$ lol. If they were like the old XTR DH cranks with removable spiders it would be a major plus, but, with built in spiders, basically they are designing something top tier racers can benefit from, and make others want it, and those others will end up damaging parts that aren't provided free to them to begin with, and basically making Shimano sell more product. Shame on you Shimano. I lost loyalty after destroying a proto set of 858 pedals at the Reno Nationals. Sacrifice everything for money as you always do.
www.chainreactioncycles.com/Models.aspx?ModelID=41335
As for reliability and stones getting trapped (etc.) that is why they are testing it for a year on the WC circuit - if the slider does not work they can look at alternatives and if the positioning of the components in relation to each other can be made better I'm sure they will... I'm pretty sure Straitline use a slider on some of their products and I've never heard complaints of that nature but I'm sure a million people will put me right now :-)
I've a standard e13 bash and wouldn't really look to replace it unless it breaks (all bash guards are stupidly expensive for what they are!) but, if I am in the market in a years time, I would at least consider this as an option.