[buildyourown]

Everyone with a Giant DH knows that the stock chainguide is complete garbage.
I was about to make a new boomerang for my buddies bike and somebody else mentioned that they would like a new boomerang that fit on the tabs that are already on the frame. So, if anyone else is interested, let me know and I can make you one too. This is a one time thing, so speak now or forever hold your peace.
Price is $30 and it includes a delrin guide block for the top. You have to supply your own bashguard and a MRP style pulley for the bottom.
They will be made from 1/8" thick 6061 Alum.

I have attached renderings of what these will look like. I'll be cutting these in the next couple of weeks.

 

[gschuette]

I hate the guide on my Giant DH too. Just curious how exactly is yous going to improve the design. Looks like a bashguard on the chainring and a truvativ style guide on top, is it? Will that hole in the bottom I see let me access the ever loosening bottom pivot. If I can access the bottom pivot and the guide will stop moving on me and you have a true bash guard I might be interested.

 

[GiantRider]

Good idea but what tabs on the frame are you talking about,ISCG tabs?Cause my bike doesnt have any.

 

[Grimey]

I assumed it was to mountain an non-Giant chainguide to a Giant frame. The Giant guide that comes on the bike uses Giant's non-ISCG mountain tabs. This way you chould use his inner plate with say MRP bashring ring guide thingies.

 

[Sir_Crackien]

i think that you should make the boomarang a little thicker like 3/16. the reason i say this is that other wise the boomerang will most likely be prone to bending(this is from past experince with one my friend make that was 1/8" and he used 6061 alum). just something to consisder

 

[ssaddict]

Everyone with a Giant DH knows that the stock chainguide is complete garbage.
I was about to make a new boomerang for my buddies bike and somebody else mentioned that they would like a new boomerang that fit on the tabs that are already on the frame. So, if anyone else is interested, let me know and I can make you one too. This is a one time thing, so speak now or forever hold your peace.
Price is $30 and it includes a delrin guide block for the top. You have to supply your own bashguard and a MRP style pulley for the bottom.
They will be made from 1/8" thick 6061 Alum.

I have attached renderings of what these will look like. I'll be cutting these in the next couple of weeks.

You'll need to rotate it forward farther than that drawing or it isn't going to work much better than stock when you bottom whatever roller you plan on using into the dirt or a rock. Tabs on the frame suck anyhow, why would you want to use them?

Just get a e13 as your going to need a bash guard to protect that low linkage anyhow right?

I'll be the first to admit its fun to build stuff just to see if you can, but sometimes all that blood and sweat isn't worth it in the end.

 

[buildyourown]

I wanted to use the tabs that come with the frame to prevent the guide from slipping. The big advantage is access to that ever loosening pivot bolt. If you use a e13 you have to remove the guide to get to this bolt.

As for thickness, my MRP is 1/8" and I have never had any problems.

I would offer bash gaurds but they are a PITA to make and cheap enough to buy.

Don't knock the design if you don't like it. I'm just putting it out there.

 

[Kornphlake]

What do you mean bash guards are hard to make, all you have to is spend a lot of time desigining one, programming a mill, setting up the fixturing to make it, sending it out for annodize and laser engraving and put it in a pretty box. To end up with something that doesn't look any different than what you could buy for $30 and doesn't do anything special it seems like not too much hassle... I made one once, just because I wanted the practice. Given an option to make one again I'd buy.

I don't think there's anything wrong with your design, all you're doing is copying what MRP has done and modifying it to fit the giant chain guide tabs. Unfortunately on this board therer's always a hand full of skeptics. If you were making an adaptor to fit an e13 guide on a vp-free with saint cranks so that the lower roller wouldn't smash the swing arm you'd be everybody's hero, at least until e13 relases the same thing in a couple months, go figure?

 

[buildyourown]

I made about 6-7 bashgaurds for myself and friends. They look cool and I like it when I can make it just fit the chainring you are using for maximum clearance. They are also extra thick with a heavy chamfer on them so they won't cut your leg but machined out where it counts so they aren't heavy. However, the alum alone is like $15-20 so it really isn't worth it.

 

[Sir_Crackien]

i like the design so don't take what i said wrong. i was just thinking about strength

 

[ssaddict]

I wanted to use the tabs that come with the frame to prevent the guide from slipping. The big advantage is access to that ever loosening pivot bolt. If you use a e13 you have to remove the guide to get to this bolt.

As for thickness, my MRP is 1/8" and I have never had any problems.

I would offer bash gaurds but they are a PITA to make and cheap enough to buy.

Don't knock the design if you don't like it. I'm just putting it out there.

Didn't mean to sound like I'm knocking it but just pointing out some things i've noticed from setting up, modifing, and adjusting a couple of hundred guides this year.

Unfortunaly tabs bend and break, seen it first hand. It shouldn't move unless it is hit by something, and if its rotated far enough back it can't get hit.

For anyone else with a Giant and e13 already, just drill a hole in the e13 backplate once it's adjusted properly to access the pivot bolt

 

[ssaddict]

If you were making an adaptor to fit an e13 guide on a vp-free with saint cranks so that the lower roller wouldn't smash the swing arm you'd be everybody's hero, at least until e13 relases the same thing in a couple months, go figure?

e13's now fit Saint, FSA, Race Face with out any modification, the mold has been changed this year so no filling is required for 99.9% of the cranks on the market (right now).

Unfortunaly e13 doesn't have the power to move chainstays which are in the way. You can take a little off the top of the inner wear plates to get more rotation out of the guide though.
You can

 

[Tootrikky]

E-13 gives you a better chainline?.
I am totally confused on this one, I have to put 2 mm of spacers behind the BB flange to keep the chain from rubbing the inner guide which I don't believe lends to a better chainline. Not trying to argue about this just wondering if I am doing something wrong?

 

[Kornphlake]

e13's now fit Saint, FSA, Race Face with out any modification, the mold has been changed this year so no filling is required for 99.9% of the cranks on the market (right now).

Unfortunaly e13 doesn't have the power to move chainstays which are in the way. You can take a little off the top of the inner wear plates to get more rotation out of the guide though.
You can

See, I can't be a hero because e13's already forseen the problem and resolved it... dang those guys are fast .

 

[ssaddict]

E-13 gives you a better chainline?.
I am totally confused on this one, I have to put 2 mm of spacers behind the BB flange to keep the chain from rubbing the inner guide which I don't believe lends to a better chainline. Not trying to argue about this just wondering if I am doing something wrong?

Umm, better chainline than what? on what bike?

Every setup is different, Ya gotta give me more info than that... whatcha got?

bike?
guide?
ICGS tabs or adaptor?
cranks?
bb length?
photo?

 

[Tootrikky]

Umm, better chainline than what? on what bike?

TRYING NOT TO BE SARCASTIC...TRYING HARD.....A GIANT DH TEAM

 

[Tootrikky]

With Stock Parts

 

[ssaddict]

Umm, better chainline than what? on what bike?

TRYING NOT TO BE SARCASTIC...TRYING HARD.....A GIANT DH TEAM

Dude, its an honest question and I can't read your mind, I'm just trying to help. I thought you might be talking about the SRS guide in general.

As long as the cranks are not offcenter, yeah your doing the right thing. From the back of the bike where does the chain look like it's in a straight line (when sitting on which cog)? If it's in the middle of the cogset, yeah it's pretty much perfect chainline.

 

[Tootrikky]

Sorry ssaddict I get a little defensive.

I don't think the SRS improves chainlines on the Giant's, but it does I admit work pretty good, and I can still back spin in all gears.The chainline would be better thoug if I didn't have to space out the BB.

 

[Tootrikky]

Thanks Stoney sounds like some good ideas. I thought about axing the tab but it looked like the linkage which is on the same plane as the end of the BB shell would hit the guide? Anyways I'll see If i can fllip the cups on the FSA BB.

 

[Tootrikky]

So It's not totally stock I forgot I put the FSA BB in their, Still have the North Shores though.

 

[Damn True]

just use an e13. even gets yoiu a better chainline then stock

Ditto

 

[narlus]

For anyone else with a Giant and e13 already, just drill a hole in the e13 backplate once it's adjusted properly to access the pivot bolt

that's a really good idea. damn, why haven't i done this yet???

 

[oly]

For anyone else with a Giant and e13 already, just drill a hole in the e13 backplate once it's adjusted properly to access the pivot bolt

That goes for any bike really.... I did that for my DHR just incase my pivot came loose. Nothing worse than having to take off a bunch of stuff to get at a silly bolt. Only had to use it once, but it was well worth it........