[Proboscis]

Anybody have any experience with any of the triple adapter kits for a double chainring? Seemed like a very inexpensive way to use a triple crankset on occasion, without having to purchase seperate set of crankarms.

 

[Kerry Irons]

Examples?

Anybody have any experience with any of the triple adapter kits for a double chainring? Seemed like a very inexpensive way to use a triple crankset on occasion, without having to purchase seperate set of crankarms.

Wouldn't you have to install a new BB or BB axle to give enough clearance for the inner chain ring? Are you sure that this is really a better approach? Without having seen one in practice, it seems like a bit of a kludge to me.

 

[Proboscis]

Thats what I thought. But it was specifically advertised for use with Double crankset, but no word on if a new BB would be needed, also doesnt mention the possible need for a different front derailleur. I would rarely need a granny gear, but it did seem interesting, even if the execution might be sketchy.

 

[elviento]

Can you post a picture and some description of the "triple adaptor kit"? The triple kits normally sold are essentially 2/3s of the group. But what you are describing seems to be some small gadget, but it's hard to tell unless you clarify a bit.

 

[Proboscis]

Ok, got a little more information on it. Called a Triplizer. It is the inner (double) chainring with some extra tabs on it that point inward (tward the bike) that are used to mount the granny gear. Yes, you have to replace the BB, and it is advisable to replace the front derailleur. So, in someways I answered some of my own questions. It doesnt seem practical. Maybe cheaper, depending on the compact crankset. But at least not easier. I will assume that since I dont see many around, might not work well.

 

[Cory]

Had a 16t quad adapter on my first mountain bike

Not that it's of any relevance here, of course...
When I got my first MB, almost 20 years ago, I was way too fat and slow to ride in the mountains where I live. It came with a 30t small ring, and I was so newbie I didn't even realize you could change that. I spent $29.95 for a Quad Adapter that required removing the crankarm (didn't know how, didn't have the tools), taking off the small ring (didn't own an allen wrench, but at least that's the point where I realized, "Hey, I could just put on a smaller one of these for about three bucks"), mounting an adapter in its place, bolting the small ring back on top of it, then putting the 16t ring on the adapter and reinstalling the crankarm.
It went together OK, considering my skill level. But I never could get it to shift right--any time I wanted the granny, I had to reach down with either my foot or my hand and nudge the chain over. I could have ridden up the Washington Monument, though.

As for the triple one, I haven't seen them, but it doesn't sound like it would be hard to design. As somebody else mentioned, BB spindle length may be an issue, and your present front derailleur might not shift a triple, though most will.

 

[Proboscis]

It looks like the 3rd gear is actually bolted to the second (now middle) gear. Doesnt sound nearely as sturdy as having a triple crankset, or maybe even a double compact. A cheap way to get a granny gear on occasion, but not considering all of the other things you may have to replace, nothing to say to any possible chainline, and shifting problems.

 

[The Walrus]

I inherited one of these things on a bike I got off eBay; the previous owner had kit-bashed a triple drivetrain out of mostly 600 parts (including a short cage rear derailleur; the only concession to the triple was a 105 triple STI lever and front mech). He did have a looo-o-o-ong spindle bottom bracket on there. It worked a lot better than it should have...but not well enough to prevent me from ulimately replacing the drivetrain with a Campy racing triple.

 

[ericm979]

The Dura-Ace 7700 9sp triple was similar to the Stronglight Tripilizer design. The granny ring bolts to the middle ring. It's plenty strong.

You do need two new deralieurs (unless you have a long cage rear already), a longer BB, and a triple front shifter (some Ultegra "double" shifters are really triple shifters so you may be ok there).