Does anybody make extra-long chainring bolts?
 

If one wanted to mount 3 chainrings to a 110 BCD double crank, are there chainring bolts long enough to do this?

Why would one want to do such an odd thing?

Mostly, because I'm a bike nerd. But also because I want both lower and tighter gearing on a bike that's currently a 42x14-26 6-speed, (as well as being my car,) and I don't want to buy a new crankset and BB. Most of my riding is flat and windy, since I live in Eureka, right on the coast. But there's plenty of hills around here, and I'm slow and weak. And it so happens that a 45/42/33 triple gives me 12 ~7% half-step gears, plus 2 low 13% full-step gears with a simple double shift from the 42x26 to the 33x23, for a total range of 34 - 86 inches.

Yeah, I know I could just do a 45/33 or 46/34 1.5-step double, and get the same range and interleaved gears, but the double-double shift pattern seems like it would be the annoying just when the even gear changes would be the most useful. (Flatland cruising in the middle of the cluster with variable winds, which is what most of my riding is like.)

The only issue is chainring bolts long enough to go through three chainrings. Do such things exist?

--Shannon

You need the bolts for a Stronglight 99 triple.

If they are (the more-or-less) standard diameters there are any number of makers and sources, and they don't seem expensive.

Bolts for any 86BCD crank like the Stronglight 99 should work. You'll probably need a longer BB spindle. Otherwise, the 3rd ring will scrape the chainstay. You have to move the crank out to make room for the other ring.

If there is room beside the carnkarm he could put the big ring on the outside, with the spacers he's going to need anyway.

Sugino Mighty Tour triple (Fuji Ameica and others) featured a triple on the 110BCD.

You need “racing triple” chainring bolts as here:https://www.amazon.ca/DYNWAVE-Cranks...xpY2s9dHJ1ZQ==

if this long link doesn’t parse correctly, use my original search term which was “racing triple chainring bolts.” This particular listing seems to be for three sets, one each of single, double, and triple, all for one suspiciously low price. But it’s the long triple ones in the upper left that you want.

And yes you will need a longer BB spindle, (...or a BB with a longer spindle if you have a cartridge), unless you are able, as suggested, to fit the large ring outboard under the crank, and if the front der will swing out far enough to reach it.

Rene Herse sells triple-length chainring bolts, too. Pretty sure they are compatible with other makes: https://www.renehersecycles.com/shop...ainring-bolts/

But everyone should note they are sold as a set of THREE.

D'oh, good catch! Buy two sets and have a spare? :lol:

Both Stronglight and Sakae Ringyo used long bolts for their 86mm BCD triple cranks:

The BB seems like it should be a 124.5 mm assymetric (26.5 mm / 16 mm), from what little information I can find online about the RT crankset. The same brochure shows the RT triple using a 129 (30.5 / 16) spindle, so the extra 3.5 mm are all on the drive side.

Measured as best I can with a standard tape measure, I've got about 7/16", maybe 13/32", from the top edge of the chainstay to the inside edge of the chainring bolt. Call it 11 mm to be conservative. With 5 mm spacing between the middle and inner ring, plus 2 mm for the other half of the mounting tab thickness, (assuming 4 mm, which seems pretty typical,) it seems like it might work as-is.

If I have to mount the big ring outboard, I should be searching for a half-step triple front derailleur, no? I have to buy a FD anyway, as I bought the bike as a singlespeed, so I've got choices there. I'll be going with a Suntour, since I put a Superbe on the rear. Recommendations here would be welcome.

--Shannon

You can get a 33t ring on a 110mm bcd crank? I thought the minimum was 34t!

But a set of triple bolts should do it for you. They usually come with spacers for the little ring. In fact if you can wait until Tuesday i can mail you a set for the cost of postage, I have extras.

T/A makes a 110x33, and there may be others. Thanks for the offer on the bolts, but I don't need 'em yet.

-Shannon

I have two sets of five long bolts each from when I ran 49-46-43 / 13-16-19-23-26 third-step on a 144mm BCD Sugino crank. Worked like a champ with SunTour Cyclone derailleurs (short cage in back).

You can buy a set of 5 generic triple chainring bolts on Ebay. I got some this spring and they were fairly cheap and look nice. I believe they are the 8 mm size but could be mistaken.

I've noticed that chainring makers often produce inner rings that are a tooth or two bigger than the minimum of the BCD -- 42T on a 144mm BCD, 39T on a 130mm BCD, 34T on a 110mm BCD, etc. I wonder if it's just to avoid headaches in manufacturing, since you have a little more tolerance that way...

That makes sense to me. Also, the true minimums usually have odd numbers of teeth, and chainring makers seem to have a religious aversion to odd numbers that aren't 39. And that exception itself lends weight to your hypothesis... when road doubles on stock bikes went from 52/42 to 53/39 around 1990, 52/38 would have made more sense for anybody slower than Sean Kelly... which is to say, anybody who pays for their bike. Plus it's only one new chainring, not two. We had to wait for Tyler Hamilton's broken collarbone in the 2003 Tour to allow roadies to ride cranks that made sense. I was working in a shop then, and we changed out a lot of 53/39s for 50/36s that year. (Of course, that requires a 110 BCD, but that should have been the standard for Japanese cranks all along... I think it's the smallest BCD that allows for a really good-looking 5-arm crank.)

--Shannon

PS - Yeah, I know, EPO, blood transfusions, the whole works. Tyler's ride in '03 was still the hardest of the hard. Dude's a stud, doped or not.

So, it has occurred to me that probably the best way to get the gearing that I want on this bike, 45/42/granny half-step triple is to buy a nice, used 52/42/30 road triple, which are everywhere, and cheap, and mostly good looking, and a bottom bracket, and a 45T chainring in whatever BCD goes with whatever crankset I buy.

Converting the existing 110 double crankset to a triple requires 2 new oddball chainrings, a 45 and a 33, the extra-long chainring bolts that this whole thread was about, and a new bottom bracket spindle unless I get really lucky with the chainstays.

The rear derailleur is a 1980 Suntour Superbe, which I want to keep on the bike, since (1) it's a 1980 Suntour Superbe, (2) It's a Fuji and Fujis should have Suntours, (3) I had to take it out of the box and untwist the twist tie from the mounting bolt when I put it on the bike, and (4) I think I paid 15 bucks for it.

Specs are 23T max cog and 26T of chainwrap. On a Suntour dropout, it easily clears the 26, and I'm pretty sure a 28 would be fine, so I'm thinking the specs were really, really conservative. 45/42/30 and a 14-26 is 27 teeth, so it should Just Work (tm).

There's even a neato gear phreak bonus: The really sweet thing about the 45/42/33 idea was that it's a half-step over 1.5-step, so you get 7% half-step gearing on the 42/45, with 2 full-step gears on the granny. So it's a simple double shift to the granny if you didn't anticipate the need. The 45/42/30 is a half-step over 2-step, so you get an 8% double-double shift to the granny, 42x26 to 30x20, and then two full 13-15% steps below that. And the low gear goes from ~34" to ~31", or one full step lower. Plus, the few duplicate gears are all on the granny and you'll almost never ride 'em.

Tl;Dr: If you want a triple, buy a triple, unless you wanna be wierd just 'cuz you can. Which is super cool and I support it.

--Shannon