Replacing 46t with 52t chainring
- Thread starter Rob55
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Jason Knight
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- Keene, NH
I made this change on my Aventure.
As the bike came from them the chain was 8 links short with the stock chainring. In the lowest gear (largest rear ring) the derailleur was stretched forward so straight, it was bending the mount. I wonder if this is why they actually seem to ship them with a spare derailleur mount?!? They sent me a second one that was longer than what they shipped me and that was fine, but when I upped to the 52 it was still too little -- thankfully I had two chains so I was able to just lengthen more.
Because I too went red I got a couple cheap Chinese chains. For mine I ended up at 125 links total to have it dialed in "just right", so basically nine over what you typically get.
Which was "fun" since I also did the wax-dip with teflon powder thing.
I also switched out the crankset on mine, since the allegedly "forged" ones were around five and a half pounds, and a cheap but decent aluminum set is closer to two.
As the bike came from them the chain was 8 links short with the stock chainring. In the lowest gear (largest rear ring) the derailleur was stretched forward so straight, it was bending the mount. I wonder if this is why they actually seem to ship them with a spare derailleur mount?!? They sent me a second one that was longer than what they shipped me and that was fine, but when I upped to the 52 it was still too little -- thankfully I had two chains so I was able to just lengthen more.
Because I too went red I got a couple cheap Chinese chains. For mine I ended up at 125 links total to have it dialed in "just right", so basically nine over what you typically get.
Which was "fun" since I also did the wax-dip with teflon powder thing.
I also switched out the crankset on mine, since the allegedly "forged" ones were around five and a half pounds, and a cheap but decent aluminum set is closer to two.
Jason Knight
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- Keene, NH
Anything over 53 isn't going to clear on the Aventure. I have a 58 here and it was an absolute no-go. Didn't clear the chainstays. I'll grab a picture come morning to show you how close the 53 is to the chainstay so you can have an idea the type of room you'd have.
Cranks were these Amazon cheapo's...
Had no issues fitting them. Square taper is square taper. It also took about 3.5 pounds off the bike because the cranks it comes with might as well be pig iron given their weight. (see the thread where I was kvetching about the "forged" designation being a crock).
A LOT of the changes I made were just to get the weight down. Even my longer cruiser bars are lighter than the short straight bars it came with. The suspension post is lighter than the steel tube they had. (delta alpha foxtrot uniform quebec?!?). I'm hoping when I deal with upgrading the front forks that even at the highest damping I'm bottoming out, that will shed some weight too.
Sadly the long bars meant putting the control pad closer to center, but honestly I don't screw with changing the PAS mode enough to worry about it being there instead of out at the grip. Besides, I used to ride 21 speeds back when the shifters were in the middle of the bike. Not a big deal. It's amazing how spoilt we've gotten having everything on or near the grips.
Chainring was an el-cheapo lite-pro that I already had on hand, but this bloke on e-fence is still selling them... and correction I'm running a 53t.
Litepro MTB alloy 130mm Folding Bike Chainwheel Chain Ring With Guard 45-58T | eBay
Find many great new & used options and get the best deals for Litepro MTB alloy 130mm Folding Bike Chainwheel Chain Ring With Guard 45-58T at the best online prices at eBay! Free shipping for many products!
www.ebay.com
I ran this same cheap brand on my 3 speed cruiser in all sorts of extremes of weather and load with no issues in a decade of riding. Which going back a decade I was a hundred pounds heavier? Some things are so simple there's no reason to light money on fire for them.
Even got some cheap chainring bolts just to have them in red.
I'm gonna probably over the next couple days snap more pics and document the changes I've done this spring with a parts list. I have a thread on here already with changes I made back in October and November when I got the thing. Like I've already swapped the grips for something a bit better, using fancier bar-ends, suspension post, etc.
My "misaventure" in e-biking
Originally this was going to be a very different post... outlining the past six months, issues with members of the community, and so forth. But I'm setting that aside for now to just talk about where I'm finally at. Having a working e-bike that I like and enjoy riding. Instead I'm just going...
electricbikereview.com
m@Robertson
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Worth mentioning: Measuring chain length on a 1x drivetrain is simpler than most chain length guides lead you to believe. You need to size the chain to the smallest cog. The biggest one will take care of itself. That is true because if you size it right, you make the chain as long as it can possibly be when you size it to the small cog, and in so doing you let the derailleur cage do its job (which is to wrap excess chain). On the smallest cog, that derailleur should be one chain link less than loose. As in just enough chain tension to be taut. Do that and the rear cage is pointing backwards on the small cog.
Here are examples, small cog and big one; sized properly.
![img_20190825_093824[1].jpg](https://forums.electricbikereview.com/attachments/img_20190825_093824-1-jpg.124838/ "img_20190825_093824[1].jpg")
![img_20190825_093641[1].jpg](https://forums.electricbikereview.com/attachments/img_20190825_093641-1-jpg.124839/ "img_20190825_093641[1].jpg")
Its not uncommon to see the derailleur cage pulled forward on the big cog by someone who has sized the chain too short. Doing that pulls the internal derailleur spring harder than it needs to be pulled, and is just the wrong way to do the job.
Here is a full description of the process with tools and pics.
www.worldwidecyclery.com
And here's a video cue'd up to the chain cut/sizing job. Jump to the previous chapter to see how to re-route the newly cut chain, and the one following it to see how to connect the chain.
Here are examples, small cog and big one; sized properly.
Its not uncommon to see the derailleur cage pulled forward on the big cog by someone who has sized the chain too short. Doing that pulls the internal derailleur spring harder than it needs to be pulled, and is just the wrong way to do the job.
Here is a full description of the process with tools and pics.
How To: Installing A New Chain For Your 1X Drivetrain (How to do it Right!)
For this MTB How To, we are going to be focusing on setting the correct chain length when installing a new mountain bike chain on a 1X drivetrain. Making sur...
www.worldwidecyclery.com
And here's a video cue'd up to the chain cut/sizing job. Jump to the previous chapter to see how to re-route the newly cut chain, and the one following it to see how to connect the chain.
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Jason Knight
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- Keene, NH
Agreed. Back when I was a kid in the '70's my old man taught me that you don't want it all the way back because then the geometry makes it harder to shift... so you set the bike regardless of how many cogs there are to smallest to smallest, and then set the chain length so that the derailleur is at a 30-45 degree to the chainstay angle. Everything else will care for itself.
And why my Aventon was such a joke when I got it chain-wise. At the smallest cog the derailleur was at about 120degrees, and putting it into 8th pulled it forward so tight it was bending the derailleur mount.
Something made all the more suspicious by the fact the bike came packed with a spare mount. Never seen that before. I ended up using the spare even though I straightened the original back out, just because bent metal == weak metal.
mikeschn
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- SE Michigan
So you're saying this dim should be 30-45 degrees at small cog to small cog?
Looking at my bikes, I suspect it more like 90 degrees large cog to large cog, and 135 degrees large cog to small cog... But what do I know... I've never played with chain lengths...
![img_20190825_093641[1].png](https://forums.electricbikereview.com/attachments/img_20190825_093641-1-png.124842/ "img_20190825_093641[1].png")
Looking at my bikes, I suspect it more like 90 degrees large cog to large cog, and 135 degrees large cog to small cog... But what do I know... I've never played with chain lengths...
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m@Robertson
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In an ideal world, yes that is correct. Specifically, the rule of thumb for perfection on the big cog is for the top pully in the cage to be a bit forward of the bottom pulley. So by that measure, the above is a little too short... but as I mentioned above, with a 1x drivetrain the big cog is what it is because if you do the chain length right (using the small cog and just-enough tension on the derailleur cage), thats as long as it can get, period. So the big cog takes care of itself.
The video above does a good job of displaying this visually in real time.
But this can happen: The two pics I showed you were my final length on that chain. Here is the textbook, perfect length on paper per the instructions I linked above, and it was my first try:
Like I mentioned above... top pulley just a bit forward of the bottom one. Visually, its perfect. But look carefully at the chain in the left pic. Its got a hair of slack in it. It rode great EXCEPT when it was wet and I was running 1500w of BBSHD on the 11T cog. The issue was the wetness of the ground coming up and slickering up the drivetrain just enough to cause a skip at full tilt. So I took two links off to increase the tension and it has remained like that since 2018 when these pics were taken until a couple months ago when I put a Box Two super long derailleur on it along with a rear cassette that goes up to 42T instead of the 32T you see here.
The above is the only time I have gotten bitten by a tolerance that is so close I had to lose a link. After these pics were taken in 2018 I did move the sliding dropouts forward to eliminate frame flex (an issue with titanium frames) and it took the cage back a little further, closer to the original, as a result.
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m@Robertson
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I've never heard of the geometry thing. Maybe thats something from the past. Back in the 1980's my road bike used direct-pull levers with friction-shift derailleurs that you had to nudge into just the right spot yourself. That was a different world from what is now the automatic alignment that comes from click shifting. Plus the kind of ball-bearing thumb levers we have now. Not an issue with modern parts. If that was an analog bike in the previous post, chain length would have never been a problem. It was just running under superman power and then only when it was wet. And when I moved the dropouts forward I got half of that tension back again and moved the derailleur cage back half the distance you see changed above.
Edit: look at that video... the cage is going straight back on the little cog. Also worth noting is its pulled forward on the big cog. There's no help for this cuz we made the chain as long as we can by putting that derailleur cage as far back as we can - letting the cage do its intended job of wrapping chain. My ti bike that now has this drivetrain is the same way. Also note the procedure for a multi-ring front system is different, but 1x is the way most people are going on modern bikes these days.
Its really common for manufacturers of budget bikes to put the chain too short. Thats part of why so many people who are new to bikes think the cage angling forward isn't a problem.
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Jason Knight
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Ooph, that's so far back I'd be worried about the chain on bumps whipping up and hitting the upper jockey pulley. Or just plain grinding against it in normal riding. I was taught zero degree mounting like that was as bad as the exact opposite. I would not want the chain that close to the actual mechanism that makes things work.
Admittedly as you said, that could be a thing of the past, was 35-40 years ago when I was taught that. I am by no means an expert on this topic.
Also anyone else ever notice larger jockey pulleys seem to make things harder to shift, as does plastic?
With the Shimano on my Aventure it shifts way smoother and with less problems on 12 tooth aluminum jp's than it did the 13 tooth plastics it came with.
And seriously? Plastic jockey pulleys? Whiskey tango foxtrot hotel! I mean I get that they're not actually on the drive side where the real forces occur, but still...
m@Robertson
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If you've got tension on that chain, its not an issue. Again look at the manufacturer's install video. They do the same thing. Slight tension. And from the written instructions I linked:
I don't have any others in front of me, but the direction I've always seen is to use just enough tension to keep the chain from contacting itself on the way back forward. I took this pic this morning (I guess its yesterday given the current time) for the how-to series I am doing on building an ebike. Same deal on this cluster. One more link and there's no contact issue, but thats because there's no tension. Derailleur cage can't go any further back. I've bounced it around pretty good. The fact it has a clutch on it I am sure is a help. No such thing in decades past. On my short cage Mavic SSC derailleur from the mid 1980's things were the same. That is a road bike so no need for a clutch. Not close to home or I'd get a pic. That thing is a work of art.
Even the best derailleurs use plastic jockey wheels/pulleys. Its the cheapie replacements that are alloy. I've gone thru anodized alloy wheels with sealed bearings that I bought because they were a pretty color and I thought they'd last longer, but what you'd think are cheapass plastics with a simple metal sleeve bearing outlast the metal wheels by literally years. The bigger wheels seem to be on the better derailleurs. 13T on the Box Two above. My SRAM EX1 on my GG uses 14T pulleys top and bottom. Enormous, but they work great and are even designed with narrow-wide teeth just like on the chainring. My Advent still uses 12T. I've never felt like pulley size makes any difference I can notice.
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Jason Knight
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Where it angles outward it's real close. It's funny at an angle it looks like there's room, from the top you can clearly see there isn't.
The 58 tooth I have didn't come close to clearing the chainstay. Was about 2mm larger than what fits.
I can see the problem now, thanks!Where it angles outward it's real close. It's funny at an angle it looks like there's room, from the top you can clearly see there isn't.
The 58 tooth I have didn't come close to clearing the chainstay. Was about 2mm larger than what fits.
JES2020
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I went from a 46 to 52 chain ring and did'nt even bother to change the chain. (when you change the chain you should also change the cassette.)
Now I just don't use the big front ring with the big back gear ( it jams up).
But because it's a 21 gear, I still get the lows and the highs I need, using different configurations.
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