SSCX chain tension with vertical dropouts and threaded BB

[sandyrs]

I'm getting a new cross bike and want to convert my old one to singlespeed. It has an English BB and vertical dropouts, so obviously EBB and dropout-based tensioning are out of the question. What's everyone's favorite chain tensioning system for this situation? I'm looking mostly at tensioners that attach at the derailleur hanger but there appear to be a few different styles.

[oldpotatoe]

I'm getting a new cross bike and want to convert my old one to singlespeed. It has an English BB and vertical dropouts, so obviously EBB and dropout-based tensioning are out of the question. What's everyone's favorite chain tensioning system for this situation? I'm looking mostly at tensioners that attach at the derailleur hanger but there appear to be a few different styles.

Shimano. Tough, useful, not expensive.

[stien]

Don't forget the ENO eccentric hub: http://www.whiteind.com/eno/

You can find them used built into a wheel for about $100 sometimes.

[sweet_johnny]

I'm running the Soulcraft Convert tensioner, but it looks like they don't make it anymore... so that's not going to do you any good.

I do have a couple thoughts though. There are some tensioners that "push" the chain towards the chainstay, some that "pull" the chain away from the chainstay, and some that do both (not at the same time, of course). In my opinion you get a better feel from the "push" drivetrain, have more teeth, and you don't have to worry about your chain flopping all over the place. The downside of a "push" tensioner is if you flat your rear, you're kinda S.O.L. for a neutral wheel (unless it's the same cog).

[sandyrs]

I'm running the Soulcraft Convert tensioner, but it looks like they don't make it anymore... so that's not going to do you any good.

I do have a couple thoughts though. There are some tensioners that "push" the chain towards the chainstay, some that "pull" the chain away from the chainstay, and some that do both (not at the same time, of course). In my opinion you get a better feel from the "push" drivetrain, have more teeth, and you don't have to worry about your chain flopping all over the place. The downside of a "push" tensioner is if you flat your rear, you're kinda S.O.L. for a neutral wheel (unless it's the same cog).

I'm not worried about wheel changes. Singlespeed races will almost always be my second race of the day, and if I flat, I'll probably just call it a race. That style of tensioner looks good to me. Do you know if it'll work with a 10sp chain? I have a Wolf Tooth narrow-wide on the front I'd like to keep if possible for extra security and it only fits 10-11 speed chains AFAIK.

[stien]

You could always stick it to the man and run a busted Di2 RD :cool:

[sandyrs]

You could always stick it to the man and run a busted Di2 RD :cool:

Lol

[p nut]

Philcentric:

https://philwood.com/products/bbpages/philcentric.php

Much more elegant looking than derailer-type tensioners, and won't have brake issues like ENO.

[AngryScientist]

ENO hub would be my definite #1 choice in this situation.

[RacerJRP]

Shimano Alfine chain tensioner. Work great, doesn't look OOP.

[11.4]

The ENO is really the best solution.

But before you get your chamois in a knot, have you tried your favorite gears on the bike to see what chain tension is like? It's surprising how often your chain just happens to work passably.

One point here: Your chain isn't supposed to be tensioned with no play. You want some dip (at least 3/4" or so and often people do more). There's a point where you start getting chain slap and that's obviously too far, but for most gearing and most frames, your best setup with a whole number of links may work just fine. And you can get half-links in 1/8" chain, which is a little heavier than 3/32" but very durable in SSCX conditions. You can run 1/8" chain on 3/32 cogs and rings, and in fact it can actually clear mud better than the narrower chain.

[oldpotatoe]

The ENO is really the best solution.

But before you get your chamois in a knot, have you tried your favorite gears on the bike to see what chain tension is like? It's surprising how often your chain just happens to work passably.

One point here: Your chain isn't supposed to be tensioned with no play. You want some dip (at least 3/4" or so and often people do more). There's a point where you start getting chain slap and that's obviously too far, but for most gearing and most frames, your best setup with a whole number of links may work just fine. And you can get half-links in 1/8" chain, which is a little heavier than 3/32" but very durable in SSCX conditions. You can run 1/8" chain on 3/32 cogs and rings, and in fact it can actually clear mud better than the narrower chain.


3/32 half links also. It 'may' work w/o one. I think 3/4 inch droop is a little high tho. Imho

[p nut]

Magic gear may work, but I found that with chain stretch, even if the fit is right on at the beginning, it just gets too sloppy within a short time period.

You can use this to find a good gear combo if you choose to go that route.

http://eehouse.org/fixin/fixin.php

[eBAUMANN]

tensioners - surly on the cheaps, or paul, or old RD - aint pretty but they will do the trick. if you have the time to come up with a better solution for racing (and you do), id stay away from tensioners...they just add a point of failure/issues.

eno hubs - require you to have a dedicated SS wheelset, and use SS freewheels - both cons in my book. they are also sorta a pain in the ass to tension and they can loosen up over time. its also ends up being a pretty heavy system overall (32h, heavy hub, heavy freewheel).

wolf tooth/narrow-wide rings - work with 8/9/10/11 speed chains, they just dont work AS WELL with 8/9 chains because the chain width/gaps in links is wider (more wiggle room = less chain retentionability), for SS this doesnt really matter.

philcentric or trickstuff exzentriker (http://www.trickstuff.de/en/products/exzentriker_KL.php)- both are cool solutions but are kinda a pain in the ass in a few ways. one, you need several tools to adjust and align the 2 cups, and they both only offer a TINY amount of adjustment, to the point where you would likely need a half link anyways. they are also decently pricey.

the best way i have found to convert a geared frame to SS is to start with a pf30 bb shell and use a beer comp eccentric bb. i have raced that setup all year and it has been utterly flawless. so much so that I am thinking of designing a future frame that i am building around that system, it just works so well, particularly for disc brakes.

also, if you dont want to call it a race when you flat, just throw your geared bike in the pit with a zip tie on it, thats what i do, saved my ass 3 times this season.

[p nut]

the best way i have found to convert a geared frame to SS is to start with a pf30 bb shell and use a beer comp eccentric bb. i have raced that setup all year and it has been utterly flawless. so much so that I am thinking of designing a future frame that i am building around that system, it just works so well, particularly for disc brakes.

I haven't used BEER, but I love Niner EBB. Simple and easy to set up. EBB is really the way to go, in my opinion.

Also, another option is to have a frame builder weld on a pair of track ends. My local guy charges $75. You will have to repaint (or just use touch up), but better than using tensioners and (IMO) eccentric hubs.

[sandyrs]

tensioners - surly on the cheaps, or paul, or old RD - aint pretty but they will do the trick. if you have the time to come up with a better solution for racing (and you do), id stay away from tensioners...they just add a point of failure/issues.

eno hubs - require you to have a dedicated SS wheelset, and use SS freewheels - both cons in my book. they are also sorta a pain in the ass to tension and they can loosen up over time. its also ends up being a pretty heavy system overall (32h, heavy hub, heavy freewheel).

wolf tooth/narrow-wide rings - work with 8/9/10/11 speed chains, they just dont work AS WELL with 8/9 chains because the chain width/gaps in links is wider (more wiggle room = less chain retentionability), for SS this doesnt really matter.

philcentric or trickstuff exzentriker (http://www.trickstuff.de/en/products/exzentriker_KL.php)- both are cool solutions but are kinda a pain in the ass in a few ways. one, you need several tools to adjust and align the 2 cups, and they both only offer a TINY amount of adjustment, to the point where you would likely need a half link anyways. they are also decently pricey.

the best way i have found to convert a geared frame to SS is to start with a pf30 bb shell and use a beer comp eccentric bb. i have raced that setup all year and it has been utterly flawless. so much so that I am thinking of designing a future frame that i am building around that system, it just works so well, particularly for disc brakes.

also, if you dont want to call it a race when you flat, just throw your geared bike in the pit with a zip tie on it, thats what i do, saved my ass 3 times this season.

So my takeaway here is that with most of a year to put together a singlespeed cross bike that won't be a pain in the ass, and considering this bike has been a pain in the ass while geared, I may just end up getting a new frame.

I'm honestly not that unhappy about that option. I'm kind of over rim brakes right now and wouldn't mind having a little brother to my incoming disc 'zetti.

New bike will have Ultegra and I would probably prefer not to be adjusting the limit screws every time I race. Planning to use the singlespeed as a pit bike for geared races, but probably not vice versa.

[eBAUMANN]

yep, id recommend looking for a pf30 based frame and start from there.

[chiasticon]

a brief OT question, since eB posed the idea and since it seems sandyrs may have resolved the question/be going another route anyway... what are people's general thoughts on people racing geared bikes in the single speed races? I know some who have done it with zip ties (as eB suggested) and that works great with sram, but I also know some who have raced shimano bikes in the SS races, which if you zip tie will mean you can shift one direction but not the other. I don't know what they've done to SS-ize their bike, if anything. are such racers forced to prove that they've locked the limit screws of their RD? or is this something that people just go on an honors system with, or depends on the field, etc? anyway, just curious...

[eBAUMANN]

a brief OT question, since eB posed the idea and since it seems sandyrs may have resolved the question/be going another route anyway... what are people's general thoughts on people racing geared bikes in the single speed races? I know some who have done it with zip ties (as eB suggested) and that works great with sram, but I also know some who have raced shimano bikes in the SS races, which if you zip tie will mean you can shift one direction but not the other. I don't know what they've done to SS-ize their bike, if anything. are such racers forced to prove that they've locked the limit screws of their RD? or is this something that people just go on an honors system with, or depends on the field, etc? anyway, just curious...

well, i cant speak for every region of the country, but here in NE most people dont really take SSCX that seriously, and therefore everything is done on the honor system. nobody checks before or after to make sure nobody has shifted through their zip ties. those of us who do the SSCX races seriously are on dedicated rigs, and should be if you care enough to race hard.

its a tough argument because there are good points to be made on both sides, but in the end, inclusiveness wins out. we would rather see more people trying SS racing and zip ties make that easy, as most people cant justify/afford a 2nd bike.

that said. i firmly believe that in any situation where any sort of championship or title is on the line (nationals for example), it should be dedicated SSCX bikes only. i think nationals is already like this but im not sure.

[chiasticon]

that makes sense and kind of what I was thinking; not only inclusiveness but also improving the quality of the race by allowing more entrants. I agree with your comments regarding nationals. that could maybe be extended to states as well but then again, around here at least, many times the podium is mostly comprised of people who raced geared bikes, and frequently those same people were also the front of the A race. with some exceptions. so excluding them from states would make it easier I'm sure, but also make it less of a victory, in a way. like you said, good arguments to both sides...

[old fat man]

So my takeaway here is that with most of a year to put together a singlespeed cross bike that won't be a pain in the ass, and considering this bike has been a pain in the ass while geared, I may just end up getting a new frame.

I'm honestly not that unhappy about that option. I'm kind of over rim brakes right now and wouldn't mind having a little brother to my incoming disc 'zetti.

New bike will have Ultegra and I would probably prefer not to be adjusting the limit screws every time I race. Planning to use the singlespeed as a pit bike for geared races, but probably not vice versa.

You should focus that "most of a year"on making sure your 'Zetti shows up. Once that happens, sell the Honey and buy a Kona (they make big sizes) with a BB30.

[eBAUMANN]

You should focus that "most of a year"on making sure your 'Zetti shows up. Once that happens, sell the Honey and buy a Kona (they make big sizes) with a BB30.

ha, truth.

[sandyrs]

Once that happens, sell the Honey and buy a Kona (they make big sizes) with a BB30.

Hah, first thing that came to mind when I read Eric's post was that I should just go to JRA and get a Private Jake.

[eBAUMANN]

or this thing (http://boston.craigslist.org/bmw/bik/5350854119.html)...though i dont really know much about bb86...if the cup diameter is the same as pf30 is should work ok for eccentric purposes.

[sandyrs]

or this thing (http://boston.craigslist.org/bmw/bik/5350854119.html)...though i dont really know much about bb86...if the cup diameter is the same as pf30 is should work ok for eccentric purposes.

Funny, I've had my eye on that but my uneducated understanding is that bb86 is for 24mm spindles- I think it's smaller than pf30

[Dirtdiggler]

In this add there is a Paul Melvin.. no affiliation..

http://mmba.org/forum/viewtopic.php?f=8&t=130691

[panache_mode]

The ENO is really the best solution.

But before you get your chamois in a knot, have you tried your favorite gears on the bike to see what chain tension is like? It's surprising how often your chain just happens to work passably.

One point here: Your chain isn't supposed to be tensioned with no play. You want some dip (at least 3/4" or so and often people do more). There's a point where you start getting chain slap and that's obviously too far, but for most gearing and most frames, your best setup with a whole number of links may work just fine. And you can get half-links in 1/8" chain, which is a little heavier than 3/32" but very durable in SSCX conditions. You can run 1/8" chain on 3/32 cogs and rings, and in fact it can actually clear mud better than the narrower chain.

I jumped in head first with using an ENO ecc hub even after reading mixed reviews. There are pros and cons to using the eccentric hub.

My two main rubs with the eno ecc are that the brake issue can be a bit annoying but once I set it is a reliable solution.

Second, It limited my tire clearance with what size tire I could run even with my 33c racing tire I had lost much of my mud clearance.

I would only suggest buying the eno ecc if you are willing to tinker and know what gear ratio you want to ride and be flexible about it.

[Neil]

Paragon Machine Works rocker dropouts all day long for this application.

[11.4]

Paragon Machine Works rocker dropouts all day long for this application.

Definitely superior, but you have to get your frame modified and at least partially repainted. I think the OP wanted a simple solution to use the frame as is. If not, definitely worth considering.