Mountain Bike Reviews Forum banner

Singlespeed Conversion Kit

29K views 35 replies 18 participants last post by  Sparticus 
#1 ·
I am looking to convert to single speed. I am considering either the Surly conversion kit or the Wheels Manufacturing conversion kit. The Surly kit is approx. $15 - $20 more. Does anyone have any experience these or any other kit? Also, what some good chain tensioners out there for vertical dropouts.
 
#3 ·
SeaBass_ said:
Surly kit with a Surly cog is a decent set up. The spacers allow you to get your chainline perfect. Try to find your magic gear before you go strapping a tensioner on, if not, the Surly Singleator is passable. Gee, I sound like a Surly Shill, don't I????
Can't believe you didn't tell him to get the "search" kit. :rolleyes:

--sParty
 
#5 ·
Sparticus said:
Can't believe you didn't tell him to get the "search" kit. :rolleyes:

--sParty
I'm in a good mood today for some reason:D . Besides, that's the set up I used when I first got into SS.

+1 on avoiding the sprung tensioner as well. Forget what I said about using the singleator. I remember now I wound up using a zip tie on my singleator to get adequate push-up tension and chain wrap. Then after getting sick of that set up, I took a dremel and made the magic gear work. Be very careful if you go that route though!
 
#11 ·
#12 ·
"BONER is named after it's designer Thomas WOOD"

Interesting, but not for $45. As the article states:

"spring loaded tensioners are FINE if you intend to convert your ride for the purposes of TESTING the waters of single-speed. As a long term solution…their relevance deteriorates.

Does seem a big improvement over the Singleator. More of a "Set it and Forget It"
 
#13 ·
If you must run a tensioner (which I would also avoid), the Rennen Rollenlager is a very good solution, you won't believe how beefy it is and how well it works. Good luck!
 
#15 ·
You mean this?

And regarding the Boner... they came up with a simple, elegant, and inexpensive (ie plastic) solution, then completely lost their minds when they priced it at an SRP of $45, which is "less than some of the fancier tensioners on the market". So in terms of marketing and competition, they are branding themselves as an inexpensive premium tensioner, but also trying to sell simple.

Price it at $20 and pitch it as being superior to tensioners at 2-4x the price. It's injection molded plastic, for pete's sake.
 
#17 ·
PoisonDartFrog said:
Price it at $20 and pitch it as being superior to tensioners at 2-4x the price. It's injection molded plastic, for pete's sake.
More likely machined plastic. Pretty easy to machine, based on the geometry. I wouldn't drop a few thousand bucks to get a mold made for that part.

Machined or molded, $20 seems about right.
 
#18 ·
Birdman said:
More likely machined plastic. Pretty easy to machine, based on the geometry. I wouldn't drop a few thousand bucks to get a mold made for that part.

Machined or molded, $20 seems about right.
the only components NOT manufactured domestically are the pulley wheel and (perhaps) the mounting hardware (that supplier is not finalized).

the QR end, the shaft and the tensioner body are all manufactured in NA.

the body is not as simple a machine job as you might expect. to make the most of the design and the specific properties of acetal, a number of the surfaces are beveled and there are a few (thickness) variations NOT visible in the photos.

waste is another issue. when the material is CNC'd you can't simply lay-up in the most cut-efficient manner, you have to mind the grain...with a mold, this isn't an issue.

first batches will be completed in hundreds, so it makes sense to stay with CNC, future batches could be molded. either way, when the batch quantities increase i would expect the srp of the tensioner to drop somewhat...50+% is unlikely. without shifting production to TW.

anyone interested in exploring a partial (or complete) barter-for-mold consideration can email me directly; peter@misfitpsycles.com
 
#20 ·
bad mechanic said:
It seems like a solution in search of a problem. There are already several excellent tensioners in the $45 range, like the DMR STS or the Rennen Rollenlager (plus they're made from aluminum, not plastic). Also, rigid tensioners (not sprung) have already proven themselves and shown a spring is simply not needed. I just don't get it.
typically i would agree to disagree but i think yours seems like an opinion in search of an argument.

'excellent' tensioners? good at best.
1) the fixed arm requires regular adjustment to compensate for chain 'stretch'.
2) the fixed arm does not allow for tolerances in chainring or cog diameters. riders must find and tolerate a compromise between these tight and loose spots.
3) the fixed length and fixed angles of the arm restrict the type and application of the conversion. for example, frames with chainstays that are (low) in relation to the hanger (center) cannot be converted or it must be done in the push-down configuration.

aluminum over 'plastic'?
i suppose that depends on the science or engineering you are considering, either way, selling one arbitrarily over the other is no less shortsighted then providing the nod based on colour.

i sell approximately 400 spring-type tensioners (like so) and 100 fixed-type tensioners (like this) per year. the price differential is a mere 7$ (25 vs 32).
over the course of 5 years i have only taken back 2 spring loaded tensioners and i have only exchanged 2 fixed tensioners (for spring style). what i mean is, i think most people know what it is they are buying and they understand the limitations of any tensioner.

i have experience converting a range of frames for a range of purposes through a range of budgets, maybe that matters, maybe not.
we set out to design a tensioner, based on experience and feedback. we set out to offer a substantial improvement on what was available...at a reasonable price...made domestically if possible.

by point of comparison, tensioners i consider 'excellent' (YESS for one) cost upwards of 80$.

we attacked what we considered the two achilles heel(s) of current tensioners, FIXED ARMS and SPRINGS.
in order to eliminate the necessity for moving parts (like springs and pulleys) we needed a material with no memory and a crazy fatigue life. aluminum (i do love it) is not appropriate for this application.

maybe the DMR style is all you need. i'm not naive, i expect it will be ALL a few other people need too.
but i fail to see how a product that eliminates specific failures in design, limits compromises and costs no-more is a bad thing.

those interested can read more on the design concepts HERE and HERE.
 
#21 ·
nogearshere said:
'excellent' tensioners? good at best.
1) the fixed arm requires regular adjustment to compensate for chain 'stretch'.
2) the fixed arm does not allow for tolerances in chainring or cog diameters. riders must find and tolerate a compromise between these tight and loose spots.
You produce frames which use sliding drop outs, which have the same issues you list above. Why not use fixed dropouts with a Boner?
 
#22 ·
bad mechanic said:
You produce frames which use sliding drop outs, which have the same issues you list above. Why not use fixed dropouts with a Boner?
excellent.
i appreciate that you did that research.

first. chain tension is measurably more important on a converted bike then it is on a singlespeed specific frame. ss specific frames have a fixed chainline and tend to be assembled using ss specific parts while the converted frame has a chainline that is estimated by the user/installer (through spacer placement) and tend to be assembled with existing chainrings and (possibly cogs). these rings/cogs are ramped and are much more prone to jumping...higher tension resists that.

second. the use of any tension system that requires the chain contact any surface other than the ring and cog (spring, fixed or a boner) suffers from a level of inefficiency.

third. evolution. it takes time. would i consider a change? sure. i just don't think that is a better solution TODAY. incidentally, i DID prototype the Boner on a diSSent frame.
 
#24 ·
bad mechanic said:
So what does the Boner offer me which the Rennen or DMR doesn't?
The Boner provides nearly constant chain tension (to the limits of a spring curve) throughout 360° of crank rotation, which a purely fixed tensioner such as the Rennen or DMR cannot. Also, it manages to do this without adding any extra moving parts compared to the aforementioned products.

The Boner is not made from the same crap plastic that they make dollar store toy swords from - the material is a carefully selected engineering material that has specific properties regarding creep and fatigue life which are perfectly suited to the design - demands that dear old aluminium can't meet for this application.

To paraphrase nogears, it is true that an SS frame, whether with sliders or an EBB, cannot compensate for out of round rings, or chain stretch. However, if you're going to add inefficiency by using a tensioner or other form of idler-type device, why not deal with another problem (chain length) while you're at it?

Finally, a solution looking for a problem? I suppose if "good enough" is all you're looking for, then you could be right...But that argument could be made for elastomer-sprung forks, early-nineties style helmets, or 7-speed drivetrains with non-ramped or pinned cassettes/rings.
 
#25 ·
tmas said:
Finally, a solution looking for a problem? I suppose if "good enough" is all you're looking for, then you could be right...But that argument could be made for elastomer-sprung forks, early-nineties style helmets, or 7-speed drivetrains with non-ramped or pinned cassettes/rings.
I was going to leave it, and nogearshere made good points, but this argument is just crap. If the tensioner is durable and keeps chain tension, then yeah, it really is good enough. There aren't any glaring issues with them. The same can't be said of your list.
 
#26 ·
I don't think you "left it," when you shortened his post to quote "stuff" and then asked what improvements the Boner offers, despite his raising good points. I clearly recall riding the old things I listed, and I remember them working...the newer alternatives are a little lighter, a little smoother, and a little more stylish. If the Boner offers an improvement, however incremental, at a comparable price, then it seems a little silly to dismiss it because current systems are "good enough." I'm not saying everyone needs to throw their current setup in the garbage because this one is infinitely better, but if there is any room for improvement for a new product, I don't see why it shouldn't be taken advantage of?
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top