Single speed MTB

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I've been interested in building a full rigid single speed mountain bike for a bit now. I started doin some research and decided I’d prob go with a Kona if I could find one on the cheap.
Well, as luck would have it, I found this 2003 Kona unit frame with a Surly instigator fork on eBay. I happen to find it the same day I was handed my Christmas bonus...

E648F870-ACBE-403E-8208-79BD51E59F0F.png

(Screen shot, forgot to take a pic when I received it)

I sent the seller an offer, and a bit later it was at my door. It’s been spray bombed colors I’m not too fond of, so that will be getting removed/ covered. I already have a lot of what I’ll need to build this up.
My goal is to build something I don’t mind beating up, and can take on local trails, camping, etc.

I do have a rigid Kona project 2 fork that I may swap for the surly one, as the surly is suspension corrected. I’ll prob mock it up and try both to decide.
 
While I wait for paint to dry I thought I’d do some inventory on what I’ve already got for it-

68858344-29E1-421E-B556-A37115D4D77F.jpeg


I had most of this already, and a few things came in over the last week.

Kenda H factor tires, 26x2.35, Mavic front rim
Moto bars, oury grips, Avid levers, cane creek sealed headset.
Wtb Silverado saddle, Fuji seatpost (soon to be swapped, but was the only 27.2 I had), salsa seatpost clamp.
Shimano XTR rear v brake, Avid bb7 front disc brake (and adapter).
Box chain tensioners, some track nuts.
Raceface turbine cranks in 180, salsa 32t chainring, sram chain.

Also, I will be using this surly rear single speed hub that is currently laced (improperly) to a 29er rim
68EB7D03-0DDC-41B4-AA4F-09C5EFADB303.jpeg


All I need is bottom bracket, stem, rear hoop (if my calculations are correct I already have the right spokes), tubes, and to pick out some pedals. And to decide on what tooth count freewheel to run.

Unfortunately, I can really only paint on the weekends, so I will be waiting until next weekend to lay the paint, then possibly another week to lay the clear. We’ll see.
 
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You should be ok. It will give You a bit more torque.
I found this to be very informative website:
http://www.gear-calculator.com

When You choose from the gears menu You automatically get the recomended gears. Single speed is 42/17, which is 2,47:1.

But since how it'd feel depends a lot on Your physical condition, weight, prefered cadence and such I think You should try Your combo first. If You didn't quite like it You could always get a smaller or a bigger rear sprocket.
 
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You should be ok. It will give You a bit more torque.
I found this to be very informative website:
http://www.gear-calculator.com

When You choose from the gears menu You automatically get the recomended gears. Single speed is 42/17, which is 2,47:1.

But since how it'd feel depends a lot of Your physical condition, weight, prefered cadence and such I think You should try Your combo first. If You didn't quite like it You could always get a smaller or a bigger rear sprocket.
Thank you, that site is rad. I have the formula memorized. I'm running 42/17 on my Kona A'ha, which is great for around town. I typically prefer in the 60-65 gear inches for most my normal riding. 42/17, 45/18, 44/19, 42/18, and 46/20 are what I'm running on a few of my bikes. But, most of those wouldn't suit me well up hill off road. I want to gear this down. So it will be almost too spiny in the streets, if that makes sense. I guess the easiest thing to do would be take my geared mountain bike for a spin and pick a gear I like and do the math.

Also, if anyone is curious, to get your gear inches, divide your chainring by your rear cog, a then multiply the result by wheel size. Example for 42/17=2.4705 2.4705 x 26= 64.233. 64.233 is your gear inches. With this, if you have a bike you really like the ratio on, you can do the math to get the same ratio (or close) with different sizes rings and cogs.
 
Stem came in while I was test fitting the disc brake adapter yesterday. I had a front load stem, but it had a drop to it. I opted for a more upright top load stem to bring the bars up about an inch.

A9199591-E67C-4EDA-A298-3B308C1A92F6.jpeg


Adapter fit fine (tested on the Kona project 2 fork)
C94D5743-F021-40DD-A407-16D26075B686.jpeg

Need to clean up that rotor!
 
Thanks for link to gear calc. Pretty intuitive. Not every combo available but enough to get a graphical picture of your gearing.
cruiser 4 gear chart 49t.jpg

As an example the above kinda represents my Giant built Schwinn Cruiser four. The 4 speed is the overdrive gears of the 7. I'm running a 49 t chainring and at my cadence it's easy to see why the bike is a workout on hills...
 
Thanks for link to gear calc. Pretty intuitive. Not every combo available but enough to get a graphical picture of your gearing.
The 4 speed is the overdrive gears of the 7.

Overdrive - does that mean it is the direct gear? Where one crank rev means one hub rev?
You could also just drag the dispayed cogs out of the graphic (or move them around with more or less teeth) and choose Your own combos if You don't find a particular hub or cassette. That gear calculator is truly awesome and very customizeable.
 
I played around with it. Could not find how to add a nexus 4 so i settled on a 7 and 4th on 7 speed equals first, ok? :crazy:
How it came from factory.
cruiser 4 gear chart factory.jpg

When I first got it ridable a couple years ago.
cruiser 4 gear chart 36t.jpg

When I transferred the guts to a real nice cruiser 7 frame I thought the 36 tooth chainring looked silly with the huge chain guard so I swapped in a 49 tooth sprocket from an old Ross...
cruiser 4 gear chart 49t.jpg
 
I slapped together a Schwinn HD for my son-in-law, and a Monocog for myself for a ~22mile group mountain bike ride this last fall. The group consisted of us with the two rigid single speeds, two Rangers with crappy older dual suspension Wally-mountain bikes, and the other Ranger and rest of the group with high-dollar full-suspension multi-speed mountain bikes.

Trail was a total of ~2200ft ascent and ~6200ft of descent. The Schwinn HD has a 44/22 combo with 26" x 2.4" tires (measure ~27" tall). The Monocog, I believe, is a 33/18 combo with 29" x 2.25" tires.

We did a lot of walking on the uphills, him less than me (25yo vs 49yo). We both finished...though I was about 99% dead. The Wally bikes and 60% of the total group did not finish. Part of the problem was the group would get strung out on the downhills...and then have to bunch up and wait for everyone at the bottom. I had planned to be able to have momentum work in our favor at the beginning of the uphills...but, that didn't happen. I plan on doing the same trip with just family members a couple times this year. Changes I'll make will be some kind of suspension (I broke/sprained my thumb when my bars left my hand in a rock garden that I came upon too fast...and in the mad scramble to get both hands back on the bars I jammed my thumb into the bars...this was on the first downhill section, less than a mile in :doh:)...and lower gearing. The ascents are brutal on a single speed.

The final results were...

The two Wally bikes (multiple breakdowns...which I fixed because I'm the only one that brought tools :grin:)...DNF, but to their credit, they made it three-quarters or so of the total. They were two of the Rangers bringing up the rear, so we had no idea when we lost them.

A 70yo women on a nice Trek ended up injured and had to be drove out...but made it ~7/8ths of the way.

Two of the five other high dollar mountain bikes FINISHED...two quit after the first leg (easier section of ~9miles, meant to weed out those who may have been in over their heads), and our last Ranger had to drop out when the above mentioned lady got injured.

The two idiots on rigid single speeds...FINISHED...but, only out of stubborness.

SOOOO, if you are going to ride it in anger on any kind of up and down terrain...GEAR LOW! REAL LOW! :grin:

Jason
 
I slapped together a Schwinn HD for my son-in-law, and a Monocog for myself for a ~22mile group mountain bike ride this last fall. The group consisted of us with the two rigid single speeds, two Rangers with crappy older dual suspension Wally-mountain bikes, and the other Ranger and rest of the group with high-dollar full-suspension multi-speed mountain bikes.

Trail was a total of ~2200ft ascent and ~6200ft of descent. The Schwinn HD has a 44/22 combo with 26" x 2.4" tires (measure ~27" tall). The Monocog, I believe, is a 33/18 combo with 29" x 2.25" tires.

We did a lot of walking on the uphills, him less than me (25yo vs 49yo). We both finished...though I was about 99% dead. The Wally bikes and 60% of the total group did not finish. Part of the problem was the group would get strung out on the downhills...and then have to bunch up and wait for everyone at the bottom. I had planned to be able to have momentum work in our favor at the beginning of the uphills...but, that didn't happen. I plan on doing the same trip with just family members a couple times this year. Changes I'll make will be some kind of suspension (I broke/sprained my thumb when my bars left my hand in a rock garden that I came upon too fast...and in the mad scramble to get both hands back on the bars I jammed my thumb into the bars...this was on the first downhill section, less than a mile in :doh:)...and lower gearing. The ascents are brutal on a single speed.

The final results were...

The two Wally bikes (multiple breakdowns...which I fixed because I'm the only one that brought tools :grin:)...DNF, but to their credit, they made it three-quarters or so of the total. They were two of the Rangers bringing up the rear, so we had no idea when we lost them.

A 70yo women on a nice Trek ended up injured and had to be drove out...but made it ~7/8ths of the way.

Two of the five other high dollar mountain bikes FINISHED...two quit after the first leg (easier section of ~9miles, meant to weed out those who may have been in over their heads), and our last Ranger had to drop out when the above mentioned lady got injured.

The two idiots on rigid single speeds...FINISHED...but, only out of stubborness.

SOOOO, if you are going to ride it in anger on any kind of up and down terrain...GEAR LOW! REAL LOW! :grin:

Jason
Nice!! That sounds like fun! So the HD was geared exactly as I was planning, 2:1, aka 52 gear inches. This unit was originally geared 32-17. I’m going to start it at 32-16 and see how I like it from there. Your monocog seems pretty close to most of what I’m reading on 29er. I figure my big ripper is geared 32-15, and as some of the ratios mentioned previously, it’s great for around town. But I wanna gear down (for me). I have 18 and 20 tooth freewheels if the 16 doesn’t cut it. In reality, most of this Bikes time will prob be communing, as I have a dirt path option most of the way to work, with out much climbing at all. So i don’t wanna go too low.
We’ll see. Right now I’m waiting on the bottom bracket. I kinda winged it on spindle length. Fingers crossed my guess is right on.
 
So the HD was geared exactly as I was planning, 2:1, aka 52 gear inches.
More like 54, as the Conti-XKings are a solid 27" tall.
This unit was originally geared 32-17. I’m going to start it at 32-16 and see how I like it from there. Your monocog seems pretty close to most of what I’m reading on 29er. I figure my big ripper is geared 32-15, and as some of the ratios mentioned previously, it’s great for around town. But I wanna gear down (for me).
I think my Monocog was around the 55-56 gear inch range...I know it was a little longer geared than the HD, but it was the biggest cog I had available on the back.

My Big Ripper is currently unreachable, but I believe the stock gearing started out as 33/16...and in recent years has gone to 33/15. My STR29 is 33/15, and they both are pretty high geared. They take a bit to get going, but when they do :thumbsup:. Like you said, great around town bike.

I ride the HD here in the shop (BIG BUILDINGS), and it is a hoot geared as is. Plenty quick, but with enough top end to get me in trouble with the slick concrete floors...I really need to swap some hookworms on it for the shop...knobbies and smooth concrete don't mix well :doh:. It would probably be just about right for me on the kind of commute you are contemplating...I'm pretty sure you have more lung and leg than I do, so you might be able to go with a bit higher gear.

But, if you are going to do a ride on top of a mountain range...GO DEEP! :rockout:
(If I were to take the HD on the same trip we did last time, I'd probably go with a 39/22 or even a 38/22...and that probably isn't deep enough :confused:)

Regardless...it is going to be one killer Unit!
 
I appreciate the first hand knowledge @RustyGold !

I forgot to take a pic, but I finished painting over the weekend. Got a second coat on frame and fork, and a whole can of gloss clear.
My rear hoop came in, and a friend contributed a 16t freewheel. So other then wanting a black seatpost as opposed to the silver I have, I have everything I need.
I’ll build the rear wheel one night this week. Then, weather permitting, I’ll build it next Saturday morning and be testing it by the afternoon!
 

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