A regressive build

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needs a better name that eludes me now.

Some background. About 4 or 5 years ago we had a guy who wanted to buy all our low end full suspension mountian bikes to make in to ski bikes. There are kit for that. Remove the wheels, levers, cables, crank, bb chain, etc. keep the fork, headset, bars, stem, seat post, seat. He was renting them at a downhill ski resort. Win-Win for both of us. The coop got $25 each for a striped down bso. And he got stripped down bsos for $25 each which was a bargain for him. I found some kits on line, $159 for the adaptors. Add your own bike and skis. IMO a full suspension bike is a better option than a hardtail or rigid fork.

I'm not building a ski bike. But we had a few of those stripped down fs-bsos for ski bikes that never got picked up. Found those when we were clearing out of the basement. So I got one to do my own build. From full suspension to no suspension. From 18 or 21 gears to 1. I didn't take a before photo. There wasn't much there anyhow. I found one of the full bike on the www to use. Got a rigid fork from the parts bins. That's repainted to black to match the rear triangle. Paint drying now. Cut & filed off the cable guides on the aluminum main frame. Scraped the decals off. The frame had a clear over the decals and aluminum so it's kinda spotty now. Still deciding how much more work I want to do to polish the aluminum.

I'll keep the v-brake bosses for brakes. Planing on a single cog freewheel and some decent mtb wheels. Maybe some street tires. This may be my next grocery getter for destinations within a mile or two from home. I have some all aluminum brake levers. I think I'l put on mostly aluminum parts to match the frame and keep the weight down.

Next Mountain Ridge, circa 2006.

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Suspension delete.
front, a rigid fork.

rear/frame. I removed the fake shock with coil spring and put in a bit of pipe. I'd seen that done years ago on a Cannondale V3000 to ill effect for that bike. But this isn't any high end Cannondale. I found a bit of pipe from a kiddie trailer that has some beef to it. About 2 millimeters wall thickness. There was a hole at one end. Just had to enlarge it to fit the stock shock mount bolts. And drill a new hole in the other end and cut to length. 6 inches hole to hole to match the shock. I've tried to tighten up these fake shocks as tight as possible to reduce frame movement but a bit of pipe should be lighter weight. Maybe I'll paint it bright yellow later on.

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I reread the rules. Bikes in this category are for hard riding off road. The streets around here are rougher than many dirt trails. Mountain bikes are the only way to ride in town. My local rides have to endure potholes, cracks, bumpy patches, ripped out sidewalks, jumping curbs and be so ugly no one would steal it.
 
Decals removed. Cable stops removed from the aluminum frame.
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Hum, a turnbuckle would allow me to fine tune this frame. Adjust the head angle and bb height. I may have to do that to get good working angles, then cut a new pipe. Replacing the shock fork with a standard fork should drop the front end a bit and change the head angle.
 
Picked up a mid size turnbuckle today and a couple of shims. Will still need some washers to keep it centered. It won't be permanent, just for a few rides to experiment.

Several years ago I visited a local frame builder to get a bike replicated and he pulled out his smart phone with a angle measuring app on it to measure the frame angles. I'll have to find a similar app.

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Might want to get some nuts to tighten up on both sides of that turnbuckle. Otherwise, I’ll bet it will that will a little bit of vibration, and the turnbuckle will loosen on its own....maybe break. I learned this by using turnbuckles on the wires to keep my new trees from blowing over with the wind. Without the nuts that tighten up to the turnbuckle, I was amazed at how quickly they loosened. ONcxe the nuts were applied and snugged up, no more problems. One nut will be reverse-threaded by the way.
 
I have right hand nuts so I'll add one. That should stop the loosening in this app.

wont be any test riding soon. Temps are headed to -40f wind chill the next few days.
 
thanks. -10F, 28mph winds, chill at -38F now. And its getting colder and windier. Garage doors didn't want to open, the snow thrower started but didn't want to go forward without help. most outdoor winter clothes are doing the job but not gloves. And I found another bike dumped in my driveway today. 16" pink.
 
Working on the wheels. Going single speed so here are some choices.

Note this Tri-Diamond does not have any removal notches. The chome is for 1/8" chains. So the Full Steel Balls will be going the bike.

Put some WTB Velocraptor tires on for now. Snow on this part of the earth means we need traction.

I might replace the rims with some decorated rims but that depends on how much I want to stink up the house with paint fumes.

Have a crank picked out and prep'd. The small ring and large ring were riveted to the swagged middle ring. Need to touch up the black ring. It was factory painted after the 3 rings were riveted together so its bare metal where they overlapped.
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Crank. A mtb triple that had the middle ring swagged to the arm and the other 2 sprockets riveted to the middle. Angle grinder to take the rivet heads off then a hammer and punch to drive the rivet body out. The overlap areas need paint. The center cover is still intact so it might go back on . Aluminum arm with a 38t thin sprocket. It's pretty light weight

fork cleared and installed.
Some old handlebars cut off to use as the shock replacement. Slightly wider and a lot stronger bit of tubing than the kiddy trailer part I had before.
Got flat so another tube installed.
Aluminum riser bars.
silver stem from the parts bin.


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Found a short bb cartridge (110mm) in the parts bins and installed the crank. Chain line is way off so I re-spaced the rear axle and re-dished the wheel. Still off about .5" or more. I may use a 5 speed freewheel with 4 gears removed. Depending on the brand, that puts the threaded on cog farther out which should improve the chain line. Some freewheels have the last gear threaded on, the rest are splined and held by the threaded cog. Those don't have much threading. Some use a threaded ring which are useless as single speeds. Some brands have 2 threaded cogs and those work well for converting to single speed.

Brake arms installed. fork installed. stem installed. tires installed.

Everything on the bike will be black or aluminum. A two tone look.

Dot matrix printed serial number. Usually hard to read. Seen on many cheap chinese bikes, cannondale bikes and John Deere tractors.

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Rolling chassis done.

Pedals from the parts bin to choose from.
The GTs have a bent axle.
the >>> are a bit over kill for this bike.
Brand new plastic pedals are light which is a goal for this bike but no plastic please.
Going with the silver cast aluminum pedals.

Some different angles on the frame adjustment. Need to get the bike ride able to try out different angles.

Brakes installed. A couple of holes drilled in the top tube to run the rear brake cable. Bars, stem, grips, levers, seat, chain , pedals installed. A test sitting and.... It's too small for me. Oh well. It will go to some charity this spring.


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Angle adjustments
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freewheels.

Not totally satisfied with the single freewheel on the bike. It is a bit grabby after being lubed and the chain line isn't perfect.

I dug out some 5, 6 & 7 speed freewheels out for consideration for converting to 1 speed.

The newest batch of chinese freewheels have threaded retainers. Seen on countless DNP, SunRace, Shimano and many other brands of freewheels that come on bsos. The cogs are all splined. The retaining ring is a bugger to remove. There are no tools available. Each brand would need it's own. The many have small dimples in the outer edge of the ring like on the Shimano pictured below. Some have notches on the inside of the ring with various notch counts. The best tool i've found for removing them is a large channellocks, a firm grip wearing gloves, the freewheel mounted on a steady vise. They are on tight. I doubt if I could put one back on tight enough. I've taken scores of them apart to get the individual cogs for art projects. I am sure this is a cheaper way to manufacture freewheels. No threading the cogs needed. useless for single speed conversion.

There are some older Shimano and other brands where there is just 1 threaded gear, usually a 13 or 14t. Too small for most single speed conversoins. Plus the single cog is at the far right side and that doesn't help chain line issues.

One good freewheel to convert to single speed is a Suntour Perfect. The two smallest cogs thread on, the 3 larger (or 4 for the 6 speed versions) are splines. Take off all the gears and thread the 17 back on. That puts the cog near the middle of the chain line. And IMO, the suntour body is a better freewheel body than any single speed freewheel body. The wider spaced bearings are more stable and the suntour last for ever. The Suntours had all kinds of options. Suntour provided dealers with cog display boards that had all the many options.

Some of the old European freewheel makers had all 5 gears thread on. The two biggest were reverse threaded and threaded on from the back side. Most had 2 right side threaded cogs. The 5th cog often threaded in to the 4th. The bods are thinnner and would work well as a single freewheel but gear choices were very limited because each of the gear positions would have a different thread diameter


Here are some photos. The Suntour Perfect is good because you can use just the 4th gear without a spacer and that puts it closer to the chain line center. You don't have to respace axles or redish wheels when converting geared bikes to single speed.

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got this wrapped up today.

I used an angle app in the phone to measure the head tube angle. Well the phone is longer than the distance from headset cup to cup and the phone buttons stick out a bit. I used a block of wood as a spacer to get a little more accurate. The head tube angle ranges from 12 - 18 degrees. Okay, subtract from 90 to get 72 - 78 degrees. Old school velodrome racing bikes (track bikes) where the steepest at about 76d. Heavy cruisers were closer to 72d. After a couple of short test rides I settled on 74d. That measures out to 155mm c-c for the shock replacement bar. I used the straight section from some old steel mountain bike bars. I figure the steel will hold up longer than aluminum at the holes for the bolts. I had to grind one end to a round shape clear the frame.

WTB (wilderness trail bikes) seat to match the WTB tires which are pretty rough riding on chip seal. But this is an off road build contest entry. If I still have the bike next summer, I might put some street tires on it. But it's too small for me so not. The bike weights 27.5 pounds. Fairly light. Nice tires would knock a couple pounds off.

URT or NOT. URT was a term, Unified Rear Triangle, tossed around in the early days of mountain bike suspension design. They sold many experimental bikes disguised as valid products. The advantage of an URT for coaster brake conversions is the distance from the crank to the rear axle doesn't change so the chain slack can be set properly. I guess I wasn't paying attention but this is no URT. The pivot is right next to the bb shell but as the suspension moves, the chain distance changes. Close but not zero. For a bike with a rear derailleur to take up the slack, it's not an issue. Since I deleted the frame shock, it's also no longer an issue. But while I was doing the test rides with different angles, the chain got super tight so re-adjusting the chain slack was in order. Now that the new link is in, the rear wheel and brakes got a final adjusting. The frame was chosen because it had horizontal dropouts so adjusting chain tension is easy.

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Love this very last pic, its a genuine mountain bike coz it has snow on the wheels, I dont care what anyone say's, snow on wheels is cool!!! and the bike, lovin the way ya canned that FAKE shock, there must be 2 million bikes with these on ha , bike looks clean , tuff and cool, well done!
and I have to say that cog breakdown segment would have to be the most informative and impressive display! thanks for that!
 
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