24” mountain bike project

Greg58

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I'm not planning on riding it much, I'd much rather ride one of my 26" bikes. This is just something I've been wanting to build for a while, this was built from spare parts I had so no real costs. This is my oldest engine, a September 2010 gt2b grubee. I went through it completely replacing crank bearings a couple years ago, the power should get better after I put a few miles on it.
 
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indian22

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I'm not planning on riding it much, I'd much rather ride one of my 26" bikes. This is just something I've been wanting to build for a while, this was built from spare parts I had so no real costs. This is my oldest engine, a September 2010 gt2b grubee. I went through it completely replacing crank bearings a couple years ago, the power should get better after I put a few miles on it.
Greg I've been going a similar route with frames and bikes this spring. I've got lots of good stuff just stored in boxes and frames as well, so I'm putting motors on them. Electric so far 'cause I'd not tried the e-bike thing and I'm really getting into the " current" trend... the next, a board track style build, was completed as a 2 stroke a couple of years back & I'm going hybrid on her with a front e hub. Use what you got to get where you want & it ends up costing not so much up front.

I like your bike and it obviously runs quite well. I really like 48 t & 44t on bikes I primarily use in town really easy on the clutch and good acceleration. your 44t coupled with 24" tires should really tackle dead stop takeoffs and most hills with no pedaling. You don't live in San Francisco do you? 28 mph with your cog and 24" tires seems great speed, but Jimmy's right a lot of rpms on the little motor, not that I think you would spin it that hard for very long, you've too much experience for that stuff.

Rick C.
 

Greg58

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This bike is where I'll test things, I've got several heads and exhausts I want to try. I'm going to build a couple of pipes from scratch to test also. I'm trying different magneto cdi combos to see what works best.
 
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indian22

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Greg my old Grubee has been my testbed for every thing 2 stroke over the last 5 years & it's been a good one. Hope you get that kind of service from your current build!

Rick C.
 

Greg58

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Rick the black bike I ride most has a eBay 48cc on it from 2011, it continues to run better than I ever expected. I had to do a few mods to get it where it’s at.
 

indian22

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It's strange Greg how one seems to find himself riding one bike more than all the rest. My Grubee has been that one & nothing about it is even close to making it my best build, quite the opposite in fact, but I guess it just suits me in some way or ways The dependability has been exceptional, but the rest is a mystery to me...

Rick C.
 
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Jimmy Bloodmaker

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It's strange Greg how one seems to find himself riding one bike more than all the rest. My Grubee has been that one & nothing about it is even close to making it my best build, quite the opposite in fact, but I guess it just suits me in some way or ways The dependability has been exceptional, but the rest is a mystery to me...

Rick C.
i hear ya, i ride my 24" the most. it's just so nimble and feels right sitting lower to the ground. i find myself cutting chains and building rims so i can swap out sprockets with ease, to match my type of riding for the day. when on the trails i slap a 44 or 48 on and wider tired rims. for more traction and hill climbing grunt. when in the street i switch to a 32 to 36, depends on where im heading in town ( big city, real big). an if i'm not sure about going to the trails or not, i slap a 40 on so i can have a little of both worlds. i could just grab another bike instead of changing chains and wheels out, but the 24" was my first. she's ugly, she's always muddy, and has eaten a few motors ( mud and water on the inside of your engine is not a good thing, trust me), but the frame is so frankistien'd, it ain't gonna break unless i get hit by a car. when i seen gregs post about a 24", you bet your rear axle i had to follow it.
 
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indian22

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Jimmy there are relatively few posts that specifically address 24" bikes, but it's not because it's a bad wheel size to ride. I've mounted 3" tires on 24" wheels and the tire diameter was 26" and it rode like a 26" bike as well. Small frames like the Schwinn choppers when customized look super with a wide rear tire on 24" wheels. The wheel police may dictate a "proper" size, but it doesn't mean we have to follow their dictates. Currently 26" is considered obsolete for mountain bikes by many self styled experts, but personally I don't like the feel of the big bikes and I'll leave riding those to the "serious" MB crowd, even though many of them haven't left town let alone ridden trails tough enough to utilize top tier bikes.

I say build & ride what you like & have some fun!

Rick C.
 
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Greg58

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This bike was something to try a few things on, I’ve found out a couple of useful things already. I have several different style heads and found a straight plug head with a hand ground squish band to be the best running overall, I’ve got another head on the way and will try it next. I cut up a stock muffler to start a exhaust with custom look to it.
 

allen standley

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View attachment 101011 Here’s a picture of the bike as it is now, I still have to add the muffler hanger and wire loom the wiring along with a mirror. Got a little more cleaning to do, the rims were covered in grime, it was so thick it looked like rust. A little elbow work with some 0000 steel wool and they cleaned up well.
Nice, Neat, Clean and simple build Greg. Looks Great!
 
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Jimmy Bloodmaker

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View attachment 101011 Here’s a picture of the bike as it is now, I still have to add the muffler hanger and wire loom the wiring along with a mirror. Got a little more cleaning to do, the rims were covered in grime, it was so thick it looked like rust. A little elbow work with some 0000 steel wool and they cleaned up well.
sweet looking ride. simple and stylish. i have a tendency of making mine look like dirt bikes. been stopped a few times because they though i was riding a dirt bike on the street. only for them to get all wowed by the fact it is a bicycle. cops around here are totally cool with these bikes, as long as you follow the rules of the road, and keep it under 30mph as law dictates. when riding in the city, i have a 32-36 ( usually 32) tooth on, i can go almost 40, but usually keep it at 25 just to be on the safe side. i just wish some of y'all lived near me, so i had someone to ride with. only person i know who has a bike is a guy down the way, but his bike runs like crap and he won't listen to me when i tell him he is way under jetted. keeps buying new carbs with the same result. i told him get a new muffler or jet it right. even offered to sell him a muffler, brand new ( i have filing cabinet upon filing cabinet of parts, i'm an addict to these bike, lol) for $20. $60 xchamber poo poo pipe, for $20, just so i have someone to ride with. here i am putting 300-400 miles a weekend on my fav bike, and he's still trying to get his to make enough power to climb his slightly slanted driveway.
 
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Greg58

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This bike is fun to ride, it still needs a little smaller jet, I have to get it hot before it runs right. The plug is a little dark, I'll solder up the jet and drill it. I got a mirror on it so I feel better about riding in traffic. I'm going to enjoy my test bike.
 

Jimmy Bloodmaker

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Nov 24, 2018
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This bike is fun to ride, it still needs a little smaller jet, I have to get it hot before it runs right. The plug is a little dark, I'll solder up the jet and drill it. I got a mirror on it so I feel better about riding in traffic. I'm going to enjoy my test bike.
if it's under 300 miles, i'd just leave it rich. lets oil build up in the crankcase. also helps retard the heat created from all the friction of the rings seating. i always went by ( i'm no 2 stroke expert, actually the first time trying to soup them up for real was with these engines, dirt bike parts cost to much) if it had a few tablespoons or so of oil in the case and the parts are coated in a film, it's perfect amount of oil. rpm and load dictate oil needs. i'm not you and won't tell you how much oil for you ride, pretty sure you got this. lol. just remember tht extra gas carries heat away from a fresh cylinder/rebuild.
 
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Greg58

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This engine I rebuilt in 2014, I don't recall how many miles I've put on since. The carb is jetted for a 66cc, I ran it on one of my other bikes. This engine has a ramped piston with the skirt notched also with extensive porting, I was hoping the little 48cc could handle the fuel but I need to reduce the jet a little.
 

allen standley

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Oct 22, 2011
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This engine I rebuilt in 2014, I don't recall how many miles I've put on since. The carb is jetted for a 66cc, I ran it on one of my other bikes. This engine has a ramped piston with the skirt notched also with extensive porting, I was hoping the little 48cc could handle the fuel but I need to reduce the jet a little.
I kept a rebuilt 66 as a spare for my bike. Havn't needed it. But, before putting it on the shelf in 2016 I too did the ramp and skirt. Also lapped the head a bit to increase comp. Because of your latest adventure (inspiration) with the 24, I decided to use this engine along with other components I've collected over the years to once again assemble another 26.
Curious what size jet in there now and what size you are going to.
 

indian22

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I kept a rebuilt 66 as a spare for my bike. Havn't needed it. But, before putting it on the shelf in 2016 I too did the ramp and skirt. Also lapped the head a bit to increase comp. Because of your latest adventure (inspiration) with the 24, I decided to use this engine along with other components I've collected over the years to once again assemble another 26.
Curious what size jet in there now and what size you are going to.
Yeah, Greg's thread plus Jimmy's input equals Allen building with what he has. Doesn't get much better than taking stuff off your shelf and putting them on the road! Good going guys.

Now what else can we put together? I've got a list somewhere...….

Rick C.
 
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Greg58

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Allen memory fails me sometimes but I think it’s a number #70 drill. I had it tuned to the 66cc with the pipe I built. I don’t remember why I changed it out, I might have jetted the new carb and just swapped them out.
 
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allen standley

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From what I understand, NT stock are #70 5mm Delorto style.
My 29 is running super rich with 70. Spotting all over the place and black plug. Lotsa smoke. I will be starting with 65, will get a 63 and 62. I'm running B.B.R. Thrush pipe. Love it. it turns on early and hangs in all the way to the top.
Way too much jet though.
 
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