diamondback mountain bike

brentemmons · May 1, 2011

I got this bike from craigs list for $120 all set up but had not run this year and neaded a chain.I got it home swapped out the chain ,cleaned carb then replaced blown head gasket.I had a good intake with a boost niple in it so I made a boost bottle for it.I road it like this for a bit then added a suspention front end with disk brake and bmx handle bars,speedo and lights.
brnot

I road it around town then one morning took it to work.I almost made it to work and the rear tire locked up for a second then broke free,the motor sounded bad then died.I took it home,tore down the motor and found a lower crank bearing gone.Parts on order going to make it beter

brentemmons · May 1, 2011

The first picture is when I got it going the second one is after all the mods before it blew up and the 3rd one is my homade boost bottle set up.I miss this bike but have my first build daily driver with over 150 miles so far this year.Drove it to work this morning 28 deg BRRRRRR.
.shft.

I am going to put a shift kit in the diamond back with my 8 speed hub and disk brake rim for the rear.I made up a better front motor mount with rubber and a muffler clamps around the frame through a plate bolted to the motor for a solid mount.I also plan on porting the new cylinder and matching up the cases also wile it is apart.The shift kit will have to wait a wile the wife is going to kill me if I spend any more money on my toys before vacation but after then mabey.
dance1

brentemmons · May 1, 2011

Well that didnt work.I have already uploaded them in a different thread,that is the picture of the bike done before it blew a rod bearing. :-||

brentemmons · May 1, 2011

This is my pair of bikes,I have had a lot of fun tweeking these out and now I get to go through the motor and make it run again.
dance1

brentemmons · May 2, 2011

I did some looking around for the 15x27x7 crank seal for my motor,punched it in on e bay .Same seal for a 76-78 xl350 honda and many others,now if honda made it its got to be good and last also looks like a double lip seal.My only concern is the the original seal is 14.8 not 15 that is the sealing edge of the crank and the bearing size is 15 as well.Its funny I work for a NOK seal manufacturing plant as a millright and I am looking for seals,we must make as well.LOL I have read posts on this site and people have had good luck running these so I will call the honda dealer later and see if they stock them also good time to take my motorcycle for a ride to concord,to long for the motor bicycle,would take me all day and probley get run over or pulled over.
.bf.

brentemmons · May 5, 2011

All my parts wil be here today ,I plan on putting the motor together tonight.I have done as much work on it as I can to help get it going but the crank was the thing holding me back.It will be here today also won a lighting coil on e bay for it 6 volt coil only $20.Got to get some good lights on it.I plan on ridding it to work next week to brake it in not brake it like last time.Also picked up a 24"mountain bike in the dump going with a 26"up front and a 24" in back with a 40 tooth sprocket when it comes in,should give me good power and speed. brnot

brentemmons · May 6, 2011

It lives again,worked to 8 pm last night.I started from bare cases and assembled the hole motor ,rewired my way,installed new front motor mount,throttle cables,choke cables,installed new head light and made a pocket bike pipe fit like my other one.She started hard with all the oil I put in the motor and gas but runs good atfer a few runs up and down the road.I will take it out tonite and run it for a wile before I try to go to work with it. dance1

I found a 24" rim that I am going to put on it and a 40 tooth sprocket is next.I think my HD hub will be in today and I can try laceing a rim next.Time to got to work . usflg

brentemmons · May 8, 2011

what do you think caused this rod bearing to fail?I broke in useing synthetic oil at 16/1 then 25/1 then 32/1 oil mix only got 115 miles and it locked up for a second then broke free and sounded bad then died.There was oil on the rod,piston and crank but it had burned off were it got hot(see blueing on crank and rod)Was this a bad bearing from the factory or does this just happen? Any ideas would be helpfull.Please dont mind the dirt I dropped it,I didnt think it would hurt it any more

:-||

brentemmons · May 8, 2011

I was told bye the company I purchased it from the blueing was from the factory when they heat it up with a torch to put it together.My buddy rebuilds cranks on vinage 2 stoke snowmobiles and he puts one side in the oven and one in the freezer,he never uses a torch to put a crank together.The grubie skyhalk has a 6 month warranty and I was told bye the company I purchased it from that at 100 miles that I have had it to long and its not under warranty.(purchased 3-21-11 )Has anyone else had this problem?I wont tell you who I purchased it from because they have a add on this site
:-||

brentemmons · May 9, 2011

Well I am going to throw this gen 2 red air filter carb in the trash,I have had it on 2 bikes and cant make it run the same every time or keep it in tune.I put the old speed carb back on and it runs great,idles fine and has good power.They shipped me the one with the K&N syle blue filter bye mistake when I ordered a H/D axle kit and I got the correct manifold from pirate cycles tried it on my first build and runs great.The only thing with that carb is the gas feed is to close to the cylinder but I zip tied it to my boost hose and is ok.Has anyone had good luck with this carb??
:-||

brentemmons · May 9, 2011

I swapped the old speed carb back on today and the diamond back runs great.I got my 6 volt coil for under the flywheel,installed it and drilled the back of the speedo for a light from a sled speedo I had.I found some 6 volt push in type dash bulbs that work great and looks cool at night.I havent pick out tail light yet I am thinking a trailer clearence light that takes those glass push in type 6 volt bulbs.Both of my bicycle tail lights fell apart from the vibration,not ment for this abuse.I am waiting for my H/D axle kit to install on my 24" rim on this bike then my disk brake top hat hub addapter for my other build.
dance1

The brakes suck on my huffy so the rear disk will help a lot and with the addapter the sprocket will be better as well brnot

brentemmons · May 12, 2011

I got in the HD hub and took my 24" rim apart then installed the hub.Never done this before cant be that hard?It took some time to get it together but the hard part was making it round then true.I spent 1 hour getting it close enough for me.I put the sprocket and drum brake together and will have to get a cable for that this after noon.I am going to get my top hat addapter for my disk rim for my huffy today and will have to get a cable for that also,cant wait to try that as well.
usflg

brentemmons · May 12, 2011

I took the diamondback out in the afternoon ,some kids stopped me and asked a million questions,I new one kid .His father callled me later and asked if I would help him and his son to put 2 of these kits together and what kit to bye,also the other kid was going to get one as well so 3 kits.What have I got myself into ?Its for the kids and for fun,I cant wait to see his dad on one.LOL
.wee.

brentemmons · May 16, 2011

The HD hub kit with a 66 cc motor and 44 toth spocket with a 24" rim didnt last very long before I stripped out the alluminum sprocket hub to rim addapter.When I put it together it looked like the weekest link,I was pulling the front wheel off the groung with poping the clutch and was getting goood at it then it just stripped out.I also weigh about 225 lb that didnt help.My wife said you 40 years old your not playing with a full deck are you.LOL
dnut

So anyway I took the old addapter to work and on my brake (LOL) I made one out of steel on the lathe,fitted the spocket and tig welded to the rim were it was once theaded on(left handed 30 mm I think didnt have a tap LOL)I am going to take the 26" rim back off and convert it over again to the 24" rim then stress test it again.I will find out if it holds up to my abuse if it ever stops raining.
.shft.

brentemmons · May 16, 2011

Has anyone else tried the HD hub?I like the way it has the drum brake built into it and roller bearings instead of loose ball bearings.I noticed the axle can be overtightend and crush in on the bearings so I removed the bearings and installed a 3/8 tube over the axle to have the inner race of the bearing tighten up on this and not crush in on the bearings.I know they are double nutted but there is a side load on them that will tare them up and become the next weakest link.
:-||

LS614 · May 16, 2011

Never owned an HD hub, but have thought about it. The name drum brake is a misnomer, it is a band brake technically, just getting that off my chest because they are never labled correctly when I see them for sale. Sorry to hear the top end bearing blew, did you get a high quality replacement?
The first time I wrote a response, I forgot to tell you, I think pieced together bikes are totally sick and really represent the hobby well. I like your builds

happy riding!
-LS

brentemmons · May 17, 2011

You are right that is a band brake,it doesnt work as well as the side pull brakes but I went with a smaller rim (26"down to a 24") so it was eather move the posts for the brakes or try the HD hub and solve both problems,if it I didnt like it or it broke I could swap it back in no time.Also I like to try things just to say I did them like lace a rim,make a motorized bike,make a pipe fit from a pocket bike stuff like that.

Its not just the ride its the adventure to get there,if your not living on the edge your taking up to much space,you only live once are some of the words I live bye
brnot

brentemmons · May 17, 2011

LS614 said:
Never owned an HD hub, but have thought about it. The name drum brake is a misnomer, it is a band brake technically, just getting that off my chest because they are never labled correctly when I see them for sale. Sorry to hear the top end bearing blew, did you get a high quality replacement?
The first time I wrote a response, I forgot to tell you, I think pieced together bikes are totally sick and really represent the hobby well. I like your builds
happy riding!
-LS

The lower rod bearing went so I just got a new crank from BGF $17 and swaped it out.It runs good now.I got this bike used and think it was abused before I got it.The rest of the engine was fine so it may have been a bad bearing from the factory?What are you talking about a high quality replacement?Do they make one and were do you get one?

.wee.

LS614 · May 17, 2011

Right on man. I love that stuff, like using bearings from other bikes, swapping forks and wheels etc. It ain't always purdy, but it's always fun

brentemmons · May 17, 2011

Ya im not in it for looks yet ,just trying to get the kinks out to find a good set up .MY next build this winter is a board track racer,I love the work everyone is doing on here and the ideas are so cool.I want to have a few bikes I can get on and ride,one for the daily drive,one to take out on the back roads a tare it up then a nice show bike someday.These bikes are cheep to build compared to the real thing (vintage Indian or harly board track racer)so I can have a few bikes and still eat and pay bills.
dance1

diamondback mountain bike

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