Noob attempts a Felt MP build: Have mercy on me.

[miked826]

That bike is sweet sure hope things work out... Another local rider is always welcome

The longer jackshaft is on the way and new air filter seems to be working fine even without having to drill the carb jet out. Any ideas on how to EASILY get 12 volts on this thing besides just buying a battery and and hoping it lasts until I can get home and charge it?

 

[F_Rod81]

I agree totally, then I wouldn't have had to do it on my own. The wheels are Felt 24" and those fat azz tires are Electra Fatti-O's 24x3. They tires also keep me more insulated from L.A.'s potholes.

Electra makes really good tires. They should last for quite a while as well. I have a pair of 26" electra retro runners with close to 2k on them and they look brand new for the most part.

 

[miked826]

Ok so I tried to see if the engine would move me from dead stop unassisted using longer jackshaft connected to a solo CC and the CC simply twisted the jackshaft out of true and the primary chain jumped off the gears. The u-bolts from Home Depot ain't gonna cut it. The 420 chain is way too big as well. The seat tube was partially crushed by the u-bolts so I cut down the original seat post and hammered it into the seat tube. No more partially crushed seat tube.
Also lowered the engine as far as possible and centered it so the pedals would
clear with a CC installed.

Total distance traveled before chain jumped overboard because of jackshaft twist: About 6"

 

[killercanuck]

Using shims in the u-bolts can let them bite tighter without crushing one spot. I found a couple of Barelyawake's old pics to show what I mean:

pic 1
pic 2
Original Thread

Hope that'll help with the twisting.

 

[miked826]

Using shims in the u-bolts can let them bite tighter without crushing one spot. I found a couple of Barelyawake's old pics to show what I mean:

pic 1
pic 2
Original Thread

Hope that'll help with the twisting.

Thanks for that info but where did you get the shims? Did you make them yourself?

 

[killercanuck]

in the original thread, he say's he found some pipe with an i.d. of the seat post size, and cut'em in half.

I'd think any sturdy steel that you can hammer around a mandrel would work better than nothing, eh?

 

[miked826]

in the original thread, he say's he found some pipe with an i.d. of the seat post size, and cut'em in half.

I'd think any sturdy steel that you can hammer around a mandrel would work better than nothing, eh?

I just happen to have a seat post laying around that is just going to waste that would work perfectly. I also installed my H3 LED light bulb into my head light but it hardly puts out any light. Only uses 2 watts as well so hard to complain really.

 

[miked826]

I got the outdated SBP "Conversion" Shift Kit because using it was a last option not a first option and I didn't even realize the design had changed. Now I know why it changed. I just have to reinforce this one and make it work is all. How hard could it be really? Sigh.

 

[Dan]

Ahh Mike, frustration is part of the fun.

When you get her the way you want, (not that they are ever done. Not until you start another build any way) she will be your pride and joy. A master piece of functional art all your own and created by you.

She will be more then worth every bit of effort and then some.

 

[miked826]

Ahh Mike, frustration is part of the fun.

When you get her the way you want, (not that they are ever done. Not until you start another build any way) she will be your pride and joy. A master piece of functional art all your own and created by you.

She will be more then worth every bit of effort and then some.

I keep telling myself the exact same thing over and over again in my head when I go to sleep at night.

 

[miked826]

Using shims in the u-bolts can let them bite tighter without crushing one spot. I found a couple of Barelyawake's old pics to show what I mean:

pic 1
pic 2
Original Thread

Hope that'll help with the twisting.

Ok no more twisting or chain jumping. I only got one problem. 1 foot pound of torque. I open the throttle wide open and it's like I'm towing an invisible yacht behind me. Is it because of my single speed freewheel?

 

[miked826]

Using shims in the u-bolts can let them bite tighter without crushing one spot. I found a couple of Barelyawake's old pics to show what I mean:

pic 1
pic 2
Original Thread

Hope that'll help with the twisting.

Good God what have I done? LOL

 

[wayne z]

Ok no more twisting or chain jumping. I only got one problem. 1 foot pound of torque. I open the throttle wide open and it's like I'm towing an invisible yacht behind me. Is it because of my single speed freewheel?

What is your overall drive ratio? By the looks in the pics, it seems that your ratio is way too tall. Not sure, but I think this motor needs about 17 or18: 1 for decent performance.

 

[miked826]

What is your overall drive ratio? By the looks in the pics, it seems that your ratio is way too tall. Not sure, but I think this motor needs about 17 or18: 1 for decent performance.

"Too tall" would be an understatement. It would not move me on the bike no matter how much gas I gave it. I tossed the jackshaft mount in the trash and ordered a 56T sprocket. I then removed the rear disc brake and am relocating it to the front tire. How good or bad is the Grubee 4G belt drive? That's what I'm looking at now.

 

[wayne z]

"Too tall" would be an understatement. It would not move me on the bike no matter how much gas I gave it. I tossed the jackshaft mount in the trash and ordered a 56T sprocket. I then removed the rear disc brake and am relocating it to the front tire. How good or bad is the Grubee 4G belt drive? That's what I'm looking at now.

Well, I wouldn't toss the jackshaft yet. Looks pretty well built. All you need to do is use a larger sprocket on the jackshaft input, and find the a larger wheel sprocket if possible.
Have you tried the gear calculator in the DIY forum list?

 

[wayne z]

If you keep the JS, you should add a piece of flatbar or maybe a turnbuckle with a locknut, as a strut, from the jackshaft plate to the engine, on the PTO side.
This would help elminate movement and stress from the aluminum frame , caused by the considerable torque of both chains working together , under power,to twist the JS off it's axis.

 

[miked826]

Well, I wouldn't toss the jackshaft yet. Looks pretty well built. All you need to do is use a larger sprocket on the jackshaft input, and find the a larger wheel sprocket if possible.
Have you tried the gear calculator in the DIY forum list?

No I haven't tried any gear ratio calc. All I know is my Jackshaft was twisting off axis because it is an extinct 1st Gen. SBP shifter that has since been replaced by a new version that is reinforced and attached to the engine mount.
The only reason I got it is because of the 203mm rear disk brake was in the way. What I really want is a 4G Grubee or a EZM QMatic. 4G's are nowhere to be found.

 

[miked826]

If you keep the JS, you should add a piece of flatbar or maybe a turnbuckle with a locknut, as a strut, from the jackshaft plate to the engine, on the PTO side.
This would help elminate movement and stress from the aluminum frame , caused by the considerable torque of both chains working together , under power,to twist the JS off it's axis.

That Jackshaft chewed up my down tube and I had to paint it black. I got steep hills to deal with as well. A fixed ratio on a 49cc engine will mean I'll have to do so pedaling. I'm not much into pedaling. LOL

 

[miked826]

 

[Dan]

Really lookin' awesome Mike.