jackshaft kit

[markeatmark]

witch would be faster a jack-shaft kit or just a 36-50 tooth sprocket? im building my first bike from a PK 50 motor and that's one of my major questions! i just switched from a Indian moped (cant find parts) to this bike project so i want it to go 40-50mph range (even just 40mph is fine)

b.t.w its a mountain bike 26inch (i think)

44tooth is what you need the one that comes kit will work

 

[matukash]

Well, i would say that you should buy a more powerful enginne with 44 toth sprocket. Or you should take off the top of your exhaust

 

[jjproctor]

is there any cheaper solution to jackshaft kits other than the whooping price at sick bike parts !!! that kit costs more than my motor and bike! im a flat land rider mostly there are some small "inclines" but not super large hills what would be the best sprocket size for speed i weigh 120 pounds i travel up-to 40mi somedays (round trip) and in some roads there are no side rails so with the jack shaft out b/c the insane price what size sprocket would you suggest im not lazy and i can pedal i just need a little speed!

btw . i was thinking 32tooth ? i found on ebay cheap!

 

[BarelyAWake]

The standard shiftkit is $180, I somehow doubt you got a engine kit and bike for less than that, unless ofc it's a $5 yardsale special and ya didn't hafta pay S&H on the engine kit...

Still, a few folks have lamented the "high" cost of SBP's shiftkit and I'd like to point out that unlike the Chinese engines yer boltin' it to - they use quality components and actually care about the product they're selling. Unlike the guys from SBP, I don't think I've ever seen a representative of "Jiangyan YuanDong Gas Engine Factory" here on the forum workin' to help figure out some newb's problems lol

Time and again people have attempted to make their own for less cost - only to find it's not as simple/cheap as it looks. The freewheel in particular is a good chunk of the expense, let's not even talk about man-hours and R&D.

None of that really matters tho, as you've mentioned you live in a really flat area - just get a $15 36t sprocket and call it good, if that amount isn't too rich for your blood you can experiment with different sizes till you find one that matches your bike, motor & body weight.

A lil warning tho - if ya really wanna go 40-50mph yer gonna hafta spend quite a bit of both money and time: http://motorbicycling.com/f13/40mph-speed-secrets-revealed-11141.html

BTW - if this post "sounds" a lil exasperated, don't sweat it - I'm not really, it's just cause I'm constantly astonished by how much these el'cheapo engine kits skews budgetary perspective. I'd love to see a custom fabricator even talk about motorcycle performance parts for $200 lol Ya get what ya pay for I figure

 

[skipu]

ive purchased 2 kits from sick i think for the money its a decent package once tuned right they work very well !! thank you sick is all ive got to say !!

 

[jjproctor]

44tooth is what you need the one that comes kit will work

yes it dose work and it is nice. but just a wee bit more speed at lower RPM's is nice!

i just unlesed the beast in my motor today! unknowingly i had the choke on 1/32th of the way and it was blocking the air from the carb.... it only did 21mph but as soon i fixed it it got up to 34.9mph! at that point it seemed as if the front forkes were on there way out

the thing is a little speed daemon almost as fast as my moped

 

[jjproctor]

ive purchased 2 kits from sick i think for the money its a decent package once tuned right they work very well !! thank you sick is all ive got to say !!

ill look into it later down the road but now im stuck at WTF when i look at price

 

[Masterm222]

When I got my first shift kit from SBP I had a few problems. Rear derailer came loose and cratered into the spokes so I upgraded from the stock Schwinn Jag. Next the freewheel locked up so I got the HD freewheel from SBP, nice unit and no more problems with that. Since then I have put on over 500 miles with a smile as I shift gears through traffic. The only time I had a problem was while racing a Nissan from stop light to stop light I cratered the rear cassette free wheel. Something about going through gears at WOT without letting up! $20 and a new mega-range "tranny" and I am even happier with the shift kit than before! Icey or snow packed steets don't stop me from riding now that I have studded tires. Great kit well worth the money and the best for winter because you can gear down and ride though the snow without sacrificing top speed when you hit dry pavement. A true all weather Montana motorized bike! Just need to figure out a heater! Old pic from when I first did the install

 

[wellington]

hello there my friends

 

[Masterm222]

I still say once you have spent the money on a shift kit, installed it and rode it for one day you will be wonering why you didn't do it a long time ago. The blue bike pictured above now has 957 miles on it without any more problems. 300 of them was on ice, snow and slush. Attest to a quality product from SBP.

 

[pj-pirate]

I still say once you have spent the money on a shift kit, installed it and rode it for one day you will be wonering why you didn't do it a long time ago. The blue bike pictured above now has 957 miles on it without any more problems. 300 of them was on ice, snow and slush. Attest to a quality product from SBP.

I live on the mountain above Plm Springs and have a shift kit on my bike. Its great being able to gear down and crawl up moutain trails and hit the flats wot and run up the gears! Only regret is I am used to motorcycles using engine braking to go down hills, thats missing on the shift kit due to the freewheels on both the rear hub and crank.

 

[OR_Chopper]

where do i buy these jackshaft kits? i've been looking for like 4 days... only found stuff relating to go-carts. am i retarted or am i missing something?

 

[Goat Herder]

Sick Bike Parts LLC - Performance parts for your motorized bicycle Right here..

 

[maximillian]

Dax sells them for cheapest...$139

 

[Masterm222]

Looks to me Dax gives you a real cheapo freewheel unlike the HD one from SBP. What I do like about the dax kit is the spacer between the crank sprockets. That is a subtle hint for my friends at SBP - the nuts and washers work but a spacer that will keep your rear chain from dropping between the sprockets would be a huge improvement to the HD kit! I am having that problem on my own bike right now every time I shift from 6th to 7th gear. I am going to try to cure it by adjusting the derailler. I don't think it is keeping the chain tight enough. The way I have been putting motorized bikes together lately I may be in the market for a shift kit soon. Three bikes in the month of may. One with a shift kit and expansion chamber exhaust.

 

[Junster]

Try taking a full link out of your chain. Put it in 1st (chain on the biggest rear ring) then pull the bottom of the chain forward so you skip 2 sprocket teeth in the front. See how much give is still in the derailer. As long as the chain isn't too tight it will work and give you a lot more tension in the higher gears. Way more than you can get with the derailer spring adjustment. I had to do this too.

BTW; the Dax spacer is avail. as a separate item.

 

[Lodsta]

The thing you need to realize when comparing the kits is that the Dax kit is really pretty junky. Sure it's $10 cheaper, but it doesn't come with a bunch of stuff and the stuff it does come with is sorta like a crappy shadow if the Sick kit. The gear teeth are lousy, the jackshaft itself is not even 5/8" (it's less the 1/2") stuff is bent, just stinks of China cheapness. No stiffeners, no chain adjuester, no jumpstopper

If your chain comes off any of the kits, it has nothing to do with the two chainring spacings - I'm gueising it's one or both chains are too loose and probably not well aligned....my chain never comes off of any of my three bikes with shift kits, so I'm alony specultaing.

 

[BarelyAWake]

A somewhat common cause of tertiary chain derailment (crank to hub) is rear axle misalignment... With my ride the torque of the engine's pull will push the axle back out of the dropout a little on the non-drive side (horizontal dropouts BTW). While I've axle locks - they only keep the axle from moving forward so they don't help the far side from moving back

Tightening the axle nut more is the obvious solution and it does work - but it's a decidedly fine line between tightened enough to keep it from moving and stripping out the nut entirely.

 

[Goat Herder]

A somewhat common cause of tertiary chain derailment (crank to hub) is rear axle misalignment... With my ride the torque of the engine's pull will push the axle back out of the dropout a little on the non-drive side (horizontal dropouts BTW). While I've axle locks - they only keep the axle from moving forward so they don't help the far side from moving back

Tightening the axle nut more is the obvious solution and it does work - but it's a decidedly fine line between tightened enough to keep it from moving and stripping out the nut entirely.

I wondered how folks were fairing off on that style of drop out . I avoided that with my Morini j shaft set up. I can't help but think there is a fix for that? Somebody could be selling it if they drummed one up.

 

[BarelyAWake]

...erm, I shoulda clarified a bit - sorry 'bout that heh

With a regular axle, horizontal dropouts are a blessing (chain tension) but I've a three speed hub so it's got flat spots on the axle shaft to keep it from rotating - reducing the available threads for the nut to grip on.

I don't think torquing the nut down enough w/o stripping would be an issue with a regular axle, but that it should be checked is all.