sbp shift kit ??'s
- Thread starter flybytaco
- Start date
Are you talking about the older or newer style kit?
You can shim between the engine and spacer on the newer one.
The older one you have to elongate the 3 mounting holes on the side bearing brackets that bolt to the engine on both sides to bring the brackets upward a smidge. Not real fun to do, keeping the jackshaft axle exactly perpendicular to the engine or you get some bad chain jump.
I built an adjustable chain tensioner on mine. Chains wear/stretch.
I'm sure Paul or Jim can help you more.
You can shim between the engine and spacer on the newer one.
The older one you have to elongate the 3 mounting holes on the side bearing brackets that bolt to the engine on both sides to bring the brackets upward a smidge. Not real fun to do, keeping the jackshaft axle exactly perpendicular to the engine or you get some bad chain jump.
I built an adjustable chain tensioner on mine. Chains wear/stretch.
I'm sure Paul or Jim can help you more.
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what a crappy setup so your telling me every time i need to tighten my chain i gotta take the engine bolts out barely accesable may i add ?
The chain is so short that any stretch in it is minimal. i doubt you will be adjusting much if any at all .been running mine for almost 6 months with no adjustment.
He's right. The left side chain doesn't require much attention. Even a bit loose it's not going anywhere.
The right side chain will need adjusting but it's simple and quick.
Bar far it's not a crappy set-up.
You can gear your bike to keep the engine right in it's sweet spot all the way thru the gears. Nice low 1st gear , real tall top gear . Close ratios in between, like a dirt bike.
Trust me, get one
It's major fun
TIM
The right side chain will need adjusting but it's simple and quick.
Bar far it's not a crappy set-up.
You can gear your bike to keep the engine right in it's sweet spot all the way thru the gears. Nice low 1st gear , real tall top gear . Close ratios in between, like a dirt bike.
Trust me, get one
It's major fun
TIM
Yes the new design is easy to adjust if you need to. You don't even need to take the engine off the bike. But like was already mentioned the chain isn't long enough to stretch so I have actually never adjusted mine. The ability to adjust is mostly so it can be universally set up with all the variances in engine castings.
installed mine yesterday, and ran it around alot. did notice the chain on the engine side did stretch (kinda good since it was a b**** to install in the first place) but like stated before, there really isn't any room for the chain to jump off anyway.
IMHO, the best thing you can do with either 2-stroke or 4-stroke SBP shift kit is install an idler on that outer ring chain, or at least a guide wheel. That way the chain tension is almost irrelevant.
I used a grubby gt4 and the 1/2" spacer was way too large. I made a 3/8" spacer and made a shim out of a stanley utility blade,they are .025" thick. When the motor chain stretches I'll replace the shim with the .035 shim provided in the kit giving me the .010" difference I expect I need to take out the slack.
My experience has not been with chain-stretch, but rather creeping misalignment. I was very disappointed when my SBP jack shaft rotated around the seat post. It is supposed to stay completely perpendicular, but the pulling force of the primary chain had managed to deform the upper steel mounting bracket.
I told the manufacturer my problem, and they sent me a replacement bracket that was reinforced with an aluminum spacer to keep it square and true. Once the riding season gets going, I'll have a better idea how well the fix works. So far so good.
I told the manufacturer my problem, and they sent me a replacement bracket that was reinforced with an aluminum spacer to keep it square and true. Once the riding season gets going, I'll have a better idea how well the fix works. So far so good.
I just looked at mine and saw there is a bit of twist in mine also. They may have to switch to a thicker mat'l for the bracket. My main problem has been the final drive chain to the derailleur, so far it has broken 2 chains, so my 3rd chain is an older thicker one that doesn't quite fit the casette (careful shifting).
It's not surprising really, since a human puts out 1/4 hp and these china girls put out 11 times that amount!
BTW, your chain will stretch, it's from wear between the pins, holes and rollers, clean and lube often to minimize. Good luck,... Gearhead.
It's not surprising really, since a human puts out 1/4 hp and these china girls put out 11 times that amount!
BTW, your chain will stretch, it's from wear between the pins, holes and rollers, clean and lube often to minimize. Good luck,... Gearhead.
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Hey gearhead, you're supposed to use a 3/32" wide chain for an externally shifted bike, otherwise you will encounter shifting issues. There are different chain widths for internally- and externally-shifted systems.
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I know that, but the thinner chain keeps breaking and I don't like pushing the bike back home when I'm 10 miles out. When the chain breaks you lose the ability to pedal the bike. So far I've gotten away with using the thicker chain, it doesn't mis shift in top or bottom gear, and only occasionally in the middle gears. I'll be using a shimano internal 7 speed hub as soon as I lace it into a 1.50" rim, so this chain/casette mismatch is only temporary. Happy wheeling,..gearhead.
Sounds like you have to align the inner crank sprocket better. The 3/32" chain is really no weaker than the standard 1/8" chain, but it is less tolerant of sprocket misalignment. Especially if the sprocket you're using isn't designed for 3/32" to begin with.
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How about just swapping the casette for the one that the bigger chain was originally used with. Aligning the front sprocket toward the center of the bike would require longer bolts as I'm at the end of where the nylocks would reliably hold (only 2 threads protruding), I'd rather wait for a new rim and spokes so I can use the nexus7 and do the alignment only once. Your assesment is correct but I'm not throwing money at something that's about to be replaced. Just hope the nexus is up to the task.
Bicycles are engineered to accept the amount of power that a human can exert. According to Wikipedia, professional cyclists are capable of 1,500-2,000 Watts (2-2.5 HP) in a sprint. I don't know the technical details, but I imagine they are actually engineered with a safety threshold beyond that. Nowadays, you rarely see a bike fail during a big race like the Tour de France.
Incidentally, thats probably why most states define Mopeds at 49cc, because the power output is typically around 1,500 Watts, or the equivalent of a really fit human rider.
What I'm getting at is that modern bikes are engineered to take everything the china girls can give. The trick is to have the mechanicals set up right. Thats why I was disappointed with the SBP shift kit, because it so easily slipped out of true.
There are other places where the kit doesn't perform well. I have some suggested solutions that every builder should consider, but I'll have to come back to them at a later post.
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Which hub are you using? . I'm using the nexus only because I have one laying around, I almost wish it was a five speed because the seven speed derailleur thought me that seven gears is more than I'll use. I usually shift 1-3-5-(6/7 dpnd on head/tail wind). Fl is flat and the tallest mntn is an overpass.
I'm using the Sturmey Archer X-RD3, 3-speed wide-ratio with built-in 70mm drum. Only 750 or so miles on it so far, I like it. Prolly shoulda went with the 90mm drum, but I'll eventually get a Nuvinci anyway 
