SBP shift kit question... a tight squeeze

In order to shoehorn the motor into the mountain bike frame I chose for my first build, I needed to cut the rear motor mount spacer down to a mere 1/8 inch;


Obviously this didn't change the distance between my rear tire and seatpost any, it's still 2 1/4 inches (where arrows indicate) but you can get a good idea of how much further back my motor sits in this pic as the rearmost curve of the clutch cover is almost flush with the back of my seatpost;


So my question would be, how critical is this spacer supplied with SBP's shift kit? Is this something I can leave out of the build without too much trouble? Do the sideplates for the jackshaft rely on the motor mount to be an exact depth?



I very much like my bike, I bugs me that I'm considering another build simply because I didn't know of the shiftkit when I built this one. Now that my engine is broken in, its got plenty of power and I hate being "stuck in third" so to speak...

Any thoughts would be appreciated

I'm sorry. I must have worded that poorly... It isn't the tire and seatpost (I perhaps shouldn't have included that pic) It's the lack of room between the engine and seatpost.

Due to the engine's placement I don't have enough room for the spacer provided in the shiftkit. I believe I do have enough room without it, the plate itself is about the same thickness as the clearance I have (see second pic) - but if that spacer is crucial then I can't install this kit as I can't move my engine enough to accommodate it.

Thanks for your prompt reply though

Your spacer;


My lack of room;

(arrow tip indicates edge of cut down stock spacer, approx 1/8" clearance between engine block and seatpost)


"The sideplates don't really care where the motormount plate is" <this fills me with hope! *crosses fingers*

Sure np, any excuse to post pics of my bike

What may be hard to tell in this pic is the forward motor mount had been ground and rebeveled to fit the unusual Dtube angle and shape. This also means I had to go the less desirable route of a bolt through the Dtube, although this hasn't proved a problem - it does mean in combo with my lack of room, the engine can't be relocated (primarily carb clearance).

Worse case scenario I will get another bike, but I'd hate to do that tbh.



an older pic of the whole bike... back when it was clean lol

Yeah, I worried that there might be a prob like that I hadn't thought of - but thank you so much for your patience and takin the time to answer

I'm thinkin a whole 'nother build anyway at this point. Although I do like this one I always planned it to be just a prototype, it just turned out much better than I expected lol I also had no idea at the time that not only your shiftkit existed - but that I would so desperately need/want it

Ah well, I'll buy up the bits for bike build beta (you guys will be hearing from me soon 'nuff), there are other aspects that suggest selling this one (disk brake conversion exceeds the value of bike alone etc.) but this should make for a really good winter project anyway!