Miele 18" motor-assist MTB build.

Merry Christmas to all!

..and a Christmas eve gift of a Bicycle Designer shipment was left in the mailbox, with the front 255mm disc and rear disc/sprocket kits that i had ordered. They look pretty much like what i was looking for, and appear to be of good quality - will know for sure when i get to play with the tools. Big brakes, here we come!

And this evening, I broke indecision on an exhaust system. Arrow Racing gets the nod with the Snake Exhaust Pipe for the Skyhawk GT2 aluminum intake frame style. I'll get her done, and make work.

I'll not be putting the pipe on, or any of the other performance goodies that i am contemplating ordering, right away. I will be breaking the motor in carefully first, in stockish setup.

HackD said:

Early photos showed the stock peanut tank taped onto the top tube - that idea likely is going to be ditched, in favor of an under-rack mount tank on the rear. This will contribute towards the 'stealthy' aspects that i wish to build into this project in terms of cop visibility. Nothing screams "come hassle me!" more, than that cheesy peanut tank sitting on the top tube of the bicycle, IMHO.

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Some things old, some things new, some things recycled..

A visit to Mum's for Christmas dinner and a dig through the crawl-space of broken dreams (stuff from previous projects that never quite made it to my own house since moving many years ago) produced something that i haven't seen in the better part of 20 years - a Bianchi Aquilotto/Avanti Sport gas tank of 2 litres capacity (http://www.mopedarmy.com/photos/brand/144/14724/) that i had salvaged out of the garbage, back in the early '90s.

Not sure if it'll work, or can be reworked - the petcock is really low, relative to the rear tire.. but i'll take a close look and see if i can do a 90 degree petcock retrofit with it. It also needs to be Kreemed in order to fully seal the spot-welded clam-shell seam that joins the two halves of the tank. The tank itself has minimal inner surface corrosion inside.

The flat under-rack style fuel tanks appear to be fairly scarce to get ahold of, and cost a fricken mint to ship due to their dimensions with the standardized shipment packaging costs that are necessary to get it to me. I might still get one, if i can 'bulk up' a shipment enough with other needed/wanted items in order to make ordering a tank + shipping worth-while, and could certainly use it on the Nishiki, if not on this Miele build - but i'll be working on integrating the vintage saddle-tank into the build, first. I'm thinking that some quality-time spent in the garage making up some custom aluminium bracketry will be in order..





Edit - yes - as in the photos, the motor appears to be just that tight. This is my new motor being played with - not the core non-op motor with all studs removed, that i was playing with in the earlier photos. As mentioned earlier in thread, I am going to have to do some engine mounting changes, including severely cutting down the rear mount spacer to make it all fit properly in frame. It's going to be a fiddly build, for sure.

KCvale said:

Nifty tank.

Those under-rack tanks are useless in my book, too low and a frustrating experience every time you want to open the gas cap.

Gravity is your friend with fuel.

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Was kind of wondering about the height issue with a gravity feed rack-mount on the compact Miele .. it would likely work better with the Nishiki's larger frame, lower mounted motor/carb setup, and a modded seat-post rack.

KCvale said:

Your tank can be mounted higher, think seat mount.

Heck, even a custom frame mount that raises the tank would work, that's the creative part of this hobby ;-}

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Yer reading my mind!

That's going to be the plan - i just plopped the gas tank onto the back tire, and snapped the photo in order to show relative scale.

Flinging metal shavings around the garage, is half of the fun of doing vehicle/fabrication builds.

255mm Bicycledesigner.com front big brake kit installed.

I like.



Edit at 9:22pm:

Rear disc/sprocket adapter kit used as intended, is an absolute Nope! It shifts everything sideways towards the frame-stay by 1/4", leaving no room whatsoever for clearance on the forward portion of the frame-stay. It would take a BFH to cure this, and i ain't doing that. I should have looked into this a little closer, before impulse-ordering.

I got couple of possibilities to ponder (bit of a brain-dump, sorry for that.).

Still go with the direct-driven method using the 40 tooth sprocket and adapter, but without the disc brake rear - use good quality Shimano rim caliper from the parts-bike, in place. Spare 255 disc that came with the kit is just that, a spare for the front.

Or Use 40 tooth sprocket and adapter on Nishiki, instead of present rag-joint - requiring additional parts to adapt.

Or go SBP shift kit with stock 160mm disc rear. Maximum disc size this appears to be retro-fittable for, is a 203mm. Going SBP shift-kit may be problematic, and i will have to look at what i can do to shorten up the front engine mount to totally clear the 1.76" front tube, if the rear engine mount cannot be altered for integration of the shift kit. If i'm going to go that route, it'll end up being the most expensive kit, for the tools that are included. Then there is the left-hand side tensioner add-on.. it's adding up again. Benefits are no left-shifter (handlebar real-estate), retained disc brake, range of speed and versatility. Cons, increasing weight, complexity, and possibility for 'shiite happens'. Things are also starting to get mechanically tight .. the carburetor setup is going to require some careful feng shui in the space remaining, for sure.

Need to ponder things further regarding the cost/value/performance ratios of all this, as per expected usage.



*BFH - Big Fuggin' Hammer

The past day and a bit was spent eyeballing, in various states of sobriety, the Frame/Engine equation.

This frame may be an 18" seat tube height frame, but it has a workable 13" inside tube height spacing. In addition to this, the frame tube angles from the crank are pinched, relative to the motor engine mount angles. One mount or the other is going to have to be designed to be angle off-set, as far as frame tube mounting bore is accounted for. The rear frame mount spacing is going to have to be as minimal as is possible, to bring the motor as far back as is possible. Exhaust port clearance with the 1.76" thick down-tube is a concern to keep in mind.

A PM to bikebobber has been dropped.. I'm sure he'll have some somewhat expensive billet thoughts on this..

The sum total of this - this is going to be a direct-drive bike. No SBP shifter kit, unfortunately. If i want to experience that, then it will be on a reworked Nishiki. Just too much going on in terms of complications with this build, to integrate that also with any reasonable degree of success.

I'll be switching the rear brake over to a good quality rim-grabber. I've got a damn good front brake in that 255mm now, and the rear brake is supposed to be of secondary 'trail' braking importance.

The intake manifold is going to be a bit of a project head-scratcher also. The astute will note in the picture below, what is going on with that, with the minimal space available. It's going to have to be a 45 degree left hand exit with this bike.

On another aspect of the project - I might also be switching the 8 gear rear cluster for a 7 gear cluster, so that i can use an older-generation Shimano shifting system that i prefer, rather than using that which is on the bike now.

KCvale said:

My build bay is only 10' from my desks swiveling office chair, I have been known to spend countless hours turn and looking that way, like right now ;-}

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My 'build bay' this year, and for the past few years running, is now the living room - not many people have fish tanks in their garage, obviously

I have even been known to strap up and tie down a project or two, right on the coffee-table proper..

I no longer have space in the single-car garage.. 1 sports sidecar rig, 1 ATV, a couple of Honda scooters and minibikes, and enough projects to keep me going for the next 20 years or so stacked up in box after box, means that anything more going in, is going to have to take the multi-layered approach to storage...

Working in such close proximity to our living space, does have it's up-side for us obsessive-compulsive types.. bonus is if you don't have a SHMBO you must defer to, in terms of using all of that apparently usable space (to us) in what is clearly an inappropriate manner (according to Her).

I'll take projecting and watching a movie on the projector at the same time, any time, every time.

Project related: A day at work didn't stop me from dropping by the bike shop for a few more bits on the way home.

A full moto-x style front mud-guard. and Blackburn EX-2 aluminium rear rack to integrate into the project and build up on to support both the rear gas tank, and to act as a mounting point for the Arrow Snake exhaust that has been ordered.

http://www.blackburndesign.com/racks/ex-2-rack-475.html#.VKHT8sCNY

Rudz said:

Your build is like deja vu

I had to cut a lot off the rear mount, but it fits, I used a offset z manifold and eventually a SHA clone carburetor and uni filter.

There's no getting high compression heads in our 18-19" frames. I wish I'd have ordered a bigger frame, but now I know...

I went with 203mm up front and cheap rim brake mounted under the bridge on the rear. I had to mount it under the bridge to clear room for the carburetor on the side.


I never need to use the rear brake, your front rotor is bigger so I doubt you will either

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Certainly is a challenge, to be overcome! As mentioned earlier, i've already done one larger, "easy build" where dimensional tolerances weren't an issue, with my Nishiki. Where there is a will, there is a way!

This weekends activities, largely consisted of online parts shopping (4 separate orders on their way) and getting the Raleigh MTB broken down for it's parts value.

Complete front end is going on the Nishiki. Crank-arms and pedals, shifter-controls and brake levers are going on the Miele. Rear brake assembly, handle-bars and stem are already on the Miele. Wheels will be kept as spares. This is really the first time that i have taken a close look at the Raleigh - she's done .. all the chain rings are well worn, and the rear suspension linkages are worn way out of specs.

... and that front-page chat-box is Evil, Pure Evil, I'll say.

Someone tipped off that gasbikes has the Skyhawk GT2A frame on sale - all things considered the shipping is going to be costly to Ontario, Canada .. but i ordered anyway.

Looks like the Nishiki will possibly be re-purposed into a concurrent GT2A build.

A big fat hmmm.

On one hand, incredibly compact conformal pipe for this bike frame. On the other, no real expansion section to speak of. Pipe would need to be cut and/or rebent to make work with the china girl head.

I think i might take a visit to a local junky knock-off china shop and see what they have hanging on the wall in the way of donor exhausts..