Aft Driven Nicolai UFO ST

dypsomaniart said:
Hey Mike, thats a bitch that it slipped again.
Maybe try the normal bike tube on the clamp? I havent used sugru, but maybe the sugru silicon rubber is slipperier than natural rubber? Or just go metal on metal and it should grip solidly if its tight enough, just might mark your frame.
I lucked out with the square section frame on the glory. No chance of slippage whatsoever.
Hope ya get it sorted and get to do some riding soon!

Hey man,
I removed the Sugru also as I wasn't taking any chances this time around & went with the section of inner tube it came with. After speaking with Jim I feel Its definitely the small diameter tube on this bike that complicates things..I have a few other DH frames but I just really wanted to use this one. If this doesn't work with the second clamp, I'll be using a Yeti 303 RDH frame that I have...We'll see.
 
Hi there
i used the inner tube with a wipe of silicon to hold it in place for assembly did it tight enough to squeeze most
of the tube from under the clamp
found it possible to pull the mounting plate in to compensate for flex
i put a spacer under the head of the bolt, on the clamp to act as a slip ring to get it nice and tight
need a pic ?
 
HY10 said:
Hi there
i used the inner tube with a wipe of silicon to hold it in place for assembly did it tight enough to squeeze most
of the tube from under the clamp
found it possible to pull the mounting plate in to compensate for flex
i put a spacer under the head of the bolt, on the clamp to act as a slip ring to get it nice and tight
need a pic ?
hey thanks man,
That would be great.
 
hey Mike
I'm sorry to hear about these problems, that's really a terrible and frustrating situation...

Sincerely I would expect a better compatibility with a conventional frame in terms of tubing like the UFO, for the $AFT. Hopefully with their good customer service you'll sort out with a good solution.

In Any case, I would say that having these power amounts clamped into a downtube that's far to be parallell to the pulling resulting force of the Chain is not that perfect setup, Mechanically.

There is also another evaluation to do....: at these days bike companies making downhill machines are looking season by season at lighter frames, that means, using Alloys, that the tubings, hydro-formed or whatever they do, are really decreasing the wall thickness mostly far from the critical areas.....the medial part of a down-tube is typically one of the thinner areas for butted or hydro tubings, so not the best point to clamp a drive able to bend Thick Plates like your AFT does.....not mentioning the Carbon ones. As an example, making our own frames, I know well how our pipes are made, And I would never clamp anything to the medial part of one of the Butted Easton PIpes we used for our old XC, frames.....same as for the CF or the Ti pipes. (about 1mm thick)....Having a frame with non round and hydro tubings, means without any doubt an even more specifically engineered variable thickness related to the stress forces the Bike (in its original form) will be subjected to....among which, such a clamping force is not included......

Using a drive made by Matt and looking at his applied concepts and solutions, I realize better also how important is to Have the primary transmission solidly made by a single billet (or in 2 but really firm as a single one) so that the drive itself couldn't move at all, and all you need to look at, is a solid mount to the frame. This means also that the primary alignments are not to be checked and you've not to be worried by that, putting all the efforts to have a properly tuned final stage.
I believe that having FR/DH bike, typically ISCG or other kind of fixed mounts, Using them for the BB mount Is a Must to do.

The pipes where I clamped My Davinci, have been all small round sections like your one. some alternate layers of rubber and engraved alloy sheets (1mm thick) have been of true help....but Again My clamping tube is parallel to the chain pull, so the slipping force is almost 0 and the drive touch the frame to stop any of its small play, plus As you well know the DaVinci Clamps are wide and strong as a common, even quality commercial clamp, couldn't be, spreading the forces into a wider pipe's area and better adapting to shims and rubbers..

Hope to see you finally happy enjoying your e-bike systems...Plus I know that the "true happy rocket system" is yet sitting on your table looking for a proper frame.....I think that a bunch of them will be available soon from multiple sources :D
 
panurge said:
hey Mike
I'm sorry to hear about these problems, that's really a terrible and frustrating situation...

Sincerely I would expect a better compatibility with a conventional frame in terms of tubing like the UFO, for the $AFT. Hopefully with their good customer service you'll sort out with a good solution.

In Any case, I would say that having these power amounts clamped into a downtube that's far to be parallell to the pulling resulting force of the Chain is not that perfect setup, Mechanically.

There is also another evaluation to do....: at these days bike companies making downhill machines are looking season by season at lighter frames, that means, using Alloys, that the tubings, hydro-formed or whatever they do, are really decreasing the wall thickness mostly far from the critical areas.....the medial part of a down-tube is typically one of the thinner areas for butted or hydro tubings, so not the best point to clamp a drive able to bend Thick Plates like your AFT does.....not mentioning the Carbon ones. As an example, making our own frames, I know well how our pipes are made, And I would never clamp anything to the medial part of one of the Butted Easton PIpes we used for our old XC, frames.....same as for the CF or the Ti pipes. (about 1mm thick)....Having a frame with non round and hydro tubings, means without any doubt an even more specifically engineered variable thickness related to the stress forces the Bike (in its original form) will be subjected to....among which, such a clamping force is not included......

Using a drive made by Matt and looking at his applied concepts and solutions, I realize better also how important is to Have the primary transmission solidly made by a single billet (or in 2 but really firm as a single one) so that the drive itself couldn't move at all, and all you need to look at, is a solid mount to the frame. This means also that the primary alignments are not to be checked and you've not to be worried by that, putting all the efforts to have a properly tuned final stage.
I believe that having FR/DH bike, typically ISCG or other kind of fixed mounts, Using them for the BB mount Is a Must to do.

The pipes where I clamped My Davinci, have been all small round sections like your one. some alternate layers of rubber and engraved alloy sheets (1mm thick) have been of true help....but Again My clamping tube is parallel to the chain pull, so the slipping force is almost 0 and the drive touch the frame to stop any of its small play, plus As you well know the DaVinci Clamps are wide and strong as a common, even quality commercial clamp, couldn't be, spreading the forces into a wider pipe's area and better adapting to shims and rubbers..

Hope to see you finally happy enjoying your e-bike systems...Plus I know that the "true happy rocket system" is yet sitting on your table looking for a proper frame.....I think that a bunch of them will be available soon from multiple sources :D
Thank you Jules,
Until I can get the frame we discussed, this is the route I will have to go. The idea of using engraved 1mm aluminum plate I very much like & I will use it if the double clamp fails. I'm sure I can get this thing to work properly its just time & patience that's needed really. I have the patience but time on the other hand is getting harder to come by...I received the double clamp yesterday so I will start work on it today by removing the whole assembly, straightening it & rebuilding everything once again. Also as you know I am not on to rest on my laurels, I began building up a Mongoose Boot'r w/my Davinci drive. I feel the tube layout on this particular frame lends itself well to the Davinci, the bottom tube is much higher than most bikes which keeps it out of the way.m3.JPG

I still want one of your frames though & when they become available, I'd like one from the first batch....Please keep me in the loop.
-Mike
 
Yes, the high downtube is an interesting feature of that frame.....It's hard to say without have it in my hands....but seems that you may swap conveniently the motor/jackshaft postitions and have the output a bit lower and maybe with a better chain route. If I can guess what could be an amazing mount on that frame, I would say: One clamp to the downtube and another to the vertical pipe for the BB....were this kind of mount possible in terms of swingarm travel and chain growth.....

In general, the primary Challenge is to get an output position that allows the power chain segment to be straight along all the suspension travel and almost parallel to the ground like the normal bike chain is. This is achieved basically in 2 ways: going around the BB (that's convenient on most hardtails but even possible with FS) and, with a similar output position, constraining the idling chain segment to go over the BB using a spring loaded seeker (that's convenient with single pivots). Than to keep the motor chain in place with any method that doesn't increase drag, noise and efficient as possible is the final challenge.

Hope to see both these systems (the AFT and the Astro) working on your hands, to have your impressions and comments.
You're now in a good position to start a collection (and hopefully reportages and comparisons) of most of the middrives available..... 8)

You're on, mate, you know..... :wink: you'll have news soon.
 
hi
hoping this helps
wiped in side the tube with silicon


down tube.jpg
 
**Update**
After the trials & tribulations of the first Aft brackets slipping as they did, I wasn't able to straighten the motor bracket for a third time. Unfortunately it was permanently deformed & I couldn't get the chain line right. So I ordered a new motor bracket(in black) & Jim was nice enough to discount it & send me the dual frame mount bracket & a new type of frame brace free of charge. I installed all of this over the last month then brought it to my friend(a master bike mechanic) at my local bike shop. He went over all of my work and tweaked anything I may have missed. It is now complete & I will be picking it up tonight. Too bad its been freezing cold here or I'd ride it home. I'm confident this time its gonna be right.
-Pics and impressions to follow, fingers crossed.
 
^^
I think the black is a perfect match for this frame. It doesn't stand out as much & keeps with the stealthy look of the bike.
I also changed the bottom bracket to Isis as I plan on riding this pretty hard.
I'm very happy with the look of it, although I may paint the chain guard & bash ring red. Hopefully the bugs are ironed out now with the slipping & with fingers crossed this thing should RIP!
 
After seeing the most recent AFT build here on ES where "Rev" incorporated the rear suspension mount to the motor bracket(great idea BTW). I thought of moving my rear shock bracket up toward the head tube a little & fabricating 2 new brackets bolted directly to the frame & the unit. This frame has so many adjustments it should help with any twisting & slipping I think. But maybe this wont be necessary, we'll see when I finally ride it.
 
@Mike: why not make a torque arm from the Motor to your front damper mount. You got a lot of threads there so you could easily stiffen things up with a simple push rod.
 
--freeride-- said:
@Mike: why not make a torque arm from the Motor to your front damper mount. You got a lot of threads there so you could easily stiffen things up with a simple push rod.

Thanks man, that's what I was thinking also, although it didn't occur to me until I saw the latest AFT build here. But maybe it wont be necessary with the double frame clamp. I'm gonna ride it this weekend and decide.
 
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