New serious Offroad bike : The Chainer

[renago]

very nice job mate :wink:
the SS 316 is a very nice steel, if you weld it with the right wire , welding is a piece of cake .
also the final result will be nice smooth and elegant .
may I ask what kind of angle did you decide on the front ?

Renago

 

[bzhwindtalker]

I ordered the parts remade out of E36 with modified tolerances to help out with the assembly and dis-assembly. I'm keeping the stainless parts aside, I will probably find a use for them! The new replacement parts costed 160 euros but they gave me a 50% discount due of the previous issues, I was expecting a lower price but they were very reactive, I don't like being an ass and argue with reasonable and responsive people!

The planned head tube angle is 64° but the real world result could be way off I will probably use this frame to build a serious adjustable JIG, as I think the frame concept is good, I would like to build one out of cro-mo next with a slightly larger frame.

 

[bzhwindtalker]

I did a mock-up and it does not look good :/ the BB is way too high and the whole frame looks smalish! Remember those are 24" wheels... I may have to start over new :/

 

[renago]

what about the Cr/mo tubes I highlighted to you .
were they open to sell some to you ?
or maybe you are using this as a prototype frame ?

I will start mine at the end of August after visiting the bike show in Germany .

Renago

 

[ejay]

could you get away with a shorter axel-crown fork and lower the swingarm any? My custom frame was wrong in the other direction, longer fork and shorter shock got it ridable....

 

[bzhwindtalker]

Yeah I could do that, get a good DJ 100mm fork up front and use my 165mm shock in the back. Hummm less offroad riding :/ But! this would get me something nice enough to ride until I build a better frame!

 

[bzhwindtalker]

This is how it looks with the suspension compressed to 160mm. The BB sits at 39Cm from the ground. It MAY work.

 

[bzhwindtalker]

Made some progress on the swingarm, it does not look that bad in the end... BB will be high that's all.
This is how the bike sits with no suspension sag :

I'm waiting for the new machined parts to weld the front of the swingarm :

The lower motor mounts could use some drillium :

If the frame ends up too heavy or the bb to high for efficient offroading, this will still make a killer commuter

 

[wildharemtbkr]

It will work perfect with 20" wheels! :lol:

 

[bzhwindtalker]

It will probabaly work ok with 24"s too :

I am still waiting the new parts, I should get them in the middle of next week, and have the bike rideable by next weekend!

 

[Whiplash]

MAN! Looking good! I leave for a month or two and you go and build an entire bike! Well done!

 

[bzhwindtalker]

What would ya expect? I'm not just fooling around haha! My parts should come in tomorow or the next day. Can't wait to wheelie my way on the trails again!

 

[fizzit]

This is beautiful! My friend wanted to build an RC bike but I convinced him to do a hub motor mid drive. He doesn't have many tools so his bike won't be so fancy but this is an awesome bike and inspiration.

 

[bzhwindtalker]

Yeah good call, for the same performance level I think a hub mid drive is way easier to set-up! The motor hitself is heavy, but gearing to the rigth speed is so easy!

 

[bzhwindtalker]

I have been making progress but there is just so many issues poping out! the left side crank arm is hitting the swingarm while the rigth side has generous clearance. The shock mount on the swingarm is not well centered, makes the shock sit a bit sideways
Assembly of all the JS parts was quite hard, dissasembly will be complicated. the big bearings are too tigth on the 20mm axle, not quite a slip fit and some smal mis-aligenements are not helping either!
I will order an even wider BB ( I have a 135mm one) to clear the swingarm and hope for the best on the other aspects of the build. I think I will stick to fake pedals on my next builds, like a small 100w scooter motor as generator.

 

[bzhwindtalker]

I just ordered the 206mm BB from SBP. 43$ Is steep for a lowish quality BB!!

 

[Ratking]

Welcome to the world of custom frame world :wink:
I have had many of the same issues as you, just keep working at them and you will conquer them.
I hope that my bike will be fool proof some day, but boy are there many things to work out.

I've found out that you need to draw every detail in a 3-d program. If you do that you won't get surprises like this.

Keep up the good work, it will be worth it at one point

 

[toolman2]

its allways takes longer than we think to work through these types of things when we make stuff from scratch, way longer usually. -but at the pace your going it seems like weeks of stuff happens in a day, so fine work. btw with the geometry you have that rear tyre will bite hard and get heaps of drive grip, it may even jack up, should be interesting.

 

[bzhwindtalker]

I'm slowly getting somewhere... I don't know where yet!

 

[nechaus]

it looks alot stronger than the last build, but looking nice as...
i really like this design

 

[bzhwindtalker]

The bike with evrything on exept some small tenstioners and the CA weigth in at 31 kg Me happy!

 

[Memran]

Looking very very nice!

One comment: You do not actually need freewheels on your jackshaft. More freewheels will mean more slop before everything engages, making it feel less good than it would without freewheels, and I guess more prone to damage when you apply power.

Still, I am jelous!

 

[rodgah]

freewheels on your jackshaft

good point, is there a reason?

http://www.sickbikeparts.com/catalog/product_info.php?cPath=21&products_id=152&osCsid=et6o36hcfi1532ttsrq9p7r7l7

excellent work, like others say, you achieve a lot in short periods of time.

keep it up

 

[bzhwindtalker]

Thanks! I try to achive my goal of an ultimate offroad electric bike that you can actually pedal properly, but it's a dificult thing to do. I may give up and just make powerfull electric dirt bikes instead!

I did the first powered test of the drivetrain under motor power, and I stripped the thread on the uber chinese freewheel adapter! I did not apply more than 1500w but torque must have been high. Well, back to the drawing board on this part...

 

[bzhwindtalker]

I welded the fw on the adapter haha, but 2 tack welds were not enougth as the welds broke under power. I now have 8 tack welds
I found a solution for my head tube cutting apart an old aluminum frame, I could not find the bearings to fit the head tube, so I made some adapters to use a 34mm semi-integrated headset. Under motor power, the frame and suspention seemed to compress (no "drive grip") but maybe it will be different under load and when rolling. I had removed most of the pressure in the shock to be able to see that. The problem is that I don't have a shock pump to get it back to its intended pressure

I'm in holidays in spain next week so I won't make any progress on the bike, but I will find motivation to get it finished after that I plan to go montain biking in the alps with it if it's reliable enough by the end of the month.