Specialized Big Hit FSR with midmount

[Tench]

I think the spring will be fine, there is loads of adjustment, i am more concerned that the forks will need to have the springs changed or their preload increased, only some serious riding will tell me this and it is not quite ready for that yet.

Here are some more pics;

[knoxie]

OMG Wow!

Like most folks start with the bike then maybe 6 months later you get the picture, your just wham! there you go! beat that ha ha brilliant job, it looks amazing, your welding skills are top notch!! are you a pro welder? you have done such a nice job on this, it looks like a pro built bike and its certainly up there with the best build on ES for sure, take that Duck Tape!! awesome job!! you must be so happy with it?

Would love to see some video of it in action too ... love the colour as well, almost KTM orange with a hint of bling, really nice! I wonder how much riding you have done and what you intend on doing with the bike, it certainly looks like a nice pedigree bike for some off road trail riding or green laning, not to mention posing on down town!

You have pretty much laid down the fattest gauntlet when it comes to mid hub motor mounts, I haven't seen a nicer one ever!

[stripedtuna]

I'm speechless..

What an amazing peice of work. Does this forum give out trophies for winning efforts such as this?

You're a gold medalist mate..

Seriously.. well done..

Ed.

[Tench]

Knoxie, been trail riding ice for 40 years all over the country, had loads of XR's and KTM's, done some competition riding and even built engines and chassis that have raced in the IOM aswell as worked as a spanner man at british and world supermoto for the then multiple british champion Sam Warren. I was a pro welder for 18 years but that was mig, tig i just play at it. , so i supose i have all the skills to do this type of stuff, the electric side i am learning fast. This bike will get some serious use up in the Derbyshire peak district when it is finished, just got to make a new hub to fit on the Cyclone crank freewheel so i can get some nice crank sprockets of a better size. I will get some pics of Sam on this bike when i see him next week and some video when it is completely finished
The idea came from owning my first build a cyclone, link to that build below, and then a Stealth Bomber, the Bomber was ok but the weight of the DD X5 in the rear wheel was just too much unsprung weight which was not to my liking, so a mid mount hubbie it was as the cyclone was just a bit lacking for a serious off roader.
This weighs 85 pounds at the mo, might get another pound or 2 off it yet, which is a heap less than the Bomber, i can carry this one!! with much lower unsprung weight, better weight distribution and about the same speed but the ability to run lower gears for climbing.
I would like to do something with a big RC motor next, i allready know how i am going to do it

Simon.

[kfong]

Excellent job with the batteries, totally enclosed and with a cf plate as well. No fire hazard to worry about. I hope you provided some vents just incase. Makes me want to do a mid drive with a BMC motor and Nuvinci hub. Damn, I have too many bikes already. You have a very well thought out design. One of the better buillds I've seen on ES. That bike should rock in the trails.

[knoxie]

Knoxie, been trail riding ice for 40 years all over the country, had loads of XR's and KTM's, done some competition riding and even built engines and chassis that have raced in the IOM aswell as worked as a spanner man at british and world supermoto for the then multiple british champion Sam Warren. I was a pro welder for 18 years but that was mig, tig i just play at it. , so i supose i have all the skills to do this type of stuff, the electric side i am learning fast. This bike will get some serious use up in the Derbyshire peak district when it is finished, just got to make a new hub to fit on the Cyclone crank freewheel so i can get some nice crank sprockets of a better size. I will get some pics of Sam on this bike when i see him next week and some video when it is completely finished
The idea came from owning my first build a cyclone, link to that build below, and then a Stealth Bomber, the Bomber was ok but the weight of the DD X5 in the rear wheel was just too much unsprung weight which was not to my liking, so a mid mount hubbie it was as the cyclone was just a bit lacking for a serious off roader.
This weighs 85 pounds at the mo, might get another pound or 2 off it yet, which is a heap less than the Bomber, i can carry this one!! with much lower unsprung weight, better weight distribution and about the same speed but the ability to run lower gears for climbing.
I would like to do something with a big RC motor next, i allready know how i am going to do it

Simon.

Hi Tench

Yes looking at the quality of the welds it was fairly obvious you had a bit of welding experience! ha ha (I am in the crane industry) albeit on the electrical side our place does a fair bit of welding again super nice job on the bike, its pretty much exactly right IMHO a perfect mix of parts. I love going off road, I have an XT600 however you are limited to just the byways and a lot of them are getting tro's on them however technically you can ride an electric ebike on them even if they have been tro'd, the law says prohibited use of mechanically powered vehicles, so maybe a gray area (get a 250W sticker for your motor!!)

I have been thinking for a while to make an electric green laner if you like, this is perfect! the motor and batteries are nicely out of the way letting you hit some (not all) of the deeper puddles, you never normally go over 15-20 mph when laning anyway and you are going to make hardly any noise compared to gas bikes (easier to pull out of the mud if you get stuck too)

I saw you were disappointed with the bomber, that's a shame as I love that bike but do understand the weight in the wheel isn't for everyone, this build of yours can really show what you can do if you put your mind to it, I cant wait to see more pictures and for sure the video will be awesome!! seriously you could make and sell these bikes!! if there is a market for the Bomber and the Optibike then there is for one of these for sure.

If you have more build photos please post them and if you need another camera man for some video then give me a shout, where abouts roughly are you in the UK? I am in North Oxfordshire.

[binlagin]

This is the sexiest bike I've ever seen.... I'm jealous

[Tench]

I was'nt dissapointed with the bomber, it is an awsome bike, but it does have a very heavy back wheel, i just thought i could do better for the more technical type of riding i like to do With DD hubs their limit is easily found on the trails, wheel rotation is often too slow to make good power and they are heavy on the watts in these conditions, a 20" wheel is an option but the tighter radius doesnt ride the rough as well as a larger one so it had to be a midmount.
I have to work on the throttle responce on this bike, it comes in a bit too fast to confidently use the lower gears on rough ground, the new chain rings should help aswell by reducing the squat which emphasises the problem, i have adjusted the shock mountings and settings this morning which has helped aswell.

I am in Derby, very close to loads of trails, a friend was the derbyshire TRF group runs organiser so i have access to all the maps of the country but i know most of the derbyshire stuff by heart anyway. We have done some awsome rides in the peak district, yorkshire, the lakes and wales over the years, we even had Blez come and stay with us who did a feature for Trail bike mag on the peak district trails (TBM issue 57 may 2000) he also did an artical on some baffles i made for the DRZ.
Yes electric for the trails is what i had in mind as loads of them have been TRO'd round here. With what i learn from this bike i should be able to make my next one even better, lighter in the motor department, more powerfull but similar overall weight carrying more batteries. And i will take into consideration cost effective production when designing it.

A few more pics cos i have them

The left side of the motor showing the new bigger O/D alloy spindle with larger seals and a spacer to protect the upgraded phase wires;



The right side showing the out rigger support bearing inside the sprocket carrier, side cover has the thread changed to L/H 30x1mm so it tightens when the motor is driving with a southpaw (lefthand) bmx freewheel (Ground down from 1/8" to 2.00mm for the 7 speed chain)
Pedal crank spiders have been used as the torque arms/motor mounts.

[pdf]

This is one for the hall-of-fame. It is, for me, one of the most impressive builds and incorporates several features hard to find in one bike:
1) it drives the gears. Really nice for serious hill climbing efficiency.
2) it uses a hub motor so it will be extremely quiet; no reduction gear whine.
3) it protects the motor
4) it integrates all the heavy components into the middle of the frame for good balance
5) it still looks like a bike; a heck of an awesome bike, but a bike.
6) it looks awesome.

Numbers 2 and 5 mean you will be able to ride it anywhere a bike can go and not get unwanted attention. This bike is flat-out one of the best implementations I've seen. I really like the hub motor to keep down the gear/chain noise. Awesome.

PS: And FTW with that charger setup. Now you are just showing off ... Mad skillz there.

[Justtoby]

I knew you had something up your sleeve but did not know it would be this good. Congratulations it looks amazing.

Nice to see such fabrication skills. I hope to see a vid of this in action.

I love the charging solution, it looks very plug and play which I think is important for usability.

[ohzee]

I am not sure what to say other then WOW !

What a bike.. Can't wait for the video you have some crazy skillz.

[Tom Tom]

3 words-

I want one!

[Tench]

Thanks guys, Toby, this is my first venture into Lipo and it was important to make it fool proof when switching from series (running) to Parralel (charging) i didnt want to make any mistakes and fry anything, coming from Life bats plug and play was the only way i knew so i worked out a way to do it.
I am just trying to source some new chain wheels then design and make a new carrier for them, possibly with another bearing to take some load off the Dicta freewheel, My CA has a fault aswell so that needs to be replaced then we can get some video!!
We should have a UK rideout this summer, there is getting to be quite a few of us now.

Simon.

[whereswally606]

I would defo be up for a UK ride out. Ive got a scott ransom with a magic pie and a norco with some dr bass torque arms ready to go 72 volts. In awe of your work here Tench, nice to see some finished articles in the UK.

want to build a norco savage with a 80/100 but dont have yet have the mad skills you have. learning though slowly, documenting on youtube as and when i can.

got any vids to document the build?

[Tench]

Not much of a Techy mate, never uploaded a vid in my life, that is something i am going to have to learn.

I like them scott ransoms and the gamblers, another i have my eye on is the giant glory 2009, have a look at the frame, perfect space with plenty of substantial fixings for mounting a large RC motor.

http://www2.giant-bicycles.com/_upload_ ... ry_dh0.jpg

But i dont see the point in building another that is the same but different, i have to take it to another level so will probably build the next frame from scratch, i have some ideas

[full-throttle]

Simon,

How much does it weight?

[whereswally606]

much the same suspension idea as on DH comp that so many on here are sporting.

The ransom was my first full susser build. havent uploaded a pic of it recently but i installed some girvin girder forks with a fox float in the head of the suspension. It give a cool moto feel to the ride and is good on roads and easy trails but not really up to proper offroading. That is going to happen with the norco's. Im in bangor at the moment studying an MSc in comp science so I take the techy remark in my stride. that said an iphone and some free video software makes it very easy to document the build.

Intrigued about you charging situation. i take it they are probo 10s packs so you are running 30s and charging at 10s on the Icharger

I have a hyperion running off a couple of hp server supplies. trying to come up with a HV bulk charger , Like you I have my ideas.

Anyway if you do get a UK ride day going please pm me.

[recumpence]

Umm, holy crap.

Excuse me while I use the little boy's room. I think I soiled myself.............

Freaking AMAZING!!!

Matt

[iovaykind]

What's really ingenious about your design is the plug that switches from series to parallel in an instant. What scares me is high power setups, whether those contacts would be good enough to handle the high current that goes through the connectors. What kind of connectors did you use for this parallel/series piece? Really an ingenious idea that you perfected right off the bat.

[carl2.0]

Where did you come from !!?? this is incredibly well laid out n professionally executed, it begs me to question ur day job... You single handedly build nuclear submarines for the government I bet

[Miles]

Crikey! Only just noticed this thread....

Nice work, Simon.

Good to see more UK representation, here

[Beachcruzer]

Brilliant. Things I've been wondering if it's even possible to do (like hubbie mid-drive with the chainring overlapping the motor, and plug-and-play series to parallel) and then, BAM. Not only possible, but absolutely beautiful.

Not much more to say. Inspired.

[biohazardman]

It's gorgeous alright. I had to go buy another keyboard as it shorted from the rivers of tears.

[Spicerack]

I can't really think of any other superlatives to use that haven't been used already. Well done! You are an artist.

What's the performance like?

[Tench]

Thanks for all the nice coments guys, a lot of thanks has to go to all the contributing ES members, i have found many answers on here and if you see an answer to your problems in my work then i have given a bit back. I see this bike as just a bit of simple fabrication, didnt even bother with the cad for this one, been doing stuff like this as a profession and for fun all my life, built loads of vehicles converted for dissabled drivers and passengers, camper vans, mini buses, ambulances, 20 years as a vehicle builder many of those years doing the design and fabrication stages but also seeing projects through to the end, these days i manage to make a living from my other hobby which is competition shooting as people like the work i do in that field, maybe ebikes will add to that in the future, at the moment this is just for me.

The connectors i used in the changer where these;
http://www.ebay.co.uk/itm/5x-6-5mm-Gold ... 4ab3e474eb

The bike as it is know weighs 85lb's or 38kg depending how old you are I think i can get a bit more off when i put smaller chainwheels on it and shorten the chains.

The day job, i would like to say what ever i feel like doing when i get up in a morning but i do have to earn a crust, Gun smith.
I will get some performance figures and video done just as soon as i have finalised the setup.

Simon.