What are good components for high-speed e-bikes?

[swbluto]

I think that the higher speeds of more powerful drives necessitate stronger gear than the average "17-mph average with periodic 30-mph burst down hills" bikes. There's a reason why motorcycles are often much heavier! The speeds I'm considering are 30-40 mph.

So, what are advised e-bike components and general "requirements", in your opinion?

It seems that a dual suspension is a must for those roads with potholes, dips and bumps. But, what kind? I've seen many dual suspension systems with different lengths of travel so what kind of travel would be advised? Also, front forks - What kind of travel would you advise on a suspended front fork? What kind of front forks, as well? They should be able to adequately stop at 40 mph, so the "average joe schmoe" bicycle fork doesn't seem like it would cut it but the expensive niche downhill equipment need not apply.

Also, what about rider comfort? Is a suspended seat-post a must? A comfortable seat? What about rider geometry? Do townie handlebars sound more comfortable?

And brakes - What kind of brakes? Disc brakes sound like a good idea but what kind of disc brake are meant to regularly stop 300 pounds of mass from 40-0 mph on a regular basis without requiring rotor replacement every 3 months?

And, also, a bike's ruggedness. It would need to be able to withstand forces associated with stopping 40mph-0.

Also, wheels? Are spokes of regular bikes able to withstand forces felt at 40 mph? Would 13 gauge quality spokes be advised? 12 gauge quality spokes? What about the rim's eyelets?

Tires - What kind of tires? Are the 2.5" maxxis hookworm tires good enough for 40 mph speeds?

I know anybody could just go the extreme route and look into downhill equipment but the problem with that is that it's more "niche sporty" than "everyday practical", so it's correspondingly exceedingly expensive. It seems adapting a scooter or motorcycle frame would be cheaper and more appropriate.

And, I'm not necessarily concerned with weight. I'll take a cheaper 80-100 pound sturdy bike over an expensive 50 lb. down-hiller any day.

 

[Anonymous]

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[GGoodrum]

I'm of a totally different opinion. I've had my Townie up to 45 mph, with no suspension at all, and it is quite comfortable, but I about peed myself running a high-end mountain bike I converted for a friend, too much over 30 mph, and it has a full suspension. The key is not whether or not you have a good suspension at all. You can get around not having a suspension by using big balloon tires, inflated to only 30 pounds. This will smooth out any road. The real key to feeling comfortable and safe, IMO, is to have a longer wheelbase. The Townie's wheelbase is about 6" longer than a "normal" bike's, which they get by separating the seat post from the bottom bracket. They call this "flat foot" technology, Anyway, it makes for a VERY comfortable ride at 40 MPH.

-- Gary

 

[swbluto]

Well, I can't really have "longer than normal" bikes since the bus's bike rack was designed for normal ones. I'm having enough trouble just getting my Balloon maxxis hookworm tires into the rack without the bus driver complaining.

So, uh, are you suggesting normal wheel-bases/lengths are inherently seemingly dangerous at higher speeds? I'm not sure if it was your friend's particular geometry or the wheel-base itself.

I'm curious, how well do you think a tandem would handle on porous/bumpy roads?

 

[Ypedal]

I"ve driven all sorts of things in my 30 year lifetime, i own a honda ATC 250sx trike and i love it .. ( yes. for the record, i've put my foot down and ran over my heels at first.. HURT like a sob ) ..

Experience on machines like this count for alot, someone in their 40's who have not been on a bicycle in over 20 should consider a slower safer system.. :wink:

Looks.. that's pretty much up there with the top things i need in a bike..

Full suspension bikes weigh more, complicate racks and battery mounting, have more components to wear out .. i'll take a quality aluminum hardtail over a 99 wallmart FS with disk brakes !..

Brakes, i like disk, keeps the rims clean ( no brake dust on pan legs ) if the rims are not perfectly true it's no problem, works in the wet, etc.. but Vbrakes work perfectly fine imo, like everything there are quality brakes and crappy brakes.. Burning thru a set of pads every 3 months, sure.. 10$.. go again.

Tires. yes.. absolutely one of the most important factors, or upgrade to any bicycle, hookworms are awsome.. nevermind knobies unless you do alot of trails.

Dual crown forks look better.

ok.. gotta head out to pick up my new PC !!!..back later for more !

 

[Almasi]

On the brake subject:

Get Hydraulic disk brake (not just cheap cable actuated one) ideally 2 or 4 pistons (Avid Juicy 7 are really good, Shimano XT 4 pistons brake) with a 8 or 9'' rotor.

I can brake from 60KM/H to 0 KM/H on a dime with that!

Robin

 

[Drunkskunk]

I think that the higher speeds of more powerful drives necessitate stronger gear than the average "17-mph average with periodic 30-mph burst down hills" bikes.

Just to clarify, a Down Hill bike is built for running over objects that would destroy a normal bike at any speed, and do it at 30-50mph, Down a rugged mountain trail. There is a reason these things cost $3000 to $7000 new.
The only real deficancy I've seen is a poorly tuned suspension. Off the shelf, the suspensions are designed for Big Hit. they can be tuned for road work, but it takes skill and patience.

A cheap full suspension bike would be dangerous at those speed, IMHO.


As for Brakes, Any Disc will due, providing it's sized right for the bike. Running dual discs on the front is an option. pads are disposable.

 

[morph999]

I'm of a totally different opinion. I've had my Townie up to 45 mph, with no suspension at all, and it is quite comfortable, but I about peed myself running a high-end mountain bike I converted for a friend, too much over 30 mph, and it has a full suspension. The key is not whether or not you have a good suspension at all. You can get around not having a suspension by using big balloon tires, inflated to only 30 pounds. This will smooth out any road. The real key to feeling comfortable and safe, IMO, is to have a longer wheelbase. The Townie's wheelbase is about 6" longer than a "normal" bike's, which they get by separating the seat post from the bottom bracket. They call this "flat foot" technology, Anyway, it makes for a VERY comfortable ride at 40 MPH.

-- Gary

Gary, or anyone, can you point me to a Townie bike. I'd like to see if I can get one with a wider wheel base for my next bike. I have a mountain bike and you are right, anything above 30 mph feels kind of scary.

 

[Anonymous]

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[Joey]

The 21-spd hardtail Giant Boulder (non-SE version) comes with a cromo frame and has worked out pretty well for me but I have never gone over 35 mph. I have a BMC V2T rear hub with 7-speed sprocket set, smallest at 11 teeth. It comes with trigger shifters that don't interfere with throttle installation. The front suspension can accommodate a disc brake but the default wheel doesn't. I upgraded the front wheel to one that accepts a disc brake. The frame does not have rear disc mounts so I kept the rear rim brakes. It's easy to mount a rear rack on this bike.

If you want a bulletproof steel frame, check out the Surly Instigator. The rear dropouts on that cromo frame look like they could take a lot of abuse.

The Gunnar Rock Tour frame is constructed with Reynolds 853 steel. If I wanted to build a lightweight electric bike and had money to spend, I'd start with that frame. The rear drop outs are nice and flat and made of steel. Also, the position of the rear disc brake mounts on this frame is somewhat unique and does not interfere with installation of a rear carrier rack.

The Rans Dynamik Trail is an intriguing design. I wish they made a version of it with a cromo frame. Lately, I've been kicking around the idea of starting with a Rans Hammertruck long wheelbase cromo frame, removing the Extracycle-like aluminum appendages in back, adding an ordinary rear carrier rack, and possibly replacing the front fork with a suspension fork. I've only seen this frame in photos but it looks like the backward slant of the seat post of this pedal-forward design would create the illusion that the back end isn't as extended as it actually is. There would be lots of places to mount controller and batteries within the confines of the frame.

Joey

 

[John in CR]

I'm with Gary, longer wheelbase makes a huge difference at speed. Sure DH bikes are made to take a pounding, but their riders wipe out all the time, so I'm not sure how much more road worthy that toughness really makes them. My dual suspension will go a very scary 50mph, but my low and stretched to extracycle length hardtail is rock solid at 55mph on a smooth road.

Disk brakes are a must IMHO at those speeds, and my cheapie mechanical ones stop me just fine as long as I take fade into consideration on longer downhills. They do require frequent adjustment with a 40+mph riding, but it's a snap compared to trying to keep regular bike brakes adjusted, at least for me.

John

 

[deardancer3]

Well, I can't really have "longer than normal" bikes since the bus's bike rack was designed for normal ones. I'm having enough trouble just getting my Balloon maxxis hookworm tires into the rack without the bus driver complaining.

For SLIGHTLY longer than normal wheelbase bikes, you can temporarily shorten the wheelbase by rotating the front stemhandlebars backward (180 degrees), making the rake of the front wheel face backwards instead of forward. This has enabled me to get several different models of flat foot bikes onto the bus racks.

One some bikes I just rotated, on others the front brake cable had to be disconnected. This enabled the flat foot Raleigh Gruv and the real long Giant Lafree and Sport models to fit on the bus racks. But dont think it is enough for real long bikes lake the day 6. Howver, it does enable one to use the bus racks. (I had to take off the heavy SLA's on the Giant Sport to be able to lift that heavy monstor).

d

 

[dogman dan]

Why didn't I think of that. My cruizer has lwb and just barely won't go on the bus rack. Brilliant.

The real bugaboo for higher speeds in my opinon is high speed wobble. Longer wheelbase and stiffer frames are the answer to that for sure. It's unbeliveable how much flex my wallbike frame has, and for that reason, I limit it to about 30 mph at all times.

I sorta lean towards keeping an ebike legalish, under 30 mph. In my state, over 25 mph on the motor and I'm a motorcycle and need all kinds of grief from MVD. To go 30-40 mph, I think a small motorcycle converted is the only sane thing, and definitely the only legal way to go for street use. You hit somebody at 40 mph, uninsured and illegal, and they'll have your house. THINK about it, in america, they'll sue you silly.

Off road, go for it. But still be carefull not to hit anybody if the trails are crowded.

 

[deardancer3]

If I had a HIGH speed ebike, I would want a security code device with two codes, one for legal within the law operation, and another code for unlimited use.

If something happens that involves the law, only the one code would exist.

 

[Anonymous]

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[dogman dan]

So who resets the codes while you are in the ambulance. Remember, you just hit somebody at 40 mph. Plus, the witnesses will most likley say you were going pretty fast for a bike. The plaintiffs lawyer is gonna love his payday.

 

[EVnewbie]

Ahhhh, the lawyers!,
After pondering my hot rodded version of my Giant Stiletto, I have settled on 25 MPH or so for top speed. My 32V 35 amp brushless motor driving through the gears on the back wheel should easily do that. When things go past 1000 watts or so, bike parts might get a little dicey and I broke many parts from just pedal power back in the day.
My rear wheel is a 24 inch wheel with double-walled eyeletted rim, a very wide rim to hold the 3" tire. It runs 48 spokes and a 178mm disc brake so should give me years of trouble free use. Don't forget the bolt on axles as quick releases are not as strong. Just keep those bearings greased/adjusted and watch spoke tension to keep the wheel together. The front wheel is a high flanged hub 24" with an even wider SAS Combat double walled/eyeletted rim with disc mounts. It runs "only" 36 spokes but is not the power driven wheel and is made for "dirt jumping" or trick riding and has not flinched at my son's trick riding on his Norco. Strong wheels are a must!
My long Stiletto frame is a steel beast! Very long so no problems with end over end action when yanking on the front disc brake. At this point, I think the front 160mm disc is good enough but I might go to 203mm in the future if needed. Eventually I'll be in the mountains and pause when I think of a 260 lb combined weight bike/rider flying down a mountain in the Ozarks. 203mm would probably be a good idea to prevent brake fade.
My weak points with the build so far are rear derailluer springs. That long cage Shimano derailluer can get weird when shifting to the 34T mega-range low gear so I'll throw a stronger spring on it to give more positive shifting. Fairly easy and cheap to do and it will prevent chain slap at higher speeds.
Going to modify the double crown stock solid fork to make it a "springer". 2 inches of suspension when coupled with a 2.35 inch wide Schwalbe Big Apple tire at 40 PSI should be fine. A lot of steel in that fork but weight is not to large of a consideration considering the stock bicycle runs about 50 pounds stock!
Since I'm going the freewheel crank route, I have calculated the max crank 48T crank speed at 188 RPM. To prevent any weirdness from the freewheel, I went with the upgraded freewheel from White Industries so I won't get my feet thrown off the pedals since the freewheel is very heavy duty stuff for trials bike cranks.
My street ride has been a recumbent for the last decade and I've hit speeds exceeding 50 MPH once on a downhill. Going over 40 MPH is common so I throw Schwalbe kevlar belted tires on all three of my families recumbents with not a single tire related problem. The Marathon Plus series is a long wearing, beefy tire that I have been unable to flat yet. The biggest tire I can get from Schwalbe is a 24x2.35" with kevlarguard so it will be my new front tire. The rear 3" might be slime tubed since I can't get one that big from Schwalbe.
Don't forget the chain guard for the back spokes! If you throw a chain at speed, it can eat your spokes while is jams your drive train so put one of those "pie plates" on there for extra protection.
It has been my experience that SRAM makes the best chains strength wise. Avid makes great brakes. Wider double wall rims are better with eyelets and the thickest spokes that will fit. Park makes very good bicycle tools. Get the strongest cables with teflon housings for cable operated disc brakes and you won't be sorry.

 

[julesa]

I think a small motorcycle converted is the only sane thing, and definitely the only legal way to go for street use. You hit somebody at 40 mph, uninsured and illegal, and they'll have your house. THINK about it, in america, they'll sue you silly.

Even aside from the legal issues, motorcycle tires are wider, and have a much larger contact patch on the ground, stronger rims, brakes designed for those speeds, a stronger frame... For 40mph and up, I'd convert a motorcycle just for the larger contact patch on the asphalt, if nothing else.

 

[swbluto]

I think a small motorcycle converted is the only sane thing, and definitely the only legal way to go for street use. You hit somebody at 40 mph, uninsured and illegal, and they'll have your house. THINK about it, in america, they'll sue you silly.

Even aside from the legal issues, motorcycle tires are wider, and have a much larger contact patch on the ground, stronger rims, brakes designed for those speeds, a stronger frame... For 40mph and up, I'd convert a motorcycle just for the larger contact patch on the asphalt, if nothing else.

That seems like it'd be sane, but are there lightweight lower speed motorcycles out there? I was under the impression that weight wasn't so much of a selective pressure on gasoline vehicles and so that's why so many common motorcycles are so heavy. I would think some version of moped might fit the bill, but again, I'm not sure if they've adapted moped design to be lighter weight as is important to electric vehicles. Also, it seems like junk motorcycles sell for $1000-$2000 which seems a bit rich for just the frame, wheels and drive system as would be used in an electric vehicle conversion.

 

[fifthmass]

Guys,

My crash yesterday was only a combined velocity of maybe 20 mph between myself and the SUV. I went to the emergency room and my donor bike was totaled.

Over thirty mph on a bicycle frame is flirting with danger. 40+ is insanity. I'll add one caveat, going down a long steep grade is a special situation and high speed can be expected on even a conventional bicycle. However day to day riding at over 30 mph is motorcycle territory.

I'm worried that someone here is going to be killed someday. Once lots of people start having high speed accidents then the present golden days of (relatively) unregulated ebiking will come to an end. We'll all have to get motorcycle licenses, bikes will have to be approved by the nation's DOT (or non-USA equal agency), pay registration, pay insurance, be banned from bike paths, onandonandonandon...

Please be safe.

Bill

 

[julesa]

That seems like it'd be sane, but are there lightweight lower speed motorcycles out there? I was under the impression that weight wasn't so much of a selective pressure on gasoline vehicles and so that's why so many common motorcycles are so heavy. I would think some version of moped might fit the bill, but again, I'm not sure if they've adapted moped design to be lighter weight as is important to electric vehicles. Also, it seems like junk motorcycles sell for $1000-$2000 which seems a bit rich for just the frame, wheels and drive system as would be used in an electric vehicle conversion.

Yeah, I would want to pay less than $1000 for a bike I was just going to rip the engine out of anyway. I guess if it runs you could sell the engine. Maybe an old Kawasaki Ninja 250 off Craigslist.... I prefer the cruiser look, but the fairing would help cover up the batts for stealth, aka theft prevention.

Here we go... '95 Ninja 250 for $1600...
http://seattle.craigslist.org/est/mcy/1166445667.html

You'd still end up paying over $1000 after selling the engine, but you could easily spend that much on a nice bicycle.

 

[swbluto]

Guys,

My crash yesterday was only a combined velocity of maybe 20 mph between myself and the SUV. I went to the emergency room and my donor bike was totaled.

Over thirty mph on a bicycle frame is flirting with danger. 40+ is insanity. I'll add one caveat, going down a long steep grade is a special situation and high speed can be expected on even a conventional bicycle. However day to day riding at over 30 mph is motorcycle territory.

I'm worried that someone here is going to be killed someday. Once lots of people start having high speed accidents then the present golden days of (relatively) unregulated ebiking will come to an end. We'll all have to get motorcycle licenses, bikes will have to be approved by the nation's DOT (or non-USA equal agency), pay registration, pay insurance, be banned from bike paths, onandonandonandon...

Please be safe.

Bill

Don't worry, in regards to physical situations, realistically what could happen *will* happen to someone - as long as there's some small risk with each ride of a certain situation, in large numbers, that risk actualizing is inevitable. Give us ebikers enough time and at least one of us will come across whatever individually seemingly remote risk.

Anyways, my god man! What happened? You should make a special thread for this considering how important it is for everyone to be aware of the risks, whatever they are, especially with the metallic gorillas roaming the roads.

 

[fifthmass]

Don't worry, in regards to physical situations, realistically what could happen *will* happen to someone - as long as there's some small risk with each ride of a certain situation, in large numbers, that risk actualizing is inevitable. Give us ebikers enough time and at least one of us will come across whatever individually seemingly remote risk.

Anyways, my god man! What happened? You should make a special thread for this considering how important it is for everyone to be aware of the risks, whatever they are, especially with the metallic gorillas roaming the roads.

I was stupidly going the wrong way up a one way residential side street. Road was empty except for the SUV that pulled out and sideswiped me. Driver was looking for traffic coming from the right way and didn't look the wrong way where I was coming from.

Car ran over my bike and left foot. No broken bones or ligament damage. Slight swelling and limping. Two days later already more than half way back to normal.

Been a bad week for crashes. So far all of them our faults.

Bill

 

[Toshi]

That seems like it'd be sane, but are there lightweight lower speed motorcycles out there? I was under the impression that weight wasn't so much of a selective pressure on gasoline vehicles and so that's why so many common motorcycles are so heavy. I would think some version of moped might fit the bill, but again, I'm not sure if they've adapted moped design to be lighter weight as is important to electric vehicles. Also, it seems like junk motorcycles sell for $1000-$2000 which seems a bit rich for just the frame, wheels and drive system as would be used in an electric vehicle conversion.

i'd definitely start with a moped or motorcycle. you know that sound speed has converted a Tomo, no? http://soundspeedscooters.com/content/electric-tomos-moped-completed looks like the post was truncated when they switched site layouts. they also sell naked moped frames! http://soundspeedscooters.com/store/parts/frames

in any case i'd look into something that was designed by a reputable manufacturer to be streetworthy at sub-highway speeds. some examples off the top of my head:

honda monkey (which, in fuel injected guise, gets 250+ mpg at a constant 30 kph, btw: http://www.autobloggreen.com/2009/01/23/honda-injects-fuel-into-monkey-bike-gets-252-mpg-in-return/):

honda super cub, the best selling motorcycle in the world:

honda EZ90 "cub", which i really wanted as a kid btw! (not so practical when one is growing up in new york city!):

tomos ST, under $1500 brand new btw:

ok, i'm spent. point is that there are a lot of city-speed powered two-wheelers out there, and they've already addressed the problems for which you seek solutions. also, with regard to the bus system around seattle, keep in mind that the nominal weight limit is 55 lbs and that you won't be able to sneak anything on the rack that looks more overtly "motorcycle-like" than my e-bike.

 

[Toshi]

hell, for that matter if might make more sense to buy one of the $600 costco electric "baja" scooters and then put in decent lithium and a stronger motor: http://greginthedesert.net/2009/02/baja-be500-500-watt-electric-scooter/