SamTexas
1 MW
These categories appear to be quite arbitrary to me. So is there an RJ (rock jumping), a CJ (cliff) or a SJ (suicidal)? 
Which bicycle can comfortably and confidently handle 35mph?
- Thread starter SamTexas
- Start date
sn0wchyld
100 kW
SamTexas said:These categories appear to be quite arbitrary to me. So is there an RJ (rock jumping), a CJ (cliff) or a SJ (suicidal)?
your right actually...
rj = rockjumper. cj =crackhead jumper. sj exist too, but they're kinda hard to find secondhand in good condition... :wink:
It looks like most would recommend a DH frame. However don't give up on a good long hard tail frame.
My Electra Townie pedal forward frame has a wheel 47" wheel base and with the 24" rear, 26" front tire with White Bros. triple clamp FS fork gives me a head tube angle of 67*. The ride is plenty smooth with the Thud buster seat post and 2.5" hookworms @ 40 psi. While out riding yesterday, I had no trouble riding with no hands at 35 mph. It is both stable and predictable at those speeds.
Maybe a full suspension bike might be better, but I'm happy with what I have. Plus I can fit 18s/15ah in the triagle. 8)
My Electra Townie pedal forward frame has a wheel 47" wheel base and with the 24" rear, 26" front tire with White Bros. triple clamp FS fork gives me a head tube angle of 67*. The ride is plenty smooth with the Thud buster seat post and 2.5" hookworms @ 40 psi. While out riding yesterday, I had no trouble riding with no hands at 35 mph. It is both stable and predictable at those speeds.
Maybe a full suspension bike might be better, but I'm happy with what I have. Plus I can fit 18s/15ah in the triagle. 8)
SamTexas
1 MW
That's good to know. Thanks.nicobie said:
What was the reason for you to use 24" rim in the rear? Wouldn't the stock 26" be even better for balance and stability? Do you feel that the front is too light?
SamTexas said:
The 24" rim plus 2.5 hook worm is the same as a 26". 1.5" setup. I was looking for a street set up with my H series 3525 motor that would hit 39 mph right now and not cook itself.
I got lucky
Hangdog98
10 W
Having ridden and raced everything on two wheels and designed bicycles for all applications I would suggest that a DH bike is only right for you if you plan to ride your e-bike down the downhill trails. If you plan to ride on the road then you need road geometry. Road racing cyclists travel at 60mph all the time down mountain passes, around rutted hairpin turns on skinny 23mm tires with rim brakes on carbon bikes weighing just 16lbs. 10,000 riders do this every weekend throughout Europe. They even shuttle their flat-bar roadbikes to the top of 10,000ft high mountain passes and bomb down the roads (between the cars!) at 60mph any day of the week. The hot set up is road geometry AND quality components that don't fail.
If you do choose a suspension bike, try to get one with NO MORE than 4" of travel, a single pivot design and an adjustable AIR shock (to pump it up WAY harder to suit your weight and road use). Road motorcycles which are MUCH heavier don't have more than 5" of travel unless they're designed for adventure travel (or designed by the marketing dept) and they cope fine with roads and 100mph+.
The problem with a DH bike is that the geometry is designed for a bike that is always pointing downhill and hitting massive bumps so the forks are kicked out to compensate and the rear suspension is soft. If you converted a DH bike you would need to change to a MUCH harder rear spring to avoid squatting the rear suspension down which causes the forks to kick out even further. If you did put the right spring in there, then the bike would sit very very high and have an equally high center of gravity which makes steering feel quite ponderous.
Look at a Ducati monster to see how the moto boys solve the problem. 16" wheels, Fat(ish) tires, Cro-mo tube frame, Centralized mass, Less than 5" of suspension travel, Disc brakes.
The bike I'm building for 35mph+ commuting will look like a road racer with a steel (cro-mo) frame with 50mm longer chainstays than you'd normally see on a regular road bike. The geometry will be classic road geometry of 73 x 73 degrees with a wheelbase of 1100mm The steel gives it strength yet absorbs road chatter but has no pivots to wear out and get wobbly. It has 26" x 24mm wide rims, 36 spokes, Schwalbe Big Apple tires, drop bars and disc brakes. The frame is still on the CAD but it will have the necessary mounts and tabs welded to the frame. I'm going for the stealth e-bike look that looks like a Tour deFrance bike with big fat tires and no obvious signs that it has a motor to the untrained observer, (obviously anyone here will spot the X5 motor straight away).
Kinda like this but with 26" fat slicks and an X5 in the rear.
If you do choose a suspension bike, try to get one with NO MORE than 4" of travel, a single pivot design and an adjustable AIR shock (to pump it up WAY harder to suit your weight and road use). Road motorcycles which are MUCH heavier don't have more than 5" of travel unless they're designed for adventure travel (or designed by the marketing dept) and they cope fine with roads and 100mph+.
The problem with a DH bike is that the geometry is designed for a bike that is always pointing downhill and hitting massive bumps so the forks are kicked out to compensate and the rear suspension is soft. If you converted a DH bike you would need to change to a MUCH harder rear spring to avoid squatting the rear suspension down which causes the forks to kick out even further. If you did put the right spring in there, then the bike would sit very very high and have an equally high center of gravity which makes steering feel quite ponderous.
Look at a Ducati monster to see how the moto boys solve the problem. 16" wheels, Fat(ish) tires, Cro-mo tube frame, Centralized mass, Less than 5" of suspension travel, Disc brakes.
The bike I'm building for 35mph+ commuting will look like a road racer with a steel (cro-mo) frame with 50mm longer chainstays than you'd normally see on a regular road bike. The geometry will be classic road geometry of 73 x 73 degrees with a wheelbase of 1100mm The steel gives it strength yet absorbs road chatter but has no pivots to wear out and get wobbly. It has 26" x 24mm wide rims, 36 spokes, Schwalbe Big Apple tires, drop bars and disc brakes. The frame is still on the CAD but it will have the necessary mounts and tabs welded to the frame. I'm going for the stealth e-bike look that looks like a Tour deFrance bike with big fat tires and no obvious signs that it has a motor to the untrained observer, (obviously anyone here will spot the X5 motor straight away).
Kinda like this but with 26" fat slicks and an X5 in the rear.
hillzofvalp
100 kW
That'd be nice, but road cycling at 35 mph is much different than ebiking at 35 mph. You have to have experience and focus to regularly go 35+ on a road bike... and that's usually on familiar roads.
I'm riding the big apples on my 29er build.. with 80mm-100mm travel on reba fork. It works so far.. and I like the upright position that makes it easier to check behind for cars or passers.
I'm riding the big apples on my 29er build.. with 80mm-100mm travel on reba fork. It works so far.. and I like the upright position that makes it easier to check behind for cars or passers.
Hangdog98
10 W
I do both and I find that road geometry is better for the road at speeds up to 60mph. My Dh bike is crap on the road by comparison, particularly at higher speeds. It's great on a DH track though.hillzofvalp said:
oatnet
1 MW
Hangdog, with a big heavy hub motor like a 10.5kg CroMotor or a 15kg 54xx, what do you think of using suspension travel to protect the spokes and rims during pothole impacts?
-JD
-JD
hillzofvalp
100 kW
I had my eye on one of those Paris Roubaix (sp?) frames.. when they had short travel front road forks in the 90s. Bianchi made a full suspension road bike as well.
kfong
100 kW
I got rid of my ten speed road bike because if find the position uncomfortable. I much rather prefer a mountain bike stance. I would never have a bike without suspension. Too much road chatter over miles of riding making my wrist sore. I do mostly trail riding so I'm a bit biased towards those types of geometry. My utility bike used mostly on roads is a chrome moly mountain bike going at 30mph. I recently bought a new front suspension for it to replace the crappy shorter 2" travel. I find I need 4" travel for the streets here. Way too many cracks and poor roads. The rear is fixed, but suspension would of protected the rear wheels. I've damage them a few times hitting curbs way too hard. I picked up a DH frame as a backup bike, but I plan to ride it faster than my normal trail bike. It has larger brakes than most bikes which makes me more confident at higher speeds. I don't really plan to go faster than 35 mph with it since I don't like to share the road with main traffic. My requirements are a bit different than others. Hangdog, your views are very valid, but I think it comes down to personal preference and riding style. I like to jump stuff occasionally even on the streets.
Two very popular ebikes for high powered setups have been the Kona Stinky, and the Team Giant. Both are DH bikes.
Two very popular ebikes for high powered setups have been the Kona Stinky, and the Team Giant. Both are DH bikes.
mr.electric
10 kW
I have never built an electric bike from a road bike like hangdog recommends. I have always assumed the vibration, pinch flats and overall lack of comfort on a 60lb road bike would make the finished bike unridable. Hangdog let's see a photo of an electric road bike. I have only seen one, the Yamaha built single speed race pace bike.
I have to agree with Live4physics, dual suspension bikes tend to have too much play in the rear suspension to work very well. I always feel a wierd looseness on dual sus bikes when I transition from turning left to right or vice versa. The play is not apparent on some rides but other times it is scary.
Seems the last choice is a hard tail mountain bike. I may build one for my next ebike. I wonder how jarring a hard tail is at 35. Probably pretty bad.
I have to agree with Live4physics, dual suspension bikes tend to have too much play in the rear suspension to work very well. I always feel a wierd looseness on dual sus bikes when I transition from turning left to right or vice versa. The play is not apparent on some rides but other times it is scary.
Seems the last choice is a hard tail mountain bike. I may build one for my next ebike. I wonder how jarring a hard tail is at 35. Probably pretty bad.
Hangdog98
10 W
Vivax Assist. Motor in frame. There's others too, some secretly used in races.mr.electric said:
dogman dan
1 PW
I think road geometry would be great for a non hub motor bike. With the motor in the center, and presumably the battery as well, then it's possible to use "road bike suspension", that is, stand the pedals. Then the lightweight wheels rocker back and forth on the potholes with no problems.
It's the addition of a 15 pound ( with fat tire) hubmotor wheel, and even worse, rear carried battery that throws the monkey wrench into it. Add to that a street commute, and now you are getting forced off the smooth line by traffic, not seeing a pothole while your attention is on that bitch about to left cross you, etc.
So a FS bike that can take that kind of abuse can be good. But I don't agree the DH type is mandatory for 35 mph street riding. For sure, choosing the wrong FS frame can be a freaking disaster. Hence the original question. In my mind, you want a lot of lateral stiffness to the frame, and no sway in the rear swingarm as the starting point. For street, 80 mm travel is quite enough, and you may want to stiffen up to lessen pedal bob.
Suspension too soft? WTF? never heard of adding some air?
It's the addition of a 15 pound ( with fat tire) hubmotor wheel, and even worse, rear carried battery that throws the monkey wrench into it. Add to that a street commute, and now you are getting forced off the smooth line by traffic, not seeing a pothole while your attention is on that bitch about to left cross you, etc.
So a FS bike that can take that kind of abuse can be good. But I don't agree the DH type is mandatory for 35 mph street riding. For sure, choosing the wrong FS frame can be a freaking disaster. Hence the original question. In my mind, you want a lot of lateral stiffness to the frame, and no sway in the rear swingarm as the starting point. For street, 80 mm travel is quite enough, and you may want to stiffen up to lessen pedal bob.
Suspension too soft? WTF? never heard of adding some air?
Hangdog98 said:Vivax Assist. Motor in frame. There's others too, some secretly used in races.mr.electric said:
you're basically admitting that a road bike is only good for a 200 watt motor.
Hangdog98
10 W
How did you come to that conclusion? Mark Cavendish puts out about 1,580W in the last 100m of the sprint and his road bike seems to cope just fine. I be happy to put 5kW on mine if I could.Toorbough ULL-Zeveigh said:
you're basically admitting that your comprehension skills are well below average
or that your trolling skills are above average.
Hangdog98 said:How did you come to that conclusion? Mark Cavendish puts out about 1,580W in the last 100m of the sprint and his road bike seems to cope just fine. I be happy to put 5kW on mine if I could.
you're basically admitting that your comprehension skills are well below average
now who's lack of comprehension is showing?
you're basically admitting the road frame can handle 1580W for what, all of two or three seconds? woot!
you're also basically admitting that you gotta be a mark cavendish to supply your own meat-motor kilowatt in order to have something workable, i'll give you that.
with most people tho & specifically who's posing the question of this thread it's the other way round.
they require 500W-1500W continuous out of their motor to make up for their own zero to 50 watt contribution.
the added power doesn't magically appear without added bulk stressing an already flimsy frame.
lets say your bike could actually handle 5kW (brief peaks anyways), but if you want to do anything useful with that power it's gonna take a whole lot more than just a seat bag worth of batts to feed it that's the problem.
don't kid yourself that the average outta shape commuter is capable of pumping out even hundred watts for any meaningful length of time, like more than a couple of minutes.
to get a real world idea of how long joe-average would last just try for yourself how hard it is to keep lit at full bright a standard 60W household incandescent light bulb by cranking a demonstration bicycle dynamo at a college open house or museum sometime.
most people crap out with even the wimpy 6W friction roller generators that you can buy.
and yes you can find examples on the web where the tubing on road frames has folded like wet spaghetti from nothing else except enthusiastic cranking by serious but by no means elite cyclists.
if that's the best evidence you have to present of a road bike with a motor attached then you haven't made the case & it's the only conclusion that can be drawn.
the OP specifically requests comfortably as well as confidently which a road bike with a buttload of crap hanging off it don't make the cut in either event.
SamTexas
1 MW
Thanks all for your input. I finally settle with a KHS Solo One frame. I will use a steel SR Suntour suspension fork with it. Let's hope it works.
Hangdog98
10 W
I'm not basically admitting anything of the sort. These bizzare claims are made by you. I'm saying, that road "geometry" is more suitable for road riding than what many others have posted, which is that DH or 5" of suspension is the better choice for a bicycle which "can comfortably and confidently handle 35mph?" Your arguement is reductio ad absurdum in that you take one element of a discussion and extrapolate that idea to an extreme (incorrectly I might add) and then make absurd accusations, towit "you're basically admitting" etc etc. Using the absurd assumption that road bikes are, by design, "flimsy".Toorbough ULL-Zeveigh said:Hangdog98 said:How did you come to that conclusion? Mark Cavendish puts out about 1,580W in the last 100m of the sprint and his road bike seems to cope just fine. I be happy to put 5kW on mine if I could.
you're basically admitting that your comprehension skills are well below average
now who's lack of comprehension is showing?
you're basically admitting the road frame can handle 1580W for what, all of two or three seconds? woot!
A well made road bicycle frame had just as much chance of withstanding the rigours of electric power as most MTB and DH frames. Indeed, riding a "flimsy" frame all day in the notorious Paris Roubaix road race across the cobblestones on 24mm tubular tires under the power of the torque monster Thor Hushovd would test even a Brooklyn Cycles DH frame. Of course I'm not suggesting that the ideal frame is a 900g carbon fiber road frame, far from it. I'm suggesting that road geometry is more stable in road conditions to other frame geometries. The strength of construction, including, but not limited to, tube material, weld type, tube thickness and butting, wheelbase size and geometry, is what makes a bike strong. For my frame, I'll make it from 5083 aluminum of 42mm ID for the main tubes to house the 40152 LiFeP04's with a chromoly fork. I'll use Velocity 700c eyeletted rims with 13g stainless spokes, probably with brass washers and nipples laced to a crystalite HS3540 hub motor @ 48V with a 40A controller. I don't expect any trouble whatsoever and I am qualified to design and construct that bicycle myself to a standard that will "comfortably and confidently handle 35mph?" with consumate ease. I would bet though, that any of the Surly bike frames would handle it quite comfortably as would most custom framebuilders' frames given the brief that it was to be powered.
Mr Toorbough ULL-Zeveigh, I don't rate your opinion on the subject and I find your foolish assumptions and your combative arguements tedious. I won't be engaging your nonsense any further
SamTexas
1 MW
Good. Thank you. At one point I didn't even recognize it was my OWN THREAD!!!Hangdog98 said:
dogman dan
1 PW
Good frame choice, Now on to the folks horrified by the idea of any kind of motor on a suspension fork. :lol:
oatnet
1 MW
dogman said:
I guess that's me.
:lol: One fork failure was enough to put me off front hubbies. I see you have had a lot of milage on them though, so good on you!-JD
SamTexas
1 MW
Thanks. It was a compromise, but I got a little bit of everything I wanted: Chromoly, rear suspension and full triangle.dogman said:
After more than 2,000 miles experience with 2 different front hubs, I'm a lot less concerned now.
dogman dan
1 PW
Maybe I just go over the bars so regular I feel like it would be the same as usual. Definitely can crack an alloy fork easy.
Even using two ebikes CA torque arms I walked a wheel out of the drops instantly on the race bike. two hose clamps per arm still didn't cut it. Bolting the arm to a flange welded to the forks did the trick. Then just tried to not think about something causing the motor to shudder at 47 mph when I was riding it. It's a rear motor bike now.
Still have a front hub commuter that goes 27mph, and no problems in many thousands of miles from the front motor. Problems with water bottles, problems with f----heads walking the bike lane in black. But no motor caused crashes.
Even using two ebikes CA torque arms I walked a wheel out of the drops instantly on the race bike. two hose clamps per arm still didn't cut it. Bolting the arm to a flange welded to the forks did the trick. Then just tried to not think about something causing the motor to shudder at 47 mph when I was riding it. It's a rear motor bike now.
Still have a front hub commuter that goes 27mph, and no problems in many thousands of miles from the front motor. Problems with water bottles, problems with f----heads walking the bike lane in black. But no motor caused crashes.
SamTexas
1 MW
Solid or suspension fork? Steel or alloy? With or without torque arm?dogman said:
