Please recommend a bicycle tough enough to handle 35mph?

Dear folks,

My brilliant 15 year old autistic brother has engineered a quiet bicycle mid-drive motor that can go 30+ mph. We need to do a long-term test. The goal is 1 year. Riding two times, 6 times a week. Basically I'm going to test it for him by using a bicycle to ride to and back from work.

Height: 5'4
Weight:180 lbs
I need a tough bicycle that's tough enough to handle such high speeds and stress.
I would love to have wider tires. ( 650B 2.5"? or bigger? )
Godly brakes ( I can get aftermarket brakes if the suitable frame doesn't have good brakes )
Somewhere between a mountain bike and cruiser geometry. ( Think Specialized Roll )

Any help would be awesome. Please recommend me bikes that would be suitable for this test!

Best Regards,
Ryan

 

Unless you name your budget, no useful recommendation is possible.
Probably isn't, even if you name your budget.

And there is no bike "between a mountain bike and cruiser geometry" that'd be a sensible choice for your use anyhow.
Because no bike of such a geometry is expected to cruise at 35 mph.

The closest you can get is a real FS DH bike.
You MIGHT get one that has a chance of working for USD 2000.

Here's how it works:
Bicycles are able to look like bicycles because they're used as bicycles.
Meaning an active rider, able to compensate for no/little suspension by getting out of the saddle.
A modest average speed. A (very) modest average power.

If you want a bike to be able to do scooter speeds, with a rider sitting heavy in the saddle, then it'll need to be engineered like a scooter.

Really, there's no way around it.

 

Valid points. Budget is $2K but lower the better, of course
I was looking for wider tires and some what of an upright riding style instead of the extreme upright nature of the cruiser bikes. I wouldn't want cruiser style handlebars.

DH bike might be the way to go but I was hoping for something with a carbon fork for energy efficient rides on pavements. I don't need back suspension. Just wider tires There won't be any off-roading with this setup.

 

I can just about guarantee that you will need suspension.
If you're not fully involved in pedalling, you will sit heavier in the saddle. You will hit lumps and bumps harder. You will trash a regular bike.
Again, you expect to be travelling at scooter speeds. To survive that all your structural elements need to be as strong as on a scooter.
Scooters and mopeds aren't built as heavy as they are for the fun of it, they are built like that b/c they need it for survival.
You can skimp a little if you're not ever gonna carry a passenger, ut that's about it.

And the main reason why sus bikes are heavier to pedal is that with a human as the engine, pedalling starts with an up/down motion that makes the bike bob on the suspension.
Your power will come from rotary motion, which won't add anywhere near as much up/down and associated losses as a regularly pedaled bicycle.

 

While everything that dabac says is worth taking note of ...

I have been passed by a regular, non-suspension bike which had been converted with a gasoline engine ...

And, several years ago, I recall seeing someone's converted bike which also lacked any suspension locked-up in the WalMart parking lot ...​

And certainly, in the distant past, small "kit" scooters which were to built using a lawnmower motor lacked any suspension beyond the air in the comparatively small tires ...

So, a suspension may-or-may-not be as necessary as dabac suggests.​

THAT's not to say that a suspension frame-or-fork wouldn't be better for what you want than a rigid frame & rigid fork ...

But (with the presumption that the intended bike frame is MORE for testing the efficacy of the "engine" in a long-term, day-to-day use on a bike), if you not a careless rider who does not avoid pot holes and other road debris then you can probably get by with any STEEL framed bike which has reasonably FAT tires rather than be concerned with a suspension ...

So, I think that you should decide on the wheel-and-tire size which you want AND its general availability, first, because I think THAT should dictate the frame type to a great extent ...

If you were taller then a 29er with a front suspension fork might be an advantage over a bike which used smaller wheels because the larger wheel-and-tire circumference will make for a smoother ride ...

BUT, because of your height, a regular steel Hardtail which uses comparatively FAT 26" tires (I believe that JAMIS still makes a steel Hardtail) .

A 26er frame which uses disc brakes can certainly accommodate 650b wheels-and-tires whose hubs have disc rotors, and vice versa -- putting 650b wheels-and-tires will affect the BB height by raising it slightly; and conversely, putting 26" wheels-and-tires in a 650b frame will result in a slightly lower BB -- the latter may be a good thing if pedaling will be a last resort and pedal clearance is not a serious concern.

A steel Hybrid frame (I do not know if new ones still exist ... again, check JAMIS's lineup) would be another option which would allow you to use 700x42 tires + fenders.
​

IMO, using a Jamis Hardtail as the (¿initial?) test frame would let you know within a few miles/commutes whether or not you wanted-or-needed MORE suspension OR a better suspension fork.

BTW. For probably the wrong reasons, if you want a better suspension fork than whatever the steel Jamis Hardtail comes with then I recommend that you look at Marzocchi forks.​

​

 

Motorizing a bike as such isn't a problem, whether Electric or combustion.

Treated as a toy, conversion piece etc, a modest engineering effort will make the bike outlast its novelty value.

But building a RELIABLE motorized bike is another ball game entirely. Particularly at the average/cruising speed the OP is talking about.

Come to think of it, the OP hasn't said what mileage he hopes to reach.
2-6 times/week - let's say average 4.
To/from work. Let's say 200 ride day opportunities. 400 possible rides.
If the OP sticks to it, the mileage will add up fast even at fairly short rides.

 

I will say "Of course, you are right" for what YOU are suggesting ...

Again, I think if "...the presumption (is) that the intended bike frame is MORE for testing the efficacy of the "engine" in a long-term, day-to-day use on a bike" then most any STEEL framed bike which is sized for the rider will be reliable enough to withstand the rigors of almost any paved road conditions for a one year test of day-in-and-day-out use ...

However, as you infer, it is really a matter of whether or not the rider wants to live with the road hazards & vibration at those speeds ...

Consequently, I think the OP does need to seriously consider the caveats you cite; but (again), the question he needs to clarify is whether he is concerned with the motor's reliability or with his comfort during the test year, and beyond.

As far as commuting with a bike, I believe that I fully understand what you are saying that beyond utility & reliability, it's all about three things:

comfort, comfort, comfort!​

BTW. I think that at speeds over 25mph, the OP may want to consider "goggles" as a must-have accessory!

 

Keep in mind that kinetic energy increases with the square of the speed.
10 mph is often given as average speed for casual riding. The OP is looking to go 3 times that. 3x the speed means 9x the kinetic energy.
Energy to be dealt with at every pothole, lump and bump. And to bleed off at every stop.
And every stop will be like coming off a pretty good descent.

 

Is what you are thinking if doing even legal where you live? Because it sure isn't legal where I live.

 

The loads on a bike like that require disk brakes and full suspension. For about $350 you can get a department store full suspension bike with the correct components on it.

https://jet.com/product/detail/e4ef...&clickid=3a87b3c2-47f2-4686-b3ab-9208db7b848f

There may not be sufficient room in the fore triangle to mount your motor but at least this gives you a starting place.

 

I was chasing one of these in the street once... They go pretty fast..

 

Yeah, trikes and bents are very fast because they are low and very aerodynamic. If you want a bike that is really fast, invest in a Velomobile. I know of a guy, who rides his on the highway with cars, it can go that fast. Most people think he's driving a battery operated hybrid. Then there's this new bike that they have just started to put on the market, called The Bird of Prey. I think I will pass. Looks too uncomfortable, but you be the judge.

View: https://www.youtube.com/watch?v=K24dHLA8zpw

 

Nah.
Recumbents have their place, but supine bikes have just about never worked out well.
Check out Graeme Obree's Beastie:
http://www.cyclingweekly.com/news/graeme-obree-the-beastie-boy-19142