perfect weight distribution + tires for electric bikes

[giguana]

I have a full suspension electric mountain bike with the frame design inspired by the anchor of QE2 and kind of cross-country moto forks at the front.

since I pumped the tyres full, it's kind of unstable and has fallen over under me twice when I was turning. I think lots of weight on the front wheel of a bike makes it unresponsive and slippy...

Conversly, I have just made a bike with about 15kg extra above the back wheel, and it's a bit like a mono-cycle for weight distribution, the front wheel is free to hop about but the back has too much inertia when doing fast turns. which logically should be a lot more stable.

and what about all these crazy tire designs? either its mountain bike tyres made explicitly for wet fields or else really smooth road tyres with only one little groove in the middle...where have all the normal little groove tyre designs gone?

for example both these tyres look made for losing grip in wet tarmac conditions...

 

[Ian]

Bicycle tyres being thin, don't need any tread at all on tarmac, wet or dry. A bicycle tyre is simply too thin to trap enough water at the speeds involved to cause a problem.

The tread on road tyres is purely to make them look attractive to buyers who believe tyres should have tread. Serious racers who know better ride at high speeds in all conditions with complete confidence in their totally slick tyres.

 

[flecc]

Agreed with Ian.

For several days I've been riding on tyres with a wide smooth slick area across the middle, with just a little shallow water clearing tread at the outer edges. Throughout the recent wet weather they've been completely stable and secure, even under maximum force braking tests, and they roll very freely. Why have tread?

 

[Chris]

Roll-Down

Whilt you gentlemen are on the subject of tyres-could you please explain "roll-down".
Thanks
Chris

 

[flecc]

I understand it to be a comparative test of roll resistance Chris, which is primarily tyre "stiction" on most bikes.

Using a regular slope, letting a bike roll down down it and comparing the speed reached/maintained with other bikes/tyres tested to see the relative value.

I've just done two of those in the last week while testing.

It's not a perfect method, but a quite good indicator of performance.
.

 

[Chris]

I understand it to be a comparative test of roll resistance Chris, which is primarily tyre "stiction" on most bikes.

Using a regular slope, letting a bike roll down down it and comparing the speed reached/maintained with other bikes/tyres tested to see the relative value.

I've just done two of those in the last week while testing.

It's not a perfect method, but a quite good indicator of performance.
.

Have you done one on the Kalkhoff?
Chris

 

[allotmenteer]

Agreed with Ian.

For several days I've been riding on tyres with a wide smooth slick area across the middle, with just a little shallow water clearing tread at the outer edges. Throughout the recent wet weather they've been completely stable and secure, even under maximum force braking tests, and they roll very freely. Why have tread?

I agree there except that when running on slicks take EXTREME CARE not to let your tyre stray onto anything other than tarmac. Just a few weeks ago I was thrown from the bike when my front tyre crossed a patch of mud about a foot wide at the edge of the road. Thankfully I was fine and landed on the grass but it certainly taught me that slicks are 100% only for tarmac.

When I changed to slicks I noticed a HUGE difference in how easily my bike rolled along compared to MTB tyres. The amount of effort to maintain speed was greatly reduced. For a road going bike I'd never again use tyres with anything more than mimimal tread.

 

[flecc]

To Chris, Yes.

To Allotmenteer, as you say, only when on tarmac or a suitable road surface, grass and wet mud should be avoided.
.

 

[giguana]

do you prefer to have really high pressure in tyres or do you prefer slightly mushy- I think when there is twice the contact area it's more comfortable and twice as safe for turning.

I had the same thing falling off recently going around a road with mountain bike tires, there was a sleeping policeman so I went through the mulch on the side in a pretty normal biking manoeuvre but the heavy bike keeps on going in the same direction when the wheel turns and lays itself flat.

the lighter a bike is, the more it is an extension of the body, and when it's about half of the body weight it is really a separate entity that takes a lot of trial and error to learn the limits of.

 

[Ian]

I suggest you try some european tyres pumped up hard, the handling characteristics of many of the Chinese tyres supplies as standard leave considerable room for improvement.

 

[giguana]

i have superslick shwalbe and kona hybrids with unstable looking knobbly blobs on either side...but I think I have to get a third pair to handle off-road and that can hold onto turns on tarmac which is the absolute most important and a risky thing on a all-terrain bike.

 

[giguana]

I think the point with very hard tyres is that when they slip they just go completely suddenly like soap because the only grip is coming from the texture of the rubber, whereas softer tyres are very stable when taking bends on tarmac.