Cycling: shifting systems?

michael,
most pushbikes have gearboxes - just that they are strung out along the drive chain as cassettes, rear derailleurs, chinrings etc. all g-boxx bikes do is stick it all in one place and cover it all up so they don't eat your trousers, fall off when you hit something or get clogged up with mud. also with the weight in the frame it provides better weight distribution (something i know you aprieciate )
i must admit that they are heavy at present (both in weight and wallet terms) however once the big boys thow some r&d cash at it they'll come down in price and weight. and if not i'll be smugly riding through mud whilst those around me are having to un glue their rear mechs
cheers


julian

 

I agree Ju. The derailleur system has been around for a very long time and has lots of draw backs - crud catching, sensitivity to knocks and issues regards chain angles in certain front / rear gear combos. My full XTR setup is good but doesnt really overcome the above problems. However gearbox setups do suffer from a limited number of gears as well as cost and weight.

 

I think it's a very apt description when you see them going UP hill :lol:

 

Definitely . I think they get a bit confused when there's no ski lift to get back up the hill.

 

Ju - I wouldn't really call a derailleur system a gearbox though (it's not in a box/casing for a start). My point was that more and more, MTB's seem to be turning into motorbikes without an engine! Disc brakes, suspension, gearboxes etc. etc.

Michael.

 

I desperately want a rear disc now that I've got one on the front... In the mud there's no comparison. And for real trails suspension is an absolute must on the front... I am finding that I prefer XC full sus to a large extent, although my marin FRS isn't quite as good for precise trail placement as my hardtail was.

The demands for mountain bikes and motocross bikes are very similar. A lot of manufacturers are active in both fields (eg Fox Racing, Marzocchi, Magura, Grimeca) and technology crosses over in both directions (disc brakes and fork damping systems from mx to mtb, lightweight materials from mtb to mx). In fact, DH race bikes are looking remarkably like mx bikes now... Yesterday I overheard someone remarking that they'd thought I was on a motorbike when I passed them on the trail (I waited a moment for them to come out of a trail I was about to go down, and they'd seen me going along part of the pennine way at about 25mph), although the mud tyres (panaracer trailraker - highly recommended) do look a bit motocross like...

 

On one hand there are an awful lot of poseurs in the MTB scene IME. Folks cruising roads and gentle trails on a £3K Santa Cruz Bullit or heavyweight downhill machines. getting kitted up in full body armour and a full face lid. I guess for some its another way to compete with friends and colleagues - to have all the kit and look pro.

But this is an error in application rather then in the bike designs.


For those (and there are many) who ride serious trails and tracks, and go for freeriding the latest technology in terms of frame geo's, and suspension setups help enormously. It's not just gimmickery IMO. Things are now possible (and attempted) that were not possible before because of the way the more freerode orientated bikes handle the challenges.

Why not follow the lead taken by MX bikes? Disc brakes make perfect sense for MTB, suspension makes perfect sense for MTB, why not a gearbox concept to replace the delicate derailleur?

Micheal - I think you're showing your roadbike thinking. I have no idea as to how much exposure you have to the extreme ends of MTBing or just how popular these extremes now are, but a bike with no suss and no disc brakes would either kill the rider or it would die trying.

 

To answer your question greg, I know almost nothing about MTBs

 

Like this:

 

Exactly Isaac.

Eg. a friend who owns our local bikeshop was trying out the Santa Cruz V-10. He rode down a nice steep hill near to his home, at the bottom are the concrete steps leading to community centre - you know the type - council concrete steps, about 25 of them split with a half landing.

Straight down the hill at around 30 mph...



....straight UP the steps, no probs. The bike just ate it all up. Takes b*ll*x though.

 

only because full suspension bikes encourage riders to ride things which are beyond their skill level.

Ive seen pro's ride extremely hairy downhills at scary speeds on fully rigid £200 10 year old bikes.

I used to do it too - just a lot slower

 

I'm not so much referring even to downhill courses which, apart from sections of roots and big stones, are generally ok on a hard tail and even would be on a fully rigid bike if you take your time. I'm referring to either freeriding or proper pace DH.

In my early years we did some stupid stuff on rigid BMXs in skateparks and dirt jumping, dropping of garage rooves, quarter pipes, etc. A friend even jumped off the side of a railway bridge onto the pathway below (broke his QuadAngle frame and his arm doing it) I realise what you can do on a rigid bike, but heavyweight freeriding is something you cannot do on a rigid setup IME.