Weight reduction and faster tyres in perspective

handful

Just thought I'd share my experience, not really mtb specific but interesting anyway. I have recently got fed up with bouncing around my local 'training' road loops when I don't have time to go off road on my lardy GT I-Drive. (I like it off road but the lack of lock out makes things a bit draggy on tarmac particularly with 2.3 Nevegals).

So, I have taken advantage of Cyclescheme to buy a flat bar very light hybrid with 700c x 28 tyres. I have been out twice now on a circular loop of around 10 miles and expected my average mph to be a good 4 or 5 mph quicker than the 14-15mph I managed before bearing in mind a weight reduction of nearly 6kgs :shock: along with skinny tyres at much higher pressures and so far my average speed has improved by a massive 1.2 mph

I feel a bit disappointed so far but it was quite windy (but a circular loop so not all against the wind) and maybe I will get quicker when I get more used to the bike but but I have certainly learnt that the eternal quest to buy lighter bits and faster tyres for my mtb are likely to be a complete waste of money.

supersonic

You need to time a few loops really to get a good average. I expect it will get better!

HebdenBiker

I expect you'll get faster as your muscles train into the new position.

A certain percentage of weight lost does not equate to the same percentage of speed gained. Weight is a factor when climbing and/or accelerating. If you were to ride a hilly ride then you would find a greater performance gain with the new bike.

Wind resistance, rather than weight, is a far more important factor. If you want to see a great improvement in speed, you should have bought a drop-bar road bike. Or better still, a TT bike with tri bars

Anonymous

I think tarmac is the problem. You need lycra for a start and get yourself a different attitude. That and a blindness for traffic lights

I always make time for off road. Tarmac bores me utterly. I just adapted to the GT and worked great for exercise. If I hit trails or even roads on an uber light machine I'd probably storm up after the work out on the GT

handful

deadkenny wrote:

I think tarmac is the problem. You need lycra for a start and get yourself a different attitude. That and a blindness for traffic lights

I always make time for off road. Tarmac bores me utterly. I just adapted to the GT and worked great for exercise. If I hit trails or even roads on an uber light machine I'd probably storm up after the work out on the GT

I know what you mean deadkenny, I do find tarmac boring compared to off road but just felt I'd enjoy winter road training more on a lighter faster bike. Your theory on expecting to be quick on a light bike was mine as well, being used to carting around the weight on the 15kg I Drive gave me the expectation that I would fly on the 9.07 kg flat bar hybrid on road tyres.

Hebdenbiker, you're quite right about the weight percentage not being the same as speed increase but I did think it would make more difference than it has! Take your point about improving though, my legs do feel different, I'm trying to kick down with my heels and it doesn't feel quite natural yet so once I get used to it I'm sure I'll get 2 or 3 mph faster!! Couldn't bring myself to go full roadie though although I did try a mates Bianchi but hated the drop bar position...killed my neck muscles. The lycra put me off as well, apart from base layers it should be reserved for the circus or the olympics. It is fun when a roadie goes past in the opposite direction and I see them trying to work out whether they should nod or ignore me on my skinny tyres and wearing mtb shorts and lid!

Thanks SS, I hope you're right, £1k per mph doesn't represent a great value for money investment so far!!

stuisnew

1.2 mph quicker is still nearly 10% quicker

bluechair84

Aye, but that 1k spend on the GT; anodising random components, ti bolts and braided hoses etc would have equated to at least a rise of 1.3mph, but probably more. Spending money on an MTB rather than a roadie will always equate to betterness.

cooldad

Bit of red would double the speed. Evry fule kno that

Northwind

stuisnew wrote:

1.2 mph quicker is still nearly 10% quicker

Seriously, this- it's a massive difference. Taking 10% off a lap by getting fitter is a serious effort- and it's a new bike to you as well so chances are there's more to come.

Expecting to get a third faster by changing bike was always going to leave you disappointed tbh.

handful

Thanks for the reassurances!!

Went out earlier and managed another 0.4mph improvement, probably because it was less windy today. I looked at my Sportypal stats as well and realised I've knocked around 6.5 minutes off the 10 mile loop time which is more like 15% timewise so although I haven't got my head around that fact and why I am happier that the bike isn't to blame for me being slow!!

I may get a can of red spray paint ready though if I need to boost the performance further.

njee20

That's a collossal difference! Get into time trials - if you could save more than 6 minutes off your time you'd be utterly overjoyed! That'd be the difference between winning and coming 100th at a top level event - I expect most people would be pleased with that!

Should've done it properly though and gone drop bars. Muscles adapt, and road bikes really are quicker.

mrmonkfinger

as a cheap addition, you could get some clip-on aerobars if you fancy trying an aero position for added speed.

cheaper that a pair of drop bars & new shifters, and a lot less faff

njee20

For free you can flip your stem, and put any spacers above it. The more you can reduce your frontal area the quicker you will go.

Northwind

njee20 wrote:

That's a collossal difference! Get into time trials - if you could save more than 6 minutes off your time you'd be utterly overjoyed!

Nah, get into downhill- if you save 6 minutes off your time you'll arrive before you left, and win both the world cup and a nobel prize for physics.

nwmlarge

Northwind wrote:

njee20 wrote:

That's a collossal difference! Get into time trials - if you could save more than 6 minutes off your time you'd be utterly overjoyed!

Nah, get into downhill- if you save 6 minutes off your time you'll arrive before you left, and win both the world cup and a nobel prize for physics.

love this!

verloren

handful wrote:

I've knocked around 6.5 minutes off the 10 mile loop time which is more like 15% timewise

Sounds pretty good to me - you reduced the weight you're moving by about 10%, and got about 15% faster.

njee20

Nah, get into downhill- if you save 6 minutes off your time you'll arrive before you left, and win both the world cup and a nobel prize for physics.

HebdenBiker

handful wrote:

The lycra put me off as well, apart from base layers it should be reserved for the circus or the olympics.

I know you're probably being light-hearted but if speed is your aim then close-fitting cycling clothing will certainly make you faster.

Some people in these boards have a tribal aversion to looking like a roadie, but you've posted a thread about how to go faster on the road. You are a roadie

handful

Nooooo. don't tell me I'm a roadie!! No, seriously though I do feel much more 'comfortable' with a pair of baggie shorts over a pair of padded lycra but I take your point. I also feel much more welcome in this forum...they seem a cliquey bunch over in the road forum, and I also find most roadies are very aloof out on the road for some reason although I know this is a bit of a sweeping statement.

I'm not obsessive about speed by the way, I just expected to be able to see speeds of 4 or 5 mph higher on my bike comp with a weight drop of over 5kgs coupled with no power sapping suspension, some skinny(ish) 700c tyres instead of 2.3" knobblies on nice light American Classic Wheels. But now I have put all of your comments together to bring some perspective to my thinking and realise I was expecting far too much so for that I thank you all.

njee20

I also find most roadies are very aloof out on the road for some reason although I know this is a bit of a sweeping statement.

How do 'MTBers' know you're one of 'them'? The whole them and us thing really is a phenomenon of mountain bikers, almost like a feeling of inadequacy! Very strange.

handful

I nod to all riders whoever they are when I pass them whichever bike I'm on and find that mountainbikers generally (not always) nod back whereas roadies more often than not ignore my nod, maybe they are 'in the zone' more than a mtb rider and don't notice but they are much more receptive to a nod when I'm on skinny tyres.

No inadequacy on my part, just my own personal experience

mrmonkfinger

handful wrote:

whereas roadies more often than not ignore my nod

must admit I've never noticed a difference; some people nod back, some people don't. style of bike and tightness of shorts seems not to matter