Are different muscles used?

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paul

New Member
Location
Doncaster
After over 20 yrs of cycling on a mountain bike, 'up hill and down dale' I bought a road racer. I have spent every day for the last two weeks whilst off work for the Xmas breakcovering 30/40 miles, really enjoying the speed. Even cycling up usual hill climbs in the locality. Went back to the mountain bike for the last two days and today, doing my usual 25/30 mile circuits, but my upper leg muscles really ache after these rides. Consulted my LBS yesterday as to my riding position on both bikes, they confirmed I needed no adjustments. Why the aches? Does riding one bike differ from the other, using different muscles in different ways? I know the body position is different, does anyone else have similar aches in the legs, changing from road racer to mountain bike and vice versa?
 

yenrod

Guest
I know that MTBs usually have longer cranks (175's) and more leverage...where'as roady bikes usually have 170's..

Maybe thats the reason...
 

andygates

New Member
Different positions do use muscles differently. You should try aero-bars. Never has my arse been so sore.
 

wafflycat

New Member
andygates said:
Different positions do use muscles differently. You should try aero-bars. Never has my arse been so sore.

That's where you're going wrong - try putting your arms on them, not your arse. You should notice an immediate increase in comfort :becool:
 

monnet

Guru
yenrod said:
I know that MTBs usually have longer cranks (175's) and more leverage...where'as roady bikes usually have 170's..

Maybe thats the reason...

I have no experience of MTB's but my experience of road bikes has always been that you can specify the crank length - typically 170, 172.5 and 175. Buying a ready built bike it depends on the manufacturer (Trek seem obsessed with 175's for some reason).

The real reason for the aching is likely to be a change of position. Soreness on the top of the thighs is a sure indication that the saddle is too low; stretched calves/hamstrings a sign that it is too high.
 

yenrod

Guest
>Trek seem obsessed with 175's for some reason

Because when Armstrong was riding he used to ride them - after consulting Indurain who also rode them though I always wondered why = because he hasnt the leg length of Indurain !

Mine (bike - not Trek but a Raliegh) came with 172.5 for some reason. Why dont manufacturers offer changes in items on the bike free !
 
Crank lengths are based on your leg length, in rough terms.

Your leg length tends to vary based on your overall size, which tends to determine the size of the bike you buy.

So buy a small bike and you'll find it has 170 cranks, a medium will have 172.5, a large will have 175 : Spesh for instance fit 172.5's on a 56cm frame and 175's on a 58

Custom-build or specify and you can have whatever lengths you prefer.
Buy 'off the peg' and you'll get the size it comes with.
A better LBS will twiddle with things to make it fit you or your preferences, e.g. fitting shorter or longer stem, but a chainset is a bit more of a change.
 

monnet

Guru
I asked for 172.5's on my Spesh (54cm) and was told that was the standard for that size, though if I'd wanted longer or shorter they would have obliged. Seems they obviously think things through more than Trek in some areas.

I'm intrigued that MTB's would come with 175's though. Surely, like cross, the set up of an MTB is all about clearance so a high bottom bracket and short crank lengths are standard - I know cross cranks go down to at least 165.
 

andygates

New Member
You know, I've never noticed the difference between crank lengths. It's always struck me as about the least important bike parameter change.
 

monnet

Guru
andygates said:
You know, I've never noticed the difference between crank lengths. It's always struck me as about the least important bike parameter change.

I find it makes a massive difference. All the p1ssing about with getting positions the same is bad enough without adding in the problem of crank length. Maybe I'm just very set in my ways regarding position but I had to raise my saddle 2mm (I kid you not) when I changed my shoes. Then again I think there are two types of cyclist - the Merkcx/ Bettini obsessives (Bettini raises his saddle every winter by a couple of mm to accommodate thicker winter clothing!) and the Indurain style 'give me a bike and I'll ride it.' I guess I must be closer to the obsessive.
 
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