What's the difference between a road triple and a hybrid/MTB triple?

Twilkes

Veteran
I often read that road bike triple rings and their derailleurs are difficult to set up and clunky in operation. I've never had a problem with a hybrid 3x8 on any of my bikes, even a base level bike bought twenty years ago, and general comment seems to be that these kinds of triples are fine and work well. So what is the difference between the groupsets? Or is it down to the bike geometry being different, i.e. road bikes are more compact so there's less tolerance in the drivetrain?
 
Last edited:

YukonBoy

The Monch
Location
Inside my skull
People who write that road triples are hard to set up, will also write that hybrid triples are hard to set up. In your opinion they are not and that will apply to both.
 

DCBassman

Veteran
Location
Tavistock
Road triples are just triples. The only problem I have is of my own making, using mtb EZ Fire+ shifters to control it. It's not a perfect match. Using proper brifters, it's easier. Having said that, my road triple is quite wide range, 52-42-30, so the mech has a hard task, comparatively. A 50-39-30 should be no issue.
 

Hacienda71

Mancunian in self imposed exile in leafy Cheshire
Not sure the bcd is the same. Also historically the spiders on road bikes were five armed and mtb four armed. Not sure why one should be easier to set up than the other.
 

raleighnut

Legendary Member
Location
On 3 Wheels
The thing that often crops up is setting cable tension, the mech must be centred on the middle ring when that is selected. for some reason 'roadies' (well some anyway) don't seem able to grasp this concept and bugger around with the H-L screws to adjust shifting whereas the 'muddy bum' brigade seem to have this sussed, probably because they've ridden triple cranks for years.
I think one thing that throws people is that often when on the little ring the cable can be very slack so they wind the adjuster out to get rid of that but in doing so throw out the middle ring indexing. :rolleyes:
 

Pale Rider

Legendary Member
I think one thing that throws people is that often when on the little ring the cable can be very slack so they wind the adjuster out to get rid of that but in doing so throw out the middle ring indexing
Spot on - the mechanic in my local bike shop told me the same thing.

Also applies to Brompton hubs.

The cable needs to have a little flop in it when not under tension.
 

andrew_s

Guru
Location
Gloucester
Not sure the bcd is the same. Also historically the spiders on road bikes were five armed and mtb four armed. Not sure why one should be easier to set up than the other.
A somewhat short term view of "historically" ;)

MTB Triples are (or were originally, when mountain bikes first became mainstream) 110/74 bcd 5-arm, with a smallest middle ring of 34T and a smallest inner of 24T. 110/74 triples are still popular for touring bikes and hybrids.

Road Triples are 135 or 130/74 bcd, so the smallest middle ring is 39/38T - i.e a standard road double with a granny ring. (135 is Campag)

5-arm MTB triples then evolved, in the name of weight saving, into Microdrive (Suntour) and Compact Drive (Shimano) with 5-arm 96/56 bcd (or thereabouts, the two were different). These often came as 20/30/40T chainsets.

Then 4-arm MTB chainsets arrived, with a slightly larger bcd, so the smallest inner was 22T.

At about the same time, the original MTB triple lost its 74 mm bcd bolts and became the compact double, on road bikes for ordinary folk who weren't as strong on the hills as the pros.

It's mostly fashion, and marketing advantage over the other chap (the attempted component lock in is only ever short term).
 
Top Bottom