I have tried and tried to find someone who can suggest a way to have road gearing on my mountain bike! When I am on the flat (perhaps slightly downhill) my legs are going like a fiddlers elbow and I really am not going more than 18 MPH. My front cog is 48 - rear 11. SURELY one can fit a road front cog, I have no swing arm frame to complicate the issue. I have never ever had to use the other two smaller front cogs, nor the very lowest gears on the large cog. I know you will say "buy a road bike, but most/all of my riding is on dirt and muddy trails. But I do have the 'need for speed' often
Why can't I get the right gearing????
- Thread starter TrugMaker
- Start date
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PpPete
Legendary Member
- Location
- Chandler's Ford
48 x 11 @ 18 mph is .... 60 rpm
Fiddler's elbow it ain't.
A respectable spin speed of 100 rpm in that gear takes you to 30 mph, at which point most of us start to think about freewheeling anyway.
But, if you want to, fit a road chainset, move your front mech up the seat post a few mm, and enjoy !
Fiddler's elbow it ain't.
A respectable spin speed of 100 rpm in that gear takes you to 30 mph, at which point most of us start to think about freewheeling anyway.
But, if you want to, fit a road chainset, move your front mech up the seat post a few mm, and enjoy !
lulubel
Über Member
- Location
- Malaga, Spain
A road bike chainset isn't going to make that much difference. My road triple only has 50 teeth on the big ring.
oliver
Senior Member
- Location
- oxfordshire
More like Tennis Elbow.
Cycleops
Legendary Member
- Location
- Accra, Ghana
Try a 52 front ring but it's not going to make that much difference.
Thankyou all, really didn't expect a response at all. Have just recently discovered the joys of cycling, in my area there are so many woodland and country rides but there are times when I just need to speed (the reason I no longer drive a car). But my wife bought me a fantastic stereo that sits on the handlebars (as I think headphones are dangerous), I think the accompanying music will alleviate that urge after removing the Heavy Metal tracks!
02GF74
Über Member
the big ring on most mtb is typically 42T ot 44T. If you can spin at 100 rpm - assuming above is correct - which sees you doing 30 mph on the flat on an mtb with fat tyres, then you must be approaching super human status.... which I find somewhat hard to believe - that would be equivalent to 35 mph on road.
If you are talking about spinning out on downhills, then fitting larger ring will help but it will compromise gearing for off road riding. You may need to raise the front mech and may have trouble when shifted to the smallest chain ring as you have exceededed the capacity of the front mech.
lulubel
Über Member
- Location
- Malaga, Spain
I was going to ask about that. My understanding was that road and MTB chainsets, front mechs and shifters are not compatible - at least not Shimano ones. If you want to change the chainset, you need a new front mech and shifters as well. Is that correct, or am I way off the mark here?
PpPete
Legendary Member
- Location
- Chandler's Ford
Certainly there is a lack of compatibility between road and MTB as far the shifters & mechs are concerned (they use different cable pull amounts)
but both MTB and road mechs will usually operate the intermediate sized chainsets that are produced for hybrids and touring.Thus road mechs designed for 52/39/30 may struggle with MTB chainsets like 42/32/22 (and vice-versa) but both are probably OK with 48/38/26 even though the curvature of the mech cage may be less than ideal.
but both MTB and road mechs will usually operate the intermediate sized chainsets that are produced for hybrids and touring.Thus road mechs designed for 52/39/30 may struggle with MTB chainsets like 42/32/22 (and vice-versa) but both are probably OK with 48/38/26 even though the curvature of the mech cage may be less than ideal.
PpPete
Legendary Member
- Location
- Chandler's Ford
Unfortunately most MTB chainsets are 4 arm, whereas nearly all 52 rings are for 5 arm. Let alone the various different BCDs (bolt circle diameter).
lukesdad
Guest
Older mtb chainsets are 5 arm with same BCD as modern compact chainsets, If its a square drive BB you can pick them up cheap as chips on fleabay.
lulubel
Über Member
- Location
- Malaga, Spain
That's useful, thanks. I'd rejected my original idea of putting a 48/38/26 on my Surly for touring because I thought it would be incompatible and I'd have to give up my STI levers. It would be very nice if that isn't the case.
CopperCyclist
Veteran
+1
What you're thinking of as pedalling fast, isn't. Take Petes suggestion, find a downhill and get those legs spinning until you are doing 30mph or so!
It may help you acheive this if you try to improve your overall cadence - I.e. start dropping down a gear on the flat, but thm pedal faster to maintain the same speed - sounds like you might be to used to grinding out too big a gear if you see 60rpm as pedalling fast!
