Discussion
I've got a Claud Butler Cape Wrath D24 which I've had for a while. It's now got to the point where it's running 26x1 slicks and I'm almost always in top gear and typically doing an indicated 18MPH on the flat.
My riding is mostly on fire trails which are well pot holed and on quiet but very badly surfaced/rutted roads. I live in the fens so hills aren't an issue, in fact the only time I see them is on the TV!
So I got to thinking, rather than get a roadie (which might be a bit sensible for me) Why shouldn't I increase my gearing, pare a little more weight and have a bike that's quick yet can still handle being thrown around on badly surfaced tracks.
The geo and quick steering make sense where I ride, I like the discs for their good wet/dry performance the SDG Bel Air it now sports is comfy And I can still wheelie and behave like a fool when the mood takes me.
I'm 45 so I'm never going to win any races but I'd like the quickest road bike that can handle very bad surfaces(think of having your jaw slammed shut and you'll get the idea)
So why shouldn't I do it or if I should what should I do to improve my on road speed?
My riding is mostly on fire trails which are well pot holed and on quiet but very badly surfaced/rutted roads. I live in the fens so hills aren't an issue, in fact the only time I see them is on the TV!
So I got to thinking, rather than get a roadie (which might be a bit sensible for me) Why shouldn't I increase my gearing, pare a little more weight and have a bike that's quick yet can still handle being thrown around on badly surfaced tracks.
The geo and quick steering make sense where I ride, I like the discs for their good wet/dry performance the SDG Bel Air it now sports is comfy And I can still wheelie and behave like a fool when the mood takes me.
I'm 45 so I'm never going to win any races but I'd like the quickest road bike that can handle very bad surfaces(think of having your jaw slammed shut and you'll get the idea)
So why shouldn't I do it or if I should what should I do to improve my on road speed?
I just googled your bike and saw it has a 22/32/42 front chainset. Road bikes are typically 34/50 or 39/52 for flatter terrain so you would need bigger chainrings on yours, and a longer chain. Rear mech and shifters will work fine though.
http://www.evanscycles.com/categories/bike-compone...
However, for the money you could end up spending, I would recommend you do actually go for a test ride on a proper road bike
http://www.evanscycles.com/categories/bike-compone...
However, for the money you could end up spending, I would recommend you do actually go for a test ride on a proper road bike
itsnotarace said:
I just googled your bike and saw it has a 22/32/42 front chainset. Road bikes are typically 34/50 or 39/52 for flatter terrain so you would need bigger chainrings on yours, and a longer chain. Rear mech and shifters will work fine though.
http://www.evanscycles.com/categories/bike-compone...
However, for the money you could end up spending, I would recommend you do actually go for a test ride on a proper road bike
What price a road bike though? And I lose the MTB riding position which I know is not ideal for ultimate speed but is bloody handy for control.http://www.evanscycles.com/categories/bike-compone...
However, for the money you could end up spending, I would recommend you do actually go for a test ride on a proper road bike
I was thinking of putting a close ratio rear sprocket on so I can pull my way up to the larger front chainring. Sure, I'll lose the granny ring to a degree but I'd still have fairly low gearing.
Currently I only use the 42 tooth ring 99% of the time anyway. If I stick with a triple at the front going for 52/42/30 tooth I get a lot more usable gears and then go to 12-25 teeth at the rear?
I suppose I should probably go and count my current chainset first
I recently got a replacement 48 tooth replacement chainring for the front chainset (mine's a Shimano Deore Hollowtech), and after some shenanigans getting the front gearshift to work properly (involving fine tuning with a hammer and drift!) I have a much faster top speed. This replaced the old 44 tooth ring - and I have left the inner 2 as they were (32 and 22 teeth). Gear change is smooth and effortless!
I do use the bike off-road a lot, but it's good to have the higher ratio for the roady bits!
Also DMR Moto Digger tyres are low rolling resistance on the road, but still plenty of grip off-road - only slipping a bit on mud of a certain consistency!
I sometimes think about a road bike, but then keep getting distracted by the full sussers out there!
I do use the bike off-road a lot, but it's good to have the higher ratio for the roady bits!
Also DMR Moto Digger tyres are low rolling resistance on the road, but still plenty of grip off-road - only slipping a bit on mud of a certain consistency!
I sometimes think about a road bike, but then keep getting distracted by the full sussers out there!
Edited by Funkateer on Saturday 5th June 06:25
Noooooooooooo, I've just posted this on C+ 
I'd love a road bike, I really would but the lightnes wouldn't cope with my commute (I've got to replace a bent rear spindle this morning) and there's a section of gravel for half a mile, wouldn't fancy negotiating that on a roadie
I know what I want probably won't suit most people but I can spin out on 42/11 with a moderate tail wind now. Just wondering what I can do with the wasted 22 ring.
My current rear cassette is a CS-HG30-8I which has the following ratios
11/ 13 /15 /17 /20 /23 /26 /30
I think could swap that for an HG90 which has 12 / 13 / 14 / 15 / 17 / 19 / 21 / 23 teeth and pair it with the FC-M311 which has 48, 38 and 28 teeth.
Would it be possible to climb the odd hill (less than one a month) on 28-23 gearing and would 48-12 give me a better top speed assuming I can pull it?
I'd love a road bike, I really would but the lightnes wouldn't cope with my commute (I've got to replace a bent rear spindle this morning) and there's a section of gravel for half a mile, wouldn't fancy negotiating that on a roadie
I know what I want probably won't suit most people but I can spin out on 42/11 with a moderate tail wind now. Just wondering what I can do with the wasted 22 ring.
My current rear cassette is a CS-HG30-8I which has the following ratios
11/ 13 /15 /17 /20 /23 /26 /30
I think could swap that for an HG90 which has 12 / 13 / 14 / 15 / 17 / 19 / 21 / 23 teeth and pair it with the FC-M311 which has 48, 38 and 28 teeth.
Would it be possible to climb the odd hill (less than one a month) on 28-23 gearing and would 48-12 give me a better top speed assuming I can pull it?
If you're going to stick with the mtb I'd replace the triple with a single 44,46 or 48t chainset, remove the front mech and changer and use an 11-34 cassette on the back. Maybe replace the front forks with some rigid carbon ones too (sold on ebay).
For speed you'd be better off starting with a 700c bike though.
I built this for my father who had very similar requirements:
Specialized Sirrus (road biased) hybrid frame
Carbon cross forks
Strong 700c road racing wheels (32 thick spoked Ultegra/Mavic MA2) with 32mm cross tyres
39t single ring with 11-34t cassette.
Weighs around 18lbs, flies on road, bridleways & firetrails & can cope with light offroad.
For speed you'd be better off starting with a 700c bike though.
I built this for my father who had very similar requirements:
Specialized Sirrus (road biased) hybrid frame
Carbon cross forks
Strong 700c road racing wheels (32 thick spoked Ultegra/Mavic MA2) with 32mm cross tyres
39t single ring with 11-34t cassette.
Weighs around 18lbs, flies on road, bridleways & firetrails & can cope with light offroad.
I believe I've calculated myself into a corner
According to the Sheldon Brown ratio calculator my standard gearing is as follows:
22 32 42
11 3.6 5.2 6.8
13 3.0 4.4 5.8
15 2.6 3.8 5.0
17 2.3 3.4 4.4
20 2.0 2.9 3.8
23 1.7 2.5 3.3
26 1.5 2.2 2.9
30 1.3 1.9 2.5
If I go for a 28/38/48 chainset and a close ratio cassette I get:
28 38 48
12 4.2 5.7 7.2
13 3.9 5.2 6.6
14 3.6 4.9 6.1
15 3.3 4.5 5.7
17 3.0 4.0 5.1
19 2.6 3.6 4.5
21 2.4 3.2 4.1
23 2.2 3.0 3.7
Which seems to be about "half a gear" to me, not really a worthwhile gain?
My only option might be just to change the chainset which would give me
28 38 48
11 4.6 6.2 7.8
13 3.9 5.2 6.6
15 3.3 4.5 5.7
17 3.0 4.0 5.1
20 2.5 3.4 4.3
23 2.2 3.0 3.7
26 1.9 2.6 3.3
30 1.7 2.3 2.9
Which ups my top gear ratio by effectively one gear?
Unless anyone can see a flaw in my thinking/calcs I think I've got to lay the idea to rest.
Bum.
According to the Sheldon Brown ratio calculator my standard gearing is as follows:
22 32 42
11 3.6 5.2 6.8
13 3.0 4.4 5.8
15 2.6 3.8 5.0
17 2.3 3.4 4.4
20 2.0 2.9 3.8
23 1.7 2.5 3.3
26 1.5 2.2 2.9
30 1.3 1.9 2.5
If I go for a 28/38/48 chainset and a close ratio cassette I get:
28 38 48
12 4.2 5.7 7.2
13 3.9 5.2 6.6
14 3.6 4.9 6.1
15 3.3 4.5 5.7
17 3.0 4.0 5.1
19 2.6 3.6 4.5
21 2.4 3.2 4.1
23 2.2 3.0 3.7
Which seems to be about "half a gear" to me, not really a worthwhile gain?
My only option might be just to change the chainset which would give me
28 38 48
11 4.6 6.2 7.8
13 3.9 5.2 6.6
15 3.3 4.5 5.7
17 3.0 4.0 5.1
20 2.5 3.4 4.3
23 2.2 3.0 3.7
26 1.9 2.6 3.3
30 1.7 2.3 2.9
Which ups my top gear ratio by effectively one gear?
Unless anyone can see a flaw in my thinking/calcs I think I've got to lay the idea to rest.
Bum.
Somethings wrong here.
You say you're spinning out in top gear (42/11T) at 18mph - summerising all your posts.
You're not pedaling fast enough.
For me, at full pelt (110+ rpm cadance) offroad, in a 42/11T gear (albeit 2.1 tyres not 1.0) is 30+mph.
My On One Inbred commuter has road wheels with 36/14T single speed gears. With a rough 90rpm cadance I'm ticking over at 17/18mph.
My Cove Stiffee with 34/18T single speed set-up trundles along a 12(ish)mph at 90rpm cadance.
You say you're spinning out in top gear (42/11T) at 18mph - summerising all your posts.
You're not pedaling fast enough.
For me, at full pelt (110+ rpm cadance) offroad, in a 42/11T gear (albeit 2.1 tyres not 1.0) is 30+mph.
My On One Inbred commuter has road wheels with 36/14T single speed gears. With a rough 90rpm cadance I'm ticking over at 17/18mph.
My Cove Stiffee with 34/18T single speed set-up trundles along a 12(ish)mph at 90rpm cadance.
Spinning as fast as my knees allow I was doing an indicated 30.2 on the MTB, my sustainable speed seems to be around 17.8 every bloomin time I look at the speed, however this seems to have increased.
I've just found a combination that gives me an 8% difference per gear instead of the current 18%. The (daft) idea isn't dead in the water just yet
I've just found a combination that gives me an 8% difference per gear instead of the current 18%. The (daft) idea isn't dead in the water just yet
BliarOut said:
It's a bit of both. I've got a 12/23 on now and it's lovely through the gears but I'll easily end up pedalling too fast with a slight tail wind. The bloke in the shop reckoned I wouldn't get a 52 on there due to frame clearance issues on an MTB but I'm not so sure. Anyone done it?
I'm confused, have you found an 11t or 12t sprocket too low as top gear?An 11t sprocket will give you an extra 2.5mph over a 12 pedalling at 100rpm. A 46t chainring would provide an additional 2.5mph at the same rpm.
The bloke in the shop is right, though you may get away with a 44 or 46t big ring.
I'd have thought an 11-23 or 11-25 cassette with your 42t chainring as MK1 Fan suggests should give you a sufficiently high top gear (just under 100"). Plenty of velodrome races and time trials have been won on lower gears!
If you have not done so, you should also calculate your pedal rpms (you can just count using a watch or clock strapped to your bars), it should feel comfortable to pedal at 100rpm for extended periods, and only feel like 'spinning out' at 130rpm+, if you are bouncing or thrashing you need to work on making your technique smoother, keeping the upper body still and applying power throughout the whole pedal cycle - it will increase your power, stamina and comfort.
I didn't mention that 'your' maximum cadence and mine may be quite different. Thanks to a big motorbike accident my left knee is quite unique in function and about 2" closer to my hip than when I started out Yes, there's always one difficult bugger and I'm him... You'll just have to accept that for me with my particular skeleton and missing bits a larger chainwheel will help.
Yes, there's always one difficult bugger and I'm him... You'll just have to accept that for me with my particular skeleton and missing bits a larger chainwheel will help.48 teeth and external bearings to replace my budget BB. I think that might just be the best I'll ge. Sticking some 700 wheels on would raise the gearing a bit more I suppose 
Well I did mention cadance rates and you didn't respond.
A 52 won't fit.
Sounds like you need a road bike or a flat bar road bike or - if the frame has disc brakes - getting a set of road rims built on to mtb hubs and run an 11-23 cassette with a 48T chain ring on the Cape Wrath.
If you're regularily and easily riding along the flat at over 30mph - which you appear to be claiming - then turn Pro and get your team to supply the right bike. It's about time GB had a TdF winner.
A 52 won't fit.
Sounds like you need a road bike or a flat bar road bike or - if the frame has disc brakes - getting a set of road rims built on to mtb hubs and run an 11-23 cassette with a 48T chain ring on the Cape Wrath.
If you're regularily and easily riding along the flat at over 30mph - which you appear to be claiming - then turn Pro and get your team to supply the right bike. It's about time GB had a TdF winner.
Edited by mk1fan on Monday 7th June 14:43
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