[Jack Finucan]

My quandry is that I can’t seem to get up to speed on the AM18. The only difference between the Moulton and my other road and off-road bikes is that it came with a 172.5 mm crank instead of the 175’s that all my other bikes have. I do understand that the small wheels don’t “coast” like a 700c wheel does but it seems that I need more power output than usual to ride the AM18 fast. This morning, I went out on the Moulton and rode 10 miles (mix small hills/flats) at an average speed of 14.6 and it felt like I was struggling the whole time (120psi.Schwalbe Stelvios). I also can feel the bike “bouncing” as a I’m spinning along. Is that were my power’s going? I got home and took out my Litespeed Tachyon tri-bike and did 40 miles, averaging 16.4 on a hillier course. That ride felt completely normal. I’m baffled at this point. I had hope to build up the AM18 as a time trial bike or install a fairing but can’t seem to produce enough power. Any thoughts would be appreciated.

[Patrick Doocey]

Hi Jack
I have to admit that I had a similar experience, I simply could never get my AM nor my TSR to go as fast as my large wheeled bikes.

I found that at moderate speeds (i.e. Audax speeds, 180-200 watts and 90-95 rpm) the Moultons were quite efficient, and gave very little away to the large wheelers. The only area that they suffered was going uphill, where the extra weight was a disadvantage, and the suspension did not help. I think a more modern AM than mine would suffer less in the weight department.

However, when I was trying to go faster the Moultons tended to bounce a lot and became inefficient. It always felt like a struggle. My 10 mile time trial power is about 360 watts and cadence is about 105 rpm, and trying to ride the Moulton at anywhere near that was like riding through treacle.

The Moulton is a wonderful design and excels in many areas, but I do wonder if it is fair to expect a Moulton to perform as well as a modern lightweight high-performance bicycle.
Many of the Moulton’s performence achievents are at least 25 years old and may be less relevant today.

I like the fact that it performs as well as a 700C bicycle of similar weight under touring / audax conditions, but is it reasonable to expect a 9.1-11.4kg suspended Moulton to go as fast as a 7-8kg racing/time trial bike at racing speeds?

[Alexander Johnston]

That fits in with my experience. My TSR 30 rides at a similar speed to my Hewitt SE touring bike for about the same effort. The suspension makes it a bit more comfortable for a longer ride
It tends to be a bit slower up the hills IMO but a bit faster down them.
In terms of speed it can’t compete with modern carbon road bikes.
I put the TSR 3O in terms of performance on a par with a good light steel touring bike.
Alex

[Dave Minter]

I’ve not raced seriously for close on 20 years but feel that my TSR is on average as quick as my custom big-wheeled steel Audax bike but with better comfort. Slightly slower up hills and faster down them. Same speed on hotmix, slightly slower on chipseal, better in high winds. Flatland cruising speed is close to evens (20mph) with summer fitness, regardless of bike. My disadvantage against carbon bling isn’t the bike weight (Moulton wheels are much lighter than their’s) but the 2+kg of Audax clothing, spares, etc that stays in my Moulton bag virtually year-round.

I tend to have a slow cadence and often ride out of the saddle. Choosing the race spring and running quite a lot of damping for the front suspension works for me. I only feel disadvantaged as I wind up for a playful sprint, when the front suspension resonates with my cadence.

Moultons need the lowest rolling resistance tyres to compare with decent 700C tyres. 406 Duranos are slugs compared to Grand Prix, for instance.

[Jack Finucan]

Thank you for all your help. I changed the cranks from 172.5 to 175 and moved the seat as far forward as possible and raised the aerobar armrests and these were definete improvements. Will keep you posted. 1.5 mph faster AVS on my 50 mile loop last Sunday morning.

[Jack Finucan]

Here’s an update: on Sunday morning I was out with friends on my Litespeed 700c-wheeled bike and went down a hill, reaching 33.8 mph the first time and then 34.2 a short time later. I returned there this morning on the AM18, duplicating my start speed, helmet/jersey, and bike position and peaked at a max of 27.9 on the third time. Could aerodynamics be a factor in reaching higher speeds? I know the AeroMoulton IV reached over 50 mph but that was with a full fairing. Testing continues…

[zeeland]

What is the highest gear, in gear inches, on your 700c wheeled bike?

What is the same for your AM?

Most Moultons that I’ve come across do not have the gearing for aggressive, acceleration-minded riding.

[Alexander Johnston]

Hi Jack
That’s interesting. I’ve always thought my TSR was faster downhill than conventional bikes, mainly tourers, because I tend to overtake other riders when I ride with a group.
The explanation may simply be that I tend to brake less and ride downhill faster.
I ride the way I drive: I try not to use the brakes unnecessarily.
Moultons certainly give the impression that they go fast downhill.
Alex

[Dave Minter]

I’m interested to know how you are doing with tracking down the differences between your bikes. Any news?

[Carl Folker]

It took me about two years to get into and stay on the 56 ring on my TSR 30 and the thing that seemed to help was changing the tyres to Continental Grand Prix. Instantly I could get into the 56 and average speed went from under 15mph to around 17.5 – 19mph. Now I start and stay in the big ring Moving the saddle up, down, backwards and forwards has also been a real pain but finally I got there! Don’t have a problem keeping up with club riders and recently did a 73 miler at an average of 18.84mph. I actually thought I’d only done 50 miles!

[Jack Finucan]

Mystery solved, power back. The bike was built with Phil Wood hubs (!) and then stored for 6 years. A tech at PW responded that the rear hub is gummed up. Cleaned the hub and reoiled and WOW, what a difference! He also said PW hubs have a break in period of 500-800 miles. I’m at 587 now. Was on charity ride 2 weeks ago and rolled with the A group for the entire 25 miles.

[Dave Minter]

Excellent news. I wouldn’t have thought that the rear hub could influence speed so much but there you go. Glad you’ve solved the problem.

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