ProGlass Testing

Much of the below information is from testing our original Clubman Series propellers. The results remain as valid today as they did back then. The results from our ProGlass testing are even better but not ready for publication.

What really counts is what you, the user of our product thinks of our product. Since our first moulded props were tested in October 1995 the overwhelming response from customers has been outstanding - most tell us that the Bolly injection moulded propellers are the best available. We agree. 

Test Results - Most of our testing information is (like our design information) confidential. However we can give you an idea of the activities behind the scene in testing propellers of our own manufacture and others.

Below is a reproduction of our testing for the Clubman Series 10.5 x 7. There are several test comparisons with other propeller brands, however we have deleted the brand names in this example.

  • Engine A is a high performance .45 and standard muffler.
  • Engine B is a .90 ducted fan engine and simple exhaust system.
Noise readings (in db) were taken from to the side of the propeller (where noise from the propellers is at it's maximum) and slightly forwards (hence less affect from muffler and carby noise). The noise meter was positioned quite close the model (hence the high readings). The actual distance isn't important because we were only doing comparative testing, and it was the same position for all tests. All records were the average of at least 2 recordings.

Clubman 10.5 x 7 test results


Engine A,  max RPM

Engine A, noise at max RPM

Engine A, noise at 10,000 RPM

Engine B, noise at 18,000 RPM

Engine B max RPM

Flight Test / Comments

Clubman 10.5 x 7






Smooth & Quiet, excellent vertical. Great prop !!

Brand A 10 x 8






Almost as quiet, noticably less vertical climb.

Brand B 10.5 x 7






Flexed badly during run up, very noisy.

Brand T 10.5 x 7






High RPM but noisy and lower thrust.

Brand G 10 x 8






Noisy at low RPM. Poor thrust.

Brand M 10 x 8


Test discontinued due to shocking balance.

The above figures show that at 'normal' power levels the Clubman was a touch more load than most and quieter than all. When used at higher power / RPM levels the Clubman outperformed all the rest for RPM and all but one for noise. These figures at elevated levels are interesting as it shows the prop is flexing much less than others (hence transferring more power). Similar results have been recorded for all other tests we have done in comparison between a Clubman Series propeller and other brands.

Flight Testing 

The real test of any prop is in the air. Most of our testing is done with either aerobatics or racing style models where performance changes are easier to monitor. However with the exception of customer testimonials , it is nearly impossible to publish a commentary on flight performance without being perceived to have a bias.

The real secret to good performance is to select the correct propeller for your model and engine combination.

  • For slower / high drag models, use a prop with higher diameter and less pitch. For example .45 powered trainer aircraft will be much better with a Bolly 11.5 x 5 than a 10.5 x 6.
  • For faster / low drag models, use a propeller with lower diameter and higher pitch. For example a .45 powered racing style model will be much faster with a Bolly 9.5 x 7 than a 11.5 x 5
  • Tip speed is the biggest factor in noise levels, so keep rpm and diameter lower will help - this normall mean selecting a higher pitch than ideal - but that's the price to pay if noise is the issue (as it is at some fields). For example use a 10.5 x 8 rather than a 11.5 x 6

Having selected the correct propeller, we can guarantee that the propeller will perform at least as well as, if not better than, any competitor's propeller on the market.

The feedback we constantly receive is how much flyers are are impressed with the low noise, strong vertical 'pulling' power and durability. Try one, you'll like it!


And if you think the above is good, wait till you see our new ProGlass releases for 2009. The performance gains are quite special.


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