Category Archives: My Brompton

New Rudolph

Strange times, folks? Stay safe & keep up with your social distancing. Presently no lawn bowls & club activities, no travel, etc so plenty of reasons to blog post? Various things have happened with our Brompton family & I’ll start with my Chpt3.

I have been unable to pin down exactly what makes Rudolph so good for me to ride. From the first outing I’ve almost been able to keep up with Mrs Aussie, whereas a health condition usually sees me trailing far behind. Is it the fat & fast tyres? Is it the lighter weight than our other Bromptons?

Whatever the reason, I’ve also had the desire to avoid mods to Rudolph that moved away from the special Chpt3 look. Thinking now that Rudolph’s lightness should not be sacrificed, any changes would have to be for a very good reason. After all, most common mods (eg grips or saddle) also add weight & so I had to be careful & picky when thinking I could improve anything.

A great improvement for me has been the smaller chainring. The gear range is now far more useful, with a much-needed low 1st gear & the ready use of the highest gears (where previously I would rarely need 6th gear). Shifting through all gears during a ride provides an enjoyable flowing treat.

A rack makes a Brompton so practical for movement when folded (& stability when parked). I’m sure Andrew Ritchie never originally intended an E model Brompton & probably would agree that the folding frame geometry is flawed without mudguards or rack. (If the angle of the mainframe hinge was different, the folded E model would sit evenly on both wheels & so avoid its tilt toward the left – making it vulnerable to toppling over.) About a quarter of the weight of a standard Brompton rack (& that’s ignoring the weight of mudguards & stays), the lightweight rack suits an E model perfectly.

Another notable weight reduction is the lightweight pedals (fixed on the right, removable on the left), more than making up for the rack weight. I’ve been noting the weights of all my Brompton component changes & it’s surprising what a difference there can be. Overall, Rudolph is now lighter than original & ideally setup to assist with any weight reduction of my own?

Losing weight?

While attempting to keep Rudolph, my CHPT3 Brompton, as standard as possible, some mods have been happening (more on that soon?). This lightweight Brompton (probably?) won’t be seen with flashy wheels, more Ti, etc, so you’ll have to look hard to see changes from original.

Having said that, today’s mod fits the bill; a subtle little weight reduction that retains the original look? (Sorry, any weight weenies will have to do their own estimations for the grams saved.)

Reflecting

Having picked up my new Brompton CHPT3, & really enjoying the short about-city evening ride to dinner, the next day Mrs Aussie & I just had to get out for an appraisal/comparison session. Sydney Olympic Park was the venue for Clarence & Rudolph to cruise about.

No major hills around SOP but I’m still limited (heart-wise) in being able to keep Mrs Aussie in sight (my usual answer is to ride Ralph-e, my Brompton Alfine GrinTech-electric model). However, my pace on Rudolph really surprised me & the lively & lightweight ride was a delight in being able to keep up comfortably? (A swap to Clarence for a time wasn’t a good idea; my extra speed was gone but Mrs Aussie also appreciated the effortless performance from Rudolph.)

Reflecting on the experience was difficult. I rarely ride a Brompton without loaded front-luggage & Marathon tyres. Did the lightweight Brompton & Schwalbe One tyres make that much difference? More appraisal obviously required, although my too-brief attempt near home the next day with both Bromptons with & without luggage was inconclusive, although Rudolph seemed superior?

The call

Omafiets’ phone call told me that my Brompton CHPT3 was now ready & so without much delay I headed for the shop. After fitting lights & swapping to Presta-valve tubes, I rode off into the night to a celebratory dinner.

Momentous

Being somewhat blog-quiet of late & often wondering whether there’s something from our little rides that’s blog-worthy, I’ve just had an event (momentous even?) that probably qualifies?

Omafiets in Sydney had an event to present the latest iteration of Brompton CHPT3, the David Millar-inspired lightweight Brompton. With very limited CHPT3 numbers coming to Australia, Omafiets were conducting a ballot to purchase the 2 bikes allocated for Sydney. David was on-hand to talk about the concept & conduct the Sydney ballot draw.

A very pleasant evening of drinks, nibblies, chats & talks before the business of the draw. First number drawn went to ticket holder 01 – wasn’t that me? Yes! Congratulations came from all directions & then the next draw for another lucky winner – Sari. (See pic of winners with David Millar)

More electric

No change on the Brompton front (although little activity too) but thought I should post about our new wheels.

We’ve some riding coming up that’s more suited to MTBs so after sprucing up our (very) old steeds, I was almost ready to consider some “un-assisted” riding when I came across a couple of special-priced eMTBs. Sold!!! – following a brief test-ride & yesterday we ventured back to pickup our new toys.

The ferry ride home was a good time to contemplate the road/trail ahead?

Like the eBrompton (that may one day arrive in Australia?), our Pedalec eMTBs have 5 levels of assistance. However, since my brief test-ride the Bosch mid-drive motors have had a firmware upgrade to include an “eMTB mode” that automatically selects the level of assistance depending on the pedal pressure. Without even changing gear, heavy pedal pressure supplies Turbo mode – quite amazing!

I’ve been delighted with Ralph-e, my GrinTech-equipped electric Brompton. The assistance-level is programmable (although rarely changed after settling on a level that provides economical battery range) & the combination of a torque-sensing BB & the Alfine 11-speed rear hub provide riding bliss! How this compares to Brompton’s offering will be the $64k (or $5k?) question?

Our Brompton appearances at the Dungog PedalFest late last year was “interesting”. If it wasn’t for the generous helpings of scones with jam & cream, the rough roads could have seen some DNFs. At the time I’d thought that Ralph-e & Peregrine wouldn’t be back next time but now I’m sure the eMTBs will just love it?

Ralph-e’s overdue Hack?

Ralph-e (my Alfine 11-speed Brompton – with a GrinTech electric conversion) has had a frustrating “chain drop” issue throughout the 5 years we’ve been together. With “Murphy’s Law” timing, infrequently the chain can be dislodged from the rear cog & chain tensioner sprockets. I’ve developed a second-sense feel for a successful unparking step, although I admit to including a quick look down at the chain at the rear hub before attempting to ride away. 

The following 3 pics illustrate the scenario: (1) taut chain over the rear cog, (2) slight reduction of tension in the chain (where the chain is sagging & starting to slide down & out over the widened rear frame), (3) further reduction of tension (resulting in further chain sag over the frame & commencement of the chain moving off the teeth of the cog). At this point, if the rear wheel rotates backwards then the chain will fall off the cog & then off the tensioner sprockets. The reduction in chain tension usually comes about when parking/unparking & as long as back-pedaling is minimised then chain drop can be avoided. I believe the Alfine hub also has some slight drag when rotating backwards & so vigorous back-pedaling while riding can also achieve increased chain slack & sag over the rear frame tube; hey presto, chain drop?!



Now I think I may have resolved the issue, through setting up a “chain keeper” for the section of chain closest to the rear cog (thereby maintaining chain alignment over the cog teeth). The next 2 pics show my chain keeper in situ with the chain taut (pic 1) & chain sagging (pic 2). My keeper?: a large-sized cable tie (working great). Maybe not what Brompton would do?