Bromhopper

[shemozzle999]

I just been looking at all the pictures that have been posted on the Hopper/Viking threads and have wondered if the front end could be married onto the Brompton negating the need to spread the forks?

I know it may cause folding problems but it might make a interesting project for someone to find out if it is possible

 

[RobF]

A cheap and nasty Chinese front end on a Brompton?

Sacrilege, vandalism, there should be a law against it.

 

[shemozzle999]

A case of East meets West it is happening more and more.

 

[Deleted member 4366]

Wrong size unfortunately. 20" vs 16".

 

[RobF]

I watched the forks being spread on my Brompton when the Nano conversion was done.

I couldn't say how far they were spread, but it is only a few millimetres.

Of more concern was the bit of meat that needed to come out of the dropouts.

Must have weakened them a little, but no problems so far.

 

[shemozzle999]

Hi d8veh.

Yes, I know, it would make it go faster

Hi RobF,

Had my Sparticle forks shear but after talks with TETS they made the special washers to support the fork ends to help alleviate the problem.
I made my own version as they were waiting for another batch to be made:

http://pedelecs.co.uk/forum/threads/cheap-brompton-conversion-kit.12494/page-11#post-183633

 

[Clockwise]

I doubt it would go faster as it would handle horribly and give you some headset issues as the weight all sits on one point.

 

[shemozzle999]

It appears to be a Bafang SWXB motor so the drop out width should be 100mm thus alternative motors would fit.

Brompton details:

Steerer tube is 1" dia for SWB older style or 1 1/8" dia for LWB and 139mm length.

Head tube length is 105mm.

Hopper details: unknown.

Could any Hopper owner fill in the blanks?

Edit: Wondering now if they could be fitted to a Dahon to allow for a wider front motor.

 

[greencat]

A cheap and nasty Chinese front end on a Brompton?

Sacrilege, vandalism, there should be a law against it.

I have a Brompton myself so feel I can comment.

In fairness, the Brompton is hardly made from top notch materials and components either (unless you get the titanium one). It might have a nice fold and great ride, but the quality leaves a lot to be desired in places.

 

[shemozzle999]

Possible Hopper upgrade without changing the electrics.

Looking at the photo in the thread below, it appears to be a SWXB motor on the hopper.

http://pedelecs.co.uk/forum/threads/help-with-eco-stepper-where-to-put-bags.16604/#post-204085

If it is providing 15.5 mph then I believe it is the 290 rpm version. There is a faster wind version of 328 rpm as fitted on my Brompton which would take the speed up to 17 mph and this could easily be changed over by exchanging the innards as the side cover can be removed by undoing a few screws.

You could then rebuild the old innards into the new shell and sell it off as a spare hopper motor.

The range could be doubled by fitting a 24v,15Ah battery from BMS battery.

http://www.bmsbattery.com/24v/246-24v-lithium-ion-little-frog-abs-shell-ebike-battery-pack.html

 

[shemozzle999]

I have a Brompton myself so feel I can comment.

In fairness, the Brompton is hardly made from top notch materials and components either (unless you get the titanium one). It might have a nice fold and great ride, but the quality leaves a lot to be desired in places.

Hi greencat,

I agree that some niggley bits are long overdue a quality upgrade and have not been addressed: the lhs pedal for example requires an upgrade, it could be redesigned to make the bearing removable for servicing, but at least virtually all spares are available but some of the older model parts are now becoming obsolete.

 

[shemozzle999]

A cheap and nasty Chinese front end on a Brompton?

Sacrilege, vandalism, there should be a law against it.

One advantage of the Hopper forks is that they have been designed to accept an electric motor where as the Brompton forks have not.

 

[jerrysimon]

Its a known fact that a Brompton frame will go on for at least 10 years of daily use. Compare that to an equivalent Dahon which you will be lucky to get more than 3-5 years of daily use out of. Also try and buy a part for a Dahon (forks etc) after three years given their models change yearly. At least the Brompton design has been kept/changed in such a way that parts are still available and fit ten year old models.

BTW I have a Ti Brompton and its perfect

 

[Cyclezee]

Slightly off topic, but if anyone is looking for non powered 26" wheel folder right now this seems like good value for money http://www.evanscycles.com/products/tern/joe-c21-2013-folding-bike-ec032588

 

[shemozzle999]

It a known fact that a Brompton frame will go on for at least 10 years of daily use. Compare that to an equivalent Dahon which you will be lucky to get more than 3-5 years of daily use out of. Also try and buy a part for a Dahon (forks etc) after three years given their models change yearly. At least the Brompton design has been kept/changed in such a way that parts are still available and fit ten year old models.

BTW I have a Ti Brompton and its perfect

I am hoping for more than 10 years Jerry, the green one featured in my build thread is circa 2005 it was purchased from forum member Thunderblue back in 2009 already converted with a Sparticle kit.
It served 3 years daily service by my niece while she was at Uni and it was returned when she passed her driving test.
It required a new BB, lhs pedal, chain and head set bearings to bring it back up to top working condition.

 

[RobF]

As (most) other owners have said, the Brompton is a good, sturdy bike, let down a little by some of the minor components.

There are not many bikes which will stand up to daily use, but lots of Bromptons do, year in, year out.

Mine doesn't get that sort of hammer, but has still been faultless in the five years since I bought it.

As a dealer once said to me: "A Brompton is a bike you need only buy once."

 

[greencat]

Just a contrary opinion. Mine started failing in lots of different ways after the first year of heavy-ish commuting (5-10 miles a day in a quite hilly area). Over the following year I had to fix the following:

The chainring sheared away from the crank which meant I had to replace the entire drive chain as the cogs and chain had obviously worn.
The plastic seat insert cracked and failed.
Ditto the seat clamp

Fixing a puncture on the rear wheel is a serious pain in the backside. I can replace a tube on my mountain bike in 5 minutes, the brompton takes 40 mins as it requires dismantling of most of the rear gear system and getting the tire on/off the rim requires real ingenuity. For a commuter bike, you need to be to fix things quicker than that. I ended up using puncture proof gunk in the tube to avoid this.

Many of the parts are hardly premium either considering the price. Often you'll find steel and plastic and screws/rivets, rather than the alloy/hex bolts found on most other bikes eg brake levers, pedals, headsets.

In short, it feels like a typical British product in a way - fantastically designed, but a bit cheap on production.

I am not a heavy guy btw.

I do love the idea of the Brompton and enjoy riding it but it's not been the most reliable of rides for me. I should say, however, it's been a reliable occasional ride in the five years since I fixed the above.

 

[RobF]

The chainring sheared away from the crank which meant I had to replace the entire drive chain as the cogs and chain had obviously worn..

That is a known problem.

Some break when the rider accelerates hard from rest.

I think I lack the power to break mine.

Anyway, it's now a Nano which will reduce the stress on the drivetrain,

 

[shemozzle999]

Hi greencat,

Are you familiar with the Brompton Technical videos, lots of helpful tips and tricks to make servicing that little bit easier?

https://brompton.zendesk.com/entries/22325003-technical-videos

This one now missing but available on youtube

http://www.youtube.com/watch?feature=player_detailpage&v=qPC1ZmjVwNc

https://brompton.zendesk.com/entries/21603758-replace-a-tyre-or-the-inner-tube

For SM+ tyres I use 3 or 4 or these to hold the tyre into the well of the rim before using the tyre levers

http://www.amazon.co.uk/Natural-Reusable-Cable-3-6mm-150mm/dp/B007JIP49S/ref=sr_1_1/278-8749952-1770003?ie=UTF8&qid=1390393089&sr=8-1&keywords=reusable+tie+wraps

 

[greencat]

Thanks for those. There's a few useful tips in those.

I did estimate, however, it would take the expert in the video around 20 mins to fix a puncture. Never mind trying it on a wet and windy winter's night under the light of a street lamp.

The small wheels obviously don't help, neither do hub gears, or the fiddly frame tabs, or the Brompton's lack of a dedicated rear hanger. Taken together, however, the experience of fixing a puncture is near diabolical.

I once asked a bike shop to do it. Normal tube change price was a tenner, for the Brompton it was 20 notes. I ended up doing it myself.