Basket holes distance on Dolphin

Kathy Smith

Member
Would anyone be able to measure how many inches apart are the holes for mounting the basket? I'm hoping I can attach an adapter that can take one of the Brompton bags. My bike is coming soon and I would love to figure this out ASAP.

Thank you!
 

goldconch

Member
Would anyone be able to measure how many inches apart are the holes for mounting the basket? I'm hoping I can attach an adapter that can take one of the Brompton bags. My bike is coming soon and I would love to figure this out ASAP.

Thank you!
There are 3x10mm M5 bolts (0.8mm thread pitch), spacing is (or should be) 15mm. Max suggested weight capacity rating of 20lbs.
 

goldconch

Member
Thanks so much. This is very helpful!
Glad to help.

The OEM rack is aluminum, light, and fairly solid, but the 9"x9" layout is a tad odd, and won't accommodate the standard standard 8"x11" reusable shopping bag. I've sewn a black mesh liner that helps retain smaller loose stuff in the basket.

Design-wise, I might prefer a "shelf" to load normal reusable shopping bag, and/or bulkier objects <20lbs...I may supplement with the $69 RadPower Front Rack at some point, and just drill the three holes.
 

Kathy Smith

Member
Glad to help.

The OEM rack is aluminum, light, and fairly solid, but the 9"x9" layout is a tad odd, and won't accommodate the standard standard 8"x11" reusable shopping bag. I've sewn a black mesh liner that helps retain smaller loose stuff in the basket.

Design-wise, I might prefer a "shelf" to load normal reusable shopping bag, and/or bulkier objects <20lbs...I may supplement with the $69 RadPower Front Rack at some point, and just drill the three holes.
I want to use Brompton bags, so I'm hoping to install Brompton block adapter. It's not the same hole configuration but you can buy an adapter for Dahon which also has 15mm distance between holes. If this doesn't work I'll ask my local bike to drill holes.
 

goldconch

Member
I want to use Brompton bags, so I'm hoping to install Brompton block adapter. It's not the same hole configuration but you can buy an adapter for Dahon which also has 15mm distance between holes. If this doesn't work I'll ask my local bike to drill holes.
That'll look good. Please post pics!
 

Kathy Smith

Member
Sorry to bother you again but would you be able to look at this adapter and tell me if you think this would fit the qualisport? It does say that it uses M5 bolts.

Thank you
 

goldconch

Member
Sorry to bother you again but would you be able to look at this adapter and tell me if you think this would fit the qualisport? It does say that it uses M5 bolts.

Thank you
Maybe double check on the Tern and Dahon forum pages, but I think they might have just two front frame mounting holes 30mm apart (which would work) and I think they might be M6 (2mm larger). That just means that the holes on the adapter could be 2mm looser than the M5 that would come with the Dolphin, and you'll only be using two fastening mounting points instead of three. A couple small lock washers would resolve wiggle room, and an upgrade to slightly longer 10mm or 12mm M5's might be a good idea. I'd also mentally revise the 20lb cargo limit down to about 15lbs or less if there are fewer mounting points bearing the load.
 

Kathy Smith

Member
Maybe double check on the Tern and Dahon forum pages, but I think they might have just two front frame mounting holes 30mm apart (which would work) and I think they might be M6 (2mm larger). That just means that the holes on the adapter could be 2mm looser than the M5 that would come with the Dolphin, and you'll only be using two fastening mounting points instead of three. A couple small lock washers would resolve wiggle room, and an upgrade to slightly longer 10mm or 12mm M5's might be a good idea. I'd also mentally revise the 20lb cargo limit down to about 15lbs or less if there are fewer mounting points bearing the load.
Thanks, I will continue investigating. I might just ask bike shop guys who sell Brompton to see if they can just attach the Brompton adapter directly.
 

goldconch

Member
Thanks, I will continue investigating. I might just ask bike shop guys who sell Brompton to see if they can just attach the Brompton adapter directly.
Great idea. There are a variety of accessory blocks for Brompton, some have two; some have three holes not sure which one you have on order. For sure looks close enough to try. Even the 16mm triple spacing with M6 holes, should fit because the M6 holes would have an extra 1mm of radius in there. Minor tooling worst case. Now you have me thinking...
 

Kathy Smith

Member
Hi Goldconch,

I think that you said that you have the Qualisports basket. Can you tell me the exact screws it uses? You said 3x10mm M5 bolts (0.8mm thread pitch). Is that all?

Thanks!
 
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goldconch

Member
Hi Goldconch,

I think that you said that you have the Qualisports basket. Can you tell me the exact screws it uses? You said 3x10mm M5 bolts (0.8mm thread pitch). Is that all?

Thanks!
The Dolphin head tube is tooled with three x M5 threaded front luggage sockets and comes with the shorter 85mm M5 bolts you'd find for a std water bottle cage (which use a Metric 4mm head allen key/M4 hex tool). These are on a frame-welded luggage bar that sticks out about 7.5 mm (l) and is 45mm (h) x 15mm (w) with rough heavy duty aluminum welds. Eyeballing, it looks considerably wider than the Brompton's (see below). Depending on size of the cutout on the block adapter, it may require a bit of tooling. I'm watching this Brompton front Luggage Block installation video and I am now more confused than ever because they are using a 4mm hex tool, which I infer as the bolts being the same M5 (same as Dolphin) not the M6 as I had previously thought (slightly larger). Anyway, I wouldn't worry too much about the bolts, more the mounting block and cutout. The plastic types can be easily bored out if necessary (see last pic). Hope this helps and works. Looking forward to seeing the finished product!

Dolphin luggage bar.jpeg
Brompton,jpeg.jpeg
Brompton Adapter.jpg
 
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Kathy Smith

Member
Hi Goldconch,

I think you said that you have the Qualisports basket. Can you tell me the exact screws it uses?
The Dolphin head tube is tooled with three x M5 threaded front luggage sockets and comes with the shorter 85mm M5 bolts you'd find for a std water bottle cage (which use a Metric 4mm head allen key/M4 hex tool). These are on a frame-welded luggage bar that sticks out about 7.5 mm (l) and is 45mm (h) x 15mm (w) with rough heavy duty aluminum welds. Eyeballing, it looks considerably wider than the Brompton's (see below). Depending on size of the cutout on the block adapter, it may require a bit of tooling. I'm watching this Brompton front Luggage Block installation video and I am now more confused than ever because they are using a 4mm hex tool, which I infer as the bolts being the same M5 (same as Dolphin) not the M6 as I had previously thought (slightly larger). Anyway, I wouldn't worry too much about the bolts, more the mounting block and cutout. The plastic types can be easily bored out if necessary (see last pic). Hope this helps and works. Looking forward to seeing the finished product!

View attachment 53036 View attachment 53037View attachment 53039
Thanks for this. I bought the Brompton mounting block. I don't even think I need any adapter. Since the block is made out of plastic I'm shaping it to fit my volador. I redrilled the holes to be bigger and added another hole in the Brompton metal attachment plate. Got M6 screws but 10mm is way too short. Going to pick up longer screws. Hopefully tomorrow I will have it done. I need to figure out where to put the light now. The cable is pretty long, I just need an extension arm so the light sticks more out.
 

goldconch

Member
Thanks for this. I bought the Brompton mounting block. I don't even think I need any adapter. Since the block is made out of plastic I'm shaping it to fit my volador. I redrilled the holes to be bigger and added another hole in the Brompton metal attachment plate. Got M6 screws but 10mm is way too short. Going to pick up longer screws. Hopefully tomorrow I will have it done. I need to figure out where to put the light now. The cable is pretty long, I just need an extension arm so the light sticks more out.
Good plan. The bolts in that video look to be 20mm or longer. I put 15mm Titanium in mine. For the headlight, there's more cable hidden in the control box that can be extended out. Don't be afraid to invert the hanger and drop it down below the Brompton block. The light is mainly a safety indication for motorists. It doesn't cast a meaningful beam if it's really dark, esp at 23 mph. If you're on well-lit city streets, motorists really just need to see you, and register your speed and direction. I just ordered a Classon helmet that does a lot of that with blindspot protection, 6hrs of camera footage, signals, brake lights etc. Psyched.
 

Kathy Smith

Member
Good plan. The bolts in that video look to be 20mm or longer. I put 15mm Titanium in mine. For the headlight, there's more cable hidden in the control box that can be extended out. Don't be afraid to invert the hanger and drop it down below the Brompton block. The light is mainly a safety indication for motorists. It doesn't cast a meaningful beam if it's really dark, esp at 23 mph. If you're on well-lit city streets, motorists really just need to see you, and register your speed and direction. I just ordered a Classon helmet that does a lot of that with blindspot protection, 6hrs of camera footage, signals, brake lights etc. Psyched.
From my calculations I think I will get 22mm bolts. But I need M6 not M5. I went to a hardware store yesterday and tried.
The light is bulky and it won't fit under the Brompton block. Could I wire a different light? Any recommendations? I'm getting a Sena helmet so a hubby and I can communicate. That Classon looks awesome BTW.
 

goldconch

Member
From my calculations I think I will get 22mm bolts. But I need M6 not M5. I went to a hardware store yesterday and tried.
The light is bulky and it won't fit under the Brompton block. Could I wire a different light? Any recommendations? I'm getting a Sena helmet so a hubby and I can communicate. That Classon looks awesome BTW.
I took an unpleasant trial night ride and then snipped off the bulky 5-6v OEM light. I then hooked up a beautiful ATV-style 12v light bar under the front basket, which was, in hindsight, an electrical novice error. It burnt out a wee, but critical transistor on the mother chip of the KT-controller. Long story short, I humbly submit that episode now disqualifies me from being a good source of info on alternative wired lighting options! For now, I now use a cheap clip on indication light, if I think I'll be out after sunset. The rear OEM seatpost light is battery-powered, bright, and reliable.

That Sena R1 is very cool. Great idea to have an intercom feature for multi-riders.
 
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Kathy Smith

Member
I took an unpleasant trial night ride and then snipped off the bulky 5-6v OEM light. I then hooked up a beautiful ATV-style 12v light bar under the front basket, which was, in hindsight, an electrical novice error. It burnt out a wee, but critical transistor on the mother chip of the KT-controller. Long story short, I humbly submit that episode now disqualifies me from being a good source of info on alternative wired lighting options! For now, I now use a cheap clip on indication light, if I think I'll be out after sunset. The rear OEM seatpost light is battery-powered, bright, and reliable.

That Sena R1 is very cool. Great idea to have an intercom feature for multi-riders.
The Sena R1 Evo is even better! Unfortunately it's out of stock at the moment. I'm keeping the OEM light for now.
My project is now complete.

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