Ask a Bicycle Question - Part 5

[erwinrommel]

I shall use gear inches to measure since its a common measurment .

highllighted in pink are favourite gears to use.


The road bike and tt bike are somewhat similar easy to pedal, both using ultegra (one is 10 speed the other is 11 speed)

The toptube+ stem length is almost the same for my road bike and mini velo (635mm) somewhat similar saddle height (69X mm ) only thing different is the quality of the equipment.

I find the mini velo hard to pedal, could be due to brake rub and wheel truenesss and equipment quality.

I cant make a fair judgement till i changed to a higher grade equipment and somewhat better quality equipment.

energy used would defintely be different, only way to measure would be to mount a powermeter and ride at a certain speed

I overlap and label all for easier reference.

As you can see above, it seems like my sweet spot is gear ratio 3.5-4.2 regardless of wheel size. And my sweet spot for both gear ratios seem to be the same. I dunno whether it even make any sense. I don't have the luxury to have a 3.5-4.0 gear ratio for Brompton.

So I guess the "all other things equal" is hard to apply in your case.. which is true. Equipment weight, condition all still play a part.

 

[Jay Bee]

larger wheel with smaller gear ratio is more efficient: assuming the gears have lousy efficiency.

although smaller wheels are more "aero"

but then i think not much difference one

 

[rarenick]

that guy cycled for 20 yrs liao and yet he asked this kind of question...

Me? Don't be so fast to pass judgement.
I cycled on and off in those 20 over years, not consistent. I think i had a break of a few good years due to army and work. Two other factors are that i mainly cycled at night and that time where got people wear helmet? Last time people stare at u think u idiot.

Sent from Xiaomi MI 4I using GAGT

 

[Albedo]

Just got back from a ride. I came across this cyclist while down in Pasir Ris farmway area. He was walking his bike along the road. So, I asked if he was okay? He said that his pedal was spoilt.

I continued on, thinking that I don't really know how to fix pedals but after a minute or so I decided to go back to see what I can do. It turns out that the bolt holding his left side crank arm had come out.

It looked like it needed a hex wrench or allen key to reattach it. I whipped out my Topeak Alien II multi tool, searched for the right sized allen key and reattached the crank arm. I figure it would hold long enough for him to get home if he pedaled very carefully.

The Alien is a great multi tool and I have never regretted purchasing it. Learn how to do simple repairs and look out for one another on the roads.

Reads like adver.

But well done there for helping another cyclist.

 

[Broadwalk]

Just got back from a ride. I came across this cyclist while down in Pasir Ris farmway area. He was walking his bike along the road. So, I asked if he was okay? He said that his pedal was spoilt.

I continued on, thinking that I don't really know how to fix pedals but after a minute or so I decided to go back to see what I can do. It turns out that the bolt holding his left side crank arm had come out.

It looked like it needed a hex wrench or allen key to reattach it. I whipped out my Topeak Alien II multi tool, searched for the right sized allen key and reattached the crank arm. I figure it would hold long enough for him to get home if he pedaled very carefully.

The Alien is a great multi tool and I have never regretted purchasing it. Learn how to do simple repairs and look out for one another on the roads.

Do you have pictures? I am finding hard to visualize. Thanks.

 

[beast]

I don't think you can correlate the amount of money spent on bicycle with the speed.

You might as well say you get an entry level roadie which is cheaper than a mid range Tern.

So far, I dunno of any folding bicycle in the market right now that folds as compact as Brompton, and easily rolls around even after folding. Even if you count the Brompton clone MIT, it is still relative expensive and the folded size is still too big.

I keep my Brompton under the Ikea Galant table. The width of the table is only 60cm.

The only problem I have with Brompton is the gearing. If I have very powerful legs, it can easily go very fast.

Even on my Brompton 5th gear, the average speed with 80-90 rpm is about 28kmh. I can never use 6th gear...

Quite costly to pay for a bike so that it can fold small enough to fit under the desk. Dahon jifo folds quite compact as well.

 

[csoyzx]

hi guys..

was looking ard for a foldable bike for leisure cycle and also exercise at the same time.. shortlisted Dahon Vybe D7 and Java TT 7S.. My budget will be at $400 and I know both bikes are over my budget..

I'm going to hong kong next mth and read on some forums that Dahon bike are cheaper den in SG.. anyone bought Dahon bikes from HK before? Any shops to recommend?

 

[erwinrommel]

Quite a heavy price to pay for a bike so that it can fold small enough to fit under the desk. Dahon jifo folds quite compact as well.

I just look at the Dahon jifo specs.. It's quite shocking.

It costs about 1k, single speed, and can't roll easily after folding. It doesn't even have roller wheels to roll the bike after folding. So it's not easy to bring it into public transport.

There are many proprietary parts like brompton due to the small fold. I dunno about Dahon jifo resale price, but the brompton resale price is very high.

 

[erwinrommel]

hi guys..

was looking ard for a foldable bike for leisure cycle and also exercise at the same time.. shortlisted Dahon Vybe D7 and Java TT 7S.. My budget will be at $400 and I know both bikes are over my budget..

I'm going to hong kong next mth and read on some forums that Dahon bike are cheaper den in SG.. anyone bought Dahon bikes from HK before? Any shops to recommend?

Buy second hand lo. Check out togoparts or Carousell...

 

[erwinrommel]

Anybody buying anything from chainreactioncycle? Can help to "tompang"?

I am looking to buy shimano ultegra ten speed cassette cs 6700 23-11t.

 

[IronMac]

Do you have pictures? I am finding hard to visualize. Thanks.

Visualize what exactly?

 

[Broadwalk]

Visualize what exactly?

The tool that you mention, and how you actually make do with that to help the person to ride again?

 

[touchme]

is disc brake really much better than v-brake? how so? (both in effectiveness and maintenance/repairs)

I'm enjoying my conventional springless frame and v-brake bike, in terms of the feel, both on road and terrain, and upgrading. Not sure if I shd go for new suspension frame and disc brake?

 

[IronMac]

The tool that you mention, and how you actually make do with that to help the person to ride again?

Here's the tool...my version is slightly older by about ten years:

The tool is the leftmost tool (Allen key) on the part that is in the leftmost part of the picture. You can Google image for Allen key.

Here is a picture of an Allen bolt screwed into the bottom bracket:

You can clearly see the six sided Allen screw or Hex bolt on the rightmost side of the picture holding the crankarm into the bottom bracket.

Here's a slightly better pic:

 

[IronMac]

is disc brake really much better than v-brake? how so? (both in effectiveness and maintenance/repairs)

As someone who goes on longer rides (60-130kms in a day) and who likes to do self supported touring when possible, I would never touch disc brakes. They are too prone to being damaged and you need specialist tools to repair them. Not to mention trying to find the parts and associated expense.

V-brakes are easily repaired by the user and the parts can be found almost everywhere at really good prices. Stopping power is about the same or so I am told.

My current and future bikes will always have V-brakes for the above reasons.

 

[Jay Bee]

As someone who goes on longer rides (60-130kms in a day) and who likes to do self supported touring when possible, I would never touch disc brakes. They are too prone to being damaged and you need specialist tools to repair them. Not to mention trying to find the parts and associated expense.

V-brakes are easily repaired by the user and the parts can be found almost everywhere at really good prices. Stopping power is about the same or so I am told.

My current and future bikes will always have V-brakes for the above reasons.

i think the only "advantage" for disc brake is if you ride until the rim is muddy(not likely for most ppl)......

i can feel the braking control more with disc brakes. But it looks cooler tio bo

 

[leinad]

i think the only "advantage" for disc brake is if you ride until the rim is muddy(not likely for most ppl)......

i can feel the braking control more with disc brakes. But it looks cooler tio bo

No, the other key advantange is you don't have to change your rims when you have worn down your braking surfaces.

To be fair, they do last for quite some time, but every time you squeeze the brakes onto rims, you do scratch them. Worse when it's sandy/dusty so it acts as abrasives.

In theory, it's much less hassle and cheaper to replace disc rotors than an entire wheel (which necessitates replacing the hub and all that or rebuilding the wheels with new rims). In practise, it should last long enough.

/Dan

 

[patcheon]

Another advantage I think for disc brake wheelset is that it's tolerance for an untrue rim is higher to remain ridable. Something like if some sort of accident happened during the ride and the rim became untrue, a rim brake wheelset would have a smaller buffer before the rims to be in contact with the brake pads and become unridable to make your way back home or to the shop while a disc brake wheelset does not have brakepads in the way.

 

[batuchka]

i thought in wet weather v-brakes is as good as no brakes compared to disc?

 

[Broadwalk]

Here's the tool...my version is slightly older by about ten years:

The tool is the leftmost tool (Allen key) on the part that is in the leftmost part of the picture. You can Google image for Allen key.

Here is a picture of an Allen bolt screwed into the bottom bracket:

You can clearly see the six sided Allen screw or Hex bolt on the rightmost side of the picture holding the crankarm into the bottom bracket.

Here's a slightly better pic:

So you use allen key to act as a peddle?