jlibson

Hello,

I have read some of the posts on here regarding Dynamic Bicycles. I got one about 2 weeks ago and for the most part I like it a *lot*.

I ordered the grease gun which is good because otherwise the bike would have been unusable.

What I have found is that ever 20-30 miles I have to pump a few hits of grease into the front crank box. It makes a pretty nasty grinding noise. I have 1 "hard" hill in my commute per day. But it seems pretty crazy that it would require grease so frequently. The specs on the bike say every 600-1000 miles.

I have a few questions:

1. How often do other folks have to use the grease gun?
2. Have you found anyplace to buy additional grease?

Thanks in advance!

Regards,

Joe

DCCommuter

While there have been thousands of posts on BF about chainless bikes, I think you're the first person to post who actually owns one.

Have you tried shooting grease into the box until it oozes out somewhere? It could be that the box is empty. Otherwise I'd expect that you'd have grease all over the place at that rate.

Winter76

Is there a drain hole you should be plugging?

Miguelangel

some gearing takes a while to get well greased...maybe after more use the amount of grease needed will diminsh

jlibson

Hmmm good points. I am a tyro when it comes to the mechanics of bikes. If I add too much grease can I "gum up" the gear box?

Miguelangel I hope that you are right! That would be convenient.

I know that there are a few "DB" riders on the forum. A mriley I believe is an experienced rider. Hopefully he will read this and take pity on me.

Sixty Fiver

My friend got a Dynamic and had nothing but problems with the drive...

The front drivebox was not very well supported and he found that under high loads he would cause things to twist and Dynamic sent him a few replacement drive boxes... he finally retrofitted the bike with a brace to support the drive box which remedied the problem.

I told him that he needed to send Dynamic some information on his fix.

He also had trouble with the seals on the drive.

Miguelangel

"gum up" can be caused by many factors like changing temperatures , low quality grease or open seals that will let dirt come in... what did they say at Dynamic? are u using recommended grade and type of grease?

jlibson

I am using the grease that they sent me.

Sixty Fiver: bummer about your friend. I know that they have worked great for some people. It is new enough now that I don't really know if it will work out in the long run.

I *do* really love not having a chain though. I do not enjoy fiddling with dérailleurs! And since we have lots of small kids around it is one less source of greasy hands.

Sixty Fiver

It should be noted that my friend is a monster on a bike and lays down some obscene torque when he rides... for lighter use the Dynamic might work just fine.

nashcommguy

Hi jibson,

What model of dynamic bike did you purchase? Did you get fenders, rack, etc. w/the bike. What type of terrain...oh, nevermind you live in SF...second only to Pittsburgh in brutality of self. Would you mind expanding a little on tire size, ease of shifting, average load weight, etc? Thanks alot. Nashcommguy

eza

I've only had mine (a Sprint) since last June. I put grease in maybe 3 months after I first got it. Then I had the shaft snap on me in November. Got a replacement, and started riding again in April. So I don't put grease in at all, probably not until the fall for me. I use it for daily commuting (5 miles each way).

When I first started riding I also had the horrible grinding noise. But it went away. However that shaft did fail on me. I haven't heard any grinding with the replacement.

jlibson

Eza: so *no* need to add grease? If you don't mind my asking how big are you? Do you apply a lot of force? Or do you have a more relaxed ride?

Nashcommguy: I have the Tempo (which is a hybrid). I did get the fenders and the rack. I didn't end up putting the fenders on.

I weigh about 200 lbs, and half of the commute I am pulling my boy on the trailer (he weighs 60). I tend to pedal pretty hard when I ride.

The tires are 700x35 I believe. I don't go on the most hilly parts of town. I have one "hard" hill per day in the ride. But not one of the real monsters of SF.

The grinding is definitely worse when I crank harder on the bike. I have fairly strong legs and I am probably putting a good bit of torque on it.

It shifts fairly easily, but I am not perfectly happy with it. It slips a fair bit. I have followed the re-alignment instructions but it didn't help that much.

These are the complaints. But overall I am happy with the bike. If the grinding does not prove to be a 3 times/week kind of thing then I will upgrade my review to *very* happy with it.

ken cummings

For the limited amount of grease gunning I've done, mostly oil wells, I just added grease until it oozed out around the bearings. How do you tell you have put in enough? Perhaps a stupid question but do they recommend one and only one type of grease? Is there some other, far less expensive, type of grease you could use?

eza

As far as I can tell, no "need" to add grease. It runs pretty smoothly for me. I'm running around 190 these days. Don't apply a whole lot of force. I'm in Chicago, so nothing but flat land for me.

I'd suggest getting in touch with the Dynamic people directly. They've been pretty helpful for the couple issues I've had.

NeilM

My Tempo was doing this when I first got it - then I read the manual. Try pedaling backwards every once in a while to smear the grease around and see if the problem goes away. I just got in the habit of giving the crank a couple of reverse turns as I pull up to the stop sign at the end of the block. It's plain ol' automotive grease, injected through a plain ol' zerk fitting.

B Piddy

In a former job I worked in a few years ago I learned the following things about greasing gear boxes:

1. It is possible to over grease a bearing - blows out the seals causing all the grease to leak out, causing shorter re-greasing intervals.
2. It is possible to under grease a bearing - obvious problems
3. How much is the right amount? That is a tough question and a lot of smart people have struggled with it.

jlibson

Thanks Neil! This might have done the trick. It started to grind a little today and spinning the pedals backwards made it go away.

Finger's crossed.

NeilM

Kewl!

chainlessguy

I have been riding my Dynamic chainless for 3 years. I really do like it a lot better than chain bikes I've owned. I commute 7 miles each way - 3 days per week - on moderately hilly terrain. I try to ride fast, and I almost always use the higher gears at a fast cadence. I average about 19mph on my commute. I have found that the grease I was using lasted me about 2 months. If I don't lube the gears, they let me know with a chirp or some similar noise. It always goes away when I add grease. When I asked their engineer about this he explained that the front gearbox is where most of the torque load is. The more force put on the pedals, the faster the grease will get displaced. So for a heavy rider on very hilly terrain, it wil be more frequent. For average riders on moderate terrian, it will be less frequent. He also said the better the grease, the better the performance. Average grease will only yield average results. He said backpedaling is a good way to redistribute some of the grease already on the gears when you're out on a ride, but it will still need to get replenished eventually. I just recently bought some new grease that Dynamic just started using that they say is supposed to be 60% stronger than what they used to use. Give them a call. If the grease does not correct it for you, perhaps you have some alignment issue with the shaft drive. Ask for a warranty replacement.

huhenio

BMW Motorrad ... we has a job for you

treebound 

https://www.dynamicbicycles.com/admin/bikes/l170240.jpg

I"m not directly familiar with these bikes, but it doesn't look like there is a lot of room for a whole tube of grease unless it is somehow finding it's way up into the bicycle's framework. Seems like it would get fairly heavy after awhile.

I'm from the old school where you pump until you have enough grease or until it starts to come out someplace, maybe more applicable to cars than bikes though. How much is enough? Only experience can tell you that.

vaccinefiend

I owned a Dynamic Bicycles shaft drive bicycle. The Sussex shaft drive was not built to specifications that could handle the torque generated when pedaling uphill, or pedaling hard on level ground. The result was that the shaft drive was not maintenance free--in fact, it broke. I replaced it with a new shaft drive sent by Dynamic Bicycles. The new one began to break and I was told by their Production Manager that I was exceeding the specifications of the shaft drive. I received a verbal agreement from him to refund the purchase price of the bicycle. Dynamic Bicycles even took care of the return shipping for the bicycle.

Once they received it, however, the president of Dynamic Bicycles told me that I had owned the bicycle longer than 30 days, so the satisfaction guarantee no longer applied. I was given the option of having my bicycle returned to me with a tightened bolt and new grease, which would supposedly fix the problem, or receiving a refund minus the cost of shipping and a 15% restocking fee. Despite phone conversations, emails and then a complaint process with the Better Business Bureau In Eastern Massachusetts, Maine, Rhode Island and Vermont (https://boston.bbb.org/WWWRoot/SitePa...e-ef5cf233e6a5), the president of the company would not uphold a verbal agreement stated twice and acknowledged by email. Because I do not live in Massachusetts, the state where Dynamic Bicycles is located, it made no sense for me to pursue a mediation or claim in small claims court, which would have required my presence. I will never do business with Dynamic Bicycles again, nor would I recommend doing business with Dynamic Bicycles. I am also weary of bicycles sold with shaft drives built by Sussex.

CharlesC

I know Dynamic specifies grease for the gears but I would think GL-4 or 5 automotive gearbox lube would be a better choice if it will stay in the housing and not leak out. A puddle of liquid gear lube in the bottom of the gear case would constantly oil the gears. Grease tends to smush out of gear teeth and thus the need for backpeddling to redistribute it. Of course it uses straight cut spur gears instead of spiral cut bevel gears but my 3 speed Sutmey Archer 3 speed rear hub has been working perfectly for 46 years with 20 wt oil in it. My opinion of the 8 speed Nexus hub is there are way too many tiny parts crammed in there for it to last for centuries like a SA hub will.

Szczuldo

why are so many people afraid of derailleurs? Go single speed if you are afraid of them...There is nothing to adjusting derailleurs, it takes about 15 minutes at most, less if you don't have to retention your cable from scratch.

-=(8)=-

This copied from a recent post in the 'General' forum:

Originally Posted by vaccinefiend
I owned a Dynamic Bicycles bicycle. The Sussex shaft drive was not built to specifications that could handle the torque generated when pedaling uphill, or pedaling hard on level ground. The result was that the shaft drive was not maintenance free--in fact, it broke. I replaced it with a new shaft drive sent by Dynamic Bicycles. The new one began to break and I was told by their Production Manager that I was exceeding the specifications of the shaft drive. I received a verbal agreement from him to refund the purchase price of the bicycle. Dynamic Bicycles even took care of the return shipping for the bicycle.

Ive put about five very thorough reviews of my Dynamic/Newport shafty up
on BF if someone wants to search my name and 'Newport shaft' or something
like that. That being said, my experiences are what yours were, sort of.....On
mine it was the the bottom bracket and complications it caused because I
didnt realize it needed to be tightened almost daily. It was woefully underbuilt
for the stresses of real, utilitarian riding. I thought this bike would be a Godsend
for Vermont snow and FL sand situations but the bottom bracket and the havoc it
caused by the constantly loosening of its three, tiny 2.5 mm screws eventually
made it unusable. I ended up donating it to a bike Co-op in WPB.