echo victor 

Hi all,

I've acquired a used Dahon folding bike, but the previous owner neglected it. And at some point, someone put one of the pedals in incorrectly, so the threads on one of the cranks are thrashed, and the threads on the corresponding pedal are thrashed. The chainring is rusted, and the plastic chainring guard is cracked. So I'm looking to replace the entire crankset.

What I'm looking for: crankset with a single 48T - 52T chainring and a chainguard. Preferably within a reasonable budget ($50, maybe $60?). I've considered the FSA Metropolis City, but it seems to only be available as 45T. I'm thinking about getting a Shimano FC-A050 and removing the 39T ring, but I haven't been able to confirm whether the rings are riveted.

So has anyone got any great ideas on a crankset that would work well as a replacement on a folder?

Thanks!

az2008

Nice find, but it looks riveted. See the one without the chainguard. If you click on that photo to enlarge it, you get a much clearer image than the one shown at Amazon. Could they be drilled out without causing a problem? It looks like that way to me.

My concern with that crank is that the chainguard is plastic. Why not spend a little more on a higher-quality crankset and buy an *aluminum* bash guard? This guy sells quite a few different sizes (BCD) of bashguards on eBay.

And, on that page I see a Lasco 170x52t single-ring with aluminum bashguard for $40. I don't know anything about the quality.

I'm curious what others recommend because I want to replace my Dahon Boardwalk crankset.

echo victor 

Good point about using an aluminum chainguard instead of plastic. I should keep in mind that the current plastic one is cracked...

That Lasco crankset you linked to is certainly interesting, but I'm also unable to find any significant comments about Lasco's quality. Might be worth trying, though.

Any other recommendations? Now there's (at least) two of us looking for good crankset replacements.

chaadster

Regarding Lasco, I have two of their cranks, one which came stock on a BikesDirect bike and an aftermarket crankset branded as Brev.M but stamped with the Lasco name on the backside of the crank arms. IIRC, they model # was the same for both cranksets.

The stock unit is unattractively finished, looking like pot metal, if you know what I mean. There are visible flakes or grains in the crank, like raw aluminum. It's just very basic looking.

The Brev.M branded Lasco is polished, but only on the face and sides; the back is matte. It is also blue anodised, so while the polished faces look quite good, the finish quality difference on the unfinished backside is noticeable.

Although I've had no technical problems with either crank, I don't think I'm qualified to speak to Lasco build quality. They seem fine and are reasonably light, though clearly not top flight units, but priced accordingly.

In fact, if you want the stock silver cranks, which are 170s with a 130 BCD, I'd be happy to send them to you for just the cost of shipping. I can throw in a pair of practically new-- maybe 10 miles?-- black cage/silver body pedals, too. They're the stock items that came on the same BD bike and which I replaced for platform pedals. Like the cranks, finish quality is low to middling, but hey, they're practically free!

I'll put up some pics when I get home in a few minutes.

chaadster

vmaniqui

checkout this chainguard. i have these on my 2 bikes. https://www.ebay.com/sch/i.html?_trks...guard&_sacat=0

echo victor 

Thanks for the offer, Chaad, but I think I'm going to pass for now, as just new cranks won't solve my current issue. (Watch, I'll probably end up needing just new cranks for a different bike before the week's done, now that I've said that).

That seems like a good price on those driveline guards, vmaniqui, so then I'd just need a new crankset without a guard. How did you find the install to be? I know they come with screws, but do they replace the screws that currently attach the ring to the spider or what?

Thanks!

fietsbob

Bike friday uses aluminum chainguards, so has them FS.
My IGH bike, I have a 130bcd crankset 53t chainring + a disc chainguard
where an outer chainring would be.

there are 3 on one chainring bolt, sets, to make the 2 chainring + chainguard setups you desire.

built up a wide step double decades ago, 52, 36t + a chainguard in 144bcd,
Campag & Gippiemme, (gpm) parts ..

all sorts of interesting combinations can be made up, with a bit of ingenuity
Even if not already sold .. as is

echo victor 

Actually, fietsbob, your comments reminded me that I actually have a pair of 105 cranks I'm not using at the moment. So I could just pick up a chainring and chainguard to use with that set and be on my way. Granted, 105s might be overkill on an elderly Dahon, but it's better than having them get dustier.

echo victor 

Hey Chaad, on second thought it might not be bad for me to have those cranks as a back up in case I decide to pull the 105 cranks for some other bike in the future. Does your offer still stand? Any idea how much shipping would be from you to California (maybe even a flat-rate box)? I don't have enough posts to send PMs yet, so if you want to PM me your email address, I can follow up with you that way.

Thanks!

chaadster

Sure, offer still stands. PM sent.

fietsbob

I put a chain-minder on the seat tube , too. chain wont jump off either side, riding..

dck

I replaced the crankset on an old single speed Boardwalk with a Pake crankset. I think this crank has a 48t ring on it so I had to add a link to the chain also.

BTW, I'm also using a 5 speed SA hub so I mounted a Tektro long reach caliper on the rear. I didn't have enough reach with the brake above the bridge, so I mounted it below. Works great in any case.